Everything you need to know about bioplastics
Bioplastics
"Bioplastics" means that all or part of them are made of organic natural substances, not from traditional petroleum. Many bioplastics are biodegradable. This is also one of the greatest advantages of bioplastics. There are three terms about bioplastics to describe "bio-based plastics", "biodegradable plastics" and "compostable plastics". Although these terms are somewhat similar, they should not be confused.
Bio-based plastic
This is a very broad term, which means that some or all plastics are extracted from plants. Starch and cellulose are the two most common renewable raw materials used to make bioplastics. These raw materials usually come from corn and sugar cane. Bio-based plastics are different from common petroleum-based plastics. Although many people think that all "bio-based" plastics are biodegradable, they are not.
Biodegradable plastics
Whether plastics come from natural substances or petroleum is a matter of whether plastics can be biodegraded (the process of microbial decomposition of materials under suitable conditions). Technically, all plastics are biodegradable. However, for practical purposes, only those materials that degrade in a short time (usually weeks to months) are considered biodegradable. Not all "bio-based" plastics are biodegradable. On the contrary, some petroleum-based plastics degrade faster than "bio-based" plastics under suitable conditions.
Compostable plastic
According to the definition of American Society for Materials and Testing, compostable plastics refer to plastics that can be biodecomposed in composting sites. These plastics can not be distinguished from other types of plastics in appearance, but they can be decomposed into carbon dioxide, water, inorganic compounds and biomass (biomass refers to various organisms formed by photosynthesis, including all animals, plants and microorganisms), and there are no toxic residues. There is no toxic residue, which is one of the distinguishing features between compostable plastics and biodegradable plastics. It should also be noted that some plastics can be composted in the home garden, while others need commercial composting (the temperature rises a lot, and the composting process happens faster).
Corn and sugar cane are the two most popular raw materials for producing bioplastics. Of course, there are many other options. For example, bioplastics are produced from banana peel, mango peel and potato processing waste, and used to develop new packaging. European Snickers candy bar packaging comes from bioplastics.
What are the benefits of bioplastics?
Generally speaking, the greatest advantage of bioplastics is less pollution to ecosystem and less carbon emission from energy. At present, the problems caused by landfill can be solved by increasing the use of bioplastics. However, not all bioplastics can be degraded in a short time. For example, some bio-based plastics will remain for decades if they are not handled properly. Bioplastics are also popular because they do not contain bisphenol A(BPA). You may have noticed that there are many products marked as BPA-free in the market, especially in the food storage and infant feeding industries. For example, the European Union has banned the use of BPA in baby bottles. At present, about the use of bisphenol A, most people are concerned that BPA will destroy human hormone secretion and related activities. Bioplastics provide an alternative to this problem. Some bioplastics produce lower greenhouse gases than petroleum-based plastics. For example, polylactic acid (PLA) is a kind of bioplastics, which can be produced from existing manufacturing equipment, so the manufacturing cost is more economical.
What are the disadvantages of bioplastics?
It is difficult for consumers to understand which plastic products are biodegradable, compostable or recyclable. For this reason, many bioplastics have not been properly treated ... Most cities do not have factories for sorting and recycling plastic products, so everything is finally thrown into landfills.
For example, cups made of bio-plastic PLA look like ordinary plastics, so consumers will throw them into recycling bins. In the recycling factory, because of the extra cost, PLA cups will not be classified and screened, and they are often treated together with PET products. However, PET plastic mixed with PLA can not be recycled, and eventually they will enter the landfill together. End the service life of both plastics.
If the bioplastics are discarded improperly, it will also affect the degradation effect and pollute the environment. For example, if biodegradable forks are put into a sealed landfill, they may not degrade at all. On the contrary, when there is moisture in the environment, anaerobic degradation (decomposition without oxygen) may also occur, thus generating methane and causing air pollution. There is an interesting disadvantage in using bioplastics for food storage. A chocolate master uses biological plastic bags to store her chocolate bars. Unfortunately, insects in the yard were attracted by the bag and ate it. Therefore, bioplastics are not suitable for food storage in some specific environments.