The use of Low pressure flat mouth anti fog bag price is more and more widely, for the characteristics of low pressure flat mouth anti fog bag, there are the following points. First, the crystalline material, moisture absorption is small, does not need to be fully dry, the flow of excellent liquidity pressure sensitive, molding to the occasion with high pressure injection, material temperature uniformity, filling speed, holding pressure sufficient. Not by direct gate to prevent uneven shrinkage, stress increase. Pay attention to the choice of gate location to prevent shrinkage and deformation. Contraction and contraction of the scope is larger, the direction is obvious, easy warpage. Cooling rate should be slow, cold cave mold design and cooling system, heating time should not be too long, otherwise it will decompose, burn. Soft plastic parts with a lighter side of the groove, forced demoulding. Possible melt fracture, not with the organic solvent exposure, to prevent cracking.