How to Guarantee Flatness of PTFE High-Temperature Cloth During Sintering
PTFE cloth flatness during sintering requires precise tension, temperature, and restraint control. Core methods: stenter machine (pin plates maintain width, prevent weft shrinkage), gradient temperature profile (slow heating → 380-400°C hold → slow cooling below 310°C before releasing tension), pre-shrunk substrate (removes weaving stress before coating), and uniform coating thickness (prevents differential melting). Stenter restraint must be maintained until cooling below the PTFE crystallization point (approx. 310°C) to prevent warpage.
