Liquid plastic bottle material prospect analysis

Liquid plastic bottles have a wide application market, especially the beverage industry has attractive business opportunities, because the demand for liquid plastic bottles for soda, juice, vegetable juice and other beverages is increasing day by day. In recent years, the use of heat-resistant polyester (PET) bottles has grown rapidly in the world. In particular, PET liquid plastic bottle coating technology has been applied to plasma technology. Its barrier properties are almost the same as those of glass. At the same time, it can withstand high temperatures. Bacteria treatment, which expands its scope of application, can be used for the packaging of hot-filled tea beverages, beer and the like.

In addition, the new polyester liquid plastic bottle of polyethylene naphthalate (PEN) that has attracted the attention of the packaging industry is entering the beer industry, causing a revolution in beer packaging. Due to the similar molecular structure between PEN and PET, the naphthalene ring replaces the benzene ring, making PEN more excellent in barrier properties, UV resistance, heat resistance, and high temperature resistance than PET (non-crystalline PEN thermal transition temperatures up to 100°C, And PET is only 70 °C). At present, China only imports a small amount of PEN liquid plastic bottles. Its price is five times that of PET liquid plastic bottles. But in the near future, PEN liquid plastic bottles will enter the packaging field in large quantities, triggering another packaging revolution after PET. Naphthalene is separated from coal tar, and China has abundant resources, so industrial production will soon be realized.
The development of polypropylene transparent liquid plastic bottles is a hot topic in the packaging of liquid plastic bottles at home and abroad in recent years. With the successful development of the transparent modifier nucleating agent, the addition of 0.1% to 0.4% sorbitol xylylene (benzaldehyde) nucleating agent to ordinary PP can produce highly transparent PP, which is widely used in heat. Molding containers, foods, medicine bottles, etc., are moderately priced and are competitors to PS, ABS, PET, PE liquid plastic bottles, and have a broad market prospect.

The application of liquid plastic bottles in aseptic packaging provides a vast space for the development of aseptic packaging technology. In aseptic packaging, sterilized food and beverages, dairy products, seasonings, and the like are packaged in a sterile environment and enclosed in sterilized containers. This package has a long shelf life without preservatives and without refrigeration. The difference between aseptic packaging and non-sterile packaging is that non-sterile packaging is first packaged, then the packaging and the liquid plastic bottle - retort sterilization; and aseptic packaging using ultra-high temperature instant sterilization or microwave sterilization, take a few seconds, ten In a few seconds, it avoids excessive loss of nutrients and flavors and is a new technology. In recent years, the packaging of sterile liquid plastic bottles and sterile cup plastic bottles has rapidly developed.

Aseptic bag bags generally use 5 to 220L, up to 1000L of composite film bags, commonly used in the packaging of tomatoes, juice thick paste, usually stored in wooden boxes, cartons or drums. This large bag is mainly composed of PET aluminum film and PE compound. Sterile cup packaging uses multi-layer coextruded sheet PP/PE/EVA/PVDC/PS. Among them, PP is a peelable layer. As an aseptic packaging protective film, on the aseptic packaging, the PP film is torn open to expose the PE sterile surface, and the molding-filling-capping process is completed. EVA is an adhesive layer and PVDC has good oxygen barrier properties. It is used for packaging foods, and its shelf life is comparable to that of glass bottles and ordinary liquid plastic bottles.

At present, aseptic packaging accounts for only 5% of the beverage industry in China, 10% in dairy products, and 65% in developed countries. In addition, milk is 5.1 kilograms per person in China, and the world average is 38 kilograms. The per capita share of fruit juice in China is 1.2 kilograms, compared with 8.8 kilograms in the world. This shows that China's aseptic packaging has great room for development.

The characteristics of M-LLDPE are that it can effectively improve the performance of liquid plastic bottle materials, reduce the phenomenon of penetration cracking, and have excellent heat-sealing properties when heat-sealed bags are used. It is an ideal packaging material and is suitable for packaging milk and soy sauce. Vinegar and so on. This new material has its advantages, but due to its high molecular weight and high precision in terms of molding processing, machining with pure M-LLDPE is difficult and the equipment cannot withstand it. At present, most of them use blend modification, adding about 40% of LDPE or HDPE, and adopting multi-layer co-extrusion blow molding. This is an ordinary enterprise's practice and receives good results. In short, metallocene polyethylene has broad prospects for development.