Thermoplastic elastomer TPE pellets are a common injection molding material. In order to ensure the quality of the finished product, it is important to make adequate preparations before injection molding of TPE thermoplastic elastomer to prevent the occurrence of different situations from the test. (In fact, the main purpose is to avoid waste and to avoid various situations of injection molding). Whenever I see our customers clearing the machine with the TPE pellets we have produced, I especially want to say, stop, do not waste ah, I give you the material regardless of the price that is absolutely more than the price of PP, why do not you use PP clearing machine? In fact, it is also because some customers really do not use PP or did not think about this aspect of the situation, I will bring 2kg PP to help customers clear the machine to avoid waste.

　　1、Cleaning of barrel before injection molding of TPE material

　　Before the injection molding machine is bought and used for the first time, or the product is changed during production, the raw material and color are changed, or the plastic is decomposed, 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: SBS base material TPR, PS material is recommended to clean the barrel; SEBS base material TPE, higher hardness, PP material is recommended for cleaning, lower hardness, HDPE or EVA material is recommended for cleaning the barrel.

　　2, TPE material injection molding before doing Note the molding temperature of TPE material

　　In the processing of injection molding, the accuracy of the temperature setting will have a great impact on the appearance and performance of the product. When the temperature is set in the injection molding, the temperature of the feeding area should not be too high to prevent the blockage of the feeding area and the escape of the entrained air. 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 testing, the temperature range of TPE products in each place will be different, mainly from 160℃ to 210℃ for the barrel and 180℃ to 230℃ for the nozzle.

　　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, TPE material injection molding before doing the material to do pre-baking

　　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 better bonding of TPE and hard plastic, and the appearance of products more uniform bright.