The hottest plastic packaging waste and recycling

2022-08-16
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Plastic packaging waste and recycling value-added

I. the harm of plastic packaging and waste to human beings

the harm of plastic packaging waste to human body has been gradually known. The research shows that plastic packaging, especially as the packaging of food or food related items, is polymerized by polymers, many of which contain chlorine and benzene, so it is inevitable to produce harmful gases, which will cause the taste of the packaging contents to change, and even some carcinogens will penetrate into the food, causing consumers to suffer

the pollution caused by plastic packaging waste cannot be ignored. At present, except for a few people being collected and used, most of the plastic waste is burned and buried, and some are dumped into rivers, lakes and seas and discarded at will. It is estimated that paper can decay in seven days, while plastic can survive for 3-00-400 years. A large number of waste plastics cover the soil with garbage landfills and stay in the soil, damaging the permeability of the soil, reducing the water storage capacity of the soil, affecting the absorption of water and nutrients by crops, resulting in crop production reduction. Plastic waste poured into rivers, lakes and seas, once eaten by aquatic organisms, will cause a large number of deaths. Incineration treatment will also cause secondary air pollution, which is harmful to human beings

to sum up, waste plastics have become a major public hazard to the environment and human beings. Therefore, the advantages of plastic packaging are weakening day by day, and the voice of eliminating plastic packaging is getting higher and higher in many countries

II. International countermeasures for plastic packaging waste

1. Use legal means to prohibit and restrict plastic packaging production and strengthen recycling. For example, a bill passed by Italy prohibits the use of non biodegradable plastic sundries in Italy. For another example, Japan has long formulated the treatment and public health law, which enables the vast majority of packaging waste to be recycled and controls the use of non recyclable plastics. The Netherlands has also promulgated relevant laws and regulations in this regard. In addition, the United States, Denmark, the European Union and other countries and regions have also formulated relevant laws and regulations

2. Gradually eliminate plastic packaging and use paper packaging for production, but if the tension machine and computer fail to connect, the tension experiment cannot be carried out. It is particularly prominent in food packaging. For example, the U.S. government has made strict regulations on food packaging, requiring that handbag packaging must be feasible to decompose plastic packaging on the spot. DuPont also developed a new paper pocket called tyrek; Watanabe paper company of Japan immediately made a new type of handbag with its materials, which was used to pack milk, dairy products, feed and other foods. Switzerland and Germany also said they would phase out plastic packaging. In the United States, 50% of the packaging has been changed to new paper bag packaging

3. We are stepping up the research and promotion of degradable plastics that are harmless to the environment and human beings. There are two kinds of degradable plastics, one is microbiological degradation, and the other is photodegradation. The principle of its degradation is to break the plastic polymer chain and finally decompose it into carbon dioxide through the action of microorganisms in soil or ultraviolet rays in sunlight without the need of manpower through the cutting method and rolling direction of soil and sample, so as to degrade and eliminate the plastic in a short time. The earliest research on degradable plastics began in the 1950s. At present, there are three main methods to produce degradable plastics, namely, the use of microorganisms, biomass energy and chemical synthesis

III. measures that China should take in the face of plastic packaging

at present, it is urgent to research and develop degradable plastics and apply them. From now on, we should step up the research and application of degradable plastics in a planned and step-by-step manner. According to the research, the technology of biodegradable plastics is relatively mature, and the technical difficulty is lower than that of photodegradation technology. Therefore, priority should be given to research and development. At the same time, we should actively seek alternatives to plastic packaging in order to stabilize the competitive position of China's exports in the world

in the transitional period, it is very necessary to seek the collection, utilization and value-added of plastic packaging waste. First of all, traditional plastic packaging should be replaced, while other plastic products are still inextricable, and the demand will increase. In this case, it will be a valuable work to seek the comprehensive utilization of plastics and plastic waste to turn waste into treasure and turn harm into benefit

plastic raw materials in China are very privately owned, with large imports and high prices. Moreover, China's population accounts for 1/4 of the world's total population, while the output of plastic products is only a little more than 2% of the world's total output. The per capita consumption of plastic products in China is far lower than that in developed countries, which is 150-200kg, and also lower than the world's per capita consumption of 31kg. In the new century, China still needs to import more than 1 million tons of plastic raw materials every year. It can be seen that China is very short of plastic raw materials. If waste plastics are recycled and used, a lot of expenses can be saved. If one ton of polyethylene is recycled and reused, 1.1 tons of ethylene raw materials or 3 tons of gasoline can be saved. Therefore, it is necessary to recycle plastic packaging for recycling

there is great potential for recycling and utilizing waste plastics and their packaging in China. The recycling rate of plastic packaging waste is less than 10% in China, while it has reached 26% in Japan. It can be seen that recycling plastics has great potential

recycling plastics can not only reduce production costs, but also help reduce environmental pollution. In recent years, the high price of plastic raw materials has made the reuse of plastic waste more important. Especially in developed countries, many scientists and departments are studying the ways of recycling and value-added

