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Do Sticky Mousetraps Work?
Описание: Do Sticky Mousetraps Work? Do Sticky Mousetraps Work? When it comes to mousetraps, the most traditional method is a snap trap, also known as spring-loaded bar traps. But that's not your only option. Sticky mousetraps, or mouse glue tray, are also readily available. But do they work? This simple, natural remedy helps keep mice away for good. When mice are baited to the sticky trap, they are immobilized by an adhesive surface. They die from hypothermia since they can't move and maintain their body temperature. The glue trap consists of a flat piece of cardboard covered in specially designed sticky glue. The traps can be placed on floors and against walls where the rodents travel. You may also like these 11 strategies for DIY pest control. Sticky Mousetrap Benefits As for the benefits of a sticky mousetrap, they do not use toxic baits, they're simple and easy to use, are inexpensive and the mice die on the glue as opposed to wandering off and dying in an unknown location as they do with poison. Anywhere you see mouse droppings is a prime spot to set mouse traps. And the more traps you set, the more mice you'll catch—period. The longer a sticky mouse trap sits around the less sticky it gets. It becomes coated in dust and will no longer be effective. In general, these traps are ineffective in locations with a lot of dust, dirt or water. They're also less useful in extreme hot or cold temperatures. It's important to note that it's not exactly humane to trap, and subsequently kill, mice. However, if you have a mouse problem, this may be far from your mind. If you prefer an alternative method, you can try live-catching mousetraps, which use food baits to attract mice, with a metal door snapping closed to capture the creature. You will then need to release the mouse back into the wild. You can also try the use of deterrents like peppermint and used kitty litter. Regardless of your method, pinpointing where the mice are getting in to your home is of the utmost importance. Here's our best advice for how to have a mouse-free house. Heavy duty mouse glue traps are an excellent method for ridding your home of rats and mice. Like all traps, however, the key to their success lies in knowing how to properly place them. Read on to learn how glue traps work, what benefits they have to offer, and how to use them to get the best results. Benefits of Rodent Glue Traps Victor? glue traps are a simple and non-toxic method of rodent control. Glue traps are inexpensive, easy to use, and come in a variety of styles. There's no setting or baiting required to use them, so they are perfect for people of all experience levels. We offer both disposable glue traps, as well as refillable glue trays to suit your needs. In addition to catching rodents, snap traps for mice are also great for catching crawling insects that invade your home. Victor? Hold-Fast? Refillable Glue Trays boasts a sturdy, refillable design that allows you to use them over and over to help you control your pest problems. Each glue trap board can be conveniently popped or slid out of the tray to make set up and disposal as easy and simple as possible. Due to the large surface area of the glue traps, you can catch multiple mice and insects at once to keep your home pest-free. Victor? Hold-Fast? Disposable Glue Traps, on the other hand, can be used in over 10 different configurations so you can place them anywhere. Each trap can lay flat, folded to prevent dust or debris from getting on the glue, or they can be folded into a unique shape to place in corners, in between appliances, or underneath furniture. Their versatility does not stop there. You can even tear along the perforated edges to create two separate traps. All Victor? glue traps come pre-baited with a peanut butter scent that entices rodents to step onto the sticky surface. Once they step foot on the board, the rodents and insects become stuck fast. Always place your glue boards or glue traps along known travel paths of the rodent. Rats are cautious to interact with new environments, so make sure to place your Victor? glue trap in areas where you've seen signs of heavy rat activity. Mice, however, like to travel along walls and baseboards so be sure to place your traps along these runways in areas where evidence of mice has been seen. You have a few options when placing traps, depending on the style you are using. For example, our traditional glue boards and Hold-Fast? Disposable Glue Traps can be laid flat with the side along the wall bent up 90 degrees. This will create two catch areas, one along the wall and another on the floor. Another option is to tent or tunnel the glue trap. This is a great option when placed in a dusty or dirty area or you want to prevent children or pets from coming in contact with the adhesive. Refillable trays can only be placed flat but offer a large surface area to catch more pests as they travel along their runways. By following these simple tips, you will greatly increase your success and eliminate your rat or mouse problem. Are you looking for alternative methods of rodent control? Many people don't know it, but glue traps can be used for humane catch and release. When it's time to release your captive, just add a bit of olive oil to the glue. This will cause it to lose its stickiness and the mouse should be able to free itself. You can use the end of a pencil to assist if needed. Do not attempt to pull the mouse off without deactivating the glue first. After you've placed your trap, regularly monitor it for catches. If your goal is to catch and release the mice, it's important to make sure they're released in a timely manner. You don't want to leave them too long without access to food and water! Take the trap to a location offsite, at least 2 miles away from your home, before releasing the rodent. After all, you don't want it running right back into your home. No one wants to deal with rodents, but TOMCAT offers a wide variety of weapons to effectively battle them. Glue or adhesive traps or boards are one of many methods for control of mouse and rat issues, but they also provide a way to uncover and track rodent activity. They can be used standalone but also can be very helpful as part of a total system of rodent control in use with baits and mechanical traps. While you always want to use any rodent control in low traffic areas of the home, nipper mouse trap are pesticide-free and do not snap on hands and paws, so they can be placed in a wider variety of locations where rodents travel regularly like the kitchen or hallways. Mice and rats are creatures of habit - they like to take the same path to and from their nests. Mice are also very curious, so they'll check out any new thing along the way. Rats are more hesitant to explore new things, so slightly more time may be needed for them to encounter the trap. These behaviors will help you detect and control your rodent problem. TOMCAT Glue Traps come ready to use and provide the perfect combination of immediate grip and stretchable hold. Simply open the package, separate the traps and place. For TOMCAT Glue Boards, remove the protective paper by gripping in one corner and pull in one smooth, continuous motion. You can also use the glue boards as covered traps by folding around the fold lines, removing the protective paper, then sliding the tab into the slit to create a box with two opens ends for the pest to run through. Position traps along active rodent runways, such as along walls, under large kitchen appliances, in cupboards, and other areas where rodents travel. Be sure to fit the glue trap flush against a wall where rodents will run over and stick to it. Avoid placing traps in corners indoors. Since glue traps hold the mouse in place to show evidence, you can utilize nipper rat trap to track where rodents are traveling. If you don't catch a mouse within 2 days, move the trap to another spot. In addition to capturing mice, Tomcat Glue Traps of all varieties also trap insects such as spiders, roaches, or even scorpions. After use, dispose of the trap and captured rodent or insects in the trash. Tomcat Glue Traps and Boards are specially formulated for effective rodent control and come in a variety of styles and formulas, including Original, with Eugenol for Enhanced Stickiness, and SuperHold. Glue boards (also known as glue traps) are trays coated with an extremely sticky adhesive. Often used to get rid of rodents, insects and snakes, many buy these boards as an alternative to indiscriminate snap traps, which endanger pets and children.Animals that touch a glue board are immediately caught and stuck to the board and usually suffer a slow death by starvation or suffocation. Glue boards might seem like a safe and easy solution to pest problems but in fact, they are one of the cruelest and most dangerous. Responsible for more suffering than virtually any other wildlife control product on the market, they are readily available at grocery stores, home improvement and hardware stores and most major retailers, as well as over the Internet. Manufacturers claim that glue boards are safe for use, but there are many safety concerns that don't come on the label. In some cases, people will try to beat glue-trapped animals to death with a shovel or stick, as it is nearly impossible to safely or humanely euthanize them. While trapped animals are still alive, anyone handling the glue board risks being bitten by the them Glue boards are also dangerous to household pets and other animals that aren't the user's intended target. If the board is small, a larger animal may be able to pull it off, though they will likely lose fur or skin. Smaller animals, however, have no means of escape. Larger glue boards can entrap medium-sized animals, including pets. Cats often require veterinary help and surgery to remove glue boards. Sale, manufacture and regulation Despite bans in Victoria, BC, Australia and New Zealand, most countries, including the United States, have placed no regulations on the use of glue boards. There also is very little consumer education about these products --manufacturers and retailers provide virtually no information to alert purchasers as to the concerns that exist with the use of these devices. In all cases, please treat an animal caught on a glue board as an emergency and consult a trained professional. The animal should be safely contained and immediately transported to a local wildlife rehabilitator or veterinarian. It's very difficult for untrained individuals to release an animal from a glue board without running the risk of inflicting further injuries or possibly being injured themselves. Even if an animal appears unharmed, they could be injured in ways that aren't immediately visible, or they could need treatment for dehydration or extreme exhaustion. If you cannot immediately find a wildlife rehabilitator or veterinarian, the below method has been used successfully. Caution: Please attempt this only in the event that you cannot find a wildlife rehabilitator or veterinarian. Wild animals can be dangerous at any time when handled, but especially so when they are trapped and defending themselves. Please do not attempt this if you are not comfortable with the procedure described.
