Application of plastic packaging materials in the food industry (Part 2)
polyvinylidene chloride (PVDC) has outstanding advantages, that is, it has excellent barrier properties to gas, steam, oil and odor. Therefore, the market takes it as an important part of barrier composites, and it can also be made into lotion and coated on other substrates to improve the barrier properties of materials. Its use temperature range is -18-135 degrees, which is resistant to low-temperature refrigeration and high-temperature cooking. It is often used in some aromatic and greasy food packaging, which can greatly extend the freshness and aroma preservation time of these edible Lu
polycarbonate (PC) has good transparency, excellent mechanical properties, stable size and good heat resistance. It is a very excellent packaging material, but its wide application is limited by its high price. It can be made into films, sheets, and containers with high impact resistance. It is generally used to make food trays, bowls and many other daily necessities
polyvinyl alcohol (PVA) has high transparency, good gloss and excellent gas resistance. High strength and toughness. It has good chemical stability and is not eroded by common solvents such as hydrocarbons, alcohols and ketones, oil, etc. except for water. No static electricity, good printability. It is non-toxic and tasteless, and the film made of it can be directly used to package oily food. After compounding with other films, it overcomes the shortcomings of moisture permeability and improves the gas resistance. Therefore, it is widely used in the packaging of meat, butter, cheese and fast food
ethylene vinyl alcohol copolymer (EVOH), which is the hydrolysate of EVA, is a high barrier material. Its most outstanding advantages are its high barrier to oxygen, nitrogen, carbon dioxide and other gases and excellent fragrance retention. In addition, it has good resistance to oil and organic solvents, and can be used for the packaging of oily food and edible oil
in addition to the above plastic packaging materials, there are many other plastic packaging materials, such as P. the main reason is that the viscosity of oil is too high or the oil is too dirty. VC, PS and many deep-processing products. In particular, many composite materials of the above products are more worthy of our study and discussion
composite flexible packaging materials composite flexible packaging materials refer to multi-layer materials composed of two or more layers of different flexible materials through certain technologies. The composite substrates used include plastic, aluminum foil, paper, cellophane, etc. In food packaging, plastic packaging materials combined with other materials account for a considerable proportion. Therefore, plastic packaging materials are widely used in food packaging. Has a very important position
the composite flexible packaging materials with the participation of plastic packaging materials have good comprehensive performance, high strength, high barrier, high and low temperature resistance, good adaptability of packaging operation, health and safety, and can meet the all-round requirements of food packaging for materials. The structural requirements of composite materials used for food packaging are as follows:
the inner layer materials are required to be non-toxic, tasteless, oil-resistant, chemical resistant, and have heat sealing and adhesion. Commonly used are thermoplastic materials such as PE, CPP, EVA, etc
the outer material requires good optical properties, good printability, and high strength and rigidity. The commonly used outer materials are pet, PA, B. OOP, aluminum foil, paper and other materials in this dazzling experimental machine
if the composite material is required to have high barrier property, an intermediate layer can be set. The commonly used intermediate layer materials are aluminum foil and PVDC with high barrier property
the expression of composites is: from left to right, from outer layer to inner layer. For example, pet/pvdc/cpp, the outer layer is pet, the middle layer is PVDC, and the inner layer is CPP. The composite process methods are generally layer method, coating method of establishing Southeast Asia material trading platform, coextrusion method, vacuum coating, etc. If you need to increase the shelf life of food, plastic composite packaging materials are an ideal choice
with the deepening of market economy, food packaging is also moving forward to practical, beautiful and cheap aspects. Many packaging technicians are constantly studying and discussing the application of new plastic packaging materials in food packaging. For example, new nano technology is introduced into plastic packaging materials. With the progress of the times, it is believed that more new plastic packaging materials will be applied to food packaging in the future. The application prospect of plastic packaging materials in food packaging is infinite and broad
(author/Li Bing)
from Chinese packaging
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