How to improve the gas barrier performance of PET plastic packaging bottles
PET plastic packaging bottles have strong applicability and are widely used in daily necessities, daily chemical packaging and other fields. From mold processing to machinery and equipment, they are extremely picky. It is easy to get started, but difficult to do well.
Due to the technical trend of light weight, good preservation, and emphasizing functions such as heat resistance and pressure resistance, PET plastic packaging bottles have become the mainstream of cosmetic packaging today. Many beverages that require high-temperature sterilization to be filled, such as flavored water, fruit juice, dairy products, sports drinks, etc., are also packaged in PET plastic packaging bottles one after another. PET plastic packaging bottles have become the main packaging material for cosmetic containers. Due to its low environmental pollution and energy consumption, PET plastic packaging bottles are gradually replacing traditional packaging materials in today's rising awareness of environmental protection. With its functions of heat resistance and pressure resistance, it has nearly replaced various PVC bottles, aluminum cans, iron cans, glass bottles, etc., and has become a packaging material with great growth potential.
The strength and elasticity of PET are obviously higher than other raw materials, and it is suitable as a cosmetic plastic container with thin wall, light weight and high strength. PET plastic packaging bottle has been used in our country for many years and has a rapid development momentum. In recent years, it has become the main liquid and solid packaging container in the country. In the application of the field of pharmaceutical packaging, in the case of the same drug filling volume, the weight of PET plastic packaging bottles is only about 1/10 of that of glass bottles; for packaging bottles with the same diameter, the capacity of PET plastic packaging bottles is that of glass bottles. 1.5 times. PET raw materials can also be used to make transparent or opaque brown bottles, with various colors and exquisite appearance.
There are four main ways to improve the gas barrier performance of PET plastic packaging bottles: processing through multi-layer co-extrusion technology to make it have a multi-layer composite structure; surface coating treatment; adding some gas capture agents; and other materials with barrier properties Blend. Among them, multi-layer co-extrusion technology is a method that has been successfully used at present, but the improvement of barrier performance is small, and it is difficult to recycle, and the cost is high. Surface coating is an emerging technology for improving the gas barrier performance of PET plastic packaging bottles. It can obtain very thin gas barrier films, which can effectively prevent gas molecules from passing through the PET plastic packaging bottle wall, and can solve the problem of recycling at the same time. problem of utilization.
Some coating materials currently used have been tested in practice, among which diamond carbon film (DLC) and silicon oxide materials are very popular materials in the industry. Silicon oxide coatings were used to improve the gas barrier properties of PET films earlier than diamond carbon films. In the early 1980s, silicon oxide coatings were obtained by physical vapor deposition and chemical vapor deposition. However, the silicon oxide film is brittle and requires relatively complex treatments in order to obtain durable mechanical strength on the PET surface. In recent years, some products coated with diamond carbon film (amorphous hydrocarbon) on the surface of PET have appeared on the market, and the gas barrier performance of PET plastic packaging bottles has been greatly improved.
