Tyvek

Tyvek (/taɪˈvɛk/) is a brand of flashspun high-density polyethylene fibers, a synthetic material; the name is a registered trademark of the DuPont company, known for their production of chemicals and textiles. Tyvek is often used as housewrap, a synthetic material used to protect buildings during construction. The material is difficult to tear, but can easily be cut with scissors or a knife. Water vapor can pass through Tyvek, but liquid water cannot. All of these properties have led to Tyvek being used in a variety of applications. Tyvek (/taɪˈvɛk/) is a brand of flashspun high-density polyethylene fibers, a synthetic material; the name is a registered trademark of the DuPont company, known for their production of chemicals and textiles. Tyvek is often used as housewrap, a synthetic material used to protect buildings during construction. The material is difficult to tear, but can easily be cut with scissors or a knife. Water vapor can pass through Tyvek, but liquid water cannot. All of these properties have led to Tyvek being used in a variety of applications. 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, named Jim White. While working in an experimental lab, Jim noticed a type of white fluff coming out of a pipe in a DuPont experimental lab. That fluff was a product known as polyethylene, which DuPont requested a patent for within a year of the discovery. After technologies improved during the next few years, in 1959 DuPont discovered that when the fluff was spun at high speeds it produced a durable fabric that was able to be cut with a blade. While the product Tyvek was used since 1959, DuPont did not trademark the actual brand until 1965, making it available for commercial purposes in April 1967. As of 1970, Tyvek had reached the mainstream construction industry on both a national and global scale, and is often used for the construction of houses due to its unique ability to keep out liquid, while allowing vapor through. In 1972, DuPont released Tyvek packaging for sterile instruments that were to be used by surgeons and doctors in the medical field. In 2017, DuPont and Focus DIY entered an current agreement to sell Tyvek along with DuPont’s other products at Focus DIY stores. In 2017, the DuPont company merged with another chemical company, The Dow Chemical Company to form DowDuPont. The net worth of this newly merged company is over $150 billion as of 2017. While the DuPont company still makes Tyvek, it also produces products such as Kevlar and cellophane, among numerous other chemical products. Tyvek is currently manufactured at the Spruance plant in Richmond, Virginia, and in Sandweiler-Contern, Luxembourg. In 2018, DowDuPont announced that they would spend $400 million to increase the amount of Tyvek that could be produced in the Sandweiler-Contern factory. DuPont recommends starch, dextrin, casein, and animal-based adhesives over most synthetic-based adhesives, emphasizing the effectiveness of water-based and quick-drying glues as the best for bonding Tyvek both to itself and to a variety of substrates. DuPont also claims that the following adhesives are highly effective: Heat sealing can be used to melt Tyvek and cause it to bond to itself, but this form of bonding tends to create puckers in the otherwise flat material. Dielectric bonding can be effective in some circumstances, as is ultrasonic welding. Though Tyvek superficially resembles paper (for example, it can be written and printed on), it is plastic, and it cannot be recycled with paper. Some Tyvek products are marked with the #2 resin-code for HDPE, and can be collected with plastic bottles as part of some municipal curbside recycling programs. DuPont runs a program in the United States where disposable clothing, coveralls, lab coats, medical packaging and other non-hazardous Tyvek disposable garments can be recycled, as well as providing a mail-in recycling program for envelopes. Recently, plastic bag recycling has become more prevalent. According to the American Chemistry Council, these plastic film drop-off locations accept Tyvek. According to DuPont's Web site, the fibers are 0.5–10 µm (compared to 75 µm for a human hair). The nondirectional fibers (plexifilaments) are first spun and then bonded together by heat and pressure, without binders.