Heat shrink packaging technology and new applications for heat shrink packaging The heat shrinkage of the film was applied as early as 1936, initially using a rubber film to shrink the packaging of perishable foods. Today, heat shrink technology has evolved to pack virtually any product with plastic shrink film. In addition, shrink wrap is used to make shrink labels and shrink caps, making containers that are not easy to print or complex in shape can be labeled. Recently, new and updated application areas have been developed.
The heat shrinkage of the film was applied as early as 1936, initially using a rubber film to shrink the packaging of perishable foods. Today, heat shrink technology has evolved to pack virtually any product with plastic shrink film. In addition, shrink wrap is used to make shrink labels and shrink caps, making containers that are not easy to print or complex in shape can be labeled. Recently, new and updated application areas have been developed.
Production techniques and characteristics The production of shrink film is usually produced by extrusion blow molding or extrusion casting, and then longitudinal and transverse stretching at a high elastic temperature above the softening temperature and below the melting temperature, or only The orientation is stretched in one of the directions, and the other direction is not stretched, the former is called a biaxially stretched shrink film, and the latter is called a one-way shrink film. When used, the packaged product is wrapped by a reliable shrinkage force when it is greater than the stretching temperature or close to the stretching temperature.
Shrink wrap has the following advantages:
1) Beautiful appearance, close to the goods, so it is also called body packaging, suitable for packaging of various shapes;
2) The protection is good. If the inner packaging of the shrink packaging is combined with the transportation packaging hanging on the outer packaging, it can have better protection;
3) Good cleaning performance, especially suitable for precision instruments and high-precision electronic components packaging;
4) Good economy;
5) Good anti-theft, a variety of foods can be packaged together with a large shrink film to avoid loss;
6) The stability is good, and the product will not fall in the packaging film;
7) Transparency is good, customers can directly see the product content.
Market development and typical applications The materials used for heat shrinkable films are mainly thermoplastic films. Originally based on PVC shrink film, with the continuous development of market demand, PVC shrink film gradually reduced, and various PE, PP, PET, PVDC, POF and other multi-layer co-extruded heat shrinkable film developed rapidly and became the mainstream of the market. At present, the domestic shrink film manufacturers only have nearly 20 plastic packaging committees of the China Packaging Federation, and the output is close to 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 the largest market for heat shrink packaging. Heat shrinkable film is widely used in the packaging of various fast foods, lactic acid foods, beverages, small foods, beer cans, various alcohols, agricultural and sideline products, dry foods, and local products.
Applications in non-food applications such as labels and caps, closures, fibers and clothing, aerosol products, sporting goods, electrical products, cosmetics, pharmaceuticals, greases, detergents, stationery, toys, office supplies, kitchen supplies , daily necessities, sundries, building materials, etc.
At present, the application of heat shrinkable film in the domestic market mainly shows the following characteristics:
1) Widely used in fast food, ceramic products, tea sets, mechanical parts and other fields;
2) In the military machinery, hardware tools, the combination of heat shrinkable film and gas phase anti-rust technology to replace the anti-rust oil method, enhance the anti-rust ability, significant;
3) Heat shrinkable film is also the protector of construction and transportation materials. It is suitable for packaging of multiple products and packaging with trays. It is convenient for transportation and easy to sell. It is easy to mechanize, save labor and material resources, and can partially replace cartons and wooden boxes.
4) It is used for various PET bottled beer and beverage labels, which can reduce the process of removing labels and is easy to recycle and reuse;
5) It is used to replace the tying rope package with bottled beer to prevent bottled beer from blasting and injuring people.
Heat shrinkable film selection
Customers usually first consider the specific selection model from the cost. Heat shrinkable packaging and laminating film can usually achieve the same packaging effect, so how to decide which packaging film to use? In general, the main differences are the requirements for the packaging pattern, the frequency of packaging required, the shelf life requirements, and the physical properties of the packaging itself such as liquid, powder, granules, solids, squares, and the like.
The following guidelines will help the reader to choose the right packaging material:
The size of the food factory;
Whether the service target is industrial system or retail industry;
Adjustment requirements;
Shelf life requirements;
Anti-abuse requirements;
The shape of the product;
Whether it is used for preservation, freezing or other environmental requirements;
The consistency between the packaging production company and the customer culture.
The general retail industry requires orientation according to the needs of consumers, and pays more attention to the appeal of printing effects to consumers and the convenience of packaging.
It is different for industrial packaging, and it is more important to the uniqueness of the product and whether it is convenient for high-volume processing. In general, the choice of shrink-wrapped packaging takes into account the attractiveness of the packaging to the consumer and good sealing safety. Regarding the heat shrink film market and heat shrink film applications, there are still many corresponding technologies. Throughout the domestic and international market development, low temperature heat shrinking technology, low cost technology, multi-purpose adaptability, online packaging technology and high reliability technology have become The general trend of heat shrink packaging research. It is the continuous promotion of various new technologies, and the application fields of heat shrinkable packaging are becoming wider and wider.