Gore-Tex is a waterproof, breathable fabric membrane and registered trademark of W. L. Gore & Associates. Invented in 1969, Gore-Tex can repel liquid water while allowing water vapor to pass through and is designed to be a lightweight, waterproof fabric for all-weather use. It is composed of stretched polytetrafluoroethylene (PTFE), which is more commonly known by the generic trademark Teflon. The material is formally known as the generic term expanded PTFE (ePTFE).
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 "I decided to give one of these rods a huge stretch, fast, a jerk... and it stretched 1000%", Scientists You Must Know: Bob Gore, Science History Institute |
Gore-Tex was co-invented by Wilbert L. Gore and Gore's son, Robert W. Gore. [1] In 1969, Bob Gore stretched heated rods of polytetrafluoroethylene (PTFE) and created expanded polytetrafluoroethylene (ePTFE). His discovery of the right conditions for stretching PTFE was a happy accident, born partly of frustration. Instead of slowly stretching the heated material, he applied a sudden, accelerating yank. The solid PTFE unexpectedly stretched about 800%, forming a microporous structure that was about 70% air. [1] It was introduced to the public under the trademark Gore-Tex. [2]
Gore promptly applied for and obtained the following patents:
Another form of stretched PTFE tape was produced prior to Gore-Tex in 1966, by John W. Cropper of New Zealand. Cropper had developed and constructed a machine for this use. However, Cropper chose to keep the process of creating expanded PTFE as a closely held trade secret and as such, it had remained unpublished. [3] [4]
In the 1970s Garlock, Inc. allegedly infringed Gore's patents by using Cropper's machine and was sued by Gore in the Federal District Court of Ohio. The District Court held Gore's product and process patents to be invalid after a "bitterly contested case" that "involved over two years of discovery, five weeks of trial, the testimony of 35 witnesses (19 live, 16 by deposition), and over 300 exhibits" (quoting the Federal Circuit). On appeal, however, the Federal Circuit disagreed in the famous case of Gore v. Garlock, reversing the lower court's decision on the ground, as well as others, that Cropper forfeited any superior claim to the invention by virtue of having concealed the process for making ePTFE from the public. As a public patent had not been filed, the new form of the material could not be legally recognised. Gore was thereby established as the legal inventor of ePTFE. [3] [5]
Following the Gore v. Garlock decision, Gore sued C. R. Bard for allegedly infringing its patent by making ePTFE vascular grafts. Bard promptly settled and agreed to exit the market. Gore next sued IMPRA, Inc., a smaller maker of ePTFE vascular grafts, in the federal district court in Arizona. IMPRA had a competing patent application for the ePTFE vascular graft. In a nearly decade-long patent/antitrust battle (1984–1993), IMPRA proved that Gore-Tex was identical to prior art disclosed in a Japanese process patent by duplicating the prior art process and through statistical analysis, and also proved that Gore had withheld the best mode for using its patent, and the main claim of Gore's product patent was declared invalid in 1990. [6] In 1996, IMPRA was purchased by Bard and Bard was thereby able to reenter the market. After IMPRA's vascular graft patent was issued, Bard sued Gore for infringing it.
Gore-Tex is used in products manufactured by many different companies.
Other products have come to market exploiting similar technologies following the expiry of the main Gore-Tex patent. [7]
For his invention, Robert W. Gore was inducted into the U.S. National Inventors Hall of Fame in 2006. [8]
In 2015, Gore was ordered by the Federal Circuit Court of Appeals to pay Bard $1 billion in damages. [6] The U.S. Supreme Court declined to review the Federal Circuit's decision. [9] [10]
PTFE is a fluoropolymer made using an emulsion polymerization process that utilizes the fluorosurfactant PFOA, [11] [12] a persistent environmental contaminant. In 2013, Gore eliminated the use of PFOAs in the manufacture of its weatherproof functional fabrics. [13] [ better source needed ] Gore has published a plan for phasing out the most harmful perfluorinated compounds (PFCs) by 2025 but has defended the use of PTFE. [14] However, research in 2020 found it is not possible to conclude that the harmful effects of PTFE and other fluoropolymers on environmental and human health are of low concern. [15]
Gore-Tex materials are typically based on thermo-mechanically expanded PTFE and other fluoropolymer products. They are used in a wide variety of applications such as high-performance fabrics, medical implants, filter media, insulation for wires and cables, gaskets, and sealants. However, Gore-Tex fabric is best known for its use in protective, yet breathable, rainwear.
Before the introduction of Gore-Tex, the simplest sort of rainwear would consist of a two-layer sandwich, where the outer layer would typically be woven nylon or polyester to provide strength. The inner one would be polyurethane (abbreviated: PU) to provide water resistance, at the cost of breathability.
