Which Types of Plastics Can Be Recycled?

Plastic recycling refers to the use of a certain recycling process to recycle waste plastic to achieve the purpose of turning waste into treasure. At present, China's waste plastics are mainly plastic films, plastic wires and woven products, foam plastics, plastic packaging boxes and containers, daily plastic products, plastic bags and agricultural mulch films. ^[1]

With the increasing consumption of plastic products, waste plastics are also increasing. In addition, the annual consumption of automotive plastics in China has reached 400,000 tons, and the annual consumption of plastics for electronic appliances and home appliances has reached more than 1 million tons. These products have become one of the important sources of waste plastics after they are scrapped. It is understood that domestic waste plastics reached about 11 million tons in 2004. If these waste plastics are stored, transported, and processed, the waste plastics materials used for processing and post-processing are improper, which will certainly damage the environment and endanger people's health.

Decompose plastic in the sun

In order to facilitate the recycling of plastics, the Society of the Plastics Industry, Inc., USA proposed a labeling system that uses plastic types to classify: "Resin Identification Code" (often translated as "plastics Material code "or" plastic code "). Recyclable plastic containers will have a triangular label surrounded by three arrows. The label will indicate the type of plastic.

China National Standard Packaging Recycling Mark (GB18455-2010) stipulates that plastic packaging products or plastic containers with a volume / volume exceeding 100 ml must be marked with a plastic recycling label:

Abbreviated Name Purpose

PET polyethylene terephthalate, also commonly known as polyester, is commonly found in PET bottles.

HDPE is commonly used in lotion containers, milk bottles, and supermarket plastic bags.

PVC polyvinyl chloride is commonly used in pipes, outdoor furniture, and raincoats.

LDPE low density polyethylene is commonly found in the tube packaging of toothpaste or face wash.

PP polypropylene is commonly found in bottle caps, straws, and microwave food boxes.

PS polystyrene is classified as unexpanded or expanded. Non-foaming is Polyurethane, which is commonly found in some beverage (such as Yiliduo) containers; foamed foam is commonly known as styrofoam, which is commonly used in packaging pellets, disposable insulation plastic cups, frozen meat containers, and lunch boxes.

Other recyclable plastic products include polymethyl methacrylate (PMMA), polycarbonate (PC), polylactic acid (PLA), nylon (Nylon) and glass steel (FRP), and biaxially stretched polylactic acid film (BOPLA) Wait.

(1) Mechanical method recycling Mechanical method recycling of electronic waste plastic is suitable for places where large waste can be generated, which has a stable supply source, and where the collection point is close to dismantling manufacturers, materials processing and potential product users. ^[1]

With the large-scale application of plastics, China's plastic recycling industry market has gradually prospered since the beginning of the 21st century. Small and medium-sized enterprises such as Yongquan have emerged, and investment has been active. It is transforming and is developing into an environmentally-friendly industrial economy with clustering of recycling and processing, intensive market transactions, and a direction driven entirely by market demand and price. ^[2]

At present, there are tens of thousands of plastic recycling companies in China, with recycling outlets all over the country, and a large number of recycled plastic recycling trading markets and processing centers have been formed, mainly distributed in Guangdong, Zhejiang, Jiangsu, Fujian, Shandong, Hebei, Developed provinces of Henan, Anhui, Liaoning and other plastics processing industries. Among them, Yuyao, Ningbo, Dongyang, Cixi, and Taizhou in Zhejiang; Nanhai, Dongguan, Shunde, and Shantou in Guangdong; Xinghua, Changzhou, Taicang, Lianyungang, and Xuzhou in Jiangsu; Wen'an, Baoding, Xiongxian, and Yutian in Hebei; Laizhou, Zhangqiu, Shandong, Linyi; Henan Anyang, Changge, Luohe; Anhui Wuhe and other places, the scale of recycling, processing, and operation of recycled plastics is getting larger and larger, with annual transactions mostly ranging from several hundred million to several billion yuan, showing a booming trend. There are a large number of similar processing and trading centers around major cities around the country, such as Beijing, Shanghai, Tianjin, Chongqing, Guangzhou, Wuhan, Nanjing, Hefei, Xi'an, Taiyuan, Kunming, Chengdu, Shenyang, and Urumqi. ^[1]

The number of companies and personnel engaged in the recycling and processing of recycled plastics is huge and growing steadily, mainly by self-employed and farmers, and there are some investors in other industries. The plastic recycling industry provides a channel for rural economic growth, employment of rural surplus labor, and increased income. It has made great contributions to resource recycling and environmental protection, and is an important part of the environmental protection industry.

