Sheet pre-stretch unevenness warpage deformation (1) uneven cooling. The cooling water pipe of the mold should be increased and the cooling water pipe should be checked for blockage. (2) The wall thickness distribution is uneven. The pre-stretching and pressure-assist device should be modified to use a pressure-assist plunger. The sheet used for molding should be uniform in thickness and uniform in heating. Under the possible conditions, the structural design of the product should be properly modified, and ribs should be placed at the large plane. (3) The mold temperature is too low. The mold temperature should be appropriately raised to a temperature slightly lower than the curing temperature of the sheet, but the mold temperature should not be too high, otherwise the shrinkage rate is too large. (4) Demoulding too early. The cooling time should be increased appropriately. Air cooling can be used to accelerate the cooling of the product. The product must be cooled below the curing temperature of the sheet to release the mold. (5) The sheet temperature is too low. The heating time should be extended appropriately, the heating temperature should be increased, and the pumping speed should be accelerated. (6) Poor mold design. The design should be modified. For vacuum forming, the number of vacuum holes should be increased as appropriate, and the pre-stretch unevenness of the groove sheet of the mold on the dressing line should be increased. (1) The thickness of the sheet is not uniform. The production process conditions should be adjusted to control the thickness uniformity of the sheet. When thermoforming, it should be heated slowly. (2) The sheet is unevenly heated. The heater and the screen should be inspected for damage. (3) The production site has a large airflow. The operating site should be shielded. (4) Uneven distribution of compressed air. A wind deflector should be installed at the inlet of the pre-stretching box to make the wall of the blowing evenly corner too thin (1) improper molding process. The inflatable plug assisting process can be used instead. (2) The sheet is too thin. Thicker sheets should be used instead. (3) The sheet is unevenly heated. The heating system should be inspected so that the portion of the corner where the article will be formed should be made cooler. Before pressing, some cross lines can be drawn on the sheet to observe the flow of material during forming to adjust the heating temperature. (4) The mold temperature is uneven. It should be adjusted to be uniform.