Application status and development trend of the ho

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Application and development trend of polyester in China's packaging field

polyester is the general term of thermoplastic saturated polyester represented by pet, including PBT, pen, PCT and their copolymers. Among them, pet is the polyester product with the earliest development, the largest output and the widest application

properties and uses polyester can be divided into fiber and non fiber according to its use, and the latter includes film, container and engineering plastics. In the early stage of development, polyester is mainly used to manufacture synthetic fibers (accounting for about 70% of pet consumption). Polyester is also used to make insulating materials, tape bases, film or photographic film bases and vacuum packaging. Another major application field of polyester non fiber is the manufacture of hollow containers for filling beverages, food, etc. Secondly, polyester is also used as engineering plastics in electronics, electrical appliances and other fields, such as meter cases, hot air masks and so on, especially the development of packaging containers. At present, more than 20% of pet is used as packaging materials, and it is increasing year by year. Packaging industry has become the second largest user of pet, second only to synthetic fiber

application in the field of packaging because pet can easily obtain pet products that are basically amorphous, highly transparent and easy to stretch through rapid cooling, when used as packaging materials, pet can be made into biaxially stretched packaging film, and can also be made into high-strength, highly transparent stretch blow molded bottles from amorphous bottle blanks, and can also be directly extruded or blown into non stretched hollow containers. PET film has the properties of transparency, oil resistance, fragrance retention, sanitation and reliability, and a wide range of application temperatures (both high-temperature cooking and frozen packaging), but its thermal sealing property is poor, so it must be used in combination with other films (thermal sealing layer), and its price is higher than that of general plastic film, which limits the application of PET film in packaging. PET hollow containers, especially stretch blow molding bottles, give full play to the performance of pet, have a good display effect on the contents, and the cost is low. Therefore, when pet is used as packaging material, it is basically formed by stretch blow molding, among which the most widely used are small bottles with a volume of tens of milliliters to 2 liters, as well as large bottles with a capacity of 30 liters

beverage packaging in beverage packaging, carbonated soft drinks (CSD), such as cola and Sprite, are the most successful in the application of polyester bottles. CSD bottles have accounted for 1/3 of the total PET bottles. PET bottles have beautiful appearance, flexible design, high strength, good sealing to carbon dioxide and reliable hygiene, making polyester bottles an ideal packaging container for CSD and a plastic widely used by CSD beverage industry. The statistics of China Beverage Industry Association in 1998 showed that PET bottles accounted for 57.4% of CSD beverage packaging in China, followed by cans and glass bottles, accounting for 31% and 7% respectively

PET bottles packed with edible oil have good oil resistance, transparency, non-toxic, tasteless, and are not easy to break. They have good barrier to oxygen and UV rays. In recent years, the medical reform has gradually increased its support for medical devices, which can protect edible oil from oxidation and deterioration for a long time. It has been successfully applied abroad, and the domestic demand for this aspect has been rising in recent years

flavoring commodity packaging soy sauce and other liquid condiments are a huge potential market for polyester bottles. PET bottles have the advantages of good fragrance retention, light weight and not easy to be broken. As early as 1995, Japan's application in this area has exceeded 30000 tons, accounting for 13% of the total consumption of PET bottles. In China, such goods are still mainly packaged in glass bottles, and the application of polyester bottles is still in its infancy

beer packaging in the world, the use of plastic bottles instead of glass bottles for beer packaging is still in the stage of research, development and trial. Relevant departments and enterprises in China also pay increasing attention to the development of beer plastic packaging

packaging of pesticides, pharmaceuticals and daily chemical products 1. First, consider the maximum experimental tension range of the test material. Polyester bottles can be used for some pesticide packaging. Low cost pet pesticide bottles produced from polyester have been put into production in China. PET bottles are safe, hygienic, and have good moisture-proof, oxygen isolation and display functions, making pet bottles applied in the field of pharmaceutical packaging. Cosmetics, detergents and other daily chemical products are also a huge market for the application of polyester bottles. PBT and the company make full use of the strong scientific and technological research and development strength of the group during the period and the geographical advantages in Zhongguancun. The good chemical resistance, fragrance retention, high transparency, high gloss, UV shielding and shape design flexibility of pen bottles are the expected characteristics of cosmetics and other daily chemical products. Therefore, polyester bottles are widely used in the packaging of daily chemical products, especially the new gas blocking and UV shielding pen resin bottles will occupy a place in the packaging of perfume and cosmetics

