Defect guide · Dimensional stability

How to prevent warpage in large PDCPD parts

Large PDCPD panels combine a big surface area with an exothermic reaction, so warpage is a real risk. Dimensional stability comes from thermal control, mold design and careful handling after demolding.

1. Keep the mold temperature uniform

Temperature differences across the cavity make areas polymerize at different rates and build internal stress. A uniform thermal field keeps early-curing areas from pulling against late-curing ones.

2. Give the part room to release

Draft: where the part wraps around the core, use enough draft so it releases cleanly instead of being dragged.
Undercuts: plan the ejection direction and path. Where possible, design undercut features that flex slightly during removal without exceeding the material's yield point.

3. Even out wall thickness

Thick sections hold heat longer and shrink more than thin ones. Work with the product designer to make gradual transitions; it prevents the bowing common in large flat panels.

4. Demold carefully

Sequence: clear the flash, runner and gate first, so scrap does not anchor the part during the main lift.
Two operators: lift oversized parts with two people, vertically and evenly. Uneven force on a warm part leaves a permanent twist.

5. Use shaping fixtures

PDCPD keeps cross-linking for a short time after demolding. Place the part straight into a cooling fixture that holds the CAD shape until it has cooled and the reaction is complete. For tight tolerances on large parts, this is the most effective step.