Tyvek

Not to be confused withTyvak.

Tyvek(/ˈtaɪ.vɛk/) is abrandofsyntheticflashspunhigh-density polyethylenefibers.The nameTyvekis aregistered trademarkof the American multinational chemical companyDuPont,which discovered and commercialized Tyvek in the late 1950s and early 1960s.

Tyvek

Product type	FlashspunnonwovenHDPEfiber
Owner	DuPont
Country	United States
Introduced	April 1967(1967-04)
Related brands	YUPOsyntheticpaper
Markets	Construction,Packagingandlabeling
Tagline	What do you need to protect?
Website	dupont.com/Tyvek

Tyvek house wrap

Tyvek's properties—such as being difficult to tear but easily cut, and waterproof against liquids while allowingwater vaporto penetrate—have led to it being used in a variety of applications. Tyvek is often used ashousewrap,a synthetic material used to protect buildings during construction, or aspersonal protective equipment(PPE).

History

Tyvek is anonwovenproduct consisting of spun bondolefin fiber.It was first discovered in 1955 by a researcher for the DuPonttextilecompany working in an experimental lab, who noticed a type of white fluff coming out of a pipe.That fluff was a form ofpolyethylene,which DuPont requested a patent for within a year of the discovery. Aftertechnologiesimproved during the next few years, in 1959 DuPont discovered that when the fluff was spun at high speeds it produced a durablefabricthat 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 mainstreamconstructionindustry 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 bysurgeonsanddoctorsin the medical field.

21st century

In 2017, the DuPont company merged with anotherchemical company,The Dow Chemical Companyto formDowDuPont.DowDuPont currentlymanufacturesTyvek at the Spruance plant inRichmond, Virginia,and inSandweiler-Contern,Luxembourg.In 2018, DowDuPont announced plans to expand the Tyvek production capacity of the Sandweiler-Contern factory.

Scientific characteristics and properties

Tyvek USPS Express Mail envelope

Adhesion and bonding

To bond Tyvek to both itself and a variety of substrates, DuPont recommendsstarch,dextrin,casein,andanimal-basedadhesivesover mostsynthetic-based adhesives,emphasizing the effectiveness of water-based and quick-drying glues. DuPont also claims that the followingadhesivesare highly effective:

• Ethylene/vinyl acetate
• Acrylic pressure-sensitive tape
• Solvent-based single-componentpolyurethane
• Hot glue

Heat sealingcan 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.Dielectricbonding can be effective in some circumstances, as isultrasonic welding.

Recycling

Though Tyvek superficially resembles paper (for example, it can be written and printed on), it isplastic,and it cannot berecycledwith paper. Some Tyvek products are marked with the #2 resin-code forHDPE,and can be collected withplastic bottlesas 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, theAmerican Chemistry Councilhas recommended that plastic film drop-off recycling locations should be able to accept Tyvek.

Properties of Tyvek

According to DuPont's website, Tyvek fibers are 0.5–10 μm (2.0×10⁻⁵–0.000394 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:

• Lightweight
• Has a Class 1flammabilityrating. "When exposed to a flame, Tyvek (R) shrinks away rapidly. If the flame is made to follow the shrinking sheet, Tyvek (R) will melt at 275 F (135 C)"and will burn at 750°F (400°C)
• Chemical-resistant
• Dimensionally stabilized
• Opaque
• Has a neutralpH
• Tear-resistant

Uses

Construction/engineering

Tyvek envelopes

• Large sheets of Tyvek are frequently used ashousewrapto provide an air barrier between the outer cladding of a structure and the frame, insulation, etc., allowing water vapor to pass but restricting air infiltration.
• Tyvek was used to cover and protect theReaction Control System(RCS) thruster ports from water and debris, while the shuttle stack was exposed on the launchpad during the latter years of theSpace Shuttleprogram.The Tyvek covers were dislodged shortly after ignition and before the shuttle cleared the tower, posing no strike risk as the shuttle was travelling below 100 mph (160 km/h).
• Tom Sachsused Tyvek for the outer shell of the spacesuits used in his Space Program series of artworks.

Shipping

• Tyvek is used by theUnited States Postal Servicefor some of itsPriority MailandExpress Mailenvelopes.
• FedExalso uses it for some of its document envelopes.

Government use

• New Zealand used Tyvek for itsdriver's licencesfrom 1986 to 1999.

Banknotes

• Costa Rica(solely their 20 colones bank note, Z series),theIsle of Man,andHaitihave madebanknotesfrom Tyvek. These banknotes are no longer in circulation and have become collectors' items.

Fashion/personal use

• Race bibs, or race numbers are often produced on Tyvek paper, so they are less likely to rip during competition.
• Tyvek is often used in garment and other textile labeling due to high durability and washability.
• Tyvekwristbandsare used at festivals, conventions, and events where admission and security are concerns, as well as hospitals, resorts, nightclubs, schools, and reunions.
• In 2011, fashion retailer and manufacturerAmerican Apparelincluded white Tyvekshortsas part of its range.
• In 1976, fashion houseFioruccimade an entire collection out of Tyvek.
• Theultralight backpackingcommunity has begun to use Tyvek for the construction of extremely light yet durable backpacks.In 2012, The Open Company released a foldable city map made of one of the stiffer variants of Tyvek.
• Increasingly, reused Tyvek material is being used by home crafters. Protective sleeves forCDsandDVDs,tote bags,andorigamiwalletsalso use Tyvek-containing materials.
• Tyvek is also used as a durable fabric in shoes.

Medical

• Tyvek is extensively used for laboratory and medical packaging as the material withstands conditions such asgammairradiation orethylene oxidegas which are used to sterilize equipment and surgical devices.
• NSW Police,Australia uses Tyvek overalls to preserve the integrity of forensic evidence at a crime scene, while also protecting "the wearer from the risk of exposure to biological substances, dirt and liquid splashes."

Personal protective equipment (PPE)

Tyvek coveralls

• Tyvekcoverallsare one-piece garments used forpersonal protective equipment.They are usually white, commonly worn by mechanics, oil industry workers, painters, insulation installers, and laboratory andcleanroomworkers where disposable, one-time usecoverallis needed. They are also used for some lightHAZMATapplications, such asasbestosandradiationwork, but do not provide the protection of a fullhazmat suit.Tychem is a sub-brand of Tyvek rated for a higher level of liquidprotection,especially from chemicals. DuPont makes Tyvek clothing in different styles fromlaboratory coatsand aprons to complete head-to-toe coveralls with hoods and booties. The latter was notably used by theJapan Ground Self-Defense Forceas emergency limitedCBRNgear during theFukushima nuclear incident.
• Tyvek coveralls, coats or bodysuits are often used during pandemics, for example in the 2013–2016Western African Ebola virus epidemic,and in theCOVID-19 pandemic,to protect health care workers from infection.The Tyvek suits which are most frequently used during the COVID-19 pandemic are sold between $5-$15 USD per piece.Due to a lack of sufficient stock of adequate PPE during the coronavirus crisis, Tyvek PPE became scarce in many places.Tyvek bodysuits are generally meant for one-time use. However, Tychem suits contaminated with the virusSARS-CoV-2can be disinfected and reused a limited number of times.

See also

• Olefin fiber(for brand names of related fabrics)
• High-density polyethylenefor material
• Flashspinningfor manufacturing process

External links

• Tyvek Product Handbook
• Tyvekat DuPont
• DuPont Tyvek WB FAQ
• Tyvek – Because It Makes the Difference