With its superior performance, relatively low cost and adaptability to environmental protection, PET bottles have developed rapidly in the competition with other packaging materials (glass, tinplate, PE, PVC, etc.). However, its low heat resistance and poor gas resistance limit its application in hot filling and occasions requiring high air tightness, and have attracted great attention. In the process of improving its performance, polyester packaging has achieved new development

first, improve heat resistance. Ordinary PET bottles cannot be used for the packaging of fruit juice, tea and other items that need hot filling. At present, through research, three kinds of practical heat-resistant polyester bottles have been developed: thermosetting bottles, which can meet the requirements of 85 ℃ filling; PET/pen alloy bottles, pen has high heat resistance, and can be made on general injection, drawing and blowing equipment to meet the requirements of hot filling above 80 ℃. If heat setting treatment is carried out again, the hot filling temperature can reach above 90 ℃; It is made into multi-layer composite bottles with heat-resistant polyarylate to improve heat resistance. The second is to improve the gas resistance. Although the gas barrier property of pet is much higher than that of polyethylene, polypropylene, polystyrene and other plastics. However, products with strict requirements for freshness preservation and flavor preservation, such as beer, Baijiu and perfume, still cannot meet the requirements. There are three main methods to improve gas resistance. First, multi-layer composite, mainly pet, is added with PVDC, EVOH, MXD6, pen and other materials with good air tightness to make 3-layer or 5-layer bottles. Second, special treatment methods are adopted, such as coating epoxy barrier layer inside or outside the PET bottle, or plasma treatment (ACTIS Technology). Third, it is formed with other barrier resins, using pen or the copolymerization or blend of pen and pet as raw materials, which not only improves the gas resistance of the bottle, but also improves the heat resistance of the bottle, which can meet the requirements of beer storage for 3 ~ 6 months, but also can be washed and disinfected by alkali and reused, so as to reduce the cost. Because the first two methods have problems such as poor transparency, difficult recovery and treatment, complex process, special equipment requirements and so on, and although the air tightness is improved, the heat resistance is poor, so they can only adapt to sterile filling occasions. China's beer industry mostly adopts the technology of pasteurization after filling, so using pen or copolymerization and blend with PRT as raw materials and molding through the current pet bottle blowing equipment and process is the development direction of beer plastic packaging suitable for China's national conditions, which deserves the attention of relevant departments and enterprises

development prospect polyester packaging materials are the most energetic and promising materials that help to achieve the best indoor air quality among all kinds of packaging materials, and they are also the fastest-growing fields in many application fields of polyester. Polyester, led by PET and pen, has become the mainstream material for packaging CSD, water, fruit juice and other beverages, and will also become one of the packaging materials for beer, edible oil, cosmetics and other products

the development of polyester packaging in China began in the 1980s. Bottle grade polyester and polyester bottles started late, but China's polyester packaging industry is developing at a high speed. In recent years, CSD, pure water, fruit juice and other beverages in China have increased by more than 20%, so the demand for polyester bottles for beverage packaging has also increased by double digits. At the same time, the demand for bottle grade polyester in the non food packaging market (such as cosmetics, pharmaceuticals, pesticides, etc.) is also quietly increasing. The consumption of bottle grade polyester in China was 120000 tons in 1996, 180000 tons in 1998, and 300000 tons in 2000 according to preliminary statistics. It can be seen that China is the market with the greatest potential for bottle grade polyester and polyester packaging

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