Why do 3d pvc wall panels turn yellow?- Haining Longtime Industry Co., Ltd.

Raw material problem The main raw material of 3d pvc wall panels is PVC resin, which is extremely sensitive to heat. When the heating temperature reaches above 90 degrees, a slight thermal decomposition reaction will occur. When the temperature rises to 120 degrees, the decomposition reaction intensifies. Within 10 minutes at 150 degrees, the PVC resin gradually changes from the original white to yellow-red-brown-black.

Production process problems During extrusion, PVC is heated and sheared by the screw and barrel. If the process is not set properly, it will decompose and turn yellow to a certain extent.

solution:

Appropriately lowering the barrel temperature can improve the yellowing phenomenon. Reducing the rotation speed of the main engine within an appropriate range and increasing the feed ratio can reduce shearing and make the mixing of the materials in the spiral groove more uniform, and the stabilizer can give full play to its role, thereby Reduce yellowing. Improper boot method can also cause the product to turn yellow, restarting can solve this problem. Problems with the formula, if the manufacturer or batch or model of the additive changes, can also cause the product to turn yellow.
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