PET bottles play a big role in packaging, and their application range and number are constantly expanding. From 1940, Whinfield and Dickinson created Polyethylene Terephthalate (PET). Today, PET has become a popular trend as a beverage packaging and has even become popular 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 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 pay more attention to it, and the recovery rate is also rising. The recycling of waste PET bottles can not only reduce pollution but also increase profits. However, the issue of safe use has not been completely resolved. This is because the characteristics of the packaging material itself is that the pollutants will be transferred from the material to the food. By the same token, materials will also absorb toxic substances. If it is handled improperly, the re-use of these packaging materials will be transferred to food again, which is unfavorable to people's health. With the development of economy and technology, recycled PET bottles can already be processed into other products. The economic benefits are still relatively high.
Therefore, it is necessary to conduct in-depth analysis of the current status, recycling status, and safety reuse of PET bottles in order to find the most effective method to solve the problem of recycling and safe reuse.
PET bottle use status
Because 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 drinks. After the PET bottles were introduced, they were first adopted by American Beverage Beverage Company and Coca-Cola Company. These two big companies promoted the rapid development of PET bottles. So far, the use of PET bottles and mineral water bottles for carbonated soft drink packaging in European countries has become quite popular. It is expected that the average annual growth rate of the market before 2006 will be 5%-10%, which is lower than the average world level of the same period of 10%. Tecnon believes that from now until 2010, the average annual growth rate is 8.5%.
In addition to PET packaging, the amount of PET used in other packaging is also surprising, such as packaging for flavoring foods. As early as 1995, Japan's sales in this area had reached 30,000 tons, accounting for 13% of the total amount of PET bottles. Bottles of seasoning PET are everywhere on the market. PET is also used to package edible oils, because it has good oil resistance, good barrier to oxygen, and good barrier to ultraviolet rays, which can protect edible oils from oxidation 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 provides a great market space for the application of PET bottles. Nowadays, dairy products with paper products as mainstream packaging materials are also a promising market. At present, the five largest dairy companies in Europe have started using PET bottles, and the amount of PET bottles in the domestic dairy packaging market is also rising. Another huge potential market for PET bottles is the packaging of beer. Currently, the annual beer production volume in the world has reached 150 billion liters. Behind the huge beer brewery cost is a huge container market. The number of beer bottles consumed each year now exceeds 270 billion. With the increasing demand from consumers for quality products and convenient packaging, PET bottles are gradually being sold to the beer packaging market because of their characteristics of light weight, transparency, shatterproofness, easy molding, and resealability. 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 PET bottle cannot meet the technical requirements. Moreover, the PET beer bottle is not resistant to high temperatures, and it can only withstand the temperature of about 60~C, but the recovery and washing of the bottle requires a water temperature of 80~C, which has an adverse effect on the recovery of the beer bottle. If you use disposable plastic bottles, the cost will be relatively high.
In recent years, a variety of plastic beer bottle technologies have emerged. Some developed countries have adopted multi-layer composites, surface coating and other modification technologies to improve the gas barrier properties of PET bottles; or use heat-setting techniques to improve heat resistance; or use new-type plastic materials for PEN molding and refillability. Loading beer; or using nanotechnology to make PET bottles meet technical requirements. Although the current process technology still needs to be perfected and innovated, safety and environmental protection countermeasures have yet to be implemented, and the production costs are high or excessive, but as the plastic beer bottle manufacturing process continues to improve and innovate, the production cost will continue to decrease after mass production. The gradual establishment of relevant laws and regulations will also make plastic beer bottles popular with many beer manufacturers and consumers, and their development prospects are promising. According to "ModemPlastics" magazine forecast, in the next 3 to 10 years, the world will have 1% -5% of the beer into PET bottles. As a result, beer bottles alone will increase by 900,000 tons per year. In the next 3 to 10 years, 1% to 5% of the world's beer will be packaged in PET bottles. In 2005, the annual demand for the global plastic beer bottle market reached 30 billion.
PET bottle recycling conditions and methods
Biodegradation is undoubtedly the best way to fundamentally solve the problem of PET waste pollution, but so far there is no effective biodegradation method for PET in the world. However, PET bottles can be reused like metal cans and paper packaging to “melt†and reuse, and can be reused like glass bottles. It also has a relatively constant volume. Used PET bottles are easily categorized, and their waste recycling value is high. This makes the recycling of PET feasible; and the high consumption of PET bottles is also the main driving force for its increasing recovery.
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, and the rest are discarded at will, causing waste of raw materials and environmental pollution. Therefore, its recycling technology has broad prospects.
Although the technology for re-use is still not perfect, the degree of emphasis on PET recycling by merchants is still high. The relevant data has proved this. Before 2002, the recycling rate of China's waste plastic bottles was still less than 30%; in 2004 it had risen to 45%; in 2005, it was expected to exceed 60%, and the recovery prospects are very promising. It is understood that since 2000, China's beverage industry has grown at an average annual rate of more than 20%. In 2004, the total output of beverages in China reached 29.12 million tons, an increase of 22.7% over 2003. Experts predict that in the next 15 years, the average annual growth rate of the beverage industry in China will exceed 15%. The continuous and rapid development of the beverage industry will inevitably lead to soaring demand for beverage packaging, which in turn will generate a large amount of PET waste including PET bottles and PET flexible packaging. PET waste recycling companies have sufficient "raw material" guarantees.
Some experts say that there are roughly four methods for recycling PET waste. The first is to separate used PET bottles and flexible packaging from ordinary waste plastics and implement separate recycling of PET waste. When adding special additives such as AP-p-1000 or AP-P-1100, the thermal stability and impact strength of PET recycled material are enhanced to reach the same level as the performance of the new PET resin, and PET bottles are processed. And other soft packaging materials. The second is to separate the PET waste from the ordinary waste plastics and use it directly for the spinning weaving. For example, Jiangsu Xiake Environmental Color Textile Co., Ltd. is the recycling of used PET bottles. After cleaning, screening, sorting, and crushing, the high-temperature extruded spinnerettes turn into polyester, then the spinning fabrics, and finally the beautiful curtains and underwear. Quilts, sheets, gloves, etc. Third, PET waste is processed through special processing to make terephthalic acid and ethylene glycol. Fourth, PET waste is mixed with ordinary waste plastics and processed into plastic recycling granules, which are used as raw materials for low-grade plastic products such as wire drawing and blown film.