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rocky_555
20th April 2019, 04:44 AM
Hi, I am trying to mold thin wall container with PP random copolymer (for clarity) but I see waves in my finished item. I have checked and tried almost everything.
mold cooling, cooling timing, increase injection pressure, change material but seems that waves are not going away.

Also, random copolymer is soft, what can I mix to increase strength of finished product little bit without compromising clarity?

Horeki
23rd April 2019, 04:44 AM
Try changing screw RPM or augmenting injection speed. Another thing you should check is your temperature profiles, since you work with thin wall I assume your cycle it’s really fast and the resin stays less than 5 mins in the barrel so you can increase your middle and front temperatures a little without degrading the PP

This happened to me in the past with clarified PP but solved it augmenting screw RPM’s (120-150)and augmenting injection speed to 300mm/s.

Sadly I can’t advice you about your last question, since we inject thin wall containers with IML the label adds strength and rigidity to the container.