|
Housewrap
Housewrap (or house wrap), also known by the genericized trademark homewrap (or home wrap), generally denotes a modern synthetic material used to protect buildings. Housewrap functions as a weather-resistant barrier, preventing rain or other forms of moisture from getting into the wall assembly while allowing water vapor to pass to the exterior. If moisture from either direction is allowed to build up within stud or cavity walls, mold and rot can set in and fiberglass or cellulose insulation will lose its R-value due to heat-conducting moisture. House wrap may also serve as an air barrier if it is sealed carefully at seams. Housewrap is a replacement for the older tar paper or asphalt saturated felt on walls. It is lighter in weight, available in much wider rolls, and both faster and easier to apply. Major types * Micro-perforated, cross-lapped films * Films laminated to spunbond nonwovens (Typar or CertaWrap) * Films laminated or coated to polypropylene wovens * Superc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyvek House Wrap
Tyvek () is a brand of chemical synthesis, synthetic flashspun high-density polyethylene fibers. The name "Tyvek" is a registered trademark of the American multinational chemical company DuPont, which discovered and commercialized Tyvek in the late 1950s and early 1960s. Tyvek's properties - such as being difficult to tear but easily cut, and waterproof against liquids whilst allowing water vapor to penetrate - have led to it being used in a variety of applications. Tyvek is often used as housewrap, a synthetic material used to protect buildings during construction, or as PPE gown, personal protective equipment (PPE). History Tyvek is a Nonwoven fabric, nonwoven product consisting of spun bond olefin fiber. It was first discovered in 1955 by a researcher for the DuPont textile company working in an experimental lab, who noticed a type of white fluff coming out of a pipe. That fluff was a form of polyethylene, which DuPont requested a patent for within a year of the discovery. Af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helena, Montana
Helena (; ) is the capital city of Montana, United States, and the county seat of Lewis and Clark County. Helena was founded as a gold camp during the Montana gold rush, and established on October 30, 1864. Due to the gold rush, Helena would become a wealthy city, with approximately 50 millionaires inhabiting the area by 1888. The concentration of wealth contributed to the city's prominent, elaborate Victorian architecture. At the 2020 census Helena's population was 32,091, making it the fifth least populous state capital in the United States and the sixth most populous city in Montana. It is the principal city of the Helena Micropolitan Statistical Area, which includes all of Lewis and Clark and Jefferson counties; its population is 83,058 according to the 2020 Census. The local daily newspaper is the '' Independent Record''. The city is served by Helena Regional Airport (HLN). History The Helena area was long inhabited by various indigenous peoples. Evidence from the M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moisture Vapor Transmission Rate
Moisture vapor transmission rate (MVTR), also water vapor transmission rate (WVTR), is a measure of the passage of water vapor through a substance. It is a measure of the permeability for vapor barriers. There are many industries where moisture control is critical. Moisture sensitive foods and pharmaceuticals are put in packaging with controlled MVTR to achieve the required quality, safety, and shelf life. In clothing, MVTR as a measure of breathability has contributed to greater comfort for wearers of clothing for outdoor activity. The building materials industry also manages the moisture barrier properties in architectural components to ensure the correct moisture levels in the internal spaces of buildings. Optoelectronic devices based on organic material, generally named OLEDs, need an encapsulation with low values of WVTR to guarantee the same performances over the lifetime of the device. MVTR generally decreases with increasing thickness of the film/barrier, and increases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyvek
Tyvek () is a brand of synthetic flashspun high-density polyethylene fibers. The name "Tyvek" is a registered trademark of the American multinational chemical company DuPont, which discovered and commercialized Tyvek in the late 1950s and early 1960s. Tyvek's properties - such as being difficult to tear but easily cut, and waterproof against liquids whilst allowing water vapor to penetrate - have led to it being used in a variety of applications. Tyvek is often used as housewrap, a synthetic material used to protect buildings during construction, or as personal protective equipment (PPE). History Tyvek is a nonwoven product consisting of spun bond olefin fiber. It was first discovered in 1955 by a researcher for the DuPont textile company working in an experimental lab, who noticed a type of white fluff coming out of a pipe. That fluff was a form of polyethylene, which DuPont requested a patent for within a year of the discovery. After technologies improved during the next few ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyethylene
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging ( plastic bags, plastic films, geomembranes and containers including bottles, etc.). , over 100 million tonnes of polyethylene resins are being produced annually, accounting for 34% of the total plastics market. Many kinds of polyethylene are known, with most having the chemical formula (C2H4)''n''. PE is usually a mixture of similar polymers of ethylene, with various values of ''n''. It can be ''low-density'' or ''high-density'': low-density polyethylene is extruded using high pressure () and high temperature (), while high-density polyethylene is extruded using low pressure () and low temperature (). Polyethylene is usually thermoplastic, but it can be modified to become thermosetting instead, for example, in cross-linked polyethylene. History Polyethylene was first synthesized by the German chemis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercalendered
