1、 If the product surface is strict, it must be dry before injection. Generally hopper drying 70 ~ 80 ℃ / 2H or tray drying 80 ~ 100 ℃ / 1H. For tray drying, it should be noted that the thickness of material layer is generally not more than 50 mm. Tray drying is recommended. If there are blisters on the surface of the injection molding strip, or if the strip is cut open, and it is found that there are cavities in the strip, or if there are scattered silver wires on the surface of the product, it can be determined that the TPE / TPR raw material contains too much water.
2、 Try to use low temperature injection molding. On the premise of ensuring the plasticizing quality, the extrusion temperature should be reduced as much as possible, and the melt viscosity should be reduced by increasing the injection pressure and screw speed, so as to improve the fluidity. When the surface of the strip injected from the nozzle is smooth and bright, it can be determined that the plasticizing quality is good. If the strip injected from the nozzle is very bright, it can be determined that the barrel temperature can be reduced. Try to use low temperature injection molding, can reduce the cooling time, so as to improve customer production efficiency.
3、 Upper parabola temperature setting. The temperature in the middle zone of screw is the highest, the feeding section is slightly lower, and the nozzle is slightly lower. Typical temperature settings are 150-170 ℃ (feed), 170-180 ℃ (middle), 190-200 ℃ (front), 180 ℃ (nozzle). This temperature setting is only used as reference data. The specific temperature can be adjusted according to the specific physical properties of different TPE and TPR materials. If it is found that the contents of the product bulge (gas package inside) and the gate is easy to break when demoulding, it can be adjusted according to the second trick.
4、 Keep the pressure as low as possible. Generally, the holding pressure is smaller than the injection pressure, and the holding time can be determined by weighing the product, with the weight of the product no longer increasing, or with the shrinkage mark accepted by the customer. If it is found that the gate is easy to break during demoulding, and the second trick can not work, it should be feasible to reduce the packing pressure.
5、 If it's a few injections, the speed is from slow to fast. Because of this, the gas inside the mold is easily discharged. If there is gas in the product (internal bulge), or there is a dent, the second trick is invalid, this method can be used to adjust.