Briefly discuss the functional requirements and industry application of heat shrinkable film.

The characteristics ofheat shrinkable film  are very obvious. At first, it has relatively high flexibility, is not easy to be damaged, and has relatively strong blast resistance. At the same time, it also has corresponding impact resistance. It is precisely because of these characteristics that people use it to package goods that have just been produced. In fact, it is a protective film for goods, which protects the appearance of goods from being damaged, so as to enhance the impression in the eyes of customers. Heat shrinkable film is widely used for the whole package of wine, cans, mineral water, various beverages, cloth and other products. PVC shrink film, adding ingredients to enhance its heat resistance, toughness, ductility and so on. The upper layer of this surface film is paint, the main component in the middle is PVC, and the lower layer is back-coated adhesive.

Shrinkage film is designed based on the principle of stretching and orientation of polymer molecular chain, and is formed by rapid cooling. Its physical principle is: when the polymer is in a high elastic state, it is stretched and oriented, and then the polymer is quenched to below the glass transition temperature, and the molecular orientation is frozen. When the article is heated in the process of packaging, the stress is relaxed due to the thermal movement of the molecules, and the molecules return to their original state and shrink. This performance enables heat shrinkable film to be smoothly bonded with various shapes of beverage bottles, and it is flat and wrinkle-free. Therefore, it is very important to test and control the thermal shrinkage of PVC heat shrinkable film.

Heat shrinkable film from the functional requirements, heat-shrinkable label has the characteristics of,, impact resistance, tear resistance and tasteless, which can play an anti-counterfeiting role. Heat shrinkable labels can also protect consumers from accidental injuries caused by damaged or broken containers. It adopts the method of inner printing, which can protect pictures and texts, and enhance the degree of heat shrinkage labeling in transportation and sales. It is stable at room temperature, shrinks when heated (above the glass transition temperature), and more than 70% of it shrinks in one direction. The main raw materials of heat shrinkable film three-layer co-extruded heat shrinkable packaging film include LLDPE (linear low density polyethylene), TPP (terpolymer polypropylene), PPC (binary copolymer polypropylene) and necessary functional additives such as slip agent, anti-blocking agent and antistatic agent. These raw materials are environmentally-friendly and clean materials, which will not produce toxic gases and odors during processing and product application. The sanitary performance of the products meets the standards of FDA and USDA, and can be used for packaging food.

The materials used in heat shrinkable film are mainly various thermoplastic films. At first, PVC shrink film was the main film. With the continuous development of market demand,PVC shrink film  gradually decreased, while various multi-layer co-extruded heat shrinkable films such as PE, PP, PET, PVDC and POF developed and became the mainstream of the market. At present, there are nearly 20 shrink film manufacturers in China, only the Plastic Packaging Committee of China Packaging Federation, with an output of nearly 80,000 tons. According to experts' prediction, the domestic heat-shrinkable film market will grow at a rate of more than 20% in the next five years.

The food industry is a large market for heat-shrinkable packaging. Heat shrinkable film is widely used in the packaging of various fast food, lactic acid food, beverages, snacks, beer cans, various wines, agricultural and sideline products, dry food, local products and so on. Non-food applications are also increasing, such as labels and shapes of bottle caps, seals, fibers and clothing, aerosol products, sporting goods, electrical products, cosmetics, pharmaceuticals, oils, detergents, stationery, toys, office supplies, kitchen supplies, daily necessities, sundries, building materials and other products. Whether it is used for preservation, freezing or other environmental requirements; The consistency between packaging production company and customer culture and so on are all aspects to be considered.

PVC heat shrinkable film can package different kinds of products, and the heavy metals do not exceed the standard. It is characterized by relatively low shrinkage temperature and heat shrinkage, which can generally achieve excellent results at 80-120 degrees. The product has high transparency, clarity and strong gloss. Instant heating and easy shrinkage are suitable for all types of shrinking machines, which are widely used and suitable for low-cost and low-cost product packaging. Such as: wood products, craft gifts, candles, brochures, printed matter, electronic appliances and other industries. At the same time, it can be made into various flat pocket, arc bag, special-shaped bag and triangle bag. Tight packaging, beautiful and generous, flame retardant. Printing does not fade. PVC heat shrinkable film can be used for insulating packaging of electrical appliances and electronic components (such as the outer packaging of dry batteries); Packaging of general goods and packaging of food contact. Using it as packaging material can not only simplify the packaging process and reduce the packaging volume, but also show the color and shape of the packaged goods clearly because the shrunk transparent film tightly wraps them, so PVC heat shrinkable film is widely used in commodity packaging.

The general retail industry requires orientation according to the needs of consumers, and pays more attention to the attractiveness of printing effect to consumers and the convenience of packaging. For industrial packaging, it is different, and it pays more attention to the particularity of the product and whether it is convenient for mass processing. Generally speaking, the selection of heat-shrinkable packaging should consider the attractiveness of packaging to consumers and good sealing. There are many corresponding technologies about the heat shrinkable film market and its application. Looking at the market development, low-temperature heat shrinkable technology, low-cost technology, multi-purpose adaptability, online packaging technology and high-performance technology have become the general trend of heat shrinkable packaging research. It is the constant promotion of various kinds that the application of heat-shrinkable packaging is more and more extensive.

With the development of science and technology and the progress of human society, we advocate energy conservation and environmental protection more and more, and PVC heat shrinkable film is mainly made of plastic and paper, which undoubtedly pushes the development of paper industry to the peak, which makes the cost of packaging market expand and the price increase obviously, thus promoting the industrial development of PVC heat shrinkable film. This provides convenience for human life and promotes the harmonious development of society. At the same time, food packaging is widely used in film, which improves commercial value and realizes a win-win situation of mutual encouragement. Following the pace of the times, the continuous development of PVC heat shrinkable film technology and adjusting the industrial model will play a more important role in promoting the plastics and packaging industries.