Early Gore-Tex fabric replaced the inner layer of non-breathable PU with a thin, porous fluoropolymer membrane (Teflon) coating that is bonded to a fabric. This membrane had about 9 billion pores per square inch (around 1.4 billion pores per square centimeter). Each pore is approximately 1⁄20,000 the size of a water droplet, making it impenetrable to liquid water while still allowing the more volatile water vapor molecules to pass through.
The outer layer of Gore-Tex fabric is coated on the outside with a Durable Water Repellent (DWR) treatment. The DWR prevents the main outer layer from becoming wet, which would reduce the breathability of the whole fabric. However, the DWR is not responsible for the jacket being waterproof. Without the DWR, the outer layer would become soaked, there would be no breathability, and the wearer's sweat being produced on the inside would fail to evaporate, leading to dampness there. This might give the appearance that the fabric is leaking when it is not. Wear and cleaning will reduce the performance of Gore-Tex fabric by wearing away this Durable Water Repellent (DWR) treatment. The DWR can be reinvigorated by tumble drying the garment or ironing on a low setting. [16]
Gore requires that all garments made from their material have taping over the seams, to eliminate leaks. Gore's sister product, Windstopper, is similar to Gore-Tex in being windproof and breathable, and it can stretch, but it is not waterproof. The Gore naming system does not imply any specific technology or material but instead implies a specific set of performance characteristics. [17]
Expanded polytetrafluoroethylene is used in clothing due to its breathability and water protection capabilities. Besides use in rainwear ePTFE can now be found in space suits. [18]
Gore-Tex is also used internally in medical applications, because it is nearly inert inside the body. Specifically, expanded polytetrafluoroethylene (E-PTFE) can take the form of a fabric-like mesh. Implementing and applying the mesh form in the medical field is a promising type of technological material feature. [19] In addition, the porosity of Gore-Tex permits the body's own tissue to grow through the material, integrating grafted material into the circulation system. [20] Gore-Tex is used in a wide variety of medical applications, including sutures, vascular grafts, heart patches, and synthetic knee ligaments, which have saved thousands of lives. [21] In the form of expanded polytetrafluoroethylene (E-PTFE), Gore-Tex has been shown to be a reliable synthetic, medical material in treating patients with nasal dorsal interruptions. [22] In more recent observations, expanded polytetrafluoroethylene (E-PTFE) has recently been used as membrane implants for glaucoma surgery. [23]
Gore-Tex has been used for many years in the conservation of illuminated manuscripts. [24]
Explosive sensors have been printed on Gore-Tex clothing leading to the sensitive voltametric detection of nitroaromatic compounds. [25]
The "Gore-Tex" brand name was formerly used for industrial and medical products. [26] [27]
For applications in textiles and garments, there are a number of competing semipermeable membranes on the market that attempt to reproduce the "breathability" (water vapor transport) of ePTFE while effectively repelling water. Materials like Sympatex, Futurelight (marketed by The North Face) can be used in textile laminates much like ePTFE, but often perform less well in terms of water vapor transport and durability.
Active textile pumping technology, namely textile-based electroosmotic pumps, [28] are being developed and commercialized by companies such as LunaMicro AB. These solutions can eliminate the use of halogenated polymers like PTFE, minimizing the associated negative health and environmental hazards.
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from DuPont, which originally discovered the compound in 1938.
A raincoat is a waterproof or water-resistant garment worn on the upper body to shield the wearer from rain. The term rain jacket is sometimes used to refer to raincoats with long sleeves that are waist-length. A rain jacket may be combined with a pair of rain pants to make a rainsuit. Rain clothing may also be in one piece, like a boilersuit. Raincoats, like rain ponchos, offer the wearer hands-free protection from the rain and elements; unlike the umbrella.
Early Winters, Ltd. of Seattle, Washington, United States was founded in 1972 by William S. Nicolai, who formed the company after creating a tent called the Omnipotent. Early Winters was the first company to create and sell a consumer product made with Gore-Tex laminates produced by W. L. Gore & Associates in Elkton, Maryland. The first product made with Gore-Tex fabric debuted in 1976 and was a streamlined, two-person tent called The Light Dimension. The tent was created by Nicolai and William H. Edwards and was marketed by Ron Zimmerman.
Wilbert Lee "Bill" Gore was an American businessman and entrepreneur who co-founded W. L. Gore and Associates with his wife, Genevieve (Vieve).
Oilskin is a waterproof cloth used for making garments typically worn by sailors and by others in wet areas. The modern oilskin garment was developed by a New Zealander, Edward Le Roy, in 1898. Le Roy used worn-out sailcloth painted with a mixture of linseed oil and wax to produce a waterproof garment suitable to be worn on deck in foul-weather conditions. Oilskins are part of the range of protective clothing also known as foul weather gear.
