How Contamination Affects the Value of Industrial Plastic Scrap
Your company may generate a valuable industrial resin.
But if that resin is mixed with metal, cardboard, dirt, other polymers or general trash, its recycling value can change dramatically.
In industrial plastic recycling, what isn’t plastic can sometimes matter almost as much as what is.
Understanding contamination can help manufacturers protect scrap value, reduce rejected loads and build more efficient recycling programs.
What Is Plastic Scrap Contamination?
Contamination is any unwanted material mixed into the intended recycling stream.
That can include:
- Different polymers
- Metal
- Wood
- Cardboard
- Paper
- Dirt
- Oil
- Chemicals
- Food
- Moisture
- Labels
- Adhesives
- General trash
Some contamination is obvious.
Other contamination is much harder to detect.
HDPE mixed with polypropylene may simply look like plastic to an employee, but those polymers have different properties and cannot automatically be processed as one material.
Why Does Contamination Reduce Value?
A recycler’s customer isn’t buying garbage.
It is buying material with specifications.
If a recycler wants to produce consistent HDPE regrind, it needs reasonably consistent HDPE feedstock.
Contamination creates additional:
- Sorting
- Labor
- Processing
- Disposal
- Equipment risk
- Quality-control risk
Those costs affect the economics of the scrap.
Mixed Resins Are Contamination Too
This is one of the most important concepts for manufacturing employees.
Putting PP into an HDPE Gaylord isn’t necessarily better than putting the PP into the trash.
It may contaminate the HDPE stream.
Collection containers should therefore identify resin, not simply say:
PLASTIC RECYCLING
Use:
HDPE ONLY
or
PP RUNNERS ONLY
Specific instructions reduce mistakes.
Metal Can Create Serious Problems
Metal isn’t merely unwanted weight.
It can damage size-reduction equipment and create operational hazards.
Facilities should prevent bolts, fasteners, tools, machine components and other metal objects from entering plastic scrap streams.
Moisture and Outdoor Storage
Plastic itself may tolerate water.
The recycling process doesn’t necessarily benefit from it.
Outdoor storage can also introduce:
- Dirt
- Leaves
- Gravel
- Rainwater
- Other debris
Whenever possible, protect material from unnecessary exposure.
How to Prevent Plastic Scrap Contamination
Separate at the Source
Put collection containers where scrap is generated.
Label Containers Clearly
Specify resin and, where important, color.
Train Employees
Explain why separation matters rather than simply telling employees to recycle.
Don’t Use Recycling Gaylords for Trash
A half-empty scrap container can become an inviting garbage bin.
Make actual trash containers equally accessible.
Cover Material
Protect outdoor material where necessary.
Inspect Before Shipping
A quick visual inspection can catch obvious contamination before a problem becomes a rejected load.
Contamination Prevention Can Improve the Bottom Line
Consider a manufacturer producing 300,000 pounds of recyclable plastic scrap annually.
Even a small difference in material quality can become financially meaningful at that scale.
Better separation can potentially:
- Improve marketability
- Reduce sorting
- Reduce rejected material
- Improve consistency
- Reduce disposal
- Strengthen recycler relationships
This is why recycling quality should be treated as an operational KPI.
Need Help Evaluating a Plastic Scrap Stream?
Seraphim Plastics works with manufacturers to evaluate and recycle commercial quantities of post-industrial plastic.
If you’re unsure whether contamination is reducing the recyclability or potential value of your material, consult with Seraphim Plastics.
The easiest contamination to remove is the contamination that never enters the scrap stream.