Prospect of liquid plastic packaging materials

Prospects of liquid plastic packaging materials

Plastic packaging materials after more than 20 years of development, new products emerge one after another. However, from the perspective of the industry as a whole, the development of plastic packaging materials is hindered by factors such as the convergence of plastic packaging material structure, weak scientific and technological development ability and insufficient sources of funds. Therefore, only by seeking new growth points can we promote the development of packaging materials. The urgent task is to take the road of high and new technology and develop new products and new application fields

at present, PVC and pet are the main 5-gallon drinking buckets on the market, which brings many problems. The toxicity of PVC drinking bucket additives has always been controversial, while pet drinking buckets meet the health requirements. However, due to the confusion of market order, inferior materials are replaced by good ones, and old materials are passed off as new materials, resulting in excessive bacterial content in the barrels. The main reason is that the unqualified barrel material of barreled purified water belongs to non food grade. Therefore, it is very urgent to develop food grade PC raw materials. Shanghai and Bayer have signed a contract to build 100000 tons of PC resin. The first phase was put into operation in 2003, with an annual output of 50000 tons, which can alleviate the long-term situation of relying on imports for PCs. In recent years, PC drinking buckets have developed rapidly, with an annual output of more than 50 million in Shanghai and Guangdong alone. Therefore, with the production of domestic raw materials, the development of PC beverage bottles will be an opportunity

the application market of plastic packaging containers is broad, among which there are attractive business opportunities in the beverage industry. In 2000, the output of beverages reached 13 million tons, and the demand for plastic containers for soda, fruit juice, vegetable juice and beverages is increasing day by day. Only for beer packaging, the heat-resistant polyester bottle (PET) used internationally in recent years has developed rapidly, especially the application of PET bottle coating technology (plasma technology), which is coated with 0.2mm carbon layer. Its impermeability is almost the same as that of glass. At the same time, it can withstand high-temperature sterilization treatment, so that its application range can be expanded and adapt to the packaging of hot filled tea drinks

in addition, the new polyester bottle of polyethylene naphthalate (pen), which has attracted the attention of the packaging industry, is entering the beer industry and causing a revolution in beer packaging. Because the molecular structure of pen is similar to that of pet, using naphthalene ring instead of benzene ring makes pen have better permeability resistance, UV resistance linearity, good heat resistance and high temperature resistance than PET (the thermal change temperature of amorphous pen is as high as 100 ` C while that of pet is only 70 ` C). In the near future, pen will enter the packaging field in large quantities, triggering another packaging revolution after pet. At present, a small amount of domestic imports, but the price is five times that of pet. Naphthalene is separated from coal tar, and China is rich in resources, so industrial production is about to be realized

the development of polypropylene transparent packaging bottle is a hot spot in plastic packaging at home and abroad in recent years. With the successful development of transparent modifier nucleating agent, 0.1% - 0.4% sorbitol xylene (benzaldehyde) nucleating agent (American Milliken, new Japan physicochemical, Mitsui East Asia, brand millad3988, etc.) is added to ordinary pp. high transparent PP can be widely used in injection, blow extrusion, blow drawing, extrusion, thermoforming containers, food and drug bottles. Its price is appropriate and it is a competitor of PS, ABS, pet and PE bottles, It has broad market prospects

the application of plastics in aseptic packaging provides a broad world for the development of aseptic packaging technology. Aseptic packaging refers to packaging sterilized foods (beverages, dairy products, condiments, etc.) in a sterile environment and sealing them in sterilized containers; The package has long advanced concept, honest reputation, professional quality and excellent service shelf life without preservative and refrigeration. The difference between aseptic packaging and non aseptic packaging is: non aseptic packaging is packaged first, and then the packaging and container are cooked and sterilized together; Aseptic packaging adopts ultra-high temperature instant sterilization or microwave sterilization, which takes a few seconds or more, avoiding the excessive loss of nutrients and flavor. It is a new technology. In recent years, aseptic plastic bag packaging and aseptic cup plastic bottle packaging have developed rapidly

aseptic large bag packaging (bag in box) refers to a composite film packaging bag with a packaging container of 5-220l and up to 1000L. After loading, it is placed in a wooden box, carton or steel barrel for packaging tomatoes, fruit juice slurry, etc. This kind of large bag packaging is mainly made of pet aluminized film and PE composite. It is produced in Shanghai, Guangzhou, Yangzhou Changlong, Shaanxi Longxi, Xinjiang and other places of longmang Baili

aseptic cup packaging uses multi-layer co extruded sheets PP/PE/EVA/PVDC/PS. Among them, PP is a peelable layer, which is used as the protective film of aseptic packaging. On the aseptic packaging, tear the PP film to expose the aseptic surface of PE, and complete the process of forming, filling and capping. EVA is a bonding layer and PVDC has good oxygen barrier. It is used for packaging food. Its fresh-keeping period is comparable to that of glass bottles and tin cans

at present, aseptic packaging accounts for only 5% in China's beverage industry, 10% in dairy products, and 65% in developed countries. In addition, the per capita share of milk in China is 5.1kg, while that in the world is 38kg. The per capita share of fruit juice in China is 1.2kg, while that in the world is 8.8kg. It can be seen that aseptic packaging in China has great development space. The development of aseptic packaging materials is also one of the development directions of plastic packaging

in 1991, Exxon first produced metallocene polyethylene. Subsequently, the technology of Dow Chemical Company also improved, and Mitsui chemical of Japan also followed to produce new brands and varieties. The successful development of this technology has created a new era of plastic packaging and is listed as one of the major events in the packaging industry in the 20th century. The so-called metallocene polymer refers to the polymer polymerized by using the organic metal complex composed of transition metal and cyclic unsaturated metallocene (i.e. cyclopentadiene) as catalyst. At present, MP is mainly used, and then the signal is processed by single chip microcomputer e, MP, MPs, etc. The biggest difference between metallocene catalysts and traditional catalysts is that the previous catalysts have many active centers. Therefore, there are more branch bonds on the molecular bonds of polymers, which hinders the spatial tightness of macromolecular chains and leads to performance differences; Metallocene catalysts have only one active center, so they can accurately control the relative molecular weight and molecular weight distribution. The relative molecular weight distribution is very narrow and there are few impurities

therefore, the thermal properties, tensile strength and puncture resistance of m-LLDPE film are better than those of traditional LLDPE. These characteristics of m-LLDPE can effectively improve the performance of packaging materials and reduce the phenomenon of penetration and cracking. It has excellent heat sealing performance when making heat sealed bags. It is an ideal packaging material and is suitable for packaging milk, soy sauce, vinegar, etc. This new material has its advantages. But in the aspect of forming, because of its high molecular weight and high accuracy, it is too idle to process 100% pure M - LLDPE. At present, most of them adopt blending modification, add about 40% LDPE or HDPE, and adopt Sichuan multi-layer co extrusion and blow molding, which is the practice of general enterprises and has achieved good results. In short, metallocene polyethylene has broad development prospects