If your injection molding process is still out of control, shear heat could be the variable that is holding you back and killing your efficiency.
Here are 3 QUICK TIPS that can help when troubleshooting shear heat issues on molded parts to make sure you are getting the most out of your process.
The nozzle tip on the injection machine is the first place to look if you’re experiencing heat issues. Make sure your nozzle tip orifice is around 75-85% of the sprue bushing orifice. This could make a huge difference.
Make sure there is nothing hindering the flow of plastic through the runner system. You may need an overflow tab to reduce the chance of cold slugs getting into the gate areas and causing the material to shear even further. Remember there are ways to purge hot runners safely to prevent issues down the road.
You should again be approximately 75-85% of the nominal wall thickness to ensure good flow into the part. If the resin you are running is sensitive to jetting, you may want to bounce the material entering the gate off a wall or a sturdy boss to deflect flow.
If all else fails, check the water flow to the mold. Ensure you have enough cooling water to maintain an even temperature across the tool.
If you have any questions, please contact us directly and we'll help you work through your issue and improve productivity.