PVC pipe fittings in the production process, caused by […]
PVC pipe fittings in the production process, caused by the material temperature is too low plasticizing poor, generally known as cold spots, the following is introduced on PVC pipe fittings cold spots eliminate.
The elimination of cold spots, cold spots caused by material too raw caused. The reason for this is: the material temperature is low, poor plasticization.
able to pass:
① heating, mainly the temperature in each district increased to 2 to 4 degrees each upgrade;
② increase pre-plastic pressure, flow, do so can increase the screw speed, the friction material and the inner wall of the cylinder increases, generating a lot of heat, so as to achieve the purpose of raising the temperature of the material.
Note: The two methods have their own advantages and disadvantages of heating methods, although the material temperature plasticizing good, but the higher temperatures, the material is easy to break down, resulting in bubbles, silver, red lines, such defects, reduce the temperature is very difficult , While increasing pre-plastic pressure, flow, can maintain the same temperature, so that the operating space increases.