Дата Публикации: 24-10-22
Photography Lighting Equipment: The Essential Guide
Описание: Photography Lighting Equipment: The Essential Guide Photography Lighting Equipment: The Essential Guide When you first dive into photography lighting equipment, you're bound to feel massively overwhelmed. Studio lighting seems complex, it's full of confusing jargon, and it certainly isn't designed for the beginner. But here's the truth: While photography lighting might seem complicated, it's actually pretty easy to get started – assuming you have the right teacher. That's where this article comes in handy; I aim to share all the professional stage lighting, so that by the time you're done, you'll have a strong understanding of both studio lighting equipment and the accompanying vocabulary. Let's get started. Types of light In this section, I cover the main types of studio light. Note that each lighting type varies in terms of usefulness, portability, cost, and more. Strobes A studio strobe, sometimes referred to as a monobloc or monolight, is a dedicated flash unit. Strobes generally use cords, though more battery-powered offerings are brought to the market every day. Power output between models can vary greatly; cheaper strobes offer about as much power as cheap, third-party flashguns, while class-leading strobes are some of the strongest lights in the business. For this reason, strobes are the most common studio light used by professionals. Continuous lights serve the same function as strobes, but they don't flash. Instead, they are high-powered, constant lamps that can (usually) be fitted with modifiers. While associated with video, continuous lights still have their place in stills photography. LED lights are currently flooding the continuous light market, and many of them are viable options for stills shooters. Note that continuous lights are sometimes referred to as hotlights – because they tend to get very hot. Be careful with modifiers that sit close to the bulb, as they present a fire hazard. (This does not apply to LED lights.) Flashgun/speedlight Flashguns are small lights that mount on top of your camera. They are highly portable, and some come with reasonably high power outputs. Although flashgun versatility is ultimately limited by size and power output, they are still an extremely useful tool for any photographer interested in off-camera lighting. They're also less expensive than dedicated studio strobes. Whether you're a hobbyist or a professional, understanding that light is a vital part of the outcome of your images is crucial. Gaining extra light can be an easy fix, whether it be from a window, a lamp from your living room, or a professional lighting kit. In some cases, you will need the latter for it's convenience and the ability to control the lighting in your situation. It can be confusing to decipher which photography and lighting equipment might be best for you to utilize and potentially invest in for your business. To simplify things, ask yourself: what are your main needs? what is your purpose for using artificial lighting? These two questions can assist in shaping which lighting kit is best for you. In this article, we will provide details about the various types of lighting equipment that you can purchase to create stunning images! Light, or Visible Light, commonly refers to electromagnetic radiation that can be detected by the human eye. The entire electromagnetic spectrum is extremely broad, ranging from low energy radio waves with wavelengths that are measured in meters, to high energy gamma rays with wavelengths that are less than 1 x 10-11 meters. Electromagnetic radiation, as the name suggests, describes fluctuations of electric and magnetic fields, transporting energy at the Speed of Light (which is ~ 300,000 km/sec through a vacuum). Light can also be described in terms of a stream of photons, massless packets of energy, each travelling with wavelike properties at the speed of light. A photon is the smallest quantity (quantum) of energy which can be transported, and it was the realization that light travelled in discrete quanta that was the origins of Quantum Theory. Visible light is not inherently different from the other parts of the electromagnetic spectrum, with the exception that the human eye can detect visible waves. This in fact corresponds to only a very narrow window of the electromagnetic spectrum, ranging from about 400nm for violet light through to 700nm for red light. Radiation lower than 400nm is referred to as Ultra-Violet (UV) and radiation longer than 700nm is referred to as Infra-Red (IR), neither of which can be detected by the human eye. However, advanced scientific detectors, such as those manufactured by Andor, can be used to detect and measure photons across a much broader range of the electromagnetic spectrum, and also down to much lower quantities of photons (i.e. much weaker light levels) than the eye can detect. How does light interact with matter? It is no accident that humans can home party light. Light is our primary means of perceiving the world around us. Indeed, in a scientific context, the detection of light is a very powerful tool for probing the universe around us. As light interacts with matter it can be become altered, and by studying light that has originated or interacted with matter, many of the properties of that matter can be determined. It is through the study of light that, for example, we can understand the composition of stars and galaxies that are many light years away or watch in real time the microscopic physiological processes that occur within living cells. Matter is composed of atoms, ions or molecules and it is through their interactions with light which gives rise to the various phenomena which can help us understand the nature of matter. The atoms, ions or molecules have defined energy levels, usually associated with energy levels that electrons in the matter can hold. Light sometimes be generated by the matter, or more commonly, a photon of light can interact with the energy levels in a number of ways. We can represent the energy levels of matter in a scheme known as a Jablonski diagram, represented in Figure 2. An atom or molecule in the lowest energy state possible, known as the ground state, can absorb a photon which will allow the atom or molecule to be raised to a higher energy level state, known as an excited state. Hence the matter can absorb hybrid led laser strobe light of characteristic wavelengths. The atom or molecule typically stays in in an excited state only for a very short time and it relaxes back to the ground state by a number of mechanisms. In the example shown, the excited atom or molecule initially loses energy, not by emitting a photon, but instead it relaxes to the lower energy intermediate state by internal processes which typically heat up the matter. The intermediate energy level then relaxes to the ground state by the emission of a photon of lower energy (longer wavelength) than the photon that was initially absorbed. How do we study matter using light? Since photons that are either absorbed or emitted by matter will be of a characteristic energy, when the light that has interacted with matter is subsequently split into its constituent wavelengths using a spectrograph, the resulting spectral signature tells us a huge amount about the matter itself. The broad field of spectroscopy constitutes a multitude of spectroscopic techniques, such as raman spectroscopy, absorption/transmission/reflection spectroscopies, atomic spectroscopy, laser induced breakdown spectroscopy(LIBS) and transient absorption spectroscopy, providing a wealth of useful information on the scientific properties of atoms and molecules, as well as being able to very specifically identify the presence and quantify the amount of such materials in a sample. In fiction, some superheroes have special vision. In WandaVision, for instance, Monica Rambeau can see energy pulsing from objects all around her. And Superman has X-ray vision and can see through objects. These are definitely super talents, but it's not that different from what normal humans can do. That's because we can see also see a type of energy: visible light. Light's more formal name is electromagnetic radiation. This type of energy travels as waves, at a constant speed of 300,000,000 meters (186,000 miles) per second in a vacuum. Light can come in many different forms, all determined by its wavelength. This is the distance between the peak of one wave and the peak of another. The light we can see is called visible light (because we can, er, see it). Longer wavelengths appear as red. Shorter wavelengths look violet. The wavelengths in between fill in all the colors of the rainbow. But visible light is only a small part of the electromagnetic spectrum. Longer wavelengths just past red are known as infrared light. We can't see infrared, but we can feel it as heat. Beyond that are microwaves and radio waves. Wavelengths a bit shorter than violet are known as ultraviolet light. Most people can't see ultraviolet, but animals such as frogs and salamanders can. Even shorter than ultraviolet light is the X-ray radiation used to image inside the body. And still shorter are gamma rays. In this International Year of Light, it is particularly appropriate to review the historical concept of what is light and the controversies surrounding the extent of the visible spectrum. Today we recognize that light possesses both a wave and particle nature. It is also clear that the limits of visibility really extend from about 310?nm in the ultraviolet (in youth) to about 1100?nm in the near-infrared, but depend very much on the radiance, that is, 'brightness' of the light source. The spectral content of artificial lighting are undergoing very significant changes in our lifetime, and the full biological implications of the spectral content of newer lighting technologies remain to be fully explored. Although 'light' refers to visible radiant energy, it may refer to sources of illumination, such as sunlight or artificial sources such as a lamp and luminaires (ie, lamp fixtures). One might think of sunsets or even the nighttime sky! Throughout almost all of humankind's evolution, there was only natural sunlight—or fire (including, candles, flame torches, and later oil lamps). But today—and over the past century—electrically powered lamps have dominated our nighttime environments in the developed countries. Since the 1820s-1830s gas lamps and (later) incandescent (red-rich) lamps have dominated our indoor environment at night. Open flames and incandescent sources are described technically as having low-color temperatures, typically ?2800?Kelvins (K)—rich in longer visible (orange, red) wavelengths and infrared–near-infrared radiation. By contrast, the midday Sun is rich in shorter wavelengths with a color temperature of about 6500?K. Sunlight become red-rich when low in the sky and the significant change in spectrum is often unnoticed because of selective chromatic adaptation by our visual system. Since the 1950s, fluorescent lamps (generally rich in hybrid led strobe laser derby light and line spectra) have been widely used in indoor lit environments, at least in office and commercial settings, but rather infrequently in the home—with perhaps one exception—in the kitchen (USA experience). But the 'revolution' in optics during the 1960s—fostered largely by the invention of the laser—led to other optical technologies, including the development of new types of lenses and filters, holography, and light-emitting diodes (LEDs). LEDs were far more energy efficient than incandescent sources but initially were capable of emitting only very narrow wavelength bands, that is, single-color visible LEDs, until the invention of multi-chip LEDs and blue–violet-pumped-fluorescent LEDs to produce 'white' light. In this century, governmental emphasis on energy conservation led to pressure to employ compact fluorescent lamps (CFLs) and 'white' LEDs for illumination. Solid-state lighting by LEDs, which are even more energy efficient than CFLs, are now beginning to dominate the marketplace. However, both the early CFLs and 'white' LEDs have very blue-rich spectral power distributions (Figure 1). Some consumers began to rebel with such blue-rich lamps and demanded less 'harsh,' less 'cold-bluish' light sources. You will now find some LEDs and CFLs with greatly reduced blue emission. Nevertheless, in the past 60 years there has been an ever-increasing color temperature of artificial sources and an increase in nighttime 'light pollution.' The night sky of Western Europe as seen from space shows the enormous impact of electric lighting (Figure 2).
Дата Публикации: 24-10-22
What is the difference between Sublimation Paper and Heat Transfer Paper?
Описание: What is the difference between Sublimation Paper and Heat Transfer Paper? What is the difference between Sublimation Paper and Heat Transfer Paper? According to the experienced sublimation worker charles, the quick answer is No. You cannot use sublimation ink on ANY transfer paper for dark fabrics. Very basic information on sublimation is that it actually dyes the polyester fiber. Unlike ink on a transfer paper the image is not. You cannot dye a dark garment to any other color as for the Canon, I doubt it will work, you will get an image but it will wash out. For normal inkjet transfer you need pigment ink and are not sure what the canon has. Best to figure another way. there are those that say use a polyester spray and other methods. So, if you are in the business of printing clothes, you have an idea of what is the best costume design method. Many people pay close attention to the heat transfer paper printing method and it depends on your needs and what you intend to do. In addition, there are pros and cons here. We dig into the details to help you decide what works best for you and your business. We print on high speed sublimation paper together with the use of sublimation ink to print out the images using mirror image setting, then transfer the image onto the media by applying heat and pressure, which makes the sublimation ink turn into gaseous state and absorb by the media. Sublimation paper + ink can transfer the printed image onto polyester, mousepad, cardboard puzzles, polyester drifit tshirts, banners and hard surfaces, such as mugs, ceramic and aluminium plates etc. Heat transfer paper is applicable to heat transfer, on which images can be printed using normal home printers by heating and pressuring in order to transfer the image onto media. Heat transfer paper can accept a wider range of ink types, such as with pigment ink, solvent ink such as home / office inkjet ink, laser ink etc. You will have no issue using your home, school or company's printer. Heat transfer paper is usually transferred onto cotton. The brand of Heat Transfer Paper we carry is Neenah (a brand from US). JPSS and 3G Jet Opaque are the 2 we carry. Even though sublimation is traditionally printed with an inkjet printer, the chemical properties of the ink (which is actually a dye) are radically different from pigment-style inks, thus the paper is uniquely engineered for the process. While standard inks require a form of bonding agent to adhere to the surface of the fabric, sublimation dyes physically penetrate, bond, and re-color polymer fibers. Because of the molecular process, binding agents are not required. Thus, sublimation transfer paper is composed of a polymer management layer combined with a release agent. Unlike inkjet and laser transfer papers, the entire surface of super speed sublimation paper does not transfer, as there are no binding agents involved. The sublimation dye simply turns into a gas during the pressing phase of the process and transfers into the polymer fibers of the substrate. Also, since sublimation is sub-surface, it has no hand. One new development with sublimation transfer products is "tacky paper" (currently only available in roll form). Tacky paper is manufactured with a light adhesive within the surface and is ideal for preventing ghosting that happens if the paper shifts when releasing the heat press. Those that lack the ability to print on rolled media can apply a very light coating of spray adhesive to the transfer for the same effect. The variety of sticky sublimation paper may look similar, but different brands have different manufacturing recipes. It pays to explore the options on the market. Don't focus on cost, but look for the product that consistently delivers the highest quality images. Note that sublimation dyes do not work with non-poly fibers. Low humidity: In the humidity under 45%, it's better to choose 80gsm. When in low humidity, the paper shrinks, and the print side is hunched-up. During the process, the paper absorbs ink, which leads to the "hunch-up". 100g and 120g paper are harder than 80g, so the "hunch-up" damages the print-head. 80gsm is softer, it could relieve the "hunch-up" and protect your print-head from damage. High humidity: In the humidity above 70%. It's better to choose 110-120 gsm. Since the paper is very easy to become damp with high humidity, it will become softer and stiffness is weak at the same time. If low weight paper is used, it will be hard to print smoothly because of the stiffness and hardness go down. At this time, 110-120 gsm is the best choice. In textile printing with sublimation techniques, the paper has an important role; i.e as a medium for transferring inks to the fabric so that final graphics can be produced. This paper has a short life cycle because it cannot be used for reprinting. This study aims to propose four alternatives ways to increase the value of paper waste from textile printing with approaches in material value conservation, reverse engineering, material selection, and waste management. The four proposed alternatives are to sell paper waste rolls to the waste collector, to reuse paper waste as an underlay paper in fabric cutting, to reuse paper waste as shredded paper for packaging, and reuse paper waste as shredded paper for packaging after it has become underlay paper in fabric cutting. The first alternative contributes to a total net revenue of IDR 149,490,000 for three years. The second alternative contributes to a 74% reduction in the cost of purchasing underlay paper with a value of IDR 318,912,000 for three years. The third alternative contributes to a revenue of IDR 66,440,000 for three years, but it has not reached a break-even point due to investment in machinery which costs IDR 112,000,000. The fourth alternative contributes to a reduction in the cost of purchasing underlay paper with a value of IDR 210,234,000 for three years after deducting the cost of machine investment. From this study, it is found that the application of material value conservation in paper waste can bring economic value to the industry and the environment. The need for good quality paper for jumbo roll sublimation paper has been reported previously as a principal requirement for the process. Pigmented coated papers have gained acceptance in the traditional paper printing industry, but, despite their importance, have inspired very few reports in literature about their application in heat transfer printing.In the current work, we studied the influence of both clay and ground calcium carbonate (GCC) pigments and the incorporation of plastic pigment on the surface structure and mechanical properties of the coated paper used for transfer printing. The results showed that paper coating significantly reduced the surface roughness of the paper. The mechanical properties of the prepared coated paper, including tensile strength, stretch, tensile energy absorption (TEA), and burst index, were improved when coated compared to those of uncoated paper. The addition of plastic pigment to the coating mixture helped improve the paper's properties.The optical density of the transfer-printed polyester fabric using the prepared coated paper was also compared with that of uncoated paper. It was shown that a slight increase in optical density was evident in the coated paper.The possibility of producing a second polyester print from the exhaust paper was also investigated. Coated paper incorporating plastic pigment, in particular, showed higher optical density than did uncoated paper.We found that coated paper based on clay, GCC, clay/plastic pigment, or GCC/plastic pigment consumed less dye paste than uncoated paper though producing printed fabric with higher optical density—especially in the second print. "Sub-li-what-now?!" If you've ever wondered what this strange-looking word actually means — then wonder no more. No, it isn't an underwater warship or on-screen translations that help you understand a foreign film; it's a high-tech printing process used mostly for print on demand apparel. Today we're going to pick it apart — we'll cover what it is, how it works, discuss the pros and cons, when to use it — and when not to. What is sublimation? Let's start with the broad strokes. What exactly is sublimation? In simple terms, it's a method of printing that transfers a design into a material or fabric using ink and heat. In the world of apparel, it's a game changer in that it allows whole garment prints — designs that go seam-to-seam. The sublimation printing process So how does sublimation work? Well, 35gsm fast dry sublimation paper uses heat to essentially bring ink and fabric together as one. First, a design is printed onto special paper. The inks that are used turn into gas when brought under heat, then combine with the fabric and permanently print onto the fabric. The effects are permanent and less prone to fading, as the ink is embedded in the fabric or substrate rather than simply laying on top like a normal print. The process is almost like a tattoo, but instead of for your skin, it's for your chosen product. The heat opens up the pores of the fabric, then with the applied pressure the ink cools and returns to a solid form. The result is a permanent, full colour image that won't crack, peel or wash away from the substrate. The process allows the ink to go from a solid to a gas without turning to liquid, a bit like dry ice. The conversion is initiated by heat and controlled by pressure. This quick and effective digital print method is growing in popularity for smaller batch orders and those designs that rely on the details. Sublimation printing is also known as 'all over printing' as it allows you to choose a design that can literally go from seam to seam.
