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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 * Superca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyvek House Wrap
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 n ... [...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 ... [...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 y ... [...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 ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
