TPE material is a common injection molding material, in order to ensure the quality of manufactured products, we must pay attention to the preparatory work before injection molding TPE.
1, clean the barrel before injection molding TPE
In the injection molding machine just bought for the first time, or in the production time to change the product, change the raw material and color, or in the case of plastic decomposition, the barrel of the injection molding machine should be cleaned first. In the cleaning time is basically used to heat the barrel of the method, cleaning materials are used in many plastic raw materials.
Cleaning material selection principles: if it is SBS base material TPR, PS material is recommended to clean the barrel; if it is SEBS base material TPE, higher hardness, PP material is recommended for cleaning; lower hardness, PE or EVA material is recommended for cleaning the barrel.
2, Pay attention to the TPE material molding temperature before injection molding
In the processing of injection molding TPE, the accuracy of the temperature setting will have a great impact on the appearance and performance of the product. In the injection molding set temperature, the temperature of the feed place should not be too high, can prevent the feed place blockage, entrained air escape situation. If the masterbatch is used to improve the mixing state, the temperature of the transition area should be set above the melting point of the masterbatch. The temperature of the area closest to the injection nozzle should be relatively close to the temperature of the melt. Therefore, after the test, the temperature range of TPE products in each place will be different, mainly the barrel at 160℃ to 210℃ and the nozzle at 180℃ to 230℃.
In addition, the temperature of the mold should be higher than the condensation temperature of the injection area, so as to prevent some moisture contamination to the mold, resulting in various streaks on the TPE products. The higher temperature of the mold will often make the cycle time longer, but it can improve the appearance of the welding line and products, so the temperature of the mold is best set at 30 degrees to 40 degrees range.
3、Drying of TPE material
For some overmolding process, before the injection molding process, it is recommended that the material to do pre-baking, baking time 1 ~ 2h, baking temperature 60 ~ 80 ℃, baking material processing is conducive to TPE and hard plastic better bonding, and the appearance of products more uniform and bright.
When injection molding TPE materials, you need to do the above preparatory work to ensure the quality and performance of the product.