Canning equipment -- since different molds have been applied in many fields, professional mold manufacturing skills have also been changed and grown in this sector over the years. The design rules of vacuum forming molds are summarized.

1, shrinkage and deformation, plastic easy to shrink (such as PE), some plastic parts easy to deformation, no matter how to prevent, plastic parts in the cooling phase will occur deformation. Under this premise, it is necessary to change the shape of the molding mold to adapt to the number of plastic parts is poor. For example, although the plastic wall remains flat and curved, the reference center is just 10mm away. The base of the die can be raised to adjust the shrinkage of this deformation.

2, shrinkage, in the manufacture of plastic molding mold must consider the following shrinkage factors. (1) forming finished product shrinkage. If the shrinkage rate of the plastic is not clearly known, a sample must be taken or a similar shape of the mold must be tested. Notice: get shrinkage rate only through this kind of method, cannot get out of shape dimension. (2) the adverse effect of the medium caused by shrinkage, such as ceramics, silicone rubber, etc. (3) mold used in the shrinkage of materials, such as casting aluminum shrinkage.

3, the size remains unchanged, in the molding process, the plastic parts and the mold contact surface is better than leaving the mold department size invariance. If the thickness of the material needs to be changed due to the stiffness of the material in the future, the positive mold may be converted to the negative mold. The dimensional tolerance of plastic parts shall not be less than 10% of the shrinkage rate.