In our living environment, plastics are widely used, and while plastic bags made of plastics bring great convenience to human beings, they also seriously pollute our living environment. Non-degradable plastic bags are not easy to degrade. Even if they are buried in the ground, they will not rot for a hundred years. Not only will it affect the quality of the soil, but if it is thrown into the sea and let marine animals eat it by mistake, it will cause them to die. The "white pollution" formed by plastic waste has become a headache for people.

Everyone knows that traditional plastics can be recycled and reused, such as plastic bags, mineral water bottles, takeaway boxes, and disposable paper cups. Are these used plastic products directly discarded by us and integrated with nature, or are they recycled? In other ways? As a traditional plastic, it is a plastic raw material that can be re-obtained after processing waste plastics through physical or chemical methods such as pretreatment, melt granulation, and modification. It is the reuse of plastics. Most of the plastic bags currently on the market are non-degradable thermoplastics that can be recycled and reused.

There are more than 160 kinds of traditional plastics commonly used at present, and biodegradable materials are one of them, and the current amount is relatively small.
At present, more biodegradable materials are PLA, that is, polylactic acid products, which mainly come from the fermentation of agricultural products.

PLA is a biodegradable material that can be completely degraded into low-molecular compounds under the action of natural microorganisms such as bacteria, bacteria and algae. The principle of PLA degradation is due to the unique molecular structure. PLA biodegradable materials are different from traditional plastic materials. After a certain period of time or in a slightly harsh environment, PLA biodegradable materials will become slag. Even if they are discarded in the natural environment, they will also degrade. Oxidation continues to carbon dioxide and water, which is the basic degradation process. This kind of material can be completely degraded, and the way to deal with it is to just throw it in the ground, so landfill or something is fine. From this point of view, the recycling of biodegradable materials is a very troublesome thing. The problem is that the cost after recycling may be higher than that of new materials, which is why this material cannot be recycled.

In addition to PLA biodegradable materials, there are some other degradable plastics. The degradation principles are not all chemical or biochemical degradation methods. Some are degraded by ultraviolet light, which is difficult to recycle. For example, photosensitizers are added to plastics, which can gradually decompose plastics under sunlight; water-absorbing substances are added to plastics, which can be dissolved in water after use. They are mainly used for medical and sanitary appliances for easy destruction and Disinfected water-soluble materials; such degradable materials will not be reused, and there is no way to recycle them!

Through the above analysis, it is not difficult to understand that as biodegradable materials and products, when they are discarded to the outside world, they are generally different from traditional plastics that can be recycled, and their recycling is worthless. However, if there are scraps and waste left in the production process, the waste materials can be processed by physical or chemical methods such as pretreatment, melt granulation, and modification to obtain raw materials again, which is the reuse of degraded materials.