Дата Публикации: 24-10-22
A Guide to Types of Whatman Filter Paper Grades
Описание: A Guide to Types of Whatman Filter Paper Grades A Guide to Types of Whatman Filter Paper Grades A device that transmits part of a received signal and rejects the rest. The signal may be in the form of a beam of light or other radiation or may be an electrical signal. Optical, ultraviolet, and infrared filters are dyed plastic or gelatin, glass or glasslike substances, or confined liquids, all of which absorb incident radiation except for a relatively narrow band of wavelengths. Such filters are used in astronomical photometry, especially in measurements of magnitudes; transmitting bands typically 100 nanometers wide, they are termed broadband filters. Much narrower wavelength bands, of maybe 1 nm, can be obtained with interference and birefringent filters. Electrical filters are devices whose attenuation varies with frequency. Filters that allow low or high frequencies to pass without serious attenuation are called low-pass and high-pass filters, respectively. A filter that allows only a limited range of frequencies through is a band-pass filter while its converse is a band-stop filter. See also bandwidth. The term "filter" is also applied to a number of other devices, which are not discussed in the present article. For example, devices that pass or reject acoustic or electromagnetic waves of certain frequencies are called filters, and the term is sometimes applied to devices that separate polymer ions into fractions or remove salts from solutions by means of ion exchangers. According to the nature of the heterogeneous system, a distinction is made between liquid filters, which are used to LTE filter suspensions, and gas filters, which are used to separate out aerosols and to purify gases. The simplest filter is a vessel that is divided into two parts by a filter medium. A pressure difference is established across the filter to force the liquid or gas through the filter medium, which holds back the solid particles. Liquid filters. Liquid filters are divided according to their method of operation into two groups: filters that operate intermittently, that is, on a batch basis, and filters that operate continuously. Within each group, filters are classified according to the way the pressure difference is created (application of vacuum or pressure), the geometry of the filtering surface (plane or curvilinear), and the type of filter medium used. In an intermittent filter the entire surface of the filter medium is subjected by turns to the following operations: influx of a slurry and formation of a cake (filtration), dewatering, washing and discharge of the cake, and regeneration of the filter medium. In a continuous filter these operations occur simultaneously and independently of one another in an appropriate filter zone. The intermittent group includes filter presses and capacity, leaf, and cartridge filters. Leaf filters are used to clarify solutions and to separate slurries that contain no more than 5 percent (by volume) of a solid phase. The bands filter elements, or leaves, are circular or rectangular in shape and are usually covered with a cloth filter medium. Each leaf has an outlet through which the filtrate is discharged. The slurry is fed into the filter tank. The layer of cake is washed after all the slurry has been removed from the tank. Filter presses are used chiefly for fine slurries. They include plate-and-frame presses, chamber presses, and automatic filter presses. A plate-and-frame filter press consists of an assembly of alternating vertical plates and frames. Compression of the assembly is accomplished by a hand screw or a hydraulic or electromechanical closing device. The frames form hollow chambers, into which the slurry is fed when the filter is in operation. The filter medium is laid over each plate, whose faces are ribbed to provide drainage. Under pressure, the filtrate passes through the filter media, runs down the ribbed surface of the plates, and passes through the filtrate outlets to an open launder or a closed channel. The cake formed in the chambers is removed by separating the plates. The chamber filter press operates in a manner similar to that of the plate-and-frame filter press but permits higher pressures. In automatic chamber filter presses the filter plates are located between two supporting plates and are positioned horizontally at a certain distance from one another. The top of each filter plate is covered with a perforated sheet, over which an endless-belt filter medium is located. When the plates are compressed, chambers are formed between them. The slurry, wash liquid, and compressed air (for drying) are successively fed into the chambers from the corresponding channels. The filtrate passes through the filter medium, and the solid phase remains on it in the form of a cake. Upon completion of the filtration cycle, the plates are separated, a gap opens up between them, and the filter medium is set in motion. The cake is carried out from between the plates and is removed with scrapers. The filter operates automatically and is four to ten times more efficient than the plate-and-frame filter press. The principal application of the rotating-pan filter (Figure 4) is the dewatering of coarse slurries in, for example, the production of potassium and the preparation of hard coal and ores. The device is a vacuum filter. The filter surface is annular in shape and is divided into trapezoidal segments, each of which constitutes a filter cell. The upper part of each cell is open, and the bottom is inclined toward the center to facilitate the flow of liquid. The cell is covered by a perforated sheet, on which the filter medium is placed. The interior of each segment is connected by pipes to the channels of a distribution system, which is rigidly fastened to the housing. The 5G LTE filter is rotated by an electric motor. During one rotation a filter cell is successively connected to vacuum and compressed-air lines. The slurry is fed into the cell from above. The cake is removed with a scraper or a screw conveyor. Tilting-pan filters are used for coarse slurries. They are operated by vacuum and consist of trapezoidally shaped pans held in an annular frame. The pans are connected by pipes to a distributor, through which the filtrate and wash liquid are removed. The pans revolve as a unit around a vertical axis. Each pan consists of a shell, which, together with the drainage plates and filter medium, constitutes the working element of the filter. The slurry and wash liquid are fed into the pan from above. For discharge of the cake, the pan is automatically rotated by 180° when it is above the discharge site. Gas filters. Gas filters are continuously operating devices. They may be divided according to their structure into two groups: filters having a plane filtering surface and bag, or fabric, filters. The filters of the first group consist of a chamber that is divided by one or two perforated plates. In the case of one plate, the filter medium—which may be, for example, sand or quartz—is placed on the plate. In the case of two plates, a compressed fibrous material—such as asbestos fiber, glass fiber, or glass wool—is clamped between the plates, which are attached to each other. When the gas flows through the filter medium, the particles suspended in the gas are removed. At certain time intervals the filter medium is cleaned or replaced. Superhydrophobic and superoleophilic filter paper was successfully prepared by treating commercially available filter paper with a mixture of hydrophobic silica nanoparticles and polystyrene solution in toluene. Applications of the filter paper in separating liquids with low surface tensions such as oil and ethanol from water were investigated in detail. The oil uptake ability of the superhydrophobic filter paper was evaluated and the results show that the filter paper can selectively adsorb oil floating on a water surface or in aqueous emulsions. Furthermore, filtration of mixtures of oil and water through the paper can reduce the water content in the oil. Additionally, the filter paper can also extract ethanol from homogeneous aqueous solution. For the knowledge search results, you can configure standard and custom fields as filters to help your agents find the content and improve their productivity. You can set up the customization of knowledge article search filters by first enabling the feature, and then setting the 4G LTE filter configurations. Any filter configurations that you set will be available wherever the knowledge search experience is configured, such as, the form-based knowledge control, knowledge search page, productivity pane-based knowledge search control, embedded search control in Unified Service Desk, and the application tab search experience in Customer Service workspace. If you enable the customization of the knowledge search filters, the web client and maker experience knowledge management filter experience are deactivated. In full text search, the archived and discarded status filters are not supported. Qualitative filter papers are what most users would consider general purpose filter papers. There are a vast range of applications in and out of the laboratory. Composed of cellulose fiber, these filters are manufactured from high-quality cotton linters treated to maximize alpha cellulose. Alpha cellulose is the most stable form of cellulose, with the highest degree of polymerization. Cellulose paper made from a high percentage of alpha cellulose, such as Whatman paper, is a sign of high quality and consistency. Qualitative filter paper grades are based on various properties including particle retention, thickness, and weight. Unlike quantitative filter papers, of which ashless grades can be burned off for analytical applications, qualitative papers are more suited for general purpose use.