Recycled plastics are different types of plastics that exist based on their recycling value after the end of their useful life. Almost all thermoplastics have recycling value. Recycled plastics are produced in the production of synthetic resins, in the production and processing of plastic products and semi-finished products, in the process of plastic logistics and after consumer use. Generally, what is produced in the process of synthesis and processing is called pre-consumer plastic; what is produced after distribution, consumption and use is called post-consumer plastic. Before consumption, the amount of plastic produced is small, the quality is stable, and the recycling value is large. Generally, it is properly handled in the production process and can be completely reused. What we call recycled plastic generally refers to recyclable plastic products that have lost their use value after consumption and can be recycled. After recycling, concentration, classification, and scientific and reasonable disposal of plastics, they can obtain recycling value and realize recycling. Some of the imported waste plastics are pre-consumer plastics with good quality and high value. As a renewable raw material, a large number of imports should be encouraged. ^[2]

The major types of recycled plastic sources are plastic films (including plastic packaging bags and agricultural films), plastic wires and woven products, foam plastic products, plastic packaging boxes and containers, cable coverings and various daily sundries, sports entertainment, Plastic products for daily use such as health care, of which plastic products such as films, foams, packaging boxes and containers, woven, sheet materials are mainly used for plastic packaging. In addition, there are some other plastic packaging products (such as plastic trays), agricultural plastic products (such as agricultural plastic water-saving equipment), and decorative plastic products have higher scrap rates. ^[2]

Consumption of plastic packaging was 6.344 million tons in 2004 and more than 7 million tons in 2005. It is estimated that at least 80% was discarded within one year, and is the main source of recycled plastic. This is similar to foreign countries. For example, the amount of plastic packaging recycled in the UK in 2001 was 91.2% of the total plastic recycling. In addition, there are some recycling values that are of little value or high recycling cost and are difficult to dispose, such as plastic composites, ultra-thin packaging materials, mulch films, disposable plastic products, etc., and the impact on the environment cannot be ignored.

However, structural plastic building materials such as plastic pipe fittings, profiled materials, reinforced anti-leakage geotechnical materials (including waterproof coiled materials) have increased in use in recent years, and have a longer actual service life. So this part of the waste is not large. ^[2]

Household appliances are calculated based on a normal service life of 10-15 years. The average number of TVs to be scrapped is more than 5 million per year, the average number of washing machines is 5 million per year, and the number of refrigerators is about 4 million per year. Therefore, China will eliminate more than 15 million scraps every year. Home appliances. In recent years, the replacement of electronic communication equipment such as computers, mobile phones, VCDs, DVDs, records, and compact discs has accelerated, and the number of scraps has increased sharply each year, which has brought about serious environmental problems.

Plastic is an important part of home appliances. According to the ratio in Table 4, the annual amount of renewable plastics generated is at least 150,000 tons. If you consider the amount of renewable plastics in scrapped electronic communication equipment, the number is about 200,000. Ton. The main components of these recycled plastics are polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), ABS, etc., which have greater recycling value; while some thermosetting plastics, foamed polyurethane, and glass fiber reinforced plastics are Relatively difficult to recycle. ^[2]

Disposing of recycled plastics reasonably in the process of recycling used appliances is one of its important links. The types of plastics used in different home appliances are not the same. Because the types of plastics used by different manufacturers are different in the same product, sometimes the additives, functional masterbatches or formulas are the same for the same type of plastic. Recycling has caused certain difficulties, which must be taken seriously and strive to achieve effective recycling so as to minimize environmental pressure and energy waste. ^[2]

The amount of plastic accessories for electronic appliances has reached more than 1 million tons. It is widely used in industrial support, information, transportation, aerospace and other fields, and the products are quickly updated. As such products gradually enter a large number of scrap periods, they become an important source of waste plastics.

The biggest benefit of using plastics to make automotive parts is to reduce the weight of the car, save costs and processes, and improve certain performances of automobiles. The average amount of plastic used in automobiles in developed countries has exceeded 100 kg. The retirement of automobiles will bring about the recycling and use of plastic resources The environment handles the issue reasonably.

According to analysis by authoritative experts in the automotive industry, China's auto output reached 5.7 million in 2005, and the total car demand in 2006 reached 6.5 million. The average usage of automotive plastics in China reaches 70, with an annual consumption of more than 400,000 tons. Automotive plastics include: PVC, PP, PE, PU, ABS, PA, POM, etc. As the amount of automobile scraps increases year by year, the amount of plastics used in automobiles and household appliances and electronic appliances has steadily increased. Their recycling and reuse have also become the focus of waste plastic sources, and their treatment principles are similar. By 2012, China's automobile plastic demand will reach about 800,000 tons. Therefore, the task of recycling and recycling of scrapped plastic parts will become more and more difficult. ^[2]