A calender is a series of hard pressure rollers used to finish or smooth a sheet of material such as paper, textiles, rubber, or plastics. Calender rolls are also used to form some types of plastic films and to apply coatings. Some calender rolls are heated or cooled as needed. Calenders are sometimes misspelled ''calendars''. Etymology The word "calender" itself is a derivation of the word κύλινδρος ''kylindros'', the Greek word that is also the source of the word "cylinder". History In eighteenth century China, workers called "calenderers" in the silk- and cotton-cloth trades used heavy rollers to press and finish cloth. In 1836, Edwin M. Chaffee, of the Roxbury India Rubber Company, patented a four-roll calender to make rubber sheet. Chaffee worked with Charles Goodyear with the intention to "produce a sheet of rubber laminated to a fabric base". Calenders were also used for paper and fabrics long before later applications for thermoplastics. With the expans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypropylene
Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene. Polypropylene belongs to the group of polyolefins and is partially crystalline and non-polar. Its properties are similar to polyethylene, but it is slightly harder and more heat-resistant. It is a white, mechanically rugged material and has a high chemical resistance. Bio-PP is the bio-based counterpart of polypropylene (PP). Polypropylene is the second-most widely produced commodity plastic (after polyethylene). In 2019, the global market for polypropylene was worth $126.03 billion. Revenues are expected to exceed US$145 billion by 2019. The sales of this material are forecast to grow at a rate of 5.8% per year until 2021. History Phillips Petroleum chemists J. Paul Hogan and Robert Banks first demonstrated the polymerization of propylene in 1951. The stereoselective polymerizat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bituminous Waterproofing
Bituminous waterproofing systems are designed to protect residential and commercial buildings. Bitumen (asphalt or coal-tar pitch) is a mixed substance made up of organic liquids that are highly sticky, viscous, and waterproof. These systems are sometimes used to construct roofs, in the form of roofing felt or roll roofing products. Roofing felt Roofing felt (similar to tar paper) is the base material used to make roof shingles and roll roofing. Used for decades as waterproof coverings in residential and commercial roofs, these bitumen compositional membranes incorporate two layers. The first underside polymer membrane is used as a solid background, often reinforced with glass fibers. Mineral granules make up the self-protective top layer, with a final bituminous mixture encapsulating them both. Typical uses of felt paper are as an underlay(ment) ( sarking) beneath other building materials, particularly roofing and siding materials, and is one type of membrane used in asphalt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tar Paper
Tar paper is a heavy-duty paper used in construction. Tar paper is made by impregnating paper or fiberglass mat with tar, producing a waterproof material useful for roof construction. Tar paper is distinguished from roofing felt, which is impregnated with asphalt instead of tar, but these two products are used the same way, and their names are sometimes used informally as synonyms. Description Tar paper has been in use for centuries. Originally, felt was made of recycled rags, but modern felt is made of recycled paper products, typically cardboard, and sawdust. The most common product is #15 felt. Before the oil crisis, felt weighed about per square, hence the asphalt-impregnated felt was called "15-pound felt" (15#). Modern, inorganic mats are no longer the same weight, and to reflect this fact, the new felts are called "number 15 felt" (#15). Modern #15 mats can weigh from pounds per square, depending on the manufacturer and the standard to which felt is made (such as , , or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Barrier
Air barriers control air leakage into and out of the building envelope. Air barrier products may take several forms: *Mechanically-attached membranes, also known as housewraps, usually a polyethylene-fiber or spun-bonded polyolefin, such as Tyvek is a generally accepted moisture barrier and an air barrier (ASTM E2178). *Self-adhered membranes, which are typically also a water-resistant barrier and a vapor barrier *Fluid-applied membranes, such as heavy-bodied paints or coatings including polymeric based and asphaltic based materials *Closed-cell medium density spray-applied polyurethane foam, which typically provides insulation as well *Some open-cell spray-applied polyurethane foam that are of high density *Boardstock, which includes 12 mm plywood or OSB, 25 mm extruded polystyrene, etc. Air barriers are divided into air barrier materials, air barrier accessories, air barrier components, air barrier assemblies and air barrier systems. Air barrier materials – Building ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genericized Trademark
A generic trademark, also known as a genericized trademark or proprietary eponym, is a trademark or brand name that, because of its popularity or significance, has become the generic term for, or synonymous with, a general class of products or services, usually against the intentions of the trademark's owner. A trademark is said to become ''genericized''—or, informally, to have suffered ''genericide''—when it begins as a distinctive product identifier but changes in meaning to become generic. This typically happens when the products or services which the trademark is associated with have acquired substantial market dominance or mind share, such that the primary meaning of the genericized trademark becomes the product or service itself rather than an indication of source for the product or service. A trademark thus popularised has its legal protection at risk in some countries such as the United States and United Kingdom, as its intellectual property rights in the trad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R-value (insulation)
In the context of construction, the R-value is a measure of how well a two-dimensional barrier, such as a layer of insulation, a window or a complete wall or ceiling, resists the conductive flow of heat. R-value is the temperature difference per unit of heat flux needed to sustain one unit of heat flux between the warmer surface and colder surface of a barrier under steady-state conditions. The ''R-value'' is the building industry term for thermal resistance "per unit area." It is sometimes denoted RSI-value if the SI units are used. An R-value can be given for a material (e.g. for polyethylene foam), or for an assembly of materials (e.g. a wall or a window). In the case of materials, it is often expressed in terms of R-value per metre. R-values are additive for layers of materials, and the higher the R-value the better the performance. The U-factor or U-value is the overall heat transfer coefficient and can be found by taking the inverse of the R-value. It is a property ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
