Shrinkage of TPE overmolded products

　　In the twinkling of an eye, we have entered September, Plastic Bo TPE also entered the sprint season, we are also actively adjust the state, intend to do the final sprint. At the beginning of September, we received a call from a customer who used our products to cover ABS, and needed a TPE pellet with hardness of 70A-80A. We responded to the situation with our engineers, and brought a 75A and an 80A product to the customer's company. Unexpectedly, the first 75A product just reached the temperature of the phenomenon of shrinkage.

　　Reasons for shrinkage of TPE overmolded products

　　1, TPE shrinkage reasons, TPE particles in the overmolding will appear shrinkage is mainly due to the temperature, the temperature of the injection molding machine than the temperature of the TPE particles into the mold is higher, there will be TPE particles melt after the liquidity performance deterioration, so that the local shrinkage of the situation will occur.

　　2, TPE shrinkage reasons, TPE particles in the overmolding may also be the cause of the pressure of the injection molding machine, once the pressure of the injection molding machine does not reach the pressure value required for injection molding, it will appear. Of course this reason is very small, but also can not be ignored.

　　Countermeasures for shrinkage of TPE overmolded products

　　TPE products locally appear shrinkage, we need to reduce the first step of the injection molding machine molding temperature, look at the range of shrinkage, generally reduce the temperature in 10 degrees or so, once the lowering of the temperature does not appear to wrap the situation, then we slowly raise the temperature, the second step we can increase the pressure of injection molding, one to achieve both the package can be tightened and does not appear to be the case of shrinkage. We started to set the temperature at 180 degrees or so, the problem of shrinkage, and then lowered to 170 degrees but there is a pack not tight. Slowly debugging, and finally at a temperature of 178 degrees, wrapped firmly and no shrinkage phenomenon.