Here are some hints for purging high temperature resins (those processed at more than 600ºF (315ºC) – including polysulfone, PEEK, poly-ether-imide, many fluoropolymers and others).
- Never let them drop below their minimum melt temperature in the barrel as some will adhere tenaciously to internal metal surfaces.
- For purging, never stop the screw, as bridging is likely to occur.
- Ensure good ventilation in the area of the nozzle or die.
- To maximize purging compound effectiveness, lower heats to just above the resin’s melt point.