TPR/TPE and other injection molded products are prone to dull surface finish, or uneven luster and color.

　　Solution.

　　1. The injection speed is too fast and the material retention time is too long will also cause the surface luster of the products to drop

　　Solution: The injection speed should be reduced and the retention time should be reduced.

　　2. Poor thermal stability of the material, decomposition by heat

　　Solution: Choose materials with good thermal stability and gloss or add heat stabilizer to the materials.

　　3. Low barrel temperature and low nozzle temperature will also cause the surface gloss of the product to decrease

　　Solution to the problem: The nozzle temperature should be increased and the melt temperature should be raised.

　　4. The mold temperature is too low and the cooling speed is too fast, when the melt is still filling the mold, a hard shell is formed on the cavity wall, and the shell layer is subjected to various forces, making it white and muddy, reducing the surface gloss of the product

　　Solution: We should increase the surface temperature of the mold, reduce the cooling rate or use local heating at the mold gate.

　　5. poor surface finish of the mold, making the surface of the products lusterless

　　The solution of the problem should choose carbon tool steel and polish the mold surface carefully to improve the surface finish of the mold.

　　6. The use of too much mold release agent will also make the surface of the products with such defects

　　Solution to the problem: You should try not to use or use a small amount of mold release agent, and apply it evenly.

　　7. Too little back pressure when plasticizing will make the material unevenly plasticized, and the material and coloring agent are not mixed well, resulting in uneven color on the surface of the products.

　　Problem solution: The back pressure should be increased appropriately.

　　8. impurities mixed in the material, not dry will also make the product surface gloss decreased

　　Solution: We should remove the impurities and dry the material fully, and add hopper dryer if necessary.

　　9. The size of runner and sprue is too small, and poor exhaust will also cause the product surface gloss is not good.

　　Solution: We should increase the size of runner and gate, and add exhaust tank.