What is Tyvek®?
DuPont™ Tyvek® has introduced new dimensions of protection, security and safety in a wide variety of industries, including protective apparel, medical packaging and construction.
Made from very fine, high-density polyethylene fibers, DuPont™ Tyvek® brand protective material offers all the best characteristics of paper, film and fabric in one material. This unique balance of properties, not found in any other material, makes Tyvek® lightweight yet strong; vapor-permeable, yet water-, chemical-, puncture-, tear- and abrasion-resistant. DuPont™ Tyvek® is also low-linting, smooth and opaque.
A miracle of science from DuPont
The discovery of DuPont™ Tyvek® was a chance occurrence by a DuPont researcher, Jim White, who in 1955 noticed white polyethylene fluff coming out of a pipe in a DuPont experimental lab. A program to develop the new material was set up, and a year later DuPont submitted a patent proposal for strong yarn linear polyethylene.
The proprietary flash-spinning technology, which is the basis for what was to become DuPont’s new engineered sheet structure, took several more years to perfect. In 1959, a pilot facility was established for trial applications. In 1965, the new engineered sheet structure was registered under the trademark name DuPont™ Tyvek®, but it was not until April 1967 that commercial production of DuPont™ Tyvek® started.
Flash spinning and bonding process
DuPont™ Tyvek® is formed by a fully integrated process using continuous and very fine fibers of 100 percent high-density polyethylene that are randomly distributed and nondirectional. These fibers are first flash spun, then laid as a web on a moving bed before being bonded together by heat and pressure—without the use of binders, sizers or fillers. By varying both the lay-down speed and the bonding conditions, DuPont technicians can engineer the flashspun sheet to meet market needs, such as soft- and hard-structure DuPont™ Tyvek®.
DuPont™ Tyvek® and construction
Some of the best-known applications of DuPont™ Tyvek® are in the construction industry, where it represents a good building practice. Used to increase air and water resistance, it helps to lower heating and cooling costs in buildings while providing better protection against water and moisture intrusion. The unique qualities of DuPont™ Tyvek® help stop air flow through wall cavities; help hold out bulk water and wind-driven rain; and allow moisture vapor to escape from inside walls. Even a 10mph wind can reduce R-value of insulation by as much as 60%. A home wrapped in DuPont™ Tyvek® will maintain 94 percent of its installed R-value, compared to only 37 percent for a home without DuPont™ Tyvek®. DuPont™ Tyvek® also helps to reduce moisture within well-designed and constructed walls. It is a good choice of materials to help prevent mold and mildew. The properties in DuPont™ Tyvek® do not support mold growth.
Using DuPont™ Tyvek® results in more comfortable, energy-efficient buildings with far fewer chances for damage from degradation effects.