PET bottles play a big role in packaging, and their scope and number of applications are constantly expanding. From 1940, Whinfield and Dickinson created Polyethylene Terephthalate (PET). PET as a beverage packaging has become a popular trend and has even reached popularity in some countries.
PET is a thermoplastic linear polyester, typical of highly crystalline polymers. It is a non-toxic and odorless product developed after the United States Food and Drug Administration and the Japanese government ban PVC for food and pharmaceutical packaging. Food packaging. It has the advantages of impact resistance, transparency, non-toxicity, high barrier property and low cost, and it can maintain excellent physical properties and mechanical properties over a wide temperature range. Therefore, it has a wide range of applications.
The current recycling of PET bottles is better, and companies attach great importance to it, and the recycling rate is constantly rising. The recycling of used PET bottles can reduce pollution and increase profits. However, the problem of safe use has not been completely resolved. This is because the packaging material itself has the characteristic that the pollutants will be transferred from the material to the food. Similarly, the material will also absorb toxic substances. If it is handled improperly, it will be transferred again when these packaging materials are reused. In food, this is bad for people's health. With the development of economy and technology, recycled PET bottles can be processed into other products, the economic efficiency is still relatively high.
Therefore, it is necessary to carry out in-depth analysis of the current status, recovery status and safety reuse of PET bottles so that the most effective method can be found to solve the problem of recycling and safety reuse.
PET bottle utilization status As PET molecules are biaxial, while other plastic materials are uniaxial, it can prevent the CO2 in the bottle from seeping out, thus finding a new "home" for carbonated beverages. PET bottles After its launch, it was first adopted by American Beverage Beverage Company and Coca-Cola Company. These two large companies promoted the rapid development of PET bottles. So far, European countries have applied PET bottles and water bottles for carbonated soft drink packaging. Popularization, it is estimated that the average annual growth rate of the market before 2006 is 5% -10%, lower than the average level of the world during the same period of 10%. Tecnon company believes that from now until 2010, the average annual growth rate of 8.5%.
In addition to the use of PET in beverage packaging, the amount of other packaging used is also surprising, such as packaging for flavored foods. As early as 1995, Japan's sales in this area have reached 30,000 tons, accounting for the total amount of PET bottles 13%. PET bottles for packaging seasonings can be found everywhere on the market. PET is also used to package edible oils because of its good oil resistance, good barrier to oxygen, and good barrier to UV rays, which can protect food. The oil is protected against oxidation for a long time without deterioration. The edible oils seen on supermarket shelves are now packaged in PET bottles. As people pay more attention to health,
The rising demand for edible oil market has provided a large market space for the application of PET bottles. Nowadays, dairy products with paper products as the mainstream packaging material are also a promising market, and the five largest dairy companies in Europe are now using it. In the PET bottle packaging, the consumption of PET bottles in the domestic dairy product packaging market is also rising. Another huge potential market that PET bottles can use is the packaging of beer. At present, the annual beer production volume in the world has reached 150 billion liters, which is huge. Behind the glutinous beer costs, there is a huge container market, and the number of beer bottles consumed each year now exceeds 270 billion. As consumers demand higher quality products and convenient packaging, PET bottles have quality. Light, transparent, shatterproof, easy-to-mold and resealable, etc., are gradually stepping into the beer packaging market. However, due to the high sensitivity of the wine to the environment, especially the high gas barrier and light-shielding requirements of the beer, the general The PET bottle is not up to the technical requirements. Moreover, the PET beer bottle is not resistant to high temperatures, it can only withstand the temperature of about 60 ~ C, but the recovery and washing needs 80 ~ C water temperature, which is harmful to the recovery of beer bottles Shadows If the use of disposable plastic bottles, the cost will be relatively high.
In recent years, a variety of plastic beer bottle technology came into being. Some developed countries have adopted multi-layer composites, surface coating and other modified technologies to improve the gas barrier properties of PET bottles; or use heat-setting techniques to improve heat resistance. Or use the new plastic material PEN molding, and beer can be refilled; or using nanotechnology to meet the technical requirements of PET bottles. Although the current process technology still needs to improve and innovation, safety and environmental protection measures have yet to be implemented, and the production costs are High or too high, but with the continuous improvement and innovation of the plastic beer bottle manufacturing process, the production costs will continue to decrease after mass production, and the gradual establishment of relevant laws and regulations will also make plastic beer bottles popular with many beer manufacturers and consumers. Its development prospects are promising. According to “Modem Plastics†magazine, in the next 3 to 10 years, 1%-5% of the world's beer will be packaged in PET bottles. As a result, only one bottle of beer will increase by 90. Ten thousand tons. In the next three years - 10 years, the world will have 1% -5% of the beer into PET bottles. In 2005 the global plastic beer bottle market demand reached 30 billion.
PET bottle recycling conditions and methods Biodegradation is undoubtedly the best way to fundamentally solve PET waste pollution, but so far there is no effective biodegradation method for PET in the world. However, PET bottles can be recycled like metal cans and paper packaging. "Melting" reuse can be reused like a glass bottle. It also has a relatively constant volume, used PET bottles are easy to classify, and its waste recycling value is high, which makes PET recycling feasible; and PET bottles The high consumption is also the main driving force for its increasing recycling rate. The recycling of waste PET bottles not only reduces environmental pollution, but also turns waste into treasure. However, only a small part is currently used.
The rest are discarded at will, resulting in waste of raw materials and environmental pollution. Therefore, its recycling technology has broad prospects.
Although the re-use technology is not yet perfect, but the importance of merchants for PET recycling is still very high. The relevant data has proved this point. Before 2002, China's waste plastic bottles recycling rate is still less than 30%; 2004 has risen To 45%; 2 005 is expected to exceed 60%, the recycling prospects are very promising. It is understood that since 2000, the average annual growth of China's beverage industry more than 20%. In 2004, China's total beverage production reached 29.12 million tons, In 2003, the growth rate was 22.7%. Experts predict that in the next 15 years, the average annual growth rate of the beverage industry in China will exceed 15%. The continued rapid development of the beverage industry will inevitably lead to a surge in demand for beverage packaging, which in turn will result in a large number of PET bottles, including soft PET packaging. The PET waste in the company, PET recycling companies have ample "raw material" guarantees. Some experts said that there are four types of PET waste recycling methods. First, the separation of waste PET bottles and flexible packaging and common waste plastics, the implementation of PET Separate recovery of waste materials. Special additives such as AP-p-1000 or AP-P-1100 are added during recovery to increase the thermal stability and impact strength of PET recyclate to a level close to that of the new PET resin. Has become the raw material for processing PET beverage bottles and other flexible packaging. The
After PET waste is separated from ordinary waste plastics, it is processed directly into spinning woven fabrics. For example, Jiangsu Xiake Environmental Color Textile Co., Ltd. is the old PET bottles that will be recycled, cleaned, sifted, sorted, broken, and then extruded under high temperature. Silk becomes polyester, then weaving fabric, and finally made beautiful curtains, underwear, quilts, sheets, gloves, etc. Third, the PET waste through special processing, made of terephthalic acid and ethylene glycol and other raw materials. Is the PET waste and ordinary waste plastic after processing into plastic recycling particles for drawing, blown film and other low-grade plastic products raw materials.