Ⅰ The surface of the sheet is rough and dull
1. There is too much or too little material stored between the calender rolls. The amount of material stored between the calender rolls should be adjusted appropriately.
2. Poor mixing and plasticizing of materials. The mixing and plasticizing effect of materials should be improved.
3. The mixing temperature is too low. The mixing temperature should be increased appropriately.
4. The calendering temperature is too low. The calendering temperature should be increased appropriately.
5. The speed ratio of calendering rolls is too small, resulting in "roll off". The calender roll speed ratio should be adjusted appropriately.
6. Too little lubricant is used. The amount of lubricant should be increased appropriately.
7. The surface of the calender glazing roller is worn and the gloss is poor. Calender rolls should be repaired.
8. The amount of recycled materials is too much or the quality of raw materials is too poor. The amount of recycled materials should be appropriately reduced or replaced.
Ⅱ There are bubbles on the surface of the sheet
1. The moisture content in the raw material is too high. Kneading should be strengthened, high-speed mixing discharge temperature should be increased or drying treatment should be carried out.
2. The calendering temperature is too high. The calendering temperature should be lowered appropriately
3. The plasticizing time is too long. The plasticizing time should be appropriately shortened.
Ⅲ There are precipitates on the surface of the sheet
1. Too much lubricant or improper selection. The amount of lubricant should be reduced or the type of lubricant adjusted.
2. The additives in the formula have poor compatibility with polyvinyl chloride resin, and the design of the formula should be adjusted appropriately.
Ⅳ The sheet has color difference
1. In case of inaccurate measurement, materials should be accurately measured according to the formula, especially the amount of colorant.
2. Poor dispersion, mixing and plasticization. Dispersion, mixing and plasticization should be strengthened.
3. Improper use of lubricants and dispersants. The amount of lubricant and dispersant in the formula should be adjusted appropriately.
4. The rolling temperature is unstable. Calendering temperature should be stabilized.
5. The heat resistance of the colorant is too poor. Colorants with good heat resistance should be selected.
Ⅴ Sheet decomposition discoloration
1. The calendering temperature is too high. Calendering temperature should be lowered appropriately.
2. The heating time is too long. The heating time should be properly compressed.
3. Too much recycled material. The amount of recycled materials should be appropriately reduced.
4. The thermal stability of the formula is poor, and the formula design should be adjusted.
5. There is too much stock between the calender rolls or the stock rotation is poor. The rolling inventory should be appropriately reduced.
Ⅵ The mechanical properties of the sheet are poor
1. Poor mixing and plasticizing of materials. The mixing and plasticizing of materials should be strengthened.
2. The calendering temperature is low. The calendering temperature should be increased appropriately.
3. If the quality of raw materials is too poor or the amount of recycled materials is too much, new raw materials should be replaced or the amount of recycled materials should be reduced.