There are also plastic wastes that are "hard to understand" and black plastic trays used by supermarkets to contain fresh meat. However, like the chewing gum packaging box, the potato chips bag is also a composite material. Environmental plastic materials cannot be purified into plastic recycled materials, but can only be buried in landfills. The black plastic disc was deliberately used, but the cost was that the sorter was disturbed by the melanin, and the plastic component of the tray could not be discerned. As a result, it was treated as general garbage. One of the eco-friendly plastic materials is a plastic bag and an edible magnetic additive made of phthalate and iron oxide. It is used to insulate, block, and prevent moisture, and keep food fresh. In addition, scientists have succeeded in making films from milk for packaging foods, but they can only isolate air and do not block light. It is a matter of life to try to “mold” and increase awareness of recycling.