Дата Публикации: 24-10-22
Experimental Investigation of Steel Plate Shear Walls under Shear-Compression Interaction
Описание: Experimental Investigation of Steel Plate Shear Walls under Shear-Compression Interaction Experimental Investigation of Steel Plate Shear Walls under Shear-Compression Interaction This paper describes the derivation of the equation for evaluating the strength of bridge steel plate reinforced concrete structure (SC) and the experimental results of SC panels subjected to in-plane shear. Two experimental research programs were carried out. One was the experimental study in which the influence of the axial force and the partitioning web were investigated, another was that in which the influence of the opening was investigated. In the former program, nine specimens were loaded in cyclic in-plane shear. The test parameters were the thickness of the surface high building steel plate, the effects of the partitioning web and the axial force. The experimental results were compared with the calculated results, and good agreement between the calculated results and the experimental results was shown. In the later programs, six specimens having an opening were loaded in cyclic in-plane shear, and were compared with the results of the specimen without opening. FEM analysis was used to supplement experimental data. Finally, we proposed the equation to calculate the reduction ratio from the opening for design. Four scaled one-storey single-bay steel plate shear wall specimens with unstiffened panels were tested to determine their behaviour under cyclic loadings. The shear walls had moment-resisting beam-to-column connections. Four different vertical loads, i.e., 300?kN, 600?kN, 900?kN, and 1200?kN, representing the gravity load of the upper storeys were applied at the top of the boundary columns through a force distribution beam. A horizontal cyclic load was then applied at the top of the specimens. The specimen behaviour, envelope curves, axial stress distribution of the infill steel plate, and shear capacity were analyzed. The axial stress distribution and envelope curves were compared with the values predicted using an analytical model available in the literature. To investigate the shear resistance of single-bay low alloy plate shear walls (SPSWs), a large number of experiments have been conducted using low cyclic loading. Driver et al. carried out a cyclic test of a four-storey SPSW. A vertical load of 720?kN was applied at the top the of the boundary columns with one horizontal load at each floor level. Their results indicated that the final deflection at the top floor is nine times larger than the yield deflection. The test specimen proved to be initially very stiff and had an excellent ductility and energy dissipation. Later, because of damage to the 1st storey, only the upper three storeys of this SPSW specimen was further tested by Behbahanifard to verify their finite element model. Moghimi and Driver carried out a test of a large-scale two-storey SPSW specimen. A vertical load was also considered in their test. The results indicated an excellent performance. In addition, high ductility and energy dissipation were observed. Qu et al. performed a two-phase experimental program on a full-scale two-storey SPSW with reduced beam section connections and composite floors. Their first-phase test was pseudodynamical tests using three ground motions of decreasing intensity. The buckled infill steel plate was replaced by new panels in the subsequent test. Their results showed that the repaired specimen could survive and dissipate significant energy without severe damage to the boundary frame. The final storey drifts reached 5.2% and 5.0% at the first and second storey. Other experimental research included works on reduced beam section anchor , low-yield point SPSW , unstiffened perforated SPSWs , partially connected SPSWs , SPSWs with semirigid connected frame , shake table test of buckling restrained SPSWs , self-centering SPSW , and the use of light-gauge SPSWs . However, until today, physical experiments on the cyclic behaviour of SPSWs under concurrent gravity and horizontal load have not been reported. Most investigations were performed numerically, e.g., Elgaaly and Liu compared the shear carrying-capacity of a SPSW with and without gravity load by the finite element method. The authors concluded that the gravity load has little effect on the shear-carrying capacity. This might be caused by the low magnitude of compression and thin infill wall considered in their analyses. Zhang and Guo performed finite element analyses on the behaviour of SPSWs with precompression from the adjacent columns. Their research showed that the shear capacity of SPSWs was significantly impaired by the precompression. Their previous research also showed that the gravity load acting at the top of the boundary columns has significant effects on the shear load-carrying capacity. To evaluate the adequacy of an analytical model available in the literature in predicting the influences of gravity loads on the cyclic performance of the SPSW, physical experiments were performed in this paper. Four scaled SPSWs under compression-shear interaction were designed and tested. The envelope curves, the axial stress distribution and the maximum shear capacity obtained from the experiments were then used in the evaluation of the analytical model. The test parameter was the vertical load applied at the top boundary columns. Test specimens are one-storey walls. The height of the specimen was 0.75?m, and the width was 1.1?m. The columns were 1?m apart from center to center. Figure 1 shows the size and configuration of the specimens. The plate thickness was 2.1?mm Q235 steel with the yield strength of 255?MPa. The size of the infill plate was 600?mm?×?900?mm. The frame members are built-up sections made of Q345 steel with the yield strength of 460?MPa. The boundary columns, i.e., H-overall depth (d)?×?flange width (bf)?×?web thickness (tw)?×?flange thickness (tf), have, respectively, the dimensions of 100?mm?×?100?mm?×?6?mm?×?8?mm. The top beam, connected to the actuator, has the corresponding dimensions of 150?mm?×?100?mm?×?6?mm?×?9?mm. This beam was stiff to ensure a smooth transfer of the load to the tension field occurred below the beam. Moment connections were used at all beam-to-column joints. Connection of the beam flanges to the columns was constructed using complete penetration groove welds. The beam webs were welded to the column flange by two-sided fillet. The infill high strength plate was connected to the boundary beams and columns using the fishplates. Figure 2 shows the fishplates of 50?mm width and 3?mm thickness. Continuous fillet welds on both sides of the fishplates were used. The infill steel plate is fitted to the fishplates with a lap of approximately 20?mm all around. Figure 1 shows a sketch of the test specimen with the vertical load and the lateral cyclic load. The constant vertical load of specimens A, B, C, and D was, respectively, 300?kN, 600?kN, 900?kN, and 1200?kN. It was kept steady during the whole test. The beam that distributed the vertical load was hinged to the top of the two boundary columns. A hydraulic jack generated the vertical load at the top of the load distribution beam. It was supported by a stiff steel frame. To avoid any shear force, a roller was placed between the steel frame and the hydraulic jack. Horizontal cyclic load acted at the center line of the top beam. A hydraulic jack, supported by a laboratory reaction wall, generated the horizontal load. Up to the first yield in the steel plate, a force-controlled load was applied. Depending on the load combination, the first yielding stage was achieved by increasing the horizontal load from ±50?kN to ±200?kN with an increment of 50?kN. In the subsequent load cycles, a displacement-controlled loading was performed until the specimen failure by increasing the displacement after each three cycles from ±4?mm. Eighteen strain gauges were attached along the boundary columns to measure the axial strain, and 8 strain rosettes were attached at the surface of the infill spring steel (see Figure 1). Two linear variable differential transformers (LVDTs) were installed at the base of the boundary column and at the center line of the top beam. Table 1 lists the results of the coupon tests of the two materials Q345 and Q235. Three coupons were tested for each material, and the average value is used for the subsequent analytical analyses. Under pure gravity loads, no buckling occurred in specimens A, B, and C. However, in the case of specimen D, horizontal buckling of the infill steel plate took place. The following described the behaviour of the four specimens. In the case of specimen A, until the top displacement reached 4?mm, there was no buckling in the infill steel plate. The tension strips, formed from the lower left corner to the upper right corner, have an inclination angle near to 45°. During the first displacement cycle of 8?mm, the first loud bangs occurred. In the subsequent cycles, these noises continued to occur. With an increase of the top displacement, various parts of the infill steel plate progressed to yield. A large residual deformation formed at the end of each pull or push loading with a further increase of residual deformation in the subsequent cycles. The first tear was detected in the upper left corner between the fishplate and the infill steel plate during the first 12?mm displacement load. The tear gradually increased to nearly 30?mm at the end of the first 12?mm cycles, as shown in Figure 3. At the end of the second 12?mm displacement cycle, new tears were detected at the two lower corners. All the tears extended with an increase of the top displacement, but no new tear was observed. During the first 20?mm displacement cycle, the shear resistance of the specimen did not decrease, but the tears grew faster and the specimen was pushed over. The ultimate deformation at the top of the specimen reached more than 50?mm. The force resistance only dropped by about 15%. At the end of the test, all the tears extended to be more than 60?mm. The tension boundary column failed due to the rupture of the weld at the bottom of the column, as shown in Figure 4. Meanwhile, the compression column experienced local buckling in the flange, and only a slight out-of-plane deformation was observed. In the case of specimen B, i.e., under 600?kN vertical load, no buckling or yielding was detected. Prior to reaching the yield displacement, four load cycles with increasing magnitude from ±50?kN to ±200?kN were necessary to cause the first yielding. At the cyclic load of 150?kN, the first loud bang occurred. These noises also occurred during the unloading phase in the following cycles. However, tension strips first only occurred during the second cycle of the 2?mm level, as indicated by the diagonal lines in Figure 5. The first tear was detected at the upper left corner at the end of the third cycle of 4?mm. The length of the tear was about 10?mm, and this tear gradually grew in the following cycles. At the first 6?mm displacement cycle, new tears of about 15?mm length occurred at the upper right and lower left corners. The length of the tear at the upper left corner extended to about 20?mm. At the end of the second 10?mm displacement cycle, a slight buckling at the support of the boundary column under compression was observed. The length of tear at the upper right corner extended to about 50?mm. At the second 12?mm displacement cycle, as shown in Figure 6, the upper left tear extended to nearly 60?mm, and the shear force resistance did not decrease. During the first 16?mm displacement pull load, the specimen reached a maximum resistance at the top displacement of 13?mm. The shear resistance then began to decrease. At the second 16?mm displacement cycle, the shear resistance decreased rapidly. The failure started at the support of the column under compression where a significant buckling and yield occurred. An out-of-plane deformation increased very fast, resulting in a loss of the in-plane shear resistance. In the case of specimen C, soft noises occurred during the application of the vertical load of 900?kN, even prior to the horizontal load. However, no buckling and yielding were detected. Prior to reaching the yield displacement, three load cycles with increasing magnitude from ±50?kN to ±150?kN were necessary to cause the first yielding. The first loud bang occurred at the cycle of 150?kN. The tension strips occurred while pushing. After unloading, a large residual deformation was observed. At the first 6?mm displacement cycle, a first vertical tear occurred at the upper left corner. In the following load cycle, a new tear occurred at the upper right corner at the compression direction. At the first 8?mm displacement cycle, local buckling of the compression column appeared. The shear resistance did not decrease. At the second 8?mm displacement cycle, the tear at the upper left corner extended to about 40?mm. The global out-of-plane buckling occurred, and the shear resistance of the specimen decreased rapidly to less than 100?kN. Specimen C failed because of the global out-of-plane buckling, as shown in Figure 7. In the case of specimen D, a soft noise occurred when the vertical load reached 900?kN, and no buckling and yielding were observed in the specimen. The vertical load gradually increased to 1200?kN. The noises increased, but there was no loud bang. Slight horizontal waves due to buckling of the infill tower plate occurred. The first bang occurred at the 50?kN horizontal load cycle. These noises occurred several times during each cycle in the following load cycles. After the 150?kN load cycle, a displacement loading was applied. The shear resistance capacity was stable at 2?mm and 4?mm displacement cycles, and there were no tear. At the 6?mm displacement cycles, the shear resistance began to decrease during the pulling. The reason was the anchorage of the column under compression failed (Figure 8(a)). The failure mode is shown in Figure 8(b).
Дата Публикации: 24-10-22
What is a Ball Valve and How Does It Work?
