Abstract: A method of forming an unsintered biaxially expanded PTFE/thermoplastic polymer composite membrane is provided. The method includes blending fibrillatable polytetrafluoroethylene (PTFE) particles and thermoplastic polymer particles where the melting point of the thermoplastic polymer particles is less than the melting point of the fibrillatable PTFE particles. The method further includes forming the blend into a tape and expanding and heating the tape in a first direction at a first temperature. The expanded tape is then expanded, either concurrently or sequentially in a second direction to form an ePTFE composite membrane. The method does not include a sintering temperature. The ePTFE particles and thermoplastic polymer particles have an average particle size of less than 1 ?m. In addition, the ePTFE composite membrane has a geometric mean matrix modulus to geometric mean matrix tensile strength ratio of at least about 6 and an absolute dimensional change percentage of less than about 1.5%.

Abstract: A seal comprising a jacket comprising an annular body defining a central axis and a recess extending into the annular body concentric to the central axis, wherein the jacket comprises at least 30 wt % of a PTFE and at least 10 wt % of a filler material, and wherein the filler material comprises a boron-containing material, a nitrogen-containing material, a titanium-containing material, a silicon-containing material, a carbon fiber, a glass fiber, or a combination thereof; and an energizing element disposed in the recess.

Abstract: A seal comprising a jacket comprising an annular body defining a central axis and a recess extending into the annular body concentric to the central axis, wherein the jacket comprises at least 30 wt % of a PTFE and at least 10 wt % of a filler material, and wherein the filler material comprises a boron-containing material, a nitrogen-containing material, a titanium-containing material, a silicon-containing material, a carbon fiber, a glass fiber, or a combination thereof; and an energizing element disposed in the recess.

Abstract: A seal comprising a jacket comprising an annular body defining a central axis and a recess extending into the annular body concentric to the central axis, wherein the jacket comprises at least 30 wt % of a PTFE and at least 10 wt % of a filler material, and wherein the filler material comprises a boron-containing material, a nitrogen-containing material, a titanium-containing material, a silicon-containing material, a carbon fiber, a glass fiber, or a combination thereof; and an energizing element disposed in the recess.

Abstract: A seal comprising a jacket comprising an annular body defining a central axis and a recess extending into the annular body concentric to the central axis, wherein the jacket comprises at least 30 wt % of a PTFE and at least 10 wt % of a filler material, and wherein the filler material comprises a boron-containing material, a nitrogen-containing material, a titanium-containing material, a silicon-containing material, a carbon fiber, a glass fiber, or a combination thereof; and an energizing element disposed in the recess.