Home » Troubleshooting » Solve the warp of injection molded plastic parts

Solve the warp of injection molded plastic parts

BASF has high speed PBT grades using a nano structure additive. I don't expect this to solve the warpage, but it may allow you to control it throughout the production runs. This should reduce the plastic pressures in the cavity for less warp (fewer molecules means reduced crystalized shrinkage). Be sure to verify the mechanicals of the injection molded plastic meet customer requirements.

Other items to investigate:
1. Increase the venting of the plastic injection mold. From my experience in the connector industry, venting is the number one culprit for variations in plastic parts quality. I have had many injection mold makers tell me, the plastic injection mold can not be vented anymore. Then after another review of the injection mold, we manage to increase the venting. Sometimes the vents have no channels out to the atmosphere, ejector pins/blades are vent channels (is the injection mold maker greasing the ejectors, results in no venting) Sometimes, you may need to split an insert into several inserts as a way of increasing the venting. Vent the runners.
In the case of the beginning of a run, the holding fixtures have acceptable warpage. Then the warpage increases after 2 days. This may be an indicator the vents are plugging and need cleaning. Make sure to vent to channels before going to the atmosphere as a way to help maintain the venting condition. SPC part weight during the production as a measuring tool. You may discover that your processes are not under control to begin with.

2. Investigate the runner shapes and sizing for proper pressure drops. Try different style of gating. Investigate the melt flipper technology for large plastic parts to maintain melt temperature in the center of the flow. Multi-cavity? Cavities balanced?

3. Injection molding machine size or tonnage may be too large for the injection mold. Is the clamp pressure set too high? Excessive clamp pressures reduce the overall venting and cause damage to parting lines. The parting line vents may be non-existent afterwards.

4. Injection molding machine may not be capable of reaching the speeds needed to keep the pressures down.

Post a Comment:

    
Plz Calculate (5 + 2) =
(Your comment will show after approved.)

You may also like:

Featured Articles
Plastic Injection Molding Process ... Plastic Injection Molding Process SimulationThe propositions behind injection molding process simulation are very basic. First, that although our plastic materials and ...
Visit injection molding factory in ... Visit injection molding factory in China before closing the dealNot being in the injection molding industry, I was looking for tips on how to judge a company or factory on their capability or ...
Injection Mold Cooling Design Injection Mold Cooling DesignThe design of the injection mold cooling system is very important. The cooling time takes up 70% to 80% of injection molding ...
Plastic injection molding hot runner ... Plastic injection molding hot runner systemHot runner is a set of temperature control heating-device, installed in the plastic injection mold, it is part of the mold. A Hot ...
How to choose plastic injection mold ... How to choose plastic injection mold steel?Hardness and wear resistance Surface roughness, dimensional accuracy of plastic parts and injection mold life heavily rely on the ...