Описание: What is a Ball Valve and How Does It Work? What is a Ball Valve and How Does It Work? A ball valve is a shut-off valve that allows, obstructs, and controls the flow of liquids, gases, and vapors in a piping system by rotating the ball having a bore inside the valve. The ball is mounted against two seats and has a shaft that connects it to the operating and control mechanism that rotates the ball. When the cross-section of the bore is perpendicular to the area of the flow, the fluid is not permitted to pass through the valve. The fluid flows through from the valve, and the fluid flow rate depends on the area of the bore exposed to the floor. Ball valves are a type of quarter-turn valve along with plug valves and butterfly valves. They can be operated manually or by using an actuator. The simplest operation of a floating ball valve is through the use of a wrench or a lever manually turned by an operator. Torque is applied to rotate the lever arm by 90° by either clockwise or counterclockwise to open or close the valve. If the lever arm is parallel to the pipe, it indicates that the valve is open. If the lever arm is perpendicular to the pipe, it indicates that the valve is closed. Ball valves come in many designs and features to satisfy various industrial needs. The standards and specifications for ball valves vary depending on the industry where it is utilized. The ball is a sphere that has a hole in its center. The hole in its center is called the bore. The bore serves as the flow opening of the fluid when the cross-section of the fluid flow path and the bore is coplanar. Otherwise, the flow is throttled. A ball valve may have a solid ball or a hollow ball. A solid ball has a constant opening diameter throughout its structure, which helps the fluid to smoothly flow at a constant velocity. A hollow ball, on the other hand, has a hollow internal structure, and the space inside it allows more fluid to pass through the valve. However, the larger space creates turbulence and high velocities. A hollow ball is more lightweight and cheap compared to a solid ball. Shaft The shaft connects the ball to the control mechanism that rotates the ball. The shaft has seals such as O-rings and packing rings to seal the shaft and the bonnet to avoid leakage of the fluid. The shaft may be manually operated by a lever or a handwheel or operated by an electric, pneumatic, or hydraulic actuation. Bonnet The bonnet is an extension of the valve housing that contains and protects the shaft and its packing. It may be welded or bolted to the body. It is also made of hard metal and it covers the opening made from connecting the shaft to the external control mechanism. Seat The valve seats provide sealing between the ball and its body. The upstream seat is adjacent to the inlet side of the valve. The downstream seat is found on the opposite side of the upstream seat which is adjacent to the discharge side of the valve. A one-piece ball valve has a single-piece cast body that houses the internal components of the trunnion mounted ball valve. This eliminates the risk of leakage of the fluid from the valve. One-piece ball valves are the cheapest ball valves and always have a reduced bore. A welded one-piece ball valve is more common but cannot be dismantled for cleaning and repaired once damaged; therefore, it is only used for applications with a low possibility of particle build-up, and where sanitation is not a major concern. On the other hand, screwed one-piece ball valves can be cleaned, serviced, and repaired, but dismantling requires special tools. The floating ball is the most common ball design in ball valves. The ball is suspended inside the valve and free to move in a lateral direction when the valve is in a closed position. It is sandwiched between two seats that support the valve and hold it in place. The ball is connected to the shaft in a slot on one end while the other end is free. When the valve is in an open position, the shaft connection to the slot at the top of the ball prevents the ball from moving laterally. The sealing action is only dependent on fluid pressure. During an operation of a floating ball valve, the inlet pressure of the fluid forces the ball to the outlet seat which prevents the fluid from escaping from the valve body. The fluid pressure on the ball and the seats are higher when the ball valve is in the closed position. Floating ball valves have the simplest design. They come in smaller diameters and are suitable for liquids and gases operating under low to moderate pressures. The application of floating ball valves is limited by the amount of pressure the seats can handle. At high fluid pressure, the seats can be deformed from the pressure exerted by the ball which can affect the sealing characteristics of the valve under low pressure. Furthermore, the torque to rotate the stem depends on the force required to counteract the same fluid force acting on the ball and seals. In a trunnion ball valve, the ball is supported by an additional shaft at its bottom which is called the trunnion. This holds the ball in its place and limits the movement of the ball to its axis. The ball can only move if the valve shaft rotates. Trunnion ball valves also feature spring-loaded seats. The inlet fluid pressure activates the springs towards the ball held by the trunnion, which creates a tight sealing. Trunnion ball valves are available in small to large diameters, but it is more expensive than floating ball designs. They can operate efficiently in a wide range of pressures and they are ideal for high-pressure applications since the fluid pressure is also dissipated to the trunnion and the springs of the seats. Hence, they are easier to operate with a lower operating torque or a small actuator. A vented ball valve is constructed and operates in the same way as a standard fully welded ball valve, except that the vented ball has small orifices drilled into its side. When the valve is closed, the orifice is directed to the outlet side of the valve. The drilled hole is used to vent trapped gases which causes a build-up of internal pressure inside the valve, to prevent leaking, valve failure, and explosion. Vented ball valves are used in compressed air systems, cryogenic processing and conveying volatile liquids are also referred to as the "cryogenic valve" because of their usefulness in cryogenic processing. A full bore has a bore diameter similar to the pipe diameter. The flow area for the fluid for full bore valves remains constant, therefore the flow resistance offered by this type is very low. Minimal frictional loss is encountered during fluid flow; hence the pressure drop is low. A high pressure drop in a piping system causes pumping more difficult. However, since the bore diameter should be equal to the pipe size, it requires a larger ball size and housing which makes it more expensive than a reduced bore. Full bore ball valves are easier to maintain and clean. In pipelines, the pipes are maintained and inspected by an operation called pigging. A spherical or cylindrical device called pigs is allowed to flow in the pipes to detect and remove any build-up without interfering with the fluid inside the pipeline. This operation is possible with an installed full-bore ball valve. Full bore ball valves are also used in conveying liquids with mixed solids where flow restrictions cause the build-up of particles that can eventually cause separation of the mixtures that will flow through it. A reduced bore has a bore diameter smaller by a pipe size than the (connection) pipe diameter. The actual reduction is determined by the agreement between the manufacturer and the customer. The flow area for the fluid becomes narrower at the downstream outlet, therefore there are frictional losses that are introduced which result in a pressure drop. Since the amount of flow discharge remains constant, the velocity increases with the decrease in the flow area. Reduced bore ball valves are more common than full bore ball valves. They are used in applications where product flow rate and turbulence are not potential concerns and particle build-up is not likely to occur. The reduced bore is less expensive than the full bore since it requires a smaller ball size and housing. Compared to other types of valves, the reduced bore ball valves have relatively smaller pressure drop. A segmented ball valve has a V-shaped notch on its ball. A segmented 3 way ball valve has good flow rate control which depends on the ball rotation. Aside from that, it also has a good shut-off capability. The flow characteristic in a segment ball valve approaches an equal percentage flow characteristic. The flow rate in a segmented ball valve increases exponentially as the ball reaches its fully opened position. A cavity-filled ball valve has a seat design that fills the gap between the ball and its body. This eliminates the possibility of entrapped media or particle build-up over time around the ball which can cause contamination or blocking of the fluid flow. Cavity-filled ball valves are easier to clean and maintain. Cavity-filled ball valves are valuable in industries where sanitation is crucial, such as in food, pharmaceutical, and bioprocessing industries. They are ideal in handling solid-liquid mixtures such as slurries. Multi-port ball valves are used in diverting, combining, splitting, or shutting off multiple fluid streams through the use of a ball with an L-shaped or T-shaped bore segmented through its middle. A flow upstream to the inlet of a multi-port valve can be split into multiple outlet streams. It can split a flow, but cannot distribute the flow to its outlet streams in pre-determined flow rates. It can also join multiple flow streams into a single stream, or simply change the direction of the fluid flow. The schematic diagram below shows possible flow configurations of an L-shaped and a T-shaped multi-port ball valve. Brass is an alloy of copper and zinc that can be distinguished by its dull yellowish to reddish color, depending on the amount of zinc. It is the most common material for ball valves. Brass is a tough, strong, and durable metal that can withstand high temperatures and pressures. The copper in brass alloy has antimicrobial properties that inhibit the growth and reproduction of microbes on its surface. Brass has good chemical, corrosion, and biofouling resistance. It is inert to most acids, alkalis, and bases, except for solutions with high chlorine content. Chlorine can cause dezincification, a reaction where chloride ions strip away zinc from the alloy, causing a porous structure. Dezincification can drastically reduce the strength of the material. Brass ball valves are not difficult to fabricate because of their malleability, and they are also easy to cast and weld. They are lighter and cheaper than steel ball valves. They are also easy to assemble in the piping system. Common applications of brass ball valves are in food, chemical, and oil and gas processing, and in conveying gaseous fluids. It is also safe to use in the delivery of potable drinking water. Stainless steel is a type of steel that contains higher chromium content and some amounts of nickel. The chromium content of stainless steel makes it acquire a superior corrosion resistance. Stainless steel is known for its excellent strength, toughness, and durability. It also retains its strength in high temperatures and pressures. Stainless steel ball valves are commonly constructed in 304 and 316 Stainless Steel grades. The 304 Stainless Steel has 18% chromium and 8% nickel, while 316 Stainless Steel has 18% chromium and 10% nickel and trace amounts of molybdenum. The combination of nickel and molybdenum makes the 316 Stainless Steel resistant to chlorides. There are applications where the use of a stainless-steel ball valve is an excellent choice. They are used in swimming pools to handle chlorinated water. In harsh industrial environments such as desalination and petroleum refining plants, they offer better resistance to corrosive chemicals under high temperatures and pressures. In breweries, stainless steel pipes and valves are used to handle wort, a reactive liquid that is extracted during the mashing process. PVC is a tough, rigid and durable plastic material. Compared to brass and stainless-steel alloys, they generally have lower strength but they are cheaper. They are resistant to corrosion and most acids, bases, and salt solutions. However, they are not resistant to aromatic compounds and hydrocarbons. PVC ball valves have a lower temperature and pressure rating, for up to 150 psi and 140°F, respectively. Application of PVC ball valves includes plumbing, irrigation, and water distribution systems. Chlorinated PVC (CPVC) is a type of PVC that has been chlorinated by a free radical reaction initiated by UV light. The chlorination of PVC results in higher temperature resistance. CPVC ball valves can handle higher temperatures of up to 200°F. PP is a tough, durable, lightweight, and flexible thermoplastic made from propylene monomer. It offers good resistance to most acids and bases, but has selective compatibility with organic substances and solvents. Its chemical resistance decreases with increasing temperatures. The maximum operating temperature of PP is 82°C. PP ball valves are suitable for regulating the flow of fluids with a wide range of viscosity. They are used as materials for ball valves in the manufacturing of sugar, fertilizers, chemicals, paper, and others. PVDF is a high purity, durable, thermoplastic fluoropolymer with high molecular weight. It is synthesized from gaseous vinylidene fluoride monomer by a free-radical polymerization process. It is also resistant to abrasion. This material has excellent chemical resistance that makes it suitable for handling reactive liquids and gaseous substances such as sulfuric acid, hydrochloric acid, nitric acid, hydrocarbons, fuels, and solvents that are aromatic, aliphatic, and halogenated in nature. It is used as a material for ball valves in industries such as water purification, wastewater treatment, and in food and pharmaceutical processing because of its good biofouling properties that is resistant to the growth of microbial films. It also remains unaffected by exposure to sunlight and UV. The maximum operating temperature of PVDF is around 115°C.
