Plastic causes cold block and how to exclude:
  一.defect feature, plastic block is the main performance: with some formed by cold material, performance and body color plastic are different plastic in plastic, the plastic quality severely damage.
  二. The causes of defects and its elimination method, main reason is: cold cold block material produced in the melt injection molding process into a cavity formed by cold block, the concrete analysis is as follows. 1: if the injection mold gating system without cold well, cold material produced in the casting may enter into a cavity formed cold block, therefore, should open the cold slug well suitable in the passage; if the cold slug well capacity in gating system is too small, or position, make the cold material can not be to accommodate and into the cavity to form cold block, as the cold slug well this, should be the cold slug well on the right place, and make the appropriate capacity; for direct feed mould, due to the lack of a cold well, during operation, the cold nozzle must be removed from the mold closing before in the mold, plastic parts, the cold feed sprue removal of residues, avoid cold material into the cavity. 2 injection molding process, if the melt temperature is too low, the melt will plasticating, to produce cold block, therefore, should increase the melt temperature; if the injection pressure is too low, the melt into the cavity will produce cold material more, if into the cavity to form cold block, therefore, may be appropriate to increase the injection pressure; if the mould the temperature is too low, easy to produce more material melt into the cold die, if not all of these cold material for cold well contained, which will enter the cavity and become cold block, therefore, should be appropriate to raise the mold temperature. 3 injection molding machines, injection molding machine if the plasticizing capacity is not enough, plasticizing capacity is small, plasticizing capacity is close to the quality of plastic parts, the forming time is shorter and the generation of cold block, therefore, should be replaced with large size injection molding machine; if the material feeding system of injection molding machine is not stable, supply shortage, but also easy to generate cold block, in this regard, should be careful maintenance of feeding system, so that it can work.