Tyvek

Tyvek ( /tˈvɛk/) is a brand of flashspun high-density polyethylene fibers, a synthetic material; the name is a registered trademark of DuPont. The material is very strong; it is difficult to tear but can easily be cut with scissors or a knife. Water vapor can pass through Tyvek (highly breathable), but not liquid water, so the material lends itself to a variety of applications: envelopes, car covers, air and water intrusion barriers (housewrap) under house siding, labels, wristbands, mycology, and graphics. Tyvek is sometimes erroneously referred to as "Tyvex."

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History

Tyvek is a nonwoven product consisting of spunbond olefin fiber. It was first discovered in 1955 by DuPont researcher Jim White who saw polyethylene fluff coming out of a pipe in a DuPont experimental lab.[1] It was trademarked in 1965 and was first introduced for commercial purposes in April 1967.[2]

According to DuPont's website, 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.[3]

Tyvek is manufactured at the Spruance plant in Richmond, Virginia, and in Contern/Luxembourg.

Properties

Among Tyvek's properties are:

Uses

Large sheets of Tyvek are frequently used as "house wrap," to provide a water barrier between the outer cladding of a structure and the frame, insulation, etc., allowing water vapor to pass yet restricting air infiltration.[4]

Tyvek is used by the United States Postal Service for some of its Priority Mail and Express Mail envelopes. New Zealand used it for its driver's licenses from 1986 to 1999,[5] and Costa Rica,[6] the Isle of Man,[7] and Haiti[8] have made banknotes from it. These banknotes are no longer in circulation and have become collectors' items.

Tyvek coveralls are one-piece garments made of Tyvek, usually white in color. They are often worn by mechanics over their clothes to avoid contact with oil and fuel. They can also be worn for painting to protect skin and clothes from splattered paint, for installation of fiberglass insulation, by workers in laboratories and cleanrooms, and for any other use where a disposable, one-time use coverall is needed. Tyvek coveralls are also used for some light hazardous materials applications, such as asbestos and radiation work but do not provide the level of protection of a full hazmat suit. Tychem is a sub-brand of Tyvek rated for a higher level of liquid protection, especially from chemicals. DuPont makes Tyvek clothing in different styles from laboratory coats and aprons to complete head-to-toe coveralls with hoods and booties.

In 1976, fashion house Fiorucci made an entire collection out of Tyvek.[9] More recently fashion retailer and manufacturer American Apparel has included white Tyvek shorts as part of its range.[10] Rock band Devo is known for wearing large, two-piece Tyvek suits with black elastic belts and 3-D glasses. In 1979 Devo appeared with Tyvek leisure suits and shirts made specifically for the band, with the band's own designs and images. In 2005 Dynomighty Design[11] introduced a Tyvek wallet made from a single sheet of Tyvek.

Increasingly, reused Tyvek material is being used by home crafters. Protective sleeves for Compact Discs and DVDs, tote bags,[12] and origami wallets [13] also use Tyvek-containing materials.

Tyvek is also used as a durable fabric in shoes. The shoe brand Unstitched Utilities pioneered Tyvek's use in its line of footwear.[14]

Tyvek is a strong, waterproof cover that serves various purposes. One example from sporting goods is its use in archery. This is due to its waterproof properties. Tyvek is used to construct target faces, replacing paper faces which are easily damaged when wet.

Recycling

Though Tyvek superficially resembles paper (for example, it can be written and printed on), it is plastic, and it cannot be recycled with paper. Despite the fact that some Tyvek products are marked with the #2 resin-code for HDPE, it is not usually collected with plastic bottles as part of municipal curbside recycling programs. Instead, DuPont runs a program in the United States where disposable clothing, coveralls, lab coats, and other Tyvek disposable garments can be recycled, as well as providing a mail-in recycling program for envelopes.[15]

References

External links