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Pressure-sensitive Adhesive
Pressure-sensitive adhesive (PSA, self-adhesive, self-stick adhesive) is a type of nonreactive adhesive which forms a bond when pressure is applied to bond the adhesive with a surface. No solvent, water, or heat is needed to activate the adhesive. It is used in pressure-sensitive tapes, labels, glue dots, stickers, sticky note pads, automobile trim, and a wide variety of other products. As the name "pressure-sensitive" indicates, the degree of bond is influenced by the amount of pressure which is used to apply the adhesive to the surface. Surface factors such as smoothness, surface energy, removal of contaminants, etc. are also important to proper bonding. PSAs are usually designed to form a bond and hold properly at room temperatures. PSAs typically reduce or lose their tack at low temperatures and reduce their shear holding ability at high temperatures; special adhesives are made to function at high or low temperatures. Structural and pressure-sensitive adhesives Adhesi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laptop Stickers
A laptop, laptop computer, or notebook computer is a small, portable personal computer (PC) with a screen and alphanumeric keyboard. Laptops typically have a clam shell form factor with the screen mounted on the inside of the upper lid and the keyboard on the inside of the lower lid, although 2-in-1 PCs with a detachable keyboard are often marketed as laptops or as having a "laptop mode". Laptops are folded shut for transportation, and thus are suitable for mobile use. They are so named because they can be practically placed on a person's lap when being used. Today, laptops are used in a variety of settings, such as at work, in education, for playing games, web browsing, for personal multimedia, and for general home computer use. As of 2022, in American English, the terms ''laptop computer'' and ''notebook computer'' are used interchangeably; in other dialects of English, one or the other may be preferred. Although the terms ''notebook computers'' or ''notebooks'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Van Der Waals Forces
In molecular physics, the van der Waals force is a distance-dependent interaction between atoms or molecules. Unlike ionic or covalent bonds, these attractions do not result from a chemical electronic bond; they are comparatively weak and therefore more susceptible to disturbance. The van der Waals force quickly vanishes at longer distances between interacting molecules. Named after Dutch physicist Johannes Diderik van der Waals, the van der Waals force plays a fundamental role in fields as diverse as supramolecular chemistry, structural biology, polymer science, nanotechnology, surface science, and condensed matter physics. It also underlies many properties of organic compounds and molecular solids, including their solubility in polar and non-polar media. If no other force is present, the distance between atoms at which the force becomes repulsive rather than attractive as the atoms approach one another is called the van der Waals contact distance; this phenomenon result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass Transition
The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rubbery state as the temperature is increased. ISO 11357-2: Plastics – Differential scanning calorimetry – Part 2: Determination of glass transition temperature (1999). An amorphous solid that exhibits a glass transition is called a glass. The reverse transition, achieved by supercooling a viscous liquid into the glass state, is called vitrification. The glass-transition temperature ''T''g of a material characterizes the range of temperatures over which this glass transition occurs (as an experimental definition, typically marked as 100 s of relaxation time). It is always lower than the melting temperature, ''T''m, of the crystalline state of the material, if one exists. Hard plastics like polystyrene and poly(methyl methacrylate) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freeze Spray
Freeze spray (cold spray or vapocoolant) is a type of aerosol spray product containing a liquified gas used for rapidly cooling surfaces, in medical and industrial applications. It is usually sold in hand-held spray cans. It may consist of various substances, which produce different temperatures, depending on the application. Some of them are highly flammable. Several other types of compressed gas sprays also have a freezing effect: for example, tetrafluoroethane, gas dusters, liquid nitrogen, and carbon dioxide fire extinguishers. Applications Industrial For spot-cooling of electronic components during troubleshooting, dimethyl ether or tetrafluoroethane may be used. Freeze sprays are also used to contract metal for assembly or disassembly of interference fit parts. The extreme temperature can cause viscoelastic materials to change to glass phase. Thus it is useful for removing many types of pressure sensitive adhesives. Medical In medical applications, spray cans co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dry Ice
Dry ice is the solid form of carbon dioxide. It is commonly used for temporary refrigeration as CO2 does not have a liquid state at normal atmospheric pressure and sublimates directly from the solid state to the gas state. It is used primarily as a cooling agent, but is also used in fog machines at theatres for dramatic effects. Its advantages include lower temperature than that of water ice and not leaving any residue (other than incidental frost from moisture in the atmosphere). It is useful for preserving frozen foods (such as ice cream) where mechanical cooling is unavailable. Dry ice sublimates at at Earth atmospheric pressure. This extreme cold makes the solid dangerous to handle without protection from frostbite injury. While generally not very toxic, the outgassing from it can cause hypercapnia (abnormally elevated carbon dioxide levels in the blood) due to buildup in confined locations. Properties Dry ice is the solid form of carbon dioxide (CO2), a molecule ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvents
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners (toluene, turpentine); as nail polish removers and solvents of glue (acetone, methyl acetate, ethyl acetate); in spot removers (hexane, petrol ether); in detergents ( citrus terpenes); and in perfumes (ethanol). Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transdermal Patch
A transdermal patch is a medicated adhesive patch that is placed on the skin to deliver a specific dose of medication through the skin and into the bloodstream. An advantage of a transdermal drug delivery route over other types of medication delivery (such as oral, topical, intravenous, or intramuscular) is that the patch provides a controlled release of the medication into the patient, usually through either a porous membrane covering a reservoir of medication or through body heat melting thin layers of medication embedded in the adhesive. The main disadvantage to transdermal delivery systems stems from the fact that the skin is a very effective barrier; as a result, only medications whose molecules are small enough to penetrate the skin can be delivered by this method. The first commercially available prescription patch was approved by the U.S. Food and Drug Administration in December 1979. These patches administered scopolamine for motion sickness. In order to overco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-it Note
A Post-it Note (or sticky note) is a small piece of paper with a re-adherable strip of glue on its back, made for temporarily attaching notes to documents and other surfaces. A low-tack pressure-sensitive adhesive allows the notes to be easily attached, removed and even re-posted elsewhere without leaving residue. Originally small yellow squares, Post-it Notes and related products are available in various colors, shapes, sizes and adhesive strengths. As of 2019, there are at least 26 documented colors of Post-it Notes. Although 3M's patent expired in 1997, "Post-it" and the original notes' distinctive yellow color remain registered company trademarks, with terms such as "repositionable notes" used for similar offerings manufactured by competitors. While use of the trademark 'Post-it' in a representative sense refers to any sticky note, no legal authority has ever held the trademark to be generic. History In 1968, Dr. Spencer Silver, a scientist at 3M in the United States, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Masking Tape
Masking tape, also known as painter's tape, is a type of pressure-sensitive tape made of a thin and easy-to-tear paper, and an easily released pressure-sensitive adhesive. It is available in a variety of widths. It is used mainly in painting, to mask off areas that should not be painted. The adhesive is the key element to its usefulness, as it allows the tape to be easily removed without leaving residue or damaging the surface to which it is applied. The tape is available in several strengths, rated on a 1–100 scale based on the strength of the adhesive. Most painting operations will require a tape in the 50 range. Household masking tape is made of an even weaker paper and lower-grade adhesive. History Masking tape was created in 1925 by 3M employee Richard Drew. Drew observed autobody workers growing frustrated when they removed butcher paper they had taped to cars they were painting. The strong adhesive on the tape peeled off some of the paint they had just applied. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HVAC
Heating, ventilation, and air conditioning (HVAC) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. HVAC system design is a subdiscipline of mechanical engineering, based on the principles of thermodynamics, fluid mechanics, and heat transfer. " Refrigeration" is sometimes added to the field's abbreviation as HVAC&R or HVACR, or "ventilation" is dropped, as in HACR (as in the designation of HACR-rated circuit breakers). HVAC is an important part of residential structures such as single family homes, apartment buildings, hotels, and senior living facilities; medium to large industrial and office buildings such as skyscrapers and hospitals; vehicles such as cars, trains, airplanes, ships and submarines; and in marine environments, where safe and healthy building conditions are regulated with respect to temperature and humidity, using fres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post It Notes
Post or POST commonly refers to: *Mail, the postal system, especially in Commonwealth of Nations countries ** An Post, the Irish national postal service **Canada Post, Canadian postal service **Deutsche Post, German postal service ** Iraqi Post, Iraqi postal service **Russian Post, Russian postal service ** Hotel post, a service formerly offered by remote Swiss hotels for the carriage of mail to the nearest official post office **United States Postal Service or USPS **Parcel post, a postal service for mail that is heavier than ordinary letters *Post, a job or occupation Post, POST, or posting may also refer to: Architecture and structures * Lamppost, a raised source of light on the edge of a road *Post (structural), timber framing *Post and lintel, a building system * Steel fence post *Trading post *Utility pole or utility post Military *Military base, an assigned station or a guard post **Outpost (military), a military outpost **Guardpost, or guardhouse Geography * Post, Iran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
