Testing PTFE emulsion quality involves six key indicators: solid content (60±2% per T/FSI 067-2021), pH (9.0-11.0), particle size distribution (laser diffraction/DLS), viscosity (12-30 mPa·s at 25°C), stability (centrifugal, thermal, freeze-thaw), and appearance. This guide covers standard test methods for each parameter.
For PTFE high-temperature tapes under long-term immersion, the PTFE substrate remains chemically inert, but the adhesive layer is the weak point. Water weakens silicone PSA; saltwater accelerates corrosion. For aggressive chemicals, fluorosilicone or perfluoropolyether adhesives – or adhesive-free PTFE tape – are required. Peel strength loss up to 40% after 48 hours in water.
PTFE high-temperature tape used in food contact applications must stay within defined temperature limits: ≤260°C for continuous use, ≤300°C for short peaks (minutes), and never above 327°C (decomposition). FDA and EU regulations do not specify a universal time limit – safe contact duration depends on temperature and must be verified by migration tests simulating actual conditions.