Waterproof fabrics are fabrics that are, inherently, or have been treated to become, resistant to penetration by water and wetting. The term "waterproof" refers to conformance to a governing specification and specific conditions of a laboratory test method. They are usually natural or synthetic fabrics that are laminated or coated with a waterproofing material such as rubber, polyvinyl chloride (PVC), polyurethane (PU), silicone elastomer, fluoropolymers, and wax. Treatment could be either of the fabric during manufacture or of completed products after manufacture, for instance by a waterproofing spray. Examples include the rubberized fabric used in Mackintosh jackets, sauna suits and inflatable boats.
Durable water repellent, or DWR, is a coating added to fabrics at the factory to make them water-resistant (hydrophobic). Most factory-applied treatments are fluoropolymer based; these applications are quite thin and not always effective. Durable water repellents are commonly used in conjunction with waterproof breathable fabrics such as Gore-Tex to prevent the outer layer of fabric from becoming saturated with water. This saturation, called 'wetting out,' can reduce the garment's breathability and let water through. As the DWR wears off over time, re-treatment is recommended when necessary. Many spray-on and wash-in products for treatment of non-waterproof garments and re-treatment of proofed garments losing their water-repellency are available.
Fluorinated ethylene propylene (FEP) is a copolymer of hexafluoropropylene and tetrafluoroethylene. It differs from the polytetrafluoroethylene (PTFE) resins in that it is melt-processable using conventional injection molding and screw extrusion techniques. Fluorinated ethylene propylene was invented by DuPont and is sold under the brandname Teflon FEP. Other brandnames are Neoflon FEP from Daikin or Dyneon FEP from Dyneon/3M.
SympaTex is a type of fabric that is branded as waterproof but "breathable", made or licensed by SympaTex Technologies GmbH a company founded in 1986. The fabric features a waterproof, windproof and breatheable membrane that is laminated to fabrics either on its inner surface or sandwiched between two fabric layers. The latter system offers greater durability, by better protecting the integrity of the SympaTex layer from abrasion to both the outside and the inside of the garment.
Windstopper is a windproof breathable fabric laminate made by W. L. Gore & Associates. One of its most common applications is a lamination with polar fleece, to compensate for fleece's lack of wind resistance.
W. L. Gore & Associates, Inc. is an American multinational manufacturing company specializing in products derived from fluoropolymers. It is a privately held corporation headquartered in Newark, Delaware. It is best known as the developer of waterproof, breathable Gore-Tex fabrics.
Polyurethane laminate is a compound fabric made by laminating a cloth fabric to one or both sides of a thin film of polyurethane. Polyurethane laminated fabrics have a wide range of applications in medical, automotive and garment uses.
Layered clothing is a fashion technique that is utilized by dressing many garments that are worn on top of each other. Flexible clothing can be worn to suit the requirements of each situation by adding or removing layers, or by changing one layer and leaving the others. Two thin layers can be warmer yet lighter than one thick layer, because the air trapped between layers serves as thermal insulation.
Ventile, is a registered trademark used to brand a special high-quality woven cotton fabric first developed by scientists at the Shirley Institute in Manchester, England. Originally created to overcome a shortage of flax used for fire hoses and water buckets, its properties were also found to be ideal for pilots' immersion suits.
Robert W. Gore was an American engineer and scientist, inventor and businessman. Gore led his family's company, W. L. Gore & Associates, in developing applications of polytetrafluoroethylene (PTFE) ranging from computer cables to medical equipment to the outer layer of space suits. His most significant breakthrough was likely the invention of Gore-Tex, a waterproof and breathable fabric popularly known for its use in sporting and outdoor gear.
Garlock Sealing Technologies, an Enpro Company that, produces sealing products. Garlock has a global presence, with 1,887 employees, at 14 facilities, in twelve countries.
Breathability is the ability of a fabric to allow moisture vapor to be transmitted through the material.
A non-stick surface is engineered to reduce the ability of other materials to stick to it. Non-stick cookware is a common application, where the non-stick coating allows food to brown without sticking to the pan. Non-stick is often used to refer to surfaces coated with polytetrafluoroethylene (PTFE), a well-known brand of which is Teflon. In the twenty-first century, other coatings have been marketed as non-stick, such as anodized aluminium, silica, enameled cast iron, and seasoned cookware.
Rain pants, also called rain trousers, are waterproof or water-resistant pants worn to protect the body from rain. Rain pants may be combined with a rain jacket to make a rain suit. Rain gaiters may also be used for further protection.
The global market for chemicals from fluorine was about US$16 billion per year as of 2006. The industry was predicted to reach 2.6 million metric tons per year by 2015. The largest market is the United States. Western Europe is the second largest. Asia Pacific is the fastest growing region of production. China in particular has experienced significant growth as a fluorochemical market and is becoming a producer of them as well. Fluorite mining was estimated in 2003 to be a $550 million industry, extracting 4.5 million tons per year.
