Injection molding materials are made from various plastics such as polystyrene, polycarbonate, polypropylene, polyamide and many more. Depending on the plastic Different technologies are used in recycling - grinding, shredding, regranulation, etc. .
Grinding is the most common processing method. However, there are some challenges. For example, depending on the grinding process, the dust content in the ground materials can have a detrimental effect on product quality in subsequent processing steps.. As a result, more and more users are convinced of the advantages of the regranulation process. The reasons for this are explained in the following blog.
A method for processing injection molding materials that contain glass fibers is repelletizing. Using this method has several advantages.
The following points highlight the advantages of repelletizing:
Grinders are often used to grind injection molding materials containing fiberglass. The problem with this method is that it produces fiberglass particles that are released into the air people breathe. This poses an enormous health and safety problem. To prevent this health risk, extraction systems need to be purchased. This, of course, means an additional cost for the processor.
Another disadvantage is that grinding often causes problems in the downstream process:
Regrind material has a different bulk density and pourability than recycled pellets.
If the two materials are combined and used in an injection molding machine, the mold filling characteristics will deteriorate. The reason for this is that the combination of components does not ensure effective mixing. The result is a higher number of rejects.
And if the regrind material contains metal parts, they can damage the mold during re-injection. The reason for this is that there is no safety filter in the grinder system.
Suction intake and transport are more difficult because of the dust content.