We’ve all noticed that most plastic containers these days have a recycling symbol on them.
I’ve noticed that when a plastic container has a lid, and they are both marked for recycling, they almost never contain the same kind of plastic. A tub of Cool Whip, for instance, may be made of type 2, while its lid will be of type 4.
Anyone know why this is so?
-Van
Their performance requirements are different.
The tub needs to stand up under its own weight and the weight of its contents, and so it needs to be stiff and unyeilding.
However, the lid needs to be more supple so that it can be “stretched” across the rim of the tub and make a tight seal without cracking or ripping.
Different types of plastics meet these requirements, and they have different recycleable sorting numbers.