Tyvek

Tyvek (/ˈtaɪ.vɛk/) 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 while 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).
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 years, in 1959 DuPont discovered that when the fluff was spun at high speeds it produced a durable fabric that could 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. By 1970, Tyvek had reached the mainstream construction industry on both a national and global scale. Its products were often used for the construction of houses due to its 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, the DuPont company merged with another chemical company, The Dow Chemical Company to form DowDuPont. DowDuPont currently manufactures Tyvek at the Spruance plant in Richmond, Virginia, and in Sandweiler-Contern, Luxembourg. In 2018, DowDuPont announced plans to expand the Tyvek production capacity of the Sandweiler-Contern factory.
To bond Tyvek to both itself and a variety of substrates, DuPont recommends starch, dextrin, casein, and animal-based adhesives over most synthetic-based adhesives, emphasizing the effectiveness of water-based and quick-drying glues. 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.
As plastic bag recycling has become more prevalent in the United States, the American Chemistry Council has recommended that plastic film drop-off recycling locations should be able to accept Tyvek.
According to DuPont's website, Tyvek fibers are 0.5–10 μm (2.0×10–0.000394 in) (compared to 75 μm (0.0030 in) for a human hair). The nondirectional fibers (plexifilaments) are first spun and then bonded by heat and pressure, without binders.
Tyvek is also: