Expanded PTFE sheet (also called ePTFE sheet or soft PTFE sheet) is a highly compressible sealing sheet made from 100% virgin PTFE. The expansion process creates a soft, fibrous structure that conforms perfectly to uneven sealing faces and seals at very low bolt load — properties that standard skived or moulded PTFE sheet cannot match. It is FDA compliant, resists virtually all chemicals from pH 0 to 14, and does not exhibit the cold flow problems of virgin PTFE or the hardness problems of filled PTFE. Kaxite supplies expanded PTFE sheet in standard 1500 × 1500 mm size, thickness 0.5–6 mm, with properties comparable to GORE, KLINGER and TEADIT sheet materials.
The Expanded PTFE sheet is a highly compressible sealing sheet made from 100% virgin PTFE. The expansion process creates a soft, fibrous structure that conforms perfectly to uneven sealing faces and seals at very low bolt load — properties that standard skived or moulded PTFE sheet cannot match. It is FDA compliant, resists nearly all chemicals from pH 0 to 14, and does not exhibit the cold flow problems of virgin PTFE or the hardness problems of filled PTFE. Standard size 1500 × 1500 mm, thickness 0.5–6 mm.
Expanded PTFE sheet is manufactured from 100% virgin PTFE resin that has been stretched under controlled conditions to create a soft, fibrous, highly compressible structure. Unlike skived PTFE sheet — which is peeled from a dense cylindrical billet and stays hard — expanded PTFE sheet deforms easily under bolt load and springs back when the load is released. That combination of high compressibility and good recovery is what lets it seal where standard PTFE fails.
Specify expanded PTFE sheet when any of the following applies:
Expanded PTFE sheet is supplied in the standard size below. Other sheet sizes and cut panels can be produced to order.
For gasket cutting, the most common thicknesses are 1.5 mm, 2 mm and 3 mm — thick enough to fill flange irregularities and thin enough to keep bolt load reasonable. Thicker sheet (4–6 mm) is used where the flange gap is larger or the surface is heavily damaged. Thin sheet (0.5–1 mm) is used where the joint clearance is tight.
These are the properties that distinguish expanded PTFE sheet from dense PTFE sheet, and the reasons it is specified on difficult joints.
Conforms to very uneven sealing faces
The expanded fibrous structure flows into pits, scratches and surface irregularities. It seals flanges that would leak with a dense PTFE gasket.
Very high sealability at very low stress
Seals at a fraction of the bolt load that dense PTFE needs. Ideal for glass-lined vessels, plastic flanges and older equipment with limited bolt capacity.
Excellent chemical corrosion resistance
Resists nearly all aggressive chemicals from pH 0 to 14 — strong acids, alkalis, solvents and oxidisers. No leaching or contamination of the process medium.
Superior resistance to creep and cold flow
Does not exhibit the cold flow problems of virgin PTFE or the hardness problems of filled PTFE. Bolt load is retained over time and through thermal cycling.
Very clean and soft sealing material
100% virgin PTFE with no fillers. Suitable for food, beverage and pharmaceutical service. Separates cleanly from the flange after use — no scraping.
Non-aging, unlimited shelf life
Does not degrade in storage. Conforms to FDA standard. Easy to cut with standard workshop tools and simple to install.
The figures below are typical values for KXT B302 expanded PTFE sheet. Use them for joint design and for verifying incoming material against the standard.
| Property | Test Standard | Value |
|---|---|---|
| Colour | — | White |
| Density | ASTM D792 | 0.75–0.95 g/cm³ |
| Operating temperature | — | −240 to +260 °C |
| Compressibility | ASTM F36 | 45% |
| Recovery | ASTM F36 | 12–13% |
| Creep relaxation | ASTM F38 | 35–36% |
| Sealability (nitrogen) | ASTM F37B | 0.15 ml/hr |
| Sealability (Fuel A) | ASTM F37B | 0.02 ml/hr |
| Service pressure | — | Full vacuum to 19 MPa |
| Tensile strength, both directions | ASTM D638 | 16–17 MPa |
| Weather resistance | — | Excellent |
| Chemical resistance | — | Excellent |
Expanded PTFE sheet is used as a cut-gasket material in chemical, food, pharmaceutical and general industrial service — especially where the flange is not ideal or the medium is aggressive.
[01]What is expanded PTFE sheet?
Expanded PTFE sheet is a highly compressible sealing sheet made from 100% virgin PTFE. The expansion process creates a soft, fibrous structure that conforms perfectly to uneven sealing faces and seals at very low bolt load. It is FDA compliant, resists virtually all chemicals from pH 0 to 14, and does not exhibit the cold flow problems of virgin PTFE or the hardness problems of filled PTFE.
[02]What is the difference between expanded PTFE sheet and standard PTFE sheet?
Standard skived or moulded PTFE sheet is dense and hard, with very low compressibility, and requires well-machined flanges to seal. Expanded PTFE sheet is soft and fibrous, with 45% compressibility and high recovery. It conforms to irregular flange surfaces, seals at very low bolt load and resists creep and cold flow — which is why it is used where standard PTFE sheet would leak.
[03]What sizes and thicknesses are available?
Standard size is 1500 × 1500 mm. Thickness ranges from 0.5 mm to 6 mm. Other sizes can be produced on request — send your required sheet size and thickness and we will confirm availability.
[04]What are the key performance figures of your expanded PTFE sheet?
Density 0.75–0.95 g/cm³ (ASTM D792). Operating temperature −240 to +260 °C. Compressibility 45% (ASTM F36). Recovery 12–13% (ASTM F36). Creep relaxation 35–36% (ASTM F38). Sealability 0.15 ml/hr with nitrogen and 0.02 ml/hr with Fuel A (ASTM F37B). Service pressure full vacuum to 19 MPa. Tensile strength 16–17 MPa in both directions (ASTM D638).
[05]Is expanded PTFE sheet FDA compliant?
Yes. Expanded PTFE sheet is made from 100% virgin PTFE and conforms to FDA standard, making it suitable for food, beverage and pharmaceutical processing applications. It also resists nearly all aggressive chemicals from pH 0 to 14.
[06]Can expanded PTFE sheet replace GORE, KLINGER or TEADIT sheet?
Yes. Kaxite expanded PTFE sheet is designed as a direct alternative to GORE, KLINGER and TEADIT expanded PTFE sheet materials. It is made from the same 100% virgin PTFE base polymer and meets comparable compressibility, recovery, sealability and FDA requirements. Send us the competitor part number and we will confirm the equivalent Kaxite specification.
Page reviewed and updated by the Kaxite technical team · Rev. 2026-01 · Ningbo Kaxite Sealing Materials Co., Ltd, No. 432, Zhenhai Middle Road, Luotuo Street, Zhenhai District, Ningbo City, Zhejiang, China.
