Food-Grade Pure PTFE Gasket for Equipment​

Product Overview

The DH-G-PF Pure PTFE Gasket is a high-purity sealing component crafted from 99.95% virgin PTFE resin via isostatic pressing and precision machining. Designed for critical chemical and food applications, it meets FDA 21 CFR 177.1550, USP Class VI, and ISO 22262-1 standards. Standard sizes range from 25×25mm to 3000×3000mm (thickness 0.2mm-12mm); custom shapes (including complex cutouts) are available with CNC machining (± 0.1mm tolerance).

Product Features

Chemical Inertness: Resists all chemicals except molten alkali metals and elemental fluorine; no extractables in food-grade applications.

Temperature Performance: Continuous -260℃ to +260℃, intermittent 280℃; stable after 1000 thermal cycles (-196℃ to 260℃).

Mechanical Properties: Compression rebound ≥ 40%, creep relaxation ≤ 10% (1000h, 5MPa); tensile strength 28MPa.

Sealing Efficiency: Helium leak rate ≤ 1×10⁻⁸ Pa·m³/s (ISO 12747-2); no volume swell in 150℃ ethanol (ASTM D471-16).

Surface Finish: Ra 0.2-0.4μm for optimal flange contact; anti-stick surface reduces installation force by 30%.

Applications

Semiconductor: Wafer cleaning equipment seals (HF-compatible), CMP slurry tank flanges.

Food & Pharma: Sterile reactor manholes, beverage bottling line valves (no taste/odor transfer).

Chemical Processing: Acid storage tank flanges (98% HNO₃), solvent transfer pipe joints.

Cryogenics: Liquid helium dewars, LN₂ storage tank seals (-196℃).

FAQ

How to avoid cold flow in high-pressure applications?

Cold flow (plastic deformation) is minimized by:

Using glass microfiber-reinforced variants (10% glass content) for pressures > 10MPa.

Limiting compression to 15-20% of thickness (vs. 25% for non-reinforced PTFE).

Installing with metal retainer rings for flanges > 1000mm diameter.

What flange roughness is required?

Optimal flange roughness: Ra 0.4-0.8μm (ISO 3601-3:2022). Rougher surfaces (>Ra 1.0μm) cause leakage; smoother surfaces (<Ra 0.2μm) reduce friction, leading to gasket creep. Polish flanges with 400-grit sandpaper for best results.

What is the shelf life and storage requirement?

Shelf life is 5 years when stored at 10-25℃, RH < 60%, away from UV radiation and ozone sources. Avoid stacking > 50mm thickness to prevent permanent deformation; store flat on wooden pallets.