In the actual use of chemical plastic barrels, the thickness of the barrel wall is too large, which causes the deformation of chemical plastic barrels. This has caused the plastic machinery manufacturing enterprises to attach great importance to it, and has begun to improve this aspect. Most chemical plastic barrel manufacturers have also made active improvements in mold equipment. Chemical plastic barrels can be divided into two major categories: extrusion-blow molding and injection-blow molding. The main difference between the two is the preparation of the parison, and then the blow molding process is essentially the same. On the basis of these two molding methods are: extrusion-stretching-blow molding (referred to as extrusion-pull-blowing), injection-stretching-blow molding (referred to as injection-pull-blowing) and multi-layer reflection Plastic and so on.