July 14, 2022

In-house scrap for injection molding

blog aco mold

Some suggestions for effectively using in-house scrap, whether for injection molding, extrusion, vacuum forming (which generates a lot of offcuts).

1. For companies producing multiple products, a good strategy would be to use up in-house scrap in components/molding with lesser service severity requirements molded from the same polymer. e.g. scrap from moldings of high aesthetic requirements could be used up in molding where aesthetics are not so important/darker in color. Load bearing molding regrind could be used up in non-load bearing items.
Sometimes it is safer to use up all the regrind in a dark, non-critical item if such an item is in the manufacturing mix in sufficient numbers to be a scrap sink.

2. For processes generating a lot of scrap like vacuum forming, it is of paramount importance to keep the offcuts clean. Plastics attract dust like magnets because of static electricity and dust coated offcut quickly degenerates cash into useless warehouse ballast. So grind up the offcuts and store in sealed bags ASAP. When re-extruding the scrap (which may sometimes require 30-40% blending with prime) be sure to compensate the additives which are likely to be depleted in the primary processing. These will depend on the polymer being processed, and are typically antioxidants, stabilizers, and most important, impact modifiers. If the impact modifier is correctly chosen the sheets produced may have better properties than the parent sheets. Of course all this is best done if vacuum forming shops have their captive sheet extrusion line, but can also be followed by those who vendor out the offcut conversion.

Related Blogs

blog aco mold
How to choose the hot runner for injection mold?

Hot runner technology, with its advantages of low scrap rats, shorter the molding cycle times, has become an important direction of development of plastic injection molding process. In western countries, …

blog aco mold
Running mold filling simulation for the best outcome

Spend the money on mold filling simulation analysis and allow the mold flow analyst to do the same things that create the variation, analyzing potential variables and review the results …

blog injection molding
Does your company make a right tooling buying decision?

More companies are putting decisions in the hands of purchasing with little or no regards to engineering (engineers and toolmakers are becoming the Red Haired Bastard Step Children in the …

blog aco mold
Injection Mold Sprue and Runner System

The sprue and runner system is the conduit that connects the machine nozzle to the cavities. During the injection phase of the molding cycle, the molten material flows through the …

Tell us your request right now and contact us today about getting started on your next project together!

Email:
sales@acomold.com

Or Fill Out The Contact Form Below:

Support Your Business with Better Molding Solution

Contact Info
Copyright © 2023, ACO Mold. Terms of Service and Privacy Policy. All rights reserved.  Powered by ACO MOLD.
1 1.png

Join Our Network

Please email to sales@acomold.com
or fill out the contact form below: