Polytetrafluoroethylene film production process is resin, pigment → mixing → molding → sintering → cooling → turning non-orientation film → rolled semi-directional film
The main process parameters:
Mixing: Currently, there are two main methods of mixing color PTFE films: dry mixing and wet mixing. Studies have shown that wet mixing is more common than dry mixing, but processes are more expensive
High, need to add solvent, in order to ensure the average product is generally used wet mixing.
Process is the PTFE resin, pigment plus solvent → mixing → drying → removal of solvents → color materials.
Molding pre-formation: Fair choice of pre-formed unit pressure is an important process prerequisite for the production of PTFE color film. Mainly based on the fineness of the resin, the compression ratio, the fineness of the pigment type and other conditions to choose, generally 20 ~ 40MPa.
Sintering Cooling: Because the color film contains pigments, the thermal conductivity, thermal expansion coefficient and the polytetrafluoroethylene are not the same. Therefore, during the sintering process, the temperature of the lift is slower than that of the ordinary PTFE film, the sintering temperature is lower than the ordinary film, the lifting temperature is 20-30°C/h, and the sintering temperature is 375°C. The normal film heating rate is 50-60°C/h before 327°C, and 30-40°C/h after 327°C.
The sintering temperature is 380°C and the cooling rate is 20-50°C/h.
Turning non-orientation film: The angle of the tool tip is 40° to 45°, which is slower than ordinary PTFE.
Calender semi-directional film: The calendering temperature varies with film thickness, generally 5 μm thick, 110°C ± 5°C; 30 μm thick, 130°C ± 10°C. The rolling multiple is 215-310.