The "white pollution" caused by plastic bags has always been an important environmental issue that countries around the world are concerned about. Since most of the plastic bags currently used by people are non-degradable, they will not decompose after being buried in the ground for hundreds of years, and therefore have had a great negative impact on the environment globally.
In some of the world’s most famous bays, corals on the sea’s bottom are covered with sunlight and are smothered by a large number of plastic bags floating on the sea. In Dhaka, the capital of Bangladesh, about 10 million plastic bags have been thrown away every day, and many of them have blocked the sewers, causing the floods in Bangladesh to become increasingly severe. In South Africa, plastic bags were thrown into the streets casually, and the number of them caused some residents to mistakenly think that it was snowing in the winter.
According to the statistics of the British statistics department, the British public now use 8 billion plastic bags every year. In some under-developed countries, the consumption of plastic bags can reach up to 100 million per day, which makes the development of eco-friendly plastic bags become The top priorities for governments and companies in various countries.
To this end, a British supermarket chain Co-op has recently developed a new type of plastic bag that can be completely degraded within 18 months. By the end of December this year, one-third of the shopping bags provided by the supermarket will be the new plastic bags. By mid-2000, the shopping bags provided by this supermarket will all be replaced with environmentally friendly plastic bags. The appearance, feel and tenacity of this new type of plastic bag are almost the same as the plastic bags currently in use, but they will be completely decomposed into water and a small part of carbon dioxide after one and a half years, and disappear in the air without a trace. This feature is very conducive to environmental protection.
Experts pointed out that the reason why the new type of plastic bag can be completely degraded in such a short time is because the developer added a harmless metal ion decomposer to the plastic bag and it will be used in the final process of the plastic bag processing. This disintegrant can be injected into the polyethylene mixture. In addition, by changing the content and ratio of metal ion decomposers, manufacturers can also determine the service life of plastic bags based on the user's different needs.
According to industry sources, ordinary plastic bags are difficult to degrade because they consist of large, inseparable molecular chains. In fact, the molecular weight of polyethylene, the main component of plastic bags, is as much as 15,000 times that of water molecules, and the strength of the connecting chains formed between polyethylene molecules is so great that it is extremely difficult to disassemble them.
The researchers who developed the new plastic bags stated that this technology is not a new invention but it was already available in the 1970s. It is only a technology that has not made a substantial breakthrough for decades. This time, the researchers added a cornstarch liquid in addition to the metal ion decomposer in polyethylene. This liquid can act to soften the polyethylene chain, making the metal ion decomposer more effective. However, at the same time, the addition of disintegrants and corn starch also led to a substantial increase in the production costs of plastic bags, which are said to have doubled the cost of ordinary plastic bags.
Environmentalists believe that the high cost of new plastic bags may become a major obstacle to restricting the widespread promotion of such environmentally friendly products. For example, supermarkets may charge a portion of the additional fees when they provide customers with such plastic bags. Cause customer dissatisfaction.
But in any case, this kind of green plastic bag will become an effective tool to solve the "white pollution". The development staff said that if consumers can quickly accept the new plastic bag, then they will also apply the same environmental protection technology to other Packaging, plastic packaging such as plastic foam, frozen foods, and packaging of fresh vegetables, fruits, and flowers.
Surveys show that two-thirds of the items people buy in supermarkets are packaged with plastic products. If these plastic products are all replaced with new ones that can be completely degraded, it will have significant and far-reaching significance in solving the pollution of plastic bags. .