Дата Публикации: 24-10-22
Research on the effect of yield strength of circular saw blade on roll tensioning process
Описание: Research on the effect of yield strength of circular saw blade on roll tensioning process Research on the effect of yield strength of circular saw blade on roll tensioning process In this paper, a 2-D and 3-D finite element model of roll tensioning process of woodworking saw blade were established by Static/General module of ABAQUS software based on finite element method. The rolling force and tensioning stress distribution of circular saw blade were calculated by these two models which were proved to be true and reliable. The effects of yield strength of circular saw blade on tensioning stress distribution and rolling force were studied. The research achievements showed that a circular saw blade made with high yield strength obtained a higher tangential compressive stress and radial compressive stress in the rolled region during roll tensioning process, which has both advantages and disadvantages for the stability of the saw blade. Besides, a circular saw blade made with high yield strength also put forward higher requirements for roll tensioning equipment because of the large rolling force during roll tensioning process. Circular saw blade is an important tool and is widely used in wood industry. Its stability, cutting precision, and material-saving ability are the most important features, especially for wood processing industry because of the shortage of precious wood. The Chinese government strongly supports the improvement of timber utilization. Therefore, TCT saw blade for wood is becoming thinner and thinner currently for reducing kerf loss and improving the utilization of materials. However, thermal stress is produced when circular saw blade is working, because the temperature at the edge of the blade is higher than that in other regions of the blade. It will cause high tangential compressive stress on the edge of the circular saw blade, causing a buckling deformation that reduces cutting precision, increases kerf loss, and shortens the saw's life . Thin TCT saw blade for wood composite is more easily affected by thermal stress. For saving materials, the stability of saw blade is very important, especially for thin circular saw blade. Tensioning is the most important and advanced technological process for production of circular saw blade for avoiding the above-mentioned phenomenon. Among all the tensioning processes, roll tensioning process is most widely applied in the cutting tool industry. The tangential tensile tensioning stress field is produced which can compensate for the tangential compressive stress caused by thermal stress and improve the stability of circular saw blade . However, circular saw blade can also obtain radial compressive tensioning stress during roll tensioning process which is easy for the blade to lose stability and buckle into a "dish" shape. The thin circular saw blade requires higher tangential tensile tensioning stress and lower radial compressive tensioning stress for maintaining stability, which brings a challenge to roll tensioning process of thin circular saw blade. At present, the effects of tensioning on the dynamic stability of the blades have been mainly focused . The generation of tensioning stress during tensioning processes has been studied by a few researchers. A theoretical model for roll tensioning process was established by Szymani and Mote . A model for roll tensioning process was established by Nicoletti based on the finite element method . A finite element model (FEM) for roll tensioning process, which allowed for the investigation of various roll tensioning parameters, was developed by Heisel . A mathematical model of tangential tensioning stress in the edge of a circular saw blade tensioned by multi-spot pressure was established for the quality control of circular saw blades by Li . Yield strength is the lowest stress value when plastic deformation is produced, which is an important indicator for metal materials and has a great effect on metal forming process such as roll tensioning process. Circular saw blade with different yield strength could obtain tangential tensile and radial compressive tensioning stress with different values, and different rolling force will be applied to the roll for making the blade to produce plastic deformation. However, to date, for circular saw blades, there is no related research about the effect of yield strength on the generation of tensioning stress during roll tensioning process. Therefore, the effect of yield strength of circular saw blade on the generation of tensioning stress during roll tensioning process was analyzed in this paper, which can demonstrate the effect of yield strength on roll tensioning process. In step 1, the roll moved slowly down and elastic–plastic deformation was produced to the metal cutting saw blade. In step 2, the roll slowly raised and the saw blade was no longer under any load. The residual stress of saw blade was the tensioning stress. A vertical displacement constraint was applied to the axial center plane. The 4 node axially symmetrical reduced integral element CAX4R was chosen for the circular saw blade. The number of elements was increased within the contact area between the circular saw blade and the roll for improving the accuracy of calculation, as shown in Fig. 1. The roll was modeled as an analytical rigid body because the deformation of roll is not the focus of this paper, which can also improve the calculation efficiency. Vertical downward displacement was applied to the roll. Coulomb friction model was applied between the circular saw blade and the roll. The friction coefficient was set to 0.1. The material model of circular saw blade was set as linear strengthening elastic–plastic model (bilinear model) because the plastic deformation of circular saw blade during roll tensioning process was very little. Its Elastic modulus and Poisson ratio were 210 GPa and 0.3. The dimension of circular saw blade was shown below. The diameter was 360 mm; the thickness was 2.2 mm; and the diameter of the hole was 60 mm. The dent depth of rolled region was 10 μm. The radius of rolled region was 105 mm. 3-D FEM model for calculation of rolling force A half model was established considering the symmetry of the model by Static/General Module of ABAQUS, as shown in Fig. 2. The 3-D FEM model was used to calculate rolling force, because it can truly reflect the contact status between the roll and the saw blade. Taking into account its efficiency, the roll in the 3-D FEM model only needs to rotate a small angle, with the rolling force reaching a steady state. The dimension of roll was shown in Fig. 3. Its radius was 30 mm. In step 1, the roll moved slowly down and elastic–plastic deformation was produced to the saw blade. In step 2, the roll began to rotate and the rotation of the roll drove the saw blade to rotate. The vertical force acting on the roll calculated by the model was the rolling force. The three-dimensional 8 node reduced integral element C3D8R was chosen for the rolling ring of circular saw blade for metal and the 4-node general-purpose reduced integral shell S4R was chosen for the medial and lateral regions, which can reduce the number of elements to the maximum extent and improve the computational efficiency. The three parts were tied together through the way of shell-to-solid coupling. The number of elements was increased within the contact area between the circular saw blade and the roll for improving the accuracy of calculation, as shown in Fig. 3. The other parameters of the 3-D FEM model were the same as the 2-D model. Roll tensioning experiment was done. Parameters of circular saw blade were shown below: material, 65 Mn; hardness, HRC42; yield strength, 430 MPa; strain hardening rate, 1000 MPa. Parameters of the roll were shown below: hardness, HRC60. The other parameters of the saw blade and the roll were the same as the FEM model. The dent depth of rolled region was 10 μm and tensioning stress distribution along the radial direction of upper surface in circular saw blade was measured by X-ray stress meter. The vertical downward displacement applied to the roll in the 2-D FEM model was adjusted for making the depth of rolled region to be 10 μm, and the tensioning stress of nodes along the radial direction of upper surface in circular saw blade was obtained. The contrast between the tensioning stress of the circular saw blade calculated by the FEM model and the measured results in the radial path was shown in Fig. 4. As shown in Fig. 4, the tensioning stress distribution of the circular saw blade calculated by the FEM model followed the same trend as previous research results . The values of tensioning stress of the circular saw blade calculated by the FEM model and the measured results in radial path of the circular saw blade were similar in most regions. The results mentioned above demonstrated that the tensioning stress of the circular saw blade calculated by the model in this paper was true and reliable. The tensioning stress distribution of circular saw blade after roll tensioning process was the key analysis object in the following. As shown in Fig. 5, the rolling force increased slowly during pressing process of roll. The rolling force reached a steady state during rolling process. As shown in Fig. 6a, the rolling force was increased with the vertical downward displacement of the roll. Elastic–plastic deformation was produced in the contact region of circular saw blade. To obtain the dent depth 10 μm of rolled region, the vertical downward displacement applied to the roll was 13.4 μm because of the rebound deformation of circular saw blade. As shown in Fig. 6b, the rolling force was about 8000 N and was not changed approximately with the rotation angle of the roll during rolling process. The elastic–plastic deformation was produced in ring rolling region during this process. The calculation result of rolling force was in conformity with the actual situation. Rolling force of steady state was the object of analysis in the following too. For tangential tensioning stress, the tangential tensioning stress difference between outer edge of the saw blade and rolled region was increased with yield strength when circular saw blade was under the same deformation, which meant that the tensioning effect was improved with the increase of yield strength, because the greater tangential tensioning stress difference between edge of the saw blade and rolled region meant that the circular saw blade could maintain stability during large temperature differences when it was at work. However, for radial tensioning stress, the radial tensioning stress difference between inner edge of the saw blade and rolled region was increased with yield strength when circular saw blade was under the same deformation, which was not conducive to the improvement of the stability of the saw blade because the stress state is easy for the blade to lose stability and buckle into a "dish" shape. As shown in Fig. 8, rolling force was increased linearly with yield strength of circular saw blade when dent depth of rolled region is 10 μm because plastic deformation resistance was increased with yield strength. When yield strength of circular saw blade was 1200 MPa, the rolling force had reached to 19.2 kN. The substantial increase in rolling force brought challenges to the roll tensioning equipment of cermet saw blade.
Дата Публикации: 24-10-22
PP Woven and Non-Woven Reusable Bags
Описание: PP Woven and Non-Woven Reusable Bags PP Woven and Non-Woven Reusable Bags Plastic is quickly becoming a vulgarity within the environmental community. Its production requires the use of nonrenewable resources, many types of plastics are difficult or impossible to recycle, and lightweight plastics easily end up in our oceans killing our wildlife. But, not all plastic is the same, and some plastic materials can actually be more environmentally friendly than some non-plastic materials. This study, for example, recommends multi-use plastics over single-use biodegradable options, like paper. Such is the case with pp bag. Although they are still a plastic material, because they can be reused many times, they're a much better option than single-use plastic bags, and some studies have shown that they can even be a better option than cotton reusable bags due to the significant environmental footprint involved in the production of cotton. Unconvinced? Here's a quick guide to polypropylene pp rice bag, their environmental impact, and the difference between them. Polypropylene is a thermoplastic polymer. In basic terms, it's a type of plastic. One of the most common plastics in the world, polypropylene is inexpensive, lightweight, durable, water resistant, and malleable, making it useful for several applications. Polypropylene is used in plastic containers, luggage, outdoor furniture, reusable water bottles, and more. A non-woven PP reusable bag is a shopping bag made from a non-woven polypropylene textile. This textile is created by spinning polypropylene into threads that are then bonded together using heat. This creates a durable textile that's similar to canvas. It's inexpensive, lightweight, and provides a common alternative to the single-use plastic bag. In fact, many retailers offer non-woven PP bags to their customers at little or no cost, like they would a single-use plastic bag. You can even find laminated non-woven pp fertilier bag which are water resistant and slightly more durable than the non-laminated options. Although non-woven PP bags are made from plastic, studies show that non-woven PP bags are still a more environmentally-friendly alternative to single-use options as long as the bags are used multiple times. A woven polypropylene reusable bag is a shopping bag made from an interwoven polypropylene textile. It's created by weaving strips of polypropylene textile to create a durable material. Many woven PP shopping bags are also waterproof and leak resistant. Like non-woven PP reusable bags, woven PP bags are inexpensive, light, and a more eco-friendly option than single-use options as long as they are used multiple times. They are more durable than non-woven PP bags, which means that they can be used longer, and they can carry up to 40 pounds, making them an ideal option for grocery shopping or other similar activities. What is the environmental impact of PP woven and non-woven bags? It's impossible to find a material that won't have some sort of environmental impact. Even if the textile is 100% biodegradable, the process of harvesting the materials, shipping the materials, and finally creating the textile has an impact of its own. Therefore, it's important that businesses and consumers consider the entire lifespan of the reusable bag, from material production to waste management, so that they can be aware of the environmental impact and the best ways to minimize it. PP fabrics, both woven and non-woven, are durable, water resistant, and reusable. This means that you can use them for quite some time before you see wear and tear. Additionally, because they can be used multiple times, and they are recyclable, they won't end up in a landfill or as ocean-bound plastic like single-use plastic bags will. PP woven and non-woven bags are versatile, strong, recyclable, and they have a surprisingly low environmental impact for a plastic material. They're lightweight, they can come in many colors and designs, and because they're durable, they'll look good for a long time. Why should my company choose PP reusable bags? PP reusable bags offer an ideal alternative to single-use plastic bags. They boast many of the benefits of plastic bags—they're waterproof, lightweight, and inexpensive—with the added benefits of durability, reusability, and recyclability. This places them head and shoulders above single-use plastic. If your company has been interested in an alternative to pp pet feed bag, but you didn't want to invest in more expensive textile options, then PP woven and non-woven bags offer an excellent choice. Check out Bkbags' PP selection today. Polypropylene (PP) is a thermoplastic resin made by polymerizing propylene. Polypropylene woven bags also include copolymers of propylene and a small amount of ethylene. Polypropylene is usually a translucent colorless solid, odorless and non-toxic. Due to the regular structure and high crystallization of polypropylene, its melting point is as high as 167 ° C. Its finished products can be steam-sterilized is its outstanding advantage. Its density is 0.90g / cm3, which is the lightest general-purpose plastic. Its strength, rigidity, and transparency are better than polyethylene. Pacific Bags Australia has a wide range of sizes of woven polypropylene bags. These bags are an excellent solution for packing 30-50 KG of dry material. These pouches are made from a woven polypropylene fabric that is strong and resistant to punctures. PP woven sachets are available in laminated or non-laminated forms depending on the material. This material is a commonly used material, which is a translucent material in polypropylene woven bags. When using this material, it will not produce any poisonous effect, and it will not have any odor. We can process pp into plastic woven bags, which are widely used in the packaging industry. When processing this material, woven bag manufacturers need to burn it to its melting point, 167 degrees Celsius, so it will have strong heat resistance when it is used later. Steam will also be used for disinfection so that all products will not be damaged during use. It is worth mentioning that the products made from pp have a very small density, so the product is very lightweight and more convenient for us to use. Moreover, the plastic woven bag made of this material also has high strength and corrosion resistance, so as a popular packaging product now, it is not only lightweight and durable but also can be recycled after use; it is truly a popular packaging product. Advantages of polypropylene woven bag #1. Heat resistance of polypropylene woven bags: The heat resistance of polypropylene is stronger than that of polyethylene. Generally, the melting point of polypropylene is about 40% -50% higher than that of polyethylene, about 160-170 ° C, so the product can be sterilized at a temperature above 100 ° C. It does not deform at 150 ° C under the condition of no external force. Similarly, in the field of ordinary packaging bags, polyethylene packaging bags are more suitable for use below 90 ° C, while polypropylene packaging bags can also be used at relatively higher temperatures. #2 Rigidity and tensile strength of polypropylene woven bags: Polypropylene is mainly characterized by low density, better mechanical properties than polyethylene, and outstanding rigidity. For example, polypropylene has gradually started to compete with engineering plastics (PA / PC) and is widely used in Electronic appliances, automotive fields. In addition, polypropylene has high tensile strength and good bending resistance. It will not turn white when it is bent one million times, which also provides clues for us to identify polypropylene products, and also becomes a hidden mark for the recycling classification of products. #3. After decades of development, polypropylene woven bags have undergone great changes in appearance, quality, and use. In appearance, the pp woven bag woven with mixed-colour flat silk looks more beautiful and has a certain three-dimensional sense. In terms of quality, the quality of current pp woven bags is subject to national supervision, and the quality must meet the unified national standards before it can flow to the market. In terms of use, pp flour bag have been used not only for transportation of food and grain or construction of dams but also for shopping and shopping as a tote bag, which is more environmentally friendly. At the same time, some stores also use it as a packaging bag. 1.Agricultural product packaging and replacing paper cement packaging bags Currently, due to product resource and price issues, 6 billion woven bags are used in cement packaging in China each year, accounting for more than 85% of bulk cement packaging. With the development and application of flexible container bags, plastic woven bags are widely used in marine, transportation, packaging, and agricultural products. In agricultural product packaging, plastic woven bags have been widely used in aquatic product packaging, poultry feed packaging, and farm covering materials. Common products: feed woven bags, chemical woven bags, the putty powder is woven bags, urea woven bags, vegetable mesh bags, fruit mesh bags, etc. d36f5a170b48f4ab34945f0d987adf6f 2.Food packaging In recent years, rice, flour, and other food packaging have gradually been packed in pp woven bags. Common woven bags are rice woven bags, flour woven bags, corn woven bags, and other woven bags. 3.Tourism and transportation Temporary tents, parasols, and various travel bags have plastic woven fabrics. Various tarpaulins are widely used as covering materials for transportation and storage, replacing cotton tarpaulins that are prone to mildew. It is also widely used in fences and nets in construction. Common products: logistics bags, logistics packaging bags, freight bags, freight packaging bags, etc. 4. Daily necessities Working, farming, shipping, and gathering, no one does not use plastic woven products, in stores, warehouses, homes, plastic woven products are everywhere. The padding material for chemical fiber carpets has also been replaced by plastic braids. 