1, polystyrene foam, the largest amount. This is the white pollution and disposable lunch box mentioned before.

2. Polyurethane foam. There are many kinds of polyurethane foams, both soft and hard.

3. Rubber-based foams, such as foam tapes, are mostly EPDM and butyl rubber.

4. Polyethylene and polypropylene foams.

Bubbles are many small bubbles that get together. A dispersion system in which insoluble gases are dispersed in a liquid or molten solid. The extended meaning of a bubble is a metaphor for the apparent prosperity of something, but it is actually illusory and untrue.