PTFE heat shrink tube has the characteristics of heat shrinkage, so it can be tightly wrapped on the surface of other workpieces so that the workpiece has corrosion resistance, electrical insulation, and anti-sticking properties. It is widely used in electrical, chemical, machinery, printing, and other industries. It is reported that the maximum shrinkage rate of the PTFE heat shrink tube is greater than 75%.
It is made of dispersed PTFE resin. The principle is that PTFE produces forced high elastic deformation after being stressed during processing. This deformation is reversible and freezes at low temperatures. If it is reheated and frozen, the forced high elastic deformation will gradually disappear. Return to the original state.
The typical formula for producing PTFE heat shrink tube:
Disperse PTFE resin 100 (parts by weight)
Extrusion aid 20~22
Production process:
PTFE resin, extrusion aid → mixing → storage → pre-forming → pressing → drying → sintering → cooling → heat treatment → inflation → cooling → product.
Production process parameters:
The front part is the same as the ordinary PTFE tube.
Heat treatment: the process of further sintering the dried and sintered tube at high temperature and then quenching it, the temperature is 390℃±2℃, and the cooling liquid is -5℃.
Blowing: at about 310℃, filled with compressed gas below 0.98MPa, the inflation rate is 200%~400%. Main equipment: inflator, the others are the same as ordinary PTFE tube.