Board foam shrinks and deforms

Board foam shrinks and deforms

During the production process of XPS, EPS, and PET insulating foam boards, shrinkage and deformation of the foam boards are common issues we encounter. For this, we have provided corresponding solutions for different causes.

Possible reasons:

1. Insufficient foaming agent injection: Adjust the foaming agent injection amount according to the foam board parameters (Based on experience, it is usually because the foaming agent injection amount is too high, causing the cells to shrink and leading to warping and deformation of the extruded plastic board).

2. Melt temperature is too high: Adjust the melt temperature according to raw material parameters (if the temperature is too high, bubbles will burst and gas will escape).

3. The melt index of the raw material is too high, resulting in insufficient strength: Replace with master batch with a lower melt index (appropriately increase viscosity).

4. If the temperature of the left, right, or center of the mold is too high: Reduce the overall temperature of the mold.

5. If there is a situation where the foam board does not shrink in the middle but shrinks and deforms on both sides: The temperature on the left side and the right side of the mold is too high. Lower the temperature on both sides of the mold.