Finework injection mold

Finework injection mold


Home > News > FAQ >

What is the remedy if the injection molded parts have shrinkage marks?

Time:4/14/2023 4:47:59 PM View 80
What is the remedy if the injection molded parts have shrinkage marks?☛☛✍The possible causes of shrinkage marks in injection molded parts are:

(PS: As below will just be a sharing article for your reference. Tool designer and product designer must ensure based on injection simulation analysis results before it's tooled.)

▶ The melting temperature is either too high or too low.

▶ Insufficient plastic in the cavity.

▶ The surface contacting the plastic is overheated during the cooling stage.

▶ The runner is unreasonable and the gate section is too small.

▶ Whether the mold temperature is compatible with the plastic characteristics.

▶ The product structure is unreasonable (the reinforcement is too high or too thick, and the thickness is obviously different).

▶ The cooling effect is not good, and the product continues to shrink after demoulding.

▶ Adjust the temperature of the injection cylinder.

▶ Adjust the screw speed to get the correct screw surface speed.

▶ Increase the injection volume.

▶ Make sure to use the correct padding, increase the screw forward time, the injection pressure and speed.

▶ Check whether the stop valve is installed correctly, because abnormal operation will cause pressure loss.

▶Lower the mold surface temperature.

▶ Correct the flow channel to avoid excessive pressure loss. appropriately expand the section size according to actual needs.

▶The mold temperature is properly controlled according to the characteristics of the plastic used and the product structure.

▶ Improve the product structure if it's possible.

▶ Try to keep the product coolling enough.