Technical Support : HWAQ
When it comes to sintering of polytetrafluoroethylene, the first thing to look at is which variety it is. Generally speaking, there are three types of pure polytetrafluoroethylene: dispersed powder obtained by emulsion polymerization, molded material obtained by suspension polymerization, and emulsion. Different varieties have different sintering processes.
1. Disperse powder
This kind of powder is generally extruded in paste form, and needs to be dried and sintered to obtain the product after extrusion. The sintering temperature is generally controlled at 380 to 420 degrees. If the temperature is too high, PTFE will decompose and produce toxic gases. There is a drying process before the sintering temperature to remove the previously added additives.
2. Molded material
Due to the internal stress of the molded parts, poor sintering control can lead to cracking, so it is generally placed for a period of time from the end of compression molding to before sintering to relieve the stress.
It is roughly divided into 3 steps. First, the water is evaporated at about 100 degrees, and then the surfactant in the emulsion is taken out. The temperature is adjusted according to the different active agents. Finally sintered at around 380 degrees.