2020-11-29 2606
In the context of the global plastic ban, the highest demand is to replace disposable plastic with biodegradable plastics. In the average person, this is very reasonable and very feasible. Many plastic manufacturers can continue production if they change raw materials.
Degradable plastics are general names for photodegradable plastics and biodegradable plastics. The study of photodegradable plastics in developed countries began the 1970s, and its concept is relatively mature. Generally, degradable plastics are fully biodegradable starch-based biochemical synthetic plastic, which are better starch-based biodegradable materials. There are mainly polyhydroxyfatty acid esters (PHA) and polylactic acid (PLA). Degradable plastics seem to be environmentally friendly, but because of the properties of existing commonly used biodegradable plastics, biodegradable plastics have much more problems than ordinary plastics.
1, But the complete degradation of degradable plastics is conditional.
Not discarded in nature for 3 months, unconditional microorganisms are completely decomposed. The degradation of degradable plastics is conditional, and is usually biodegradable for 2 years at a continuous temperature of not less than 40℃. There is no place in the nature of the earth that has such environmental conditions, so this condition cannot be met. Then biodegradable plastics need to be recycled and compost to completely degrade. But only things of value can be effectively recycled. Generally, degradable plastics will be brittle after 6 months, lose the value of reuse, and there is no recycling value. If it cannot be recycled for compost treatment, biodegradable plastics cannot degrade naturally. Such biodegradable plastics can do far more environmental harm than disposable plastics.
2, Biodegradable plastics are also a disaster for plastic recycling work.
Because of the public lack of expertise, it is difficult to distinguish which of the waste plastics are biodegradable and which are ordinary plastics. Ordinary plastics can be recycled, while biodegradable plastics have no utilization value, and cannot be recycled. If ordinary plastic is mixed with biodegradable plastic, then ordinary recycled plastic cannot be reused, and then the recycling of ordinary plastic will be a disaster.
Because degradable plastic is not completely natural degradation, it has actually become one of the culprits of white pollution. Biodegradable plastics are also banned in the European Union from 3 July. Really naturally degradable environmentally friendly products should be molded fiber (pulp) products, molded fiber (pulp) products is the only viable alternative to part of the plastic products. For example, in the field of pulp molding tableware packaging, pulp molding industry packaging field is a very good substitute for many plastic products.
Previously, completely natural degradable molded fiber (pulp) products seemed to have a very small share in the face of powerful biodegradable plastics. However, molded fiber (pulp) products can be naturally degraded and recycled, which is a kind of environment-friendly product. With the deepening of degradable plastic and more and more application demonstration of molded fiber (pulp) products, molded fiber (pulp) products will play a greater role in the international plastic ban action.