5. Anti-flood materials The construction of flood resistance, dams, riverbanks, railways, and highways is also indispensable for woven bags. They are anti-woven bags, drought-proof bags, and flood-proof bags! 6.Special woven bag Some industries require special woven bags, such as carbon black bags, which are not usually used due to special factors. Carbon black bag's biggest feature: sun protection. That is, the carbon black woven bag has a stronger sun protection ability than the ordinary woven bag. The ordinary woven bag cannot withstand long-term exposure to the sun. There are also anti-UV woven bags: with anti-ultraviolet function, anti-aging function, etc. Market dynamics of polypropylene woven bag According to research in the "Polypropylene Woven Bag and Sack Market", countries are passing legislation prohibiting the use of plastic bags and imposing taxes to offset the environmental impact of the production and disposal of plastic bags. Although the materials used in polypropylene woven bags and sacks are not completely biodegradable, these bags can be reused and recycled, so the environmental hazards associated with polyethylene (PE) have led to the use of PP woven bags and sacks as more sustainable s Choice. In fact, with the steady increase in demand, the production of polypropylene woven bags and sacks is becoming a profitable small business. According to the British "Daily Mail" report, in the field of fast-moving consumer goods, the expansion of the retail industry has led to a surge in retail outlets, which will continue to bode well for the growth of the PP woven bags and sacks market. Previously, the initiative on the ban on plastic bags has been widely accepted by countries in the Asia-Pacific region. Therefore, the Asia-Pacific region (excluding Japan) led by the fast-moving consumer goods industry has naturally become the backbone of the global PP woven bag and sack market. The middle-class population in the region also Is proliferating. In addition, most of the polypropylene woven bags in the Asia-Pacific region are mainly concentrated in China and India. The market demands of polypropylene woven bags. As the demand for packaging products continues to grow, major manufacturers in the Asia Pacific region realize that the needs of consumers and end-use industries are constantly changing. They will focus on the production of PP woven bags and sacks, and launch a variety of products. Strive to be a reliable manufacturer of custom woven bags. They export more than half of their products to the United States, Canada, the UAE, Australia, Germany, and the United Kingdom. These manufacturers are also accelerating their entry into Eastern European and South African polypropylene woven bags markets. From the perspective of value and sales volume, the popular open-mouth bags dominate the PP woven bags and sacks market, which together account for more than 50% of the market share. Due to cost, strength, and environmental reasons, laminated polypropylene is woven bags, and sacks are more favored than non-laminated polypropylene woven bags and sacks, accounting for 60% of global sales. According to Fac.MR (India, Pune) research, the PP woven bag market is expected to achieve a compound annual growth rate of 4% between 2018 and 2028. Since most thermoplastics are petroleum-based and non-biodegradable, they will not rot, decompose, and will not be affected by microbial degradation. The threat of resource consumption by petroleum products prompts the industry to develop and increase recycled thermoplastic materials. Plastic has become an inevitable trend of sustainable development. In addition, the growing demand for thermoplastic materials in various applications in the electronics, automotive, and manufacturing industries will also promote the development of the global recycled thermoplastic market. The Asia-Pacific region is the largest market for the production of polypropylene raw materials and recycled thermoplastics because of the huge demand for polypropylene products from the fast-moving consumer goods, packaging, and construction industries in the Asia-Pacific region, and the increasing awareness of the strong market potential of the polypropylene plastics recycling industry in the society, Driving the area to lead the world in the demand for recycled polypropylene plastics. Europe also has a considerable share of the global market for recycled thermoplastics. The increased use of recycled thermoplastics in the automotive industry, coupled with strict recycling regulations, is expected to drive growth in the European region over the forecast period in polypropylene woven bags. Conclusion: The applications of thermoplastics are diverse, but the properties of polypropylene make it more widely used. Especially with the environmental protection consciousness, people's awareness of sustainable development and renewables is gradually increasing. Because polypropylene woven bags has many outstanding advantages, the plastic woven bag industry has a preference for polypropylene from raw material suppliers to woven bag manufacturers to end consumers. In the past ten years, polypropylene's global plastics market share has increased significantly. Waste classification is becoming more and more perfect, and the recycling and utilization of plastic bags have also been put on the agenda by many countries. We always produce plastic waste in our daily life, and the various environmental pollution caused by this plastic waste is getting more and more attention. Therefore, the use of recycled polypropylene woven bags is a general trend, and its market prospects will attract much attention.
Дата Публикации: 24-10-22
Making process control valve choices
Описание: Making process control valve choices Making process control valve choices Control valves are used to manage the flow rate of a liquid or a gas and in-turn control the temperature, pressure or liquid level within a process. As such, they are defined by the way in which they operate to control flow and include globe valves, angle seat, diaphragm, quarter-turn, knife and needle valves, to name a few. In most cases the valve bodies are made from metal; either brass, forged steel or in hygienic applications 316 stainless steel. Actuators will use an on-board system to measure the position of the valve with varying degrees of accuracy, depending on the application. A contactless, digital encoder can place the valve in any of a thousand positions, making it very accurate, while more rudimentary measurements can be applied to less sensitive designs. One of the main areas of debate when specifying control valves is determining the size of the valve required. Often process engineers will know the pipe diameter used in an application and it is tempting to take that as the control valve's defining characteristic. Of greater importance are the flow conditions within the system as these will dictate the size of the orifice within the control valve. The pressure either side of the valve and the expected flow rate are essential pieces of information when deciding on the valve design. Inside the valve body, the actuator design is often either a piston or a diaphragm design. The piston design typically offers a smaller, more compact valve which is also lighter and easier to handle than the diaphragm designs. Actuators are usually made from stainless steel or polyphenolsulpide (PPS), which is a chemically-resistant plastic. The actuator is topped off by the control head or positioner. Older, pneumatically operated positioners had a flapper/nozzle arrangement and operated on 3-15psi, so no matter what the state of the valve, open closed or somewhere in between, the system was always expelling some compressed air to the atmosphere. Compressed air is an expensive commodity, requiring considerable energy to generate and when a manufacturing line is equipped with multiple pressure relief valve all venting to the atmosphere, this can equate to a considerable waste of energy. It is important to not only establish the most appropriate valve design, but also a cost-effective solution that takes account of annual running costs. Modern, digital, electro-pneumatic valves that use micro-solenoid valves to control the air in and out of the actuator have introduced significant improvements for operators. This design means that while the valve is fully open, fully closed or in a steady state, it is not consuming any air. This, and many other engineering improvements, have made substantial advances in both economy and precision. Valve seats can be interchangeable within a standard valve body, which allows the valve to fit existing pipework and the valve seat to the sized to the application more accurately. In some cases, this can be achieved after the valve has been installed, which would enable a process change to be accommodated without replacing the complete valve assembly. Selecting the most appropriate seal materials is also an important step to ensure reliable operation; Steam processes would normally use metal-to-metal seals, whereas a process that included a sterilization stage may require chemically resistant seals. Setting up and installing a new valve is now comparatively easy and much less time-consuming. In-built calibration procedures should be able perform the initial setup procedures automatically, measuring the air required to open and close the valve, the resistance of the piston seals on the valve stem and the response time of the valve itself. Improving safety Control valves should be specified so they operate in the 40-85% range so if the valve is commanded to a 10% setting, it can detect if something has potentially gone wrong with the control system and the best course of action is to close the valve completely. If the valve is commanded to a position of 10% or less this can cause very high fluid or gas velocities, which have damaging effects on the system and cause considerable noise and damage to the valve itself. Modern control functionality can offer a solution that acts as a safety device to prevent damage to the process pipework and components. By building in a fail-safe mechanism, any valve position setting below a pre-set threshold will result in the valve closing completely, preventing damage to the surrounding system. Control inputs can also include safety circuits to ensure safe operating conditions within the process equipment. For example, if an access panel on a vessel containing steam is opened, an interlock switch will open and the valve controlling the steam supply to the vessel can be automatically closed, helping mitigate any risks. Improving reliability Many process control environments offer less than ideal conditions for long-term reliability. Moisture-laden atmospheres, corrosive chemicals and regular wash-downs all have the capacity to shorten the service life of common rail control valve F00vc01334. One of the potential weaknesses of the actuator is the spring chamber where atmospheric air is drawn in each time the valve operates. One solution is to use clean, instrument air to replenish the spring chamber, preventing any contamination from entering. This offers a defense against the ingress of airborne contaminants by diverting a small amount of clean control air into the control head, maintaining a slight positive pressure, thus achieving a simple, innovative solution. This prevents corrosion of the internal elements and can make a significant improvement to reliability and longevity in certain operating conditions. While choosing the most appropriate process control valve can be a complex task, it is often best achieved with the assistance of expert knowledge. Working directly with manufacturers or knowledgeable distributors enables process control systems to be optimized for long-term reliability as well as precision and efficiency. Damien Moran is field segment manager, Hygienic – Pharmaceutical at Bürkert. This article originally appeared on the Control Engineering Europe website. Edited by Chris Vavra, associate editor, Control Engineering, CFE Media and technology, cvavra@cfemedia.com. Advanced control schemes can't produce optimum results unless the diesel common rail fuel valve F00rj01428 operate properly. Instrument technicians must understand these final control elements as well as their diagnostic software to ensure the valves in the plant operate as the system designers intended. Renewed interest in the performance of control valves is emerging, partly as a result of numerous plant audits that indicate roughly one-third of installed control valves are operating at substandard levels. Even though properly operating control valves are essential to overall plant efficiency and product quality, maintenance personnel frequently don't recognize the signs of poor performance. The basics of control valve design and operation must be well understood for end-users to reap the benefits of improved valve operation. Basic types of control valves The most common and versatile types of control valves are sliding-stem globe and angle valves (see Figure 1). Their popularity derives from rugged construction and the many options available that make them suitable for a variety of process applications, including severe service. For example, sliding stem valves typically are available with options that satisfy a range of requirements for ANSI Class pressure-temperature ratings, shutoff capability, size, temperature compatibility and flow characteristics. Achieving complete valve shutoff is important in many applications to prevent leakage that either could contaminate a process fluid or result in product loss. Tight shutoff also prevents erosion damage that could occur if a high-velocity stream leaked across seating surfaces. Many control valves are oversized as a result of inaccurate information and safety margins added by each individual or group that participates in the sizing procedure. Oversized valves are a problem for three reasons. First, the valve operation may become unstable because it never opens very far from the fully closed position. Process gain is generally high when the valve is throttling near its seat. The combined valve and process gains may be too high to maintain stable operation at low lifts. Second, excessive seat wear may result from high velocity flows between the closure member and the seating surface. Third, the design flow characteristic may not be achieved, resulting in controller tuning problems. Control valves are a common element in the process and manufacturing industry. They control the fluid flow in the attached network. The fluid goes into one side of the valve; its flow is adjusted and comes out the other side. The fluid flow can be controlled by manual or automatic mechanisms and comes in various shapes, sizes, and applications. Controlling the flow rate of process fluids enables personnel to control many relevant parameters. For example, the temperature in a closed container is directly proportional to the steam pressure being applied to it. Similarly, water flow in a vessel storage system is monitored and controlled to prevent overflow. The flow of these fluids can be effectively controlled by installing control valves. They are available for various fluids, such as steam, water, and chemicals. Some can also withstand harsh environments, such as high temperatures and toxic chemicals. Manual control valves are simple—humans manually control the opening of the valve through a manual mechanism such as a handle. The handle's motion is directly connected with the internal valve mechanism, which controls the fluid flow. Control Valves with Feedback Signals Another control valve style uses a feedback signal to control the fluid flow. Before controlling the valve working, let's briefly introduce feedback signals, electrical to pneumatic converters, and actuators. Feedback Signal The feedback signal monitors the target system for flow requirements. If the feedback signal detects any need to increase or decrease the fluid flow, it alerts the valve. The valve then responds and adjusts its opening to accommodate the fluid flow. The feedback signal can be electrical or pneumatic, and is often from a programmable logic controller (PLC) or electrical controller, which monitors the change in fluid flow requirement. Electrical to Pneumatic Signal Converter The control valve accepts feedback signals in the form of air. In the case of the electrical feedback signal, the signal is converted to equivalent pneumatic pressure. The electrical to pneumatic converter converts the incoming electrical feedback signal to equal pneumatic pressure, fed to the control valve as a feedback signal. Examples of pneumatic converters include a current-to-pressure transducer that converts the incoming current to a pneumatic signal. Actuator The actuator is a component attached to the injector control valve F00rj02130, which controls the valve movement. Without the actuator, the internal mechanism of the valve cannot be moved. The feedback pneumatic signal comes to the actuator, directly connected to the main valve body. The main control valve moves relative to the actuator. When the feedback signal becomes high—indicating a more increased flow—the actuator closes, closing the main valve. When the feedback signal decreases—indicating low flow—the actuator opens, simultaneously opening the valve to increase the flow.
