Analysis and Solution of Common Problems in PVC Trunking

01 Material easy to break down, the product surface variegated line marks

① die temperature is too high. Should reduce the die temperature.

② poor stability of raw materials and dry mix. Should check the reasons for poor thermal stability of raw materials and mixed quality.

③ nose surface has depression or accumulation. Check and clean the head.

④ die structure is unreasonable. Should try to eliminate the dead ends of the nose, reducing the material in this stay time.

02 The trunking surface is rough, with nodular and cloudy corrugations

① material mixing quality is poor, uneven. The mixing process should be checked to improve the quality

② head temperature is low. Should be appropriate to improve the head temperature.

③ outside the lubrication over the amount. Should reduce the amount of external lubricant.

④ die wall with sticky precipitates. Should clean up the die.

⑤ die resistance is not enough Should reduce the filter, filter plate cross-section, increase the amount of extrusion.

03 slot size error, deformation
① vacuum is not enough, fixed mold gap gap. Should improve the vacuum, clean up the mold gap.

② traction too fast, insufficient amount of extrusion. Should be appropriate to reduce the speed of traction, improve speed.

③ cooling stereotypes enough. Check the cooling water temperature.

04 product surface precipitation

① There is a certain amount of low molecular weight volatiles in the formulation, and the discharge effect is not good during the mixing process. Should be used with little or no low-molecular substances, with high-molecular material instead.

② low melting point of the lubricant and other components in the compatibility of poor compatibility. Should use high melting point of the lubricant or to minimize the amount of lubricant.

③ extrusion die temperature is low and too close with the stereotypes die. Should be appropriate to improve the extrusion die temperature.

④ stereotypes vacuum is too large, reduce the vacuum.

05 The inner wall of the groove is rough
① screw speed too fast. Should reduce the screw speed.

② barrel temperature is low. Should be appropriate to improve the barrel temperature.

③ high moisture content and volatile materials. Should clean up the pipeline, improve the exhaust vacuum.

④ plastic raw materials is not good.

06 white trough discoloration
① quality of titanium dioxide failed. Should be qualified qualified rutile titanium dioxide.

② group of green caused discoloration. Application of the import of acid-treated ultramarine to prevent sulfur pollution.

③ lead, cadmium as a stabilizer of the trough and sulfide contact with sulfur pollution. Formed by the lead, cadmium and other metal ion coating agent, chelating agent.

④ poor quality of the stabilizer, the amount of less stabilizer. Should use good quality PVC resin and stability together, the amount of stabilizer is higher than the lower limit.

⑤ toughener recommended ACR class, anti-aging effect is much better than CPE.

07 product crisp

① raw material is not good plastic or plasticized, the former can be added by promoting the promotion of plastic additives, which can reduce the temperature or reduce the production temperature and extrusion speed.

② material mixing quality is poor, uneven. The mixing process should be checked to improve the quality.

③ outside the lubrication over, can reduce the amount.

④ too much calcium or calcium powder head number is too low, can reduce the amount of calcium powder or the use of high mesh or active calcium carbonate.

⑤ toughening agent added too little or bad quality.