Fracture in the HDPE cover

Dear Oleg,

Very glad to write to you.
Have you solved your problem? if not, maybe our good guy---Joe(project manager) can help you, just pls contact us at below information, thanks:

My Email: Joan@wellhope-mould.com
My Tel: 0086-755-27419595
My Fax: 0086-755-27149507
Website; www.wellhope-mould.com

Optimize the material and the injection process.
1.did you using recyle material and mixing rate
2.Optimize drying process
3.Injection process, melt temperature/melt flow/Injection speed/back pressure etc.

Hope will hopeful for you.

Steven
info@lctooling.com

Oleg

Tell us the outcome? Did yo fix it? What did you do?
This forum is all about information sharing.

Bill

Bill
Thank you very much for the answer.
Indeed i think that the problem was with mold temperature controller.
Next week i'm going to run several experiments were i will try to simulate such behavior.
Regards
Oleg

Oleg

You are describing micro fracturing at the gate due to stress relief. Possible causes:

Packing with the Fill portion of the cycle
Over Packing generally
Not using the resin supplier's recommended mold temperature.
Not having the material in the middle of the melt point range recommended by the resin supplier.

The generic cause of this is somebody cooling things down and trying to get a faster cycle. Plastic has to melt and cool according to the laws of physics. While you can cold flow HDPE, the only thing you really do is stress the heck out of it and squash it into the mold. It's not nice to fool Mother Nature.

The cracks are the result of somebody trying to do better and ignoring the basics of molding

Hope this helps

Bill