A cursory look at postindustrial plastic recycling suggests that it is a profitable enterprise. Comparing it to postconsumer plastic recycling can easily lead one to wonder why the industrial model isn’t applied to municipal recycling. But when you dig a little deeper, you discover that mechanical plastic recycling has its downsides. They are very real, and they explain why municipal recycling doesn’t work so well.
Tennessee is home to an industrial plastics recycler known as Seraphim Plastics. They have been buying and recycling industrial plastic scrap in seven states for many years. While they make good money doing what they do, Seraphim Plastics also understands why their process is hard to implement in a municipal setting.
Customers who sell their postindustrial plastic scrap to Seraphim Plastics sort the materials prior to pick up. When Seraphim Plastics’ truck arrives to pick up a load of plastic pallets, for example, that’s all they get. They do not have to sort and clean the load at their own facility.
It is just the opposite with municipal recycling. Because all sorts of recycled materials get thrown in together, they need to be sorted prior to being recycled. Sorting is labor intense. It is also expensive.
Adding to the sorting issue is the reality that consumers do not cooperate like they should. Municipal recyclers frequently find that the materials they pick up are mixed with trash, organic material, and other types of waste that only contaminate loads. Heavily contaminated loads often need to be rejected in full. There is just too much work involved in removing the contaminants.
When a municipal recycler chooses to decontaminate a load, doing so can get expensive. Food containers need to be washed out. Plastics contaminated with chemicals need to be cleaned with specialized solvents. If a load contains organic contaminants, they need to be removed manually.
Contamination isn’t an issue with postindustrial plastics. The previously cited example of plastic pallets is perfect. Pallets are not contaminated with organic waste. If there are chemical contaminants to deal with, customers clean the pallets before selling them to recyclers.
Mechanical recycling relies on using equipment like grinders and shredders to reduce plastic waste to smaller pieces. Grinders produce pallets while shredders produce plastic flakes. Both types of material can be melted down and added to virgin plastic to make new products.
Although mechanical recycling produces a regrind material manufactures are happy to buy, regrind doesn’t have the same strength as virgin plastic. This creates two problems:
- It Can’t Be Used Exclusively – In many applications, plastic regrind cannot be used exclusively as the only manufacturing material. It needs to be mixed with virgin plastic at a ratio that doesn’t significantly reduce the quality of the finished product.
- It Can’t Be Recycled Forever – Because mechanical recycling reduces integrity, even the best plastics cannot be recycled forever. At some point, they all reach end-of-life. Then they need to go to the landfill.
The one exception to this rule is PET. Its chemical structure and nature are such that PET can be recycled indefinitely. Maybe that’s why it’s the most recycled plastic in the world.
Mechanical recycling is a proven process that works extremely well for industrial plastic scrap. It doesn’t work so well for consumer plastics. In fact, mechanical recycling is a tough proposition in the consumer plastics environment. The first company to successfully adopt the industrial model to the consumer sector is going to make a killing from it – if it ever happens.