About TPR Injection Molding Process

According to the characteristics of the material and the supply situation, the appearance and process performance of the material should be tested before molding. The supplied pellets often contain varying degrees of moisture, flux and other volatile low-molecular-weight substances, especially the moisture content of TPR, which has a tendency to absorb moisture, always exceeds the allowable limit for processing. Therefore, it must be dried before processing and the water content must be measured. At high temperatures, the moisture content of TPR is required to be below 5%, or even 2% to 3%, so a vacuum drying oven is commonly used for drying at 75°C to 90°C for 2 hours. The dried material must be properly sealed and stored to prevent the material from absorbing moisture from the air and losing the drying effect. For this reason, the drying chamber hopper can be used to continuously provide dry hot materials for the injection molding machine, which is useful for simplifying operations, maintaining cleanliness, and improving quality. It is advantageous to increase the injection rate.