4. There is precipitation on the surface of the cable trunking
① There is a certain amount of low-molecular volatiles in the formula components, and the discharge effect is not good during the mixed extrusion process. Low-molecular substances should be used as little as possible or not at all, and replaced with high-molecular substances.
② The low-melting-point lubricant has poor compatibility with other components in the formula. A high-melting-point lubricant should be used or the amount of lubricant should be minimized.
③ The extrusion die temperature is low and too close to the shaping die. The extrusion die temperature should be appropriately increased.
④ The shaping vacuum is too large, and the vacuum degree should be reduced.
5. The inner wall of the wire groove is rough① The screw speed is too fast. The screw speed should be reduced.
② The barrel temperature is low. The barrel temperature should be appropriately increased.
③ The material has high moisture and volatile content. The pipeline should be cleaned and the exhaust vacuum should be increased.
④ The raw material is not plasticized well.
6. White wire groove discoloration
① The quality of titanium dioxide is unqualified. Qualified rutile titanium dioxide should be selected.
② Ultramarine causes discoloration. Imported ultramarine treated with acid should be used to prevent sulfur pollution.
③ The wire groove with lead and cadmium as stabilizers comes into contact with sulfides and sulfur pollution occurs. Metal ion coating agents and chelating agents such as lead and cadmium are added to the formula.
④ The quality of the stabilizer is poor and the amount of stabilizer is small. Good quality PVC resin and stabilizer should be selected, and the amount of stabilizer is higher than the lower limit.
⑤ It is recommended to use ACR toughening agent, which has much better aging resistance than CPE.
7. The product is brittle
① The raw material is not plasticized well or over-plasticized. The former can be achieved by adding additives to promote plasticization, and the latter can reduce the temperature or reduce the production temperature and extrusion speed.
②The material mixing quality is poor and uneven. The mixing process should be checked to improve the quality.
③Excessive external lubrication can be reduced.
④Too much calcium powder or too low mesh size, the amount of calcium powder can be reduced or high mesh size or active calcium carbonate can be selected.
⑤Too little toughening agent is added or the quality is poor.
