Do biodegradable plastic bags have a shelf life? | ||
Release time:2021-04-22 / Browse:13743 | ||
Biodegradable plastic bags are biodegradable. When customizing biodegradable plastic bags, customers generally worry about whether the biodegradable plastic bags are degradable and have a shelf life? Can the biodegradable bags that have passed the shelf life continue to be used? And other related issues. Biodegradable shopping bag manufacturers come to answer. The biodegradable plastic bag material is composed of PLA (polylactic acid) and PBAT (polyadipate), which are recognized as environmentally friendly materials, harmless and environmentally friendly products. Under the conditions of compost degradation, the biodegradable plastic bags can be completely biodegraded within 180 days. The products of degradation are carbon dioxide and water, which directly enter the soil and are absorbed by plants, return to the soil, or enter the general environment and can be degraded. Pollution of the environment is truly derived from nature and attributed to nature. The use of biodegradable plastic bags greatly reduces the pollution of plastic products to the environment, and is truly environmentally friendly, healthy and sanitary, and can be used with confidence. Biodegradable shopping bag The required degradation time of biodegradable plastic bags is related to the environment. In the general daily environment, even if the time exceeds six to nine months, it will not immediately decompose and disappear, but the biological appearance remains unchanged. The physical properties of the degradation bag begin to change, and the strength and toughness gradually deteriorate over time, which are all signs of degradation. Biodegradable plastic bags cannot be stocked in large quantities and can only be purchased in moderate quantities. The storage requirements for storage are to keep them clean, dry, and not exposed to direct sunlight, and pay attention to the first-in-first-out storage management principle. Therefore, for biodegradable plastic bags, there is a contradiction in that it is impossible to require fast degradability and long storage time. Biodegradable plastic bags can be degraded into carbon dioxide and water for 180 days under natural or industrial composting conditions without pollution to the natural environment. The white pollution caused by plastic bags has become more and more serious and has been highly valued. The country has issued a new ban on plastics. Biodegradable plastic bags have become the choice to solve the white pollution problem and have become a substitute for traditional plastic bags. Although biodegradable plastic bags are not yet popular and the cost is still relatively high, professional flexible packaging manufacturer Shunxingyuan Packaging believes that it is better to use biodegradable plastic bags, which are environmentally friendly and have the practicability of traditional plastic bags. The degradable plastic bag refers to a plastic bag whose performance can meet the requirements of use performance, and the performance will not change during the storage period, but after use, it can be degraded into environmentally harmless substances under natural environmental conditions. Degradable plastic bags have their advantages in performance, practicability, degradability, and safety. In terms of performance, biodegradable plastic bags can meet or exceed the performance of traditional plastics in certain specific areas; in terms of practicality, biodegradable plastic bags have similar application performance and hygienic performance to similar traditional plastic bags; in terms of degradability, After the degradable plastic bag is used, it can be degraded quickly in the natural environment (specific microorganisms, temperature, humidity), and become fragments or non-toxic gases that are easily used by the environment, reducing the impact on the environment; in terms of safety, The substances produced or remaining in the degradation process of degradable plastic bags are harmless to the environment and will not affect the survival of humans and other organisms. The current major obstacle to replacing traditional plastic bags is also the disadvantage of biodegradable plastics in that their production costs are higher than similar traditional plastic bags or recycled plastic bags. Therefore, degradable plastic bags have alternative advantages in applications such as packaging, agricultural film, etc., which have a short use time, are difficult to recycle and separate, have low performance requirements, and have high impurity content requirements. Materials used in biodegradable plastic bags PLA: It is one of the common degradable plastics. It is a polymer polymerized with lactic acid as the main raw material. The PLA production process is pollution-free, and the product can be biodegradable. The used PLA can be composted and degraded into carbon dioxide and water at a temperature higher than 55°C or under the action of oxygen and microorganisms, realizing the material circulation in nature. Have an impact on the environment. At present, the production of polylactic acid mainly adopts lactide ring-opening polymerization process to first dehydrate lactic acid to form oligomers, then depolymerize to form lactide, and then ring-opening polymerization to form polylactic acid. PLA also has reliable biological safety, biodegradability, good mechanical properties and easy processing. It is widely used in packaging, textile industry, agricultural film and biomedical polymers and other industries. The disadvantage of PLA is that the degradation conditions are relatively harsh. However, due to the relatively low cost of PLA in biodegradable plastics, the consumption of PLA ranks in the forefront. PBS: It is formed by condensation polymerization of succinic acid and 1,4-butanediol. The raw material source is petroleum or biological resource fermentation. PBS is easily decomposed into carbon dioxide and water by a variety of microorganisms or enzymes in nature, and has good biocompatibility and bioabsorbability, and good heat resistance. PBS can be used in the fields of packaging film, tableware, foam packaging materials, daily necessities bottles, medicine bottles, agricultural films, pesticides and fertilizer slow-release materials. Due to the limited raw materials of succinic acid in our country, the derivatives of PBS, PBAT and PBSA, have been born, and their performance is basically similar to that of PBS, but the processing performance is not as good as PBS. PBAT: It is a thermoplastic degradable plastic. It generally uses aliphatic acid and butanediol as raw materials and is produced by petrochemical or biological fermentation. It has good ductility and elongation at break, as well as good heat resistance and Impact performance. Because PBAT has good film-forming properties and is easy to blow film, it is widely used in the fields of disposable packaging film and agricultural film. In addition, PBAT also has excellent biodegradability, and it is one of the degradable materials that are very active in the research of degradable plastics and are used in the market. PHA: PHAs degradable plastics include polyhydroxyalkanoate (PHA), poly-3-hydroxybutyrate (PHB), copolymer of 3-hydroxybutyrate and 3-hydroxyvalerate (PHBV) and 3- Copolymer of hydroxybutyrate and 3-hydroxyhexanoate (PHBH). PHAs degradable plastics are the products of bacteria when the growth conditions are unbalanced. Among many degradable plastics, the degradation method of PHA is special. After use, PHA can be completely degraded into β-hydroxybutyric acid, carbon dioxide and water in the body. PHAs degradable plastics have high heat distortion temperature and good biocompatibility, but they have narrow processing temperature range, poor thermal stability, high brittleness, and unstable production quality. They can be used for disposables, medical equipment, surgical gowns, packaging bags, and Compost bags, medical sutures, repair devices, bandages, orthopedic needles, anti-adhesion membranes and stents. In addition to PLA, PBAT and PHA, starch-based plastics (also known as starch compounds or starch mixtures) are used in Western Europe. Starch-based plastic is a blend of modified starch and degradable polyester (such as PLA/PBAT/PBS/PHA, etc.), which can be completely biodegradable, compostable, and has no environmental pollution. Although starch-based plastics are cheap, they have poor service life, mechanical properties, and printing performance. | ||
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