The most common customer complaints about blister parts are "surface wrinkles" and "thin here and thick there":

1. Uneven heating: The infrared heating bricks are aging or the layout is unreasonable. The temperature difference between the board surfaces is too large. The soft areas collapse first, and the hard areas cannot be pulled, causing natural wrinkles. Uniform preheating is the first step.​

2. Insufficient vacuum or blocked pores: The vacuum pump power is not enough, the pores of the mold are blocked by material chips, the sheet cannot be sucked tightly, and the parts are suspended in the air to form wrinkles.

3. The pressing speed is too fast: The sheets are formed quickly before they are completely attached, and the air has no time to be discharged, leaving bubble-like unevenness.

4. The draft angle of the mold is not enough: the sides are almost vertical, the plate is overstretched at the corners, and the thickness is suddenly reduced or even torn.​

Corresponding solution: Calibrate the heating uniformity, clean the air holes regularly, slow down the molding pace, and leave sufficient draft angle in the mold. Long-term experience is summarized into standard data.

​​​​​These four types of problems often overlap: uneven heating and insufficient vacuum, wrinkling and uneven thickness will occur together. Therefore, when troubleshooting, you should change items one by one in the order of "temperature first, then vacuum, then rhythm" instead of moving multiple variables at the same time, otherwise it will be difficult to tell which one is the main cause.​