Дата Публикации: 24-10-22
The right lighting can lift your spirits and make you more relaxed and productive
Описание: The right lighting can lift your spirits and make you more relaxed and productive The right lighting can lift your spirits and make you more relaxed and productive. Any experienced designer will tell you that lighting is an essential ingredient when you're decorating a room — not the afterthought that many of us consider it. If you're tempted to spend more of your time picking out furnishings or puzzling over layouts, remember that LED lighting can completely transform a space — not just by brightening dark corners, but by affecting your emotions. "Light is a powerful thing," said Theo Richardson, the director of development at Rich Brilliant Willing, the Brooklyn-based design studio known for its striking LED fixtures, which he founded with Charles Brill and Alexander Williams. "The right light lifts the mood, inspires productivity and motivates us. At home, light enlivens the little things — our morning routines, or the moments we spend with friends." Most designers agree that you need more than one source of light in a room. Think layered illumination: Every room should have a mix of sports lighting, including overhead, accent and task lights. In the living room, for example, you might begin by hanging a decorative ceiling fixture near the center of the room, said Nathan Orsman, a port lighting designer based in New York City and Southampton. "Then we look toward the outer walls for downlighting that can gently wash the walls, curtains and art with warm, functional brightness," he said. This can be achieved with soffit or valance lighting, or even plug-in torchier floor lamps that bounce light off the ceiling. Depending on a room's layout, he said, accent lights could be used to highlight art, and table lamps could be placed beside seating to add another layer of light. And for extra ambience, he added, "a candle never hurt." The goal, he explained, is to create contrast between the light at the center of the room and around the perimeter, and the darker spaces in between: "Without the darker, quieter moments, everything is flat and boring. It's the subtle interplay between light and dark that creates appeal." One place where bright light is more important than ambience is the kitchen. Mr. Orsman suggested flooding the space by installing high-hats or recessed lights along the edge of the ceiling. If you have a kitchen island, consider hanging pendants overhead, he said, which will light the space without taking up room you might need to eat or prepare food. Also, you'll be able "to see your guests without having to look around a hanging light." And don't forget under-cabinet light: Running LED light strips on the bottom of your upper cabinets is the easiest way to create an evenly lighted counter space for food prep and cooking. If you have a north-facing room without direct sunlight, it will generally require a little more thought. Donna Mondi, an interior designer in Chicago, installed recessed fixtures along the perimeter of a north-facing living room to complement a central pendant that spread light horizontally throughout the space. But she didn't stop there: She also used table lamps to illuminate dark corners and a pair of sconces to draw attention to a special piece of art. For a dark bedroom, she used a similar strategy, combining a central chandelier with discrete up-lights in the corners of the room, bedside lamps for reading and a pair of sconces over the fireplace opposite the bed. "The worst option is a recessed fixture over the sink, as it casts shadows that are not flattering," Ms. Mondi said. Instead, she suggested, opt for wall-mounted sconces with 75-watt bulbs installed about 66 inches off the floor, which will help cast even illumination across your face. Another "great feature to add is industrial lighting at the cabinet base," she said, which creates "a very subtle glow" like a night light if you wake up in the middle of the night. To create a sense of intimacy and spalike luxury, consider installing a sculptural pendant lamp. Janey Butler, who runs Janey Butler Interiors, the interior design wing of the Llama Group in Cheshire, England, transformed a windowless bathroom into a dramatic space by hanging Ochre's Celestial Pebble Chandelier over the tub. "The light itself is a beautiful object that meets the eye on arrival to the room and provides focus to the free-standing bath," Ms. Butler said. She also used LED strip lighting, concealed behind floating shelves, to wash the chevron-patterned floor with a subtle glow. "When you have an empty and awkward corner, one trick of the trade is to transform that space with an oversized floor lamp," said Caitlin Murray, the founder and chief executive of Black Lacquer Design, in Los Angeles. "Look for a lamp that is complementary in finish and material to the surrounding space, and an otherwise lost corner instantly becomes an intentional, polished part of the overall room design." To brighten up the space next to a desk in a bachelor's living room, Ms. Murray chose the Detrick Floor Lamp, from Arteriors, in an earthy finish with a gray-green shade. "It did the double duties of providing added light to his work space while also being a statement accent piece," she said. "It was important to find something in tone and texture that both complemented the overall design and provided enough of a contrast to the surrounding neutrals to really make a visual impact." Don't Overdo the Overheads "Over the years, we've found that one of the biggest mistakes is made with overhead commercial lighting," said Robert Highsmith, a principal at Workstead, the Brooklyn design firm he founded with his wife, Stefanie Brechbuehler, and fellow Rhode Island School of Design alum Ryan Mahoney almost a decade ago. "Often it can be excessive, generating spots and unwanted shadows." For that reason, Workstead advises residential clients not to use recessed overhead lighting. Instead, Mr. Highsmith recommends hanging a large pendant fixture or a chandelier in common areas. In the kitchen, he suggested using globe fixtures, "for even lighting" that leaves counter surfaces free. For living rooms, he said, try subtle lighting sources like wall sconces and floor lamps, and in dining rooms, "a sculptural centerpiece above a table provides depth, while accent lighting amplifies warmth." Put dimmers on all of your lights: "Workstead prefers a more analog approach that allows you to manually adjust lighting to respond to changes in natural light, seasons and so forth," Mr. Highsmith said, noting that the easiest way to adjust the light in a room is by putting a dimmer on each fixture, rather than replacing a wall switch with a dimmer that adjusts all the lights at once. In the bedroom, he suggested using a bedside light with both a dimmer and a movable shade. Workstead designed the Orbit sconce, for example, to be adjustable in both ways, with a dimmer and a swiveling reflector that allows the light to be directed or blocked. "We feel like the more flexibility, the better," he said. Don't Forget the Details "Whenever you use a shade — whether it's on a lamp, a sconce or a chandelier — use frosted or soft-white bulbs to eliminate the shadows and hot spots created by shade clips," said Paloma Contreras, an interior designer in Houston. And be sure those shades are on straight. "The harps are pliable, so you can manipulate them a bit to ensure that the shades sit on the lamp properly," Ms. Contreras said. You should also orient the lampshade so that seams are hidden. "I can't begin to tell you how many seams I have seen on lampshades in movies, on television shows and even in magazines," she added. "You wouldn't put your dress on backward, would you?" "I'm all about the LEDs now," Ms. Contreras said. "Our home is illuminated by warm-colored LED bulbs, and they look like traditional incandescents. Plus, they're made for all fixtures, including recessed cans, table lamps and sconces." For a warm, inviting light, she said, go with 2,700 to 3,000 kelvin, often advertised as "warm white." As you go higher in the color-temperature range, she said, "more blue is introduced, and this ultimately gives that dreaded warehouse look." (Those bulbs — often advertised as "daylight" — do better in a garage or a more utilitarian space.) Like many other institutional structures assembled at the end of the twentieth century, the International Space Station (ISS) was designed to incorporate fluorescent light bulbs. At present, the spacecraft is more than halfway through a lighting overhaul, and its original bulbs are being replaced, piece by piece, with light-emitting diodes (LEDs). Compared with conventional incandescent or fluorescent bulbs, LEDs use less energy, last longer and contain no glass or mercury, negating the risk of glass shards or toxic metal floating through the space station should the bulbs break in zero gravity. But researchers also hope that the new lighting system will help astronauts to sleep better at night and to stay alert during the day. The problem that engineers are trying to address is that there's no 'day' or 'night' in space. The ISS circles Earth every 90 minutes or so, which provides astronauts with frequent opportunities to see the Sun rise and set, but also wreaks havoc on the body's roughly 24-hour, or circadian, clock. Among space flight's many deleterious effects on health, disturbance of the circadian rhythm and the sleep deprivation that accompanies it have emerged as considerable worries — particularly as people contemplate travelling to more distant locations in the Solar System, says George Brainard, director of the Light Research Program at Thomas Jefferson University in Philadelphia, Pennsylvania. The LED-based lighting system being introduced to the ISS is designed to target not just rods and cones — photoreceptor cells in the eye that enable vision in dim light and in colour, respectively — but also a third type of photoreceptor cell that was discovered almost 20 years ago. Known as intrinsically photosensitive retinal ganglion cells (ipRGCs), these photoreceptors contain a light-sensitive protein called melanopsin. They don't have much of a role in vision; instead, ipRGCs serve as the body's main entry point for light that regulates biological functions such as the sleep–wake cycle, alertness and mood. Researchers are beginning to understand the extent to which too much or too little light at the wrong time of day can throw important physiological processes out of sync, whether you're an astronaut on a spacecraft, a nurse on the night shift, or just playing computer games after bedtime. Artificial lighting has extended the length of time for which people are exposed to light each day, for better or for worse. LED-based dynamic lighting systems that are capable of adjusting the colour and intensity of the light that they deliver should make it possible to design lit environments that are less detrimental to health. "There's no limit to the technology in terms of what can be done with LED lights," says Robert Lucas, a neuroscientist at the University of Manchester, UK, who studies the visual system's response to light. "That puts the onus on us, as biologists, to tell the lighting engineers exactly what they should be doing."
Дата Публикации: 24-10-22