Problem of brittleness / breakage in thin wall moulding

[chintu2525]

We are facing problems of breakage in thinwall food containers made from 65 mfi homopolymer pp.lid fitting ribs break on normal impact.can anyone suggest a solution

[brentb]

Copolymer PP or LOWer homopolymer!

KPM

brent

[JayDub]

Check that there is at least some radius at the base of the ribs - a sharp corner is a stress riser. Also watch your mold temperature - you don't want to freeze the plastic faster than it can crystallize.

[chintu2525]

Thanks.can any additive help

[rickbatey]

What are your process settings? You may be degrading the resin in the barrel due to residense time, improper screw geometry or compression ratio, too high back psi or screw rpm, or shear induced when filling the mold. Actual values will help root cause the issue.
Rick.