IV. ways and methods of recycling

through research, the main uses are as follows: 1) production and manufacturing of building materials; 2) Manufacturing daily necessities; 3) Made into chemical products; 4) Made into gasoline, diesel, etc

1. building materials. Building materials made from waste plastics are mainly made from waste PVC and polystyrene. This plastic building material has the advantages of moisture-proof, anti-corrosion, sound insulation and non deterioration. It can be used to make river bank and lakeside revetments, doors and windows, wall partitions, etc., which can replace wood and cement. In this regard, compared with some foreign countries, we have a big gap. Therefore, the domestic market potential of plastic building materials is great. For example, wood plastic raw materials and processing methods. Its raw materials are mainly thermoplastic and wood. You must adjust multiple parameter powders at one time. It is formed by high-temperature mixing and high-pressure molding. Its texture is first-class and superior to wood, and it has a wide range of uses

2. Daily necessities. Making stools, dining tables, sleeping labels, conveying tables, livestock and poultry barns with waste plastics is obtained by melting, extruding and treating different kinds of mixed plastic packaging wastes. Some European countries have also made special mechanical equipment for this research

3. chemical products. There are many ways to produce chemical products from waste plastics. Four preparation methods and applications of sealant, dry paint, adhesive and polyethylene wax for machinery are listed in Table 1. It is worth mentioning that polyethylene wax is a chemical product with high quality, which is in short supply in the domestic market and mainly depends on imports. It is widely used

4. fuel. Many countries and regions have carried out a lot of exploratory research in this area, and have made great progress. Taiwan, Japan and other regions and countries have developed the process of extracting fuel and other energy products from waste plastics, and immediately took emergency measures

Table 1 list of chemical products made from waste plastics

Product Name waste plastic variety preparation method main uses

Mechanical sealant waste polystyrene is added with a certain amount of methyl benzene and dibutyl phthalate, heated in the reactor, stirred and cooled, and the oil and water seals in the machine are sealed

dry paint waste polyethylene is added with rosin, glycerin oxidation mirror, xylene, etc., and put into the reactor for coloring, dispersion, grinding The purpose of sieving is the same as that of ordinary dry paint

adhesive waste polystyrene is mixed, dissolved and stirred with ethyl acetate and methyl acetate to obtain carpet, gravel floor, etc.

polyethylene wax is easy to clean waste plastic film, plate, pipe, plastic barrel and other polyethylene waste plastics, which undergo depolymerization reaction under specific temperature, time and pressure. Plastic additives, paint, ink and coating base materials. Wax absorbers, moisture-proof agents, lubricants, antioxidants, etc.

the method and process in Japan is to use thermal transformation, that is, use a catalytic reductant somewhere to reverse the catalytic process of three common waste plastics to torch plastics from oil, so as to obtain fuel oil. One kilogram of waste plastics can be treated to obtain half a liter of gasoline, half a liter of kerosene and diesel. The cost of converting a ton of waste plastic is about $230

Taiwan's method is thermal decomposition method, that is, in a sealed high-pressure cracking reaction furnace, the waste plastic is heated to convert the high molecular weight compounds that make up the plastic into low molecular weight compounds, and then the oil and steam with different molecular weights are recycled respectively through the oil vapor separation tower to obtain gasoline, diesel, solvent oil, heavy oil, liquefied gas and other products. The recovery rate is about 65%. 3000 tons of waste plastic can be lifted into 2000 tons of high-purity gasoline

with the progress and development of science and technology, more advanced and applicable methods and processes will continue to appear and be adopted

v. conclusion

to sum up, the traditional plastic packaging will be replaced by a new type of biodegradable plastic packaging or paper packaging. Based on China's national conditions and strength, the recycling and utilization of plastic packaging waste will bring more social and economic benefits. Therefore, it is very feasible and necessary

Author: Wang Min

reprinted from: China's packaging industry

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