In 1969, Bob Gore discovered expanded polytetrafluoroethylene (ePTFE). This revolutionary hydrophobic polymer has become the core of our patented membrane technologies. These thin, lightweight, and durable membranes serve as a foundation for producing all of our technical fabrics and can be engineered to offer many types of protection, including:
- Penetration-resistant for liquids such as fuel, blood, and body fluids
- Signature-reduction (n-IR)
- Chemical- and biological-agent resistant
Our ePTFE membranes have more than 1.4 billion pores per square centimeter. The pores are 20,000 times smaller than a drop of water, but 700 times larger than a molecule of moisture vapor. So the pores in the membrane are small enough that water in its liquid form cannot penetrate the membrane, but moisture vapor (a gas) can easily escape.
Membranes are processed into films by integrating additional materials into the ePTFE structure, such as oleophobic (oil-shedding) materials. These materials allow moisture vapor to pass through, but create a physical barrier that prevents oils, chemicals, and other contaminants from penetrating the membrane and degrading its performance.
Different types of membranes (or films) are bonded with high-performance textiles to form durable fabrics that maintain the proper balance of properties found in the individual components. For example, to construct one version of GORE-TEX fabric, we bond the GORE-TEX membrane between high-performance fabrics that are extremely breathable. Once bonded and tested, fabrics are used to make an entire garment, boot or glove, or combined with other materials to meet a specific end-use application.
Manufacturing garments, footwear, and gloves requires seams and stitching. Unfortunately, the sewing needles leave small holes in the fabric that compromise its water-and liquid-protection. That’s why they must be completely sealed.
For waterproof protection and liquid resistance, products using our fabrics rely on GORE-SEAM® Tape. Supported by reliable Gore equipment and expertise, this unique tape ensures that every seam and stitch hole is sealed.
Water and Other Liquids
The microporous structure of our ePTFE membranes have pores that are about 20,000 times smaller than a drop of water, which means no water can penetrate them. A similar structure is used in fabrics that are required to resist dangerous liquids. We have engineered our membranes to develop fabrics that provide more than water protection — they also resist blood, body fluids, many common chemicals, and petroleum-based products.
To keep you comfortable and protected in windy conditions, the ePTFE membranes in our fabrics are engineered to provide an impenetrable wind shield. By keeping the wind out, you can stay warm and comfortable.
In a single hour, your body can release ¼ cup (50 ml) of perspiration at rest, more than 4.5 cups (1 liter) during heavy exertion, and almost 17 cups (4 liters) during a full-out run. If this moisture vapor can’t escape from your gear, you will quickly become uncomfortable and possibly suffer heat stress. Many fabrics are breathable, but very few combine high breathability with protection against liquid penetration.
To minimize heat stress, we evaluate the specific breathability and protection needs for an application. We then manipulate the size and density of the membrane pores to allow water vapor to escape without sacrificing the necessary protection. When water vapor can easily pass through the membrane, you remain comfortable and dry, whether you’re servicing airplanes on the tarmac, rescuing victims at an accident scene, or responding to a fire.
Chemicals & Biological Hazards
In environments where exposure to liquid chemicals is a risk, conventional barriers often break down and become porous. However, PTFE is chemically inert, which means that our membranes are the perfect foundation for creating garments that resist contamination from chemical and biological hazards because PTFE does not degrade over time when exposed to chemicals such as DEET, jet fuel, or other petroleum products.
If you may face the additional threat of chemical and biological warfare agents, GORE® CHEMPAK® fabrics offer enhanced functionality. Thin and lightweight PTFE films are used to create head-to-toe protective gear for both civil and military applications. Because the protection you need in a hot zone is different than at the perimeter, these fabrics offer a range of protective capabilities. Many fabrics are made to be as breathable as possible in order to combat heat stress.