Abstract: In this invention a new form of polytetrafluoroethylene has been found to be compression moldable to provide strong molded articles. It is also useful as an additive or strength binder. The new form is a compression molding powder comprised of comminuted, sheared particles of expanded porous polytetrafluoroethylene, said particles having a nudular-microfibrillar structure of irregular shape, and a mean particle size between 5 and 500 micrometers, and having a coating of a thermoplastic fluoropolymer on at least a portion of the particle. By irregular shape is meant that the nodes and fibrils do not have an ordered arrangement. The bulk density is about 0.06 to 0.2 g/cc.

Abstract: A porous polytetrafluoroethylene (PTFE) structure particularly for use as a liquid filter comprises particles of granular-type PTFE fused together to form a porous integral network. The structure is formed by spraying an aqueous suspension of granular PTFE particles and baking at a temperature of 335.degree.-350.degree. C. Typically the specific gravity is 0.8 to 1.54. The crystallinity is less than 95%. The structure may be supported on a perforate substrate such as stainless steel mesh.

Abstract: An improved liner and method is taught for use in protecting a wearer's skin from moisture retention when worn with prosthetic devices and other substantially non-breathable shells. The liner is form fitted to attach to a wearer without bunching or other pressure points which can cause skin irritation. Preferably, the liner comprises a membrane of expanded polytetrafluoroethylene coated on its interior surface with a polyurethane material to aid in moisture isolation and to protect the liner from compromise due to oils and other contaminants found in perspiration. The liner is effective at shielding a wearer's skin from moisture even when worn with no separate absorbent layer.

Abstract: Waterproof, breathable, flexible, seamless shaped articles, such as gloves or socks, are described which are made of a flexible layered composite comprising:(a) a microporous thermoplastic polyester polyurethane or polyether polyurethane that is water vapor permeable, and(b) a nonporous copolymer that is waterproof but water vapor permeable which provides improved waterproofness to the microporous polymer layer.

Abstract: In this invention a new form of polytetrafluoroethylene has been found to be compression moldable to provide exceptionally strong molded articles. It is also useful as an additive or strength binder. The new form is a compression molding powder comprised of comminuted, sheared particles of expanded porous polytetrafluoroethylene, said particles having a nudular-microfibrilar structure of irregular shape, and a mean particle size between 5 and 500 micrometers. By irregular shape is meant that the nodes and fibrils do not have an ordered arrangement. The bulk density is about 0.06 to 0.2 g/cc.

Abstract: A protective glove system having at least two components including a waterproof and water vapor permeable inner glove component that provides a barrier against allergens and an outer glove component that is liquidproof. A method of using the glove system is also provided. Protective shoe systems, body suits, and headgear systems are also provided.

Abstract: The present invention is an expanded polytetrafluoroethylene (PTFE) fiber with improved handling properties. Unlike previous expanded PTFE fibers, the fiber of the present invention employs a fiber of increased thickness so that the fiber is maintained in an unfolded orientation. The improved processing steps of the present invention create a fiber that has a number of improved properties, including more uniform dimensions along its length, improved compressibility and handling, and when woven into a fabric, the fabric is more easily processed, is of higher quality, and is more uniform.

Abstract: A composite membrane is provided which includes a base material and an ion exchange resin. The base material has a microstructure characterized by nodes interconnected by fibrils, or a microstructure characterized by fibrils with no nodes present. The ion exchange resin substantially impregnates the membrane such that the membrane is essentially air impermeable.

Abstract: An vented vial stopper for use in processing freeze-dried products is provided. The stopper includes a vent passageway that is covered with a waterproof and moisture vapor permeable membrane to allow the venting of moisture during the freeze-drying process. The membrane also extends to cover most or all of the exposed surface of the stopper to protect the stopper from chemical attack during processing.

Abstract: The present invention is an expanded polytetrafluoroethylene (PTFE) fiber with improved handling properties. Unlike previous expanded PTFE fibers, the fiber of the present invention employs a fiber of increased thickness so that the fiber is maintained in an unfolded orientation. The improved processing steps of the present invention create a fiber that has a number of improved properties, including more uniform dimensions along its length, improved compressibility and handling, and when woven into a fabric, the fabric is more easily processed, is of higher quality, and is more uniform.

Abstract: A permanent hydrophilic modification for fluoropolymers is provided where the film consists of a charged polyelectrolyte complex that is reoriented. A process for producing this modification is also provided.