What happens when you accidentally put something in the recycling that isn’t meant to be recycled? Does it contaminate the entire batch? (side note: same question for Composting)

Question

I know that composting and recycling are fundamentally and scientifically different but my curiosity is the same.

In: Other

Answer 1

I worked in a prototype plastics recycling plant many, many years ago. They only recycled soda bottles that were made out of PET plastic.

The bales of crushed bottles were shredded, washed, and made into pellets that were sold to be eventually turned into new products like carpet fibers.

The main problem was separating the contaminants. This doesn’t just mean unwanted trash in the recycling stream, it actually included the labels and caps from the bottles themselves. At the time, there were still bottles made with aluminum caps so they could be separated out and sold for probably more than the plastic pellets. But the rest of the stuff was unwanted waste.

The biggest problem however was that a substantial percentage of the caps used a liner that was made out of PVC plastic. PVC does not melt at the same temperature as PET. It clogs up the machines that extrude the pellets and discolors the pellets when it burns.

I only worked there for a few months so I don’t know how (or if) they solved the PVC contamination problem. I don’t think currently manufactured bottles use PVC cap liners anymore so it’s probably not a problem like it was. Though older bottles could still easily find their way into recycling streams.