New technology of recycling waste polyester bottle

New recycling technology of waste polyester bottle chips (Part I)

Abstract: the main recycling technologies of waste polyester bottle chips at present are briefly described, the gjb150.5 temperature shock experiment practice of several new industrialized recycling technologies of waste polyester bottle chips is introduced, and the prospect of the recycling technology of waste polyester bottle chips is discussed

key words: waste polyester bottle; Recycling technology

in the past 20 years, with the rapid development of China's economy, people's packaging concept has undergone great changes. The packaging materials used in products are constantly renovated, among which plastic packaging materials have developed the fastest and gradually occupy a very important position in the packaging field. Among the plastic packaging materials, polyester beverage bottles are developing rapidly and are favored by people

the main component of polyester bottle is polyethylene terephthalate (PET, or polyester for short). It is a new type of synthetic plastic material successfully developed by ICI company in the UK. Because polyester resin has excellent mechanical properties and wear resistance, good creep resistance and rigidity, low water absorption, high dimensional stability, good thermal stability, excellent electrical insulation and excellent chemical resistance, Therefore, polyester resin was quickly developed. Polyester resin was first used to make fiber. Later, DuPont researched and developed polyester resin for bottles and began the application of polyester bottles. Polyester bottle has the characteristics of odorless, tasteless, non-toxic, light weight, high strength, good air tightness and transparency. The good transparency of polyester bottle makes the product display, which is unmatched by other packaging materials. Therefore, polyester bottles have been widely developed in food packaging, especially for carbonated beverages, mineral water, edible oil and other products

the polyester bottle resin in China is developing rapidly, and the amount of polyester bottle is increasing rapidly. In 1995, the consumption of bottle grade polyester resin was 100000 tons, including 60000 tons made in China. In 1999, the consumption of bottle grade polyester resin was 400000 tons, and in 2000, it reached 520000 tons, and it was completely localized. As the demand for bottle grade polyester resin is still growing, and people have a good forecast of a year-on-year increase of 3.8% for bottle grade polyester in the future, large polyester companies all over the world have expanded the production capacity of bottle grade polyester resin. In Asia, Formosa Plastics Group has increased the production capacity of bottle grade polyester with an annual output of 150000 tons in the United States and Taiwan respectively; Taiwan far east textile will expand its production on both sides of the Taiwan Strait, with an annual production capacity of 400000 tons of bottle grade polyester; New optical fiber is planning to increase its production capacity in Taiwan and Thailand to 500000 tons per year; Thus, the global production capacity of bottle grade polyester resin increases rapidly

most experts believe that the consumption of bottle grade polyester resin in China will increase at an annual growth rate of 20%~30% in the next five years and will reach 1.43 million tons by 2005. Such a huge amount of polyester resin is put into the market, and the recycling of polyester bottles will inevitably be raised when it enters the consumption. Since the food field does not allow the use of physically recycled disposable waste polyester bottles and polyester films, almost all polyester bottles and polyester films are disposable packaging materials. Waste polyester bottles can not degrade spontaneously when they enter the environment, which will cause serious environmental pollution and waste of resources. Therefore, waste polyester bottles and other polyester packaging materials must be recycled

at present, the recovery of waste polyester bottles in the world is 600000 tons per year, with a recovery rate of 18%, while the domestic recovery rate is 6%~10%. Therefore, it is necessary to strengthen the recycling efforts and improve the recycling rate of waste polyester bottles. However, the recycling of waste polyester bottles is very difficult, and there are many influencing factors, so the recycling rate of polyester bottles is very low all over the world

the recycling of waste polyester bottles should pay attention to the following aspects: (1) improve the recycling awareness of the whole society, establish a social recycling network in which most people participate, and take effective measures to stimulate and encourage the recycling of waste polyester bottles, such as establishing a deposit system, a reward system, and strict environmental regulations for polyester bottles; (2) Adjust policies to make the renewable industry and its products economical and make the renewable products profitable, such as the implementation of tax reduction and exemption policies; (3) Increase the research on recycling technology, expand the application fields of recycled polyester bottles and other polyester packaging materials, including automatic identification, classification, whether the quality of recycled products can be guaranteed, and other technologies must be developed in a coordinated manner; Whether the recycling technology of polyester packaging materials such as polyester bottles can be relatively economical will be the key to increase the recycling rate of waste polyester bottles

waste polyester bottle recycling technology is divided into physical recycling technology and chemical recycling technology

physical recovery technology includes:

(1) direct recovery, cleaning and reuse. If the waste polyester bottle is recycled and reused like a glass bottle, it is required that the polyester bottle should be resistant to temperature and 2%~3% sodium hydroxide solution to facilitate cleaning. The current polyester bottles are disposable and cannot be reused. In 1989, the Dutch market took the lead in launching recycled polyester bottles and special equipment designed for recycled polyester bottles. It is eager for this new technology of reusable polyester bottle to gradually enter the market

(2) after crushing, re produce the packaging. After collection, classification, cleaning and crushing, waste polyester bottles can be reused in two ways: first, waste polyester bottles can be used as products after crushing and granulation, and partially added to other plastic products to reduce the cost of the plastic; Second, after crushing and granulating, the waste polyester bottles are re inflated and stretched into new packaging containers, which can only be used for non food packaging. The reason is that some polyester molecules decompose into acetaldehyde under high-temperature blowing and stretching, and acetaldehyde is toxic, leaving acetaldehyde exceeding the standard in recycled polyester packaging containers. In this way, the economy of recycled polyester bottles and other packaging materials will be greatly reduced. Therefore, only the development of economic chemical recovery technology can effectively promote the recovery and reuse of polyester resin

chemical recovery technology includes:

(1) recovery technology for direct fiber production

(2) transform into the recovery technology of polyester resin raw materials

(3) recovery technology for direct production of various fine chemical products