New Requirements for Plastic Packaging into Green Packaging

The main function of packaging is to protect the goods, making them easy to use and save. For foods, because they are closely related to people's health, in order to prevent food from deteriorating, it is not only required that food packaging is aesthetically pleasing, convenient and practical, but more importantly, it must ensure quality and ensure food safety. Undoubtedly, this puts forward higher requirements on the performance of the food packaging material itself, whether it is green and environmental protection, and the packaging production design, production process, etc.

Materials used for food packaging must have high barrier properties, such as grease foods require high oxygen barrier and oil resistance; dry foods require high moisture resistance; aromatic foods require high resistance odor; and fruits, vegetables, fresh foods It is required to have a certain permeability of oxygen, carbon dioxide gas and water vapor. At the same time, the packaging material must have good mechanical properties, including the tensile strength of the material, tear resistance, impact resistance, etc. Chemical stability, should not have any chemical reaction with the contents of the food; In addition, there must be a higher temperature resistance, suitable for high temperature sterilization of food and low temperature storage and other characteristics. At present, in many food packaging materials, plastic products and composite packaging materials play a decisive role, but because of the inherent defects of traditional plastic materials, such as environmental pollution, the overall temperature resistance and barrier properties are not as good as metal and glass containers. Therefore, the rapid development of the food industry has raised new issues for the plastics industry—to improve the performance of existing plastics, to develop new varieties, to increase strength and barrier properties, and to minimize the amount of waste generated under the premise of satisfying packaging functionality. , To make packaging materials, packaging containers to the direction of lightweight, thin film development.

PEN will trigger another packaging revolution

The use of high-strength, high-barrier plastics can not only improve the protection of foods, but also reduce the amount of plastics used when packaging the same amount of food, and can even be reused. For processed foods requiring high barrier protection as well as vacuum packaging, pneumatic packaging, etc., composite materials are generally used for packaging, and in multilayer composite materials, there must be one or more layers of high barrier materials. At present, high barrier materials commonly used in China include aluminum foil, nylon, polyester, polyvinylidene chloride, etc. However, with the improvement of food protection requirements, copolymers with better barrier properties will become development hot spots.

At present, the new polyethylene naphthalate (PEN) packaging materials dominate the world and are very popular around the world. Since the molecular structure of PEN is similar to that of PET, only the naphthalene ring is used instead of the benzene ring. Therefore, PEN has more excellent barrier properties and heat resistance than PET, and particularly has good gas barrier properties and UV resistance. Due to the industrialization of PEN, PEN will enter the packaging field in the near future, triggering another packaging revolution after PET. Due to these advantages, PEN also has broad prospects for the packaging of beverages, beer, and cosmetics.

Inorganic high barrier microwave food package favored

Because the packaging made of aluminum foil and some plastic composite materials has the defects of being opaque, difficult to recycle, and cannot be used for microwave processing, the plated SiOX material developed in recent years can be used as a substitute. SiOX is a thin layer of silicon oxide coated on PET, PA, PP and other substrates. It not only has better barrier properties, but also has excellent atmospheric environment adaptability. Due to its high barrier property, high microwave transparency, and transparency, SiOX coating can be used in flexible packaging for high-temperature cooking and microwave processing of food, and can also be used as a packaging container for beverages and edible oils. At present, the cost of SiOX coating is high, and large-scale production technology is still not perfect. China has begun a certain amount of research, and a few developed countries have begun to apply it.

Co-extruded packaging film becomes the new choice

At present, high barrier and multifunctional soft plastic packaging materials have become a hot spot in the development of the plastic packaging industry. In recent years, not only the high permeability barrier, multifunctional cling film, and aseptic packaging film have developed rapidly, but also the original composite film has been developing in more depth. The successful development of anti-counterfeiting packaging films, especially anti-static packaging films, is also of great significance. At the same time, breakthroughs in bag making and printing technologies enabled the composite packaging film to enter the “color revolution” era; the development of multi-layer co-extrusion technology also changed the product structure of functional films and containers, and adapted to the high demands of environmental protection. .

With the growing demand for environmental protection, it is particularly important to reduce the amount of garbage produced under the premise of satisfying packaging functionality, and to make packaging films and packaging containers more lightweight and thinner. Due to the release of adhesives and solvents used in the production of high-barrier films based on dry compounding, which can easily cause pollution, the development of co-extruded packaging films has become a new choice.

With the implementation of the international environmental standard ISO14000, new degradable plastics are also receiving much attention. Germany BASF launched a brand of E-coflexd degradable polyester resin polymerized with aliphatic diols and aromatic dicarboxylic acids for film production.

Metallocene materials are organometallic coordination compounds formed by the attachment of transition metals to cyclopentadiene. Metallocene polyolefins are polymers prepared by polymerizing olefins using a melolocene catalyst as a catalyst. Metallocene polymers have many advantages, such as good processability, good transparency, high strength, and good film stability, and are therefore suitable for food and pharmaceutical packaging.

Foam plastic to zero pollution

AMUT's extruded foamed PP sheet is the latest development in foam products. It uses MONTELL's high-viscosity resin, high-strength polypropylene (HMSPP), PP copolymers, and low ODP chemical foaming agents to produce a foamed polypropylene sheet (FPP) with fine micropores and uniform distribution, with a density of 0.6 kg/m2. Compared with PP sheet with the same performance, it has a low product density, can save 20% of raw materials, and has great economic and environmental significance.

The food industry is a sunrise industry in the 21st century, but with the continuous improvement of people's quality of life and the increasing emphasis on healthy consumption, there will be higher requirements on the quality and safety of food, and it is suitable for plastics used in food packaging. Industry will also usher in a huge space for development and development potential.