Views: 2 Author: Site Editor Publish Time: 2023-07-25 Origin: Site
TPR and TPE are two commonly used thermoplastic elastomer materials, which may encounter some defects during injection molding. Here are some common causes and solutions:
1. If the injection speed is too fast, the material retention time is too long, which will cause the surface luster of the product to decline.
Solution to the problem: The injection speed should be reduced to reduce the residence time.
2. The material has poor thermal stability and thermal decomposition
How to solve the problem:
Use a material with good thermal stability and luster, or add a heat stabilizer to the material.
3. The low temperature of the barrel and the low temperature of the nozzle will lead to the reduction of the surface gloss of the product.
Problem solution: The nozzle temperature should be increased to increase the melt temperature.
4. Mold temperature is too low, cooling speed is too fast. When the melt is still filled, a hard shell is formed on the cavity wall, and the shell is subjected to various forces to make it white and cloudy, thus reducing the product. Surface gloss
The solution to the problem: the mold surface temperature should be increased, the cooling rate should be reduced, or the local heating should be used at the mold gate.
5. Poor surface finish of the mold makes the surface of the product dull.
The solution to this problem should be carbon steel, carefully polishing the mold surface to improve the surface finish of the mold.
6. Excessive release agent will also cause such defects on the surface of the product.
The solution to the problem: try not to use or use a small amount of release agent, and evenly apply.
7. When the back pressure in the plasticization process is too small, the material will be plasticized unevenly, and the mixing of materials and colorants will lead to uneven surface color of the product.
Solution to the problem: the back pressure should be appropriately increased.
8. Impurities in the material rather than drying will also reduce the gloss of the product surface
Problem solution: Consideration should be given to removing impurities, drying the material completely, and adding a hopper dryer if necessary.
9. The size of the runner and gate is too small, and poor exhaust will also lead to poor surface gloss of the product.
The above are the causes and solutions of common defects in the TPR and TPE injection molding process, and hope to help you. If you have more questions or need further assistance, please feel free to contact us.