Common problems and treatment methods during production
Edge whitening
(only for 3:2 formula and 1:1 formula)
1) Increase the color powder, first use titanium dioxide to adjust the base color, and then increase the amount of color powder.
2) Use high-quality PE wax to improve the surface gloss.
3) Increase the extrusion temperature or reduce the extrusion speed to facilitate plasticization. The better the plasticization, the better the effect.
Pinholes, pitting, blistering
(mainly caused by improper operation)
Cause analysis:
1) Improper temperature during PVC mixing, such as the temperature of 3:2 formula mixing is about 140℃, and the temperature of 2:1 formula is about 135℃. The unreasonable mixing temperature will cause blistering and pinhole phenomenon.
2) The packaging bag or the powder cylinder cover is not cleaned, and raw powder and impurities leak into it.
3) The color powder is not mixed evenly.
4) The screen is broken, and large particles of calcium powder are mixed into the ingredients. During the production process, a screen of 80-120 mesh is often added to increase pressure and screen out too coarse impurities.
Blocking of the net
The main reason is that the calcium powder is damp.
Treatment method: First stir the calcium powder to 100℃ and let the water evaporate fully. Then add PVC powder and stir.
If there are very coarse granular calcium in the CPE and it cannot be plasticized during production, it will also cause blocking of the net. The treatment method is: replace a better CPE; or find a way to enhance the plasticization effect of PVC so that the granular calcium can be plasticized.
