Compostable bags refer to a type of plastic film that can be degraded by microorganisms under natural environmental conditions. Bacteria, fungi and other microorganisms attack the plastic film. The growth of cells causes the polymer components to hydrolyze, ionize, or protonate the plastic membrane, which is mechanically damaged and split into oligomer fragments. Enzymes secreted by fungi or bacteria decompose or oxidize water-soluble polymers into water-soluble fragments, generating new small molecular compounds, until they are decomposed into CO2 and H20.
According to the degradation mechanism and damage form, degradable plastic bags can be divided into two types: fully compostable bags and additive degradable bags.
(1) The fully degradable bag is a plastic film composed of materials that can be completely decomposed by microorganisms. The substance is mainly derived from starch, cellulose, chitosan and other natural polysaccharide materials. Its degradation products are CO2 and H20, which can be completely absorbed by nature and will not cause secondary pollution to the environment. Its main types are PLA, PCL and so on. In addition, polyvinyl alcohol can also be completely degraded by water and microorganisms.
(2) Additive compostable bags are made by mixing natural or synthetic polymers with biodegradable properties, biodegradation accelerators, processing aids, etc. on the basis of general-purpose plastics that do not have biodegradable properties. Additive degradable bags are mainly composed of general-purpose plastics, starch, compatibilizers, self-oxidizing agents, and processing aids. Its typical type is polyethylene starch degradable bag.
Advantages of degradable packaging bags.
The degradable packaging bag uses biodegradable materials, which is environmentally friendly and non-toxic, and has zero pollution to the ecological environment. The use of one-time glue spraying effectively avoids secondary tearing and achieves a better one-time destruction effect. It is printed with environmentally friendly ink, which is non-toxic and harmless, and does not pollute the natural environment. It has good privacy, and has the characteristics of green, environmental protection, and pollution-free. It has the characteristics of elasticity, toughness and high temperature resistance. The degradable film can be made into a variety of packaging such as degradable garbage bags, degradable vest bags, and compostable food packaging bags and so on. It can also be printed on the degradable film to make a variety of products such as printing bags and degradable printing films. Nowadays, the agricultural film in many places requires the use of degradable agricultural film or mulch. It can be said that the degradable plastic film has a wide range of uses. The compostable bag can be used in various industries such as supermarket shopping, food and vegetables, daily portable packaging, fruit shops, express delivery industry, and catering industry and so on.