Kaxite Sealing manufactures expanded PTFE (ePTFE) sheet from 100% virgin PTFE through a controlled expansion process that creates a microporous node-and-fibril structure. It is soft, highly compressible and conforms to rough, pitted and glass-lined flanges that rigid PTFE gaskets cannot seal. We supply standard sheet 0.3–6.0 mm thick, widths up to 2500 mm, in white, black, grey and custom colours. Procurement teams choose us for factory-direct bulk pricing, documented traceability and 7–15 day lead times.
The expanded microstructure conforms to rough, pitted, scratched, glass-lined and enamel flange surfaces — a rigid skived PTFE gasket simply cannot bridge. Ideal for repair and retrofit work where the flange face is not perfect.
ePTFE sheet seals at compressive loads far lower than solid PTFE, so you can use smaller bolts, lighter flanges or lower torque specs. Combined with up to 80% compression recovery, joints stay tight through thermal cycling and vibration.
Where solid PTFE cold-flows and leaks over time, ePTFE resists creep relaxation. Standard grade test data shows < 15% creep relaxation (ASTM F38), and the high-density grade delivers < 10% — maintaining bolt load over long service intervals.
Made from 100% expanded PTFE with a uniform, highly fibrillated microstructure with fibres running in multiple directions. Soft and pliable yet tough. Inert to almost all common chemicals across pH 0–14. Free from asbestos, non-toxic, non-contaminating, unlimited shelf life. Available in Standard, High-Density and Colour-coded grades, plus custom formulations on request.
| Property | Test Method | Standard | High-Density |
|---|---|---|---|
| Density | ASTM D792 | 0.6 – 0.8 g/cm³ | 1.0 – 1.2 g/cm³ |
| Tensile Strength (MD) | ASTM D638 | 15.0 MPa min | 25.0 MPa min |
| Elongation at Break (MD) | ASTM D638 | 100% min | 80% min |
| Compression Stress @ 25% | ASTM D575 | 4.5 MPa | 10.0 MPa |
| Creep Relaxation | ASTM F38 | < 15% | < 10% |
| Service Temperature | — | -240 to +260 °C | -240 to +260 °C |
| Dimension | Standard Options | Custom Range |
|---|---|---|
| Thickness | 0.5 / 0.8 / 1.0 / 1.5 / 2.0 / 3.0 mm | 0.3 – 6.0 mm |
| Width | 1500 mm, 2000 mm | Up to 2500 mm |
| Length | Rolls of 50 m; cut sheets to request | Any length on cut sheets |
| Colour | White (Natural) | Black, Grey, Blue (MOQ applies) |
| Compliance | FDA compliant | USP Class VI on request |
MOQ negotiable for trial and prototype orders. Free cut samples of standard density and thickness available for material evaluation.
7–15 days for standard rolls and cut sheets; longer for custom colours, densities or widths. FOB Ningbo / Shanghai, CIF and DDP terms available.
Sheets supplied as full rolls of 50 m, or cut to specific lengths. Die-cut and CNC-cut gaskets from the same sheet are also available — send your drawing.
Inspection report with every shipment. Third-party testing (SGS, TÜV) on request. FDA 21 CFR 177.1550, RoHS and REACH documentation with full resin-lot traceability.
Traditional skived PTFE sheet is a solid, non-porous material cut from a molded billet. Expanded PTFE Sheet is created by stretching PTFE under controlled conditions, forming a microporous, fibrous structure. This gives ePTFE significantly higher compressibility, better conformability to uneven surfaces, improved creep resistance and often higher tensile strength — making it vastly superior for gasketing.
Yes. The microporous structure is not open-celled — the pores are small and tortuous. When compressed in a flange, the pores close, creating an impermeable barrier that effectively seals both liquids and gases, including aggressive chemicals and steam.
The expansion process does not alter the fundamental chemical structure of the PTFE polymer. ePTFE sheet therefore retains the full chemical inertness and broad temperature resistance (-240 °C to +260 °C) of virgin PTFE. It resists almost all industrial chemicals; exceptions are molten alkali metals and certain fluorine compounds at high temperature and pressure.
No. In fact, using adhesives or sealants is generally not recommended because they can fill the porous structure and reduce compressibility. ePTFE sheet gaskets are designed to be installed dry and clean. Their natural conformability and recovery allow them to seal effectively on their own when proper flange preparation and bolt torque procedures are followed.
Creep relaxation, or cold flow, is the tendency of a material to deform permanently under sustained load, which leads to a loss of sealing stress and eventually leakage. Standard PTFE is known for high creep. The expanded fibrous structure of our ePTFE sheet provides excellent resistance — typically below 15% and as low as 10% for the high-density grade (ASTM F38). This keeps bolt load and seal integrity over long service intervals.
Yes. We produce sheets with specific densities for optimised compression, thicknesses outside the standard range, custom widths up to 2500 mm, sheet sizes, and various colours for coding or identification. Additives for enhanced properties can also be incorporated. Send your drawing or specification for a quotation.
Store rolls or sheets flat in a cool, dry place away from direct sunlight. Keep them in original packaging until use to prevent contamination from dust or oils. Handle with clean gloves to avoid transferring skin oils onto the sealing surface. The material is robust but should be protected from sharp edges or abrasion during handling and cutting.
A flange surface finish between 125 and 500 microinches Ra (3.2 to 12.5 µm Ra) is typically ideal. Excessively rough surfaces may require higher bolt load to achieve conformity, while mirror-finish surfaces may reduce the gasket's ability to grip. ePTFE's excellent conformability allows it to perform well even on slightly damaged or scratched flanges where other materials would fail.
Send us your thickness, width, density grade, colour, roll or cut-sheet requirement, or finished-part drawing. Our export team replies within 24 hours and confirms lead time, packaging and documentation before you place a bulk order.
