Cause analysis of warpage of polypropylene extruded sheet

Hello, I'm glad to answer your question. Causes and solutions of warping deformation of PP plastic sheet: (1) uneven cooling of PP plastic sheet. Solution: the cooling water pipe of the mold should be enlarged, and check whether the cooling water pipe is blocked. (2) Uneven distribution of wall thickness. Solution: improve the pre-stretching pressurization device and use the pressurization plunger. The plate used for molding should be uniform in thickness and heated evenly. If possible, the structural design of the product should be modified appropriately, and stiffeners should be set on the general plane. (3) The mold temperature is too low. Solution: properly raise the mold temperature to make it slightly lower than the curing temperature of the plate, but the mold temperature should not be too high, otherwise the shrinkage rate will be too high. (4) premature demoulding. Solution: appropriately increase the cooling time, air cooling can be used to speed up the cooling speed of the product, and the product must be cooled below the curing temperature of the sheet before demoulding. (5) 5) The temperature of PP blister sheet is too low. Solution: appropriately extend the heating time, increase the heating temperature and speed up the vacuum pumping. (6) Poor mold design. Solution: The design should be modified. For example, in vacuum forming, the number of vacuum holes should be appropriately increased, and the groove of the mold on the trimming line should be increased.