By: Bozilla Corporation

My customer doesn’t like using any recycled material

Working with a Tier 1 supplier to a major OEM, there was a discussion with the molders on the floor, people molding the parts on the injection molding machine, and their personal experiences

Their experience with recycled resins is the inability to maintain a controlled injection molding process

Because they are responsible for the quality of the part they are molding, they make decisions (call an audible) and replace the recycled resin with a locally available equivalent virgin resin This protects them from producing unacceptable

Losing Control of the Process

Recycled plastic goes through several processes when it is reclaimed  In layman’s terms, it gets beaten up

Here is the rundown:

In the first phase of the plastic recycling process, the material goes through the injection molding process, which partially degrades the material (molecular weight reduction)  Then, it is potentially exposed to UV, temperature fluctuations, or chemicals, which contributes to the degradation process  Next, the plastic is ground up and typically cleaned with a thermal or chemical process, further degrading the material  Finally, the reclaimed plastic is ready to, again, be beaten up in the injection molding machine

Loss of injection molding process control

It is essential to know that the reclamation process breaks the polymer’s molecular structure down, making it lesser quality because the properties of that original polymer have been degraded  Recycled resin has a smaller molecular weight( length of chains) and varying viscosity, making it unpredictable  Virgin resin has molecular weight consistency/control with much less variation, giving it consistent properties

This lack of consistency, or better stated, lack of control of the recycled resin will affect the quality of your part

Do you see some reasons why you may reconsider using recycled plastic for your part?

Industry Response

Now, the response in the industry and all industries to using recycled materials is, when possible, to take a certain percentage of recycled material and blend it in with the virgin resin

However, it is essential to note that the percentage of added recycled material vs part quality is not a 1:1 ratio, eg, adding 20% of recycled resin does not equate to 20% loss of properties  For instance, you can test the recycled resin of 1 lot of material, and it may meet specs, but the next lot is completely different, thus knocking the process out of control  This lack of conformity