Do you know the technical standards and material characteristics of heat shrinkable film?

With the implementation of global environmental standard ISO14000, people pay more attention to new degradable plastics. BASF, Germany, has introduced a degradable polyester resin polymerized by aliphatic diol and aromatic dicarboxylic acid for ECOHEXD, which can be used for film production. According to reports, the annual demand for degradable plastics in Western Europe is 20,000 tons, mainly used in compost bags, garbage bags, plastic films, composite papers, fast food packaging containers and beverage cups. Heat shrinkable film is a thin film made by arranging chain-like molecules without ship engraving in vertical and horizontal directions through a drawing process, and the thin film family with molecular orientation obtained through drawing has excellent performance.

Foamed plastics move towards environmental protection: the extruded foamed PP village of Italian A-MUT company is a relatively new development of foamed plastics products. It uses MOH-TELL company's high viscosity resin, high melt strength polypropylene, PP homopolymer and low ODP chemical foaming agent to produce foamed polypropylene sheets with fine micropores and uniform distribution. HMSPP used in foamed PP accounts for only 12%. 5%, which has great economic and environmental significance: compared with PP sheets with the same properties, it has low product density and can save 20% of raw materials, thus saving 20% of the expenses to be paid for destroying the ecological environment. The production of foam plastics for packaging is developing along the road of CFC→HCFC→HFC→HC, and now it is advancing to a green process with zero ODP, low GWP and low pollution.

The outstanding feature of heat shrinkable film is the phenomenon of shrinkage recovery. That is, when the heat shrinkable film is created, the heating well is stretched in the corresponding direction in advance, and then the inkstone is cooled, so that the chain molecules are arranged in the stretching direction. When the film is reheated to the quietness during stretching, the chain molecules return to the original disordered state, and the thin size also returns to the size before stretching, that is, the phenomenon of shrinking X is produced. The heat shrinkable label is mainly gravure printing, and the printed graphics and texts are bright in color and good in saturation. Because it can decorate the packaging container closely, it can highlight the appearance of the goods and improve the appearance decoration of the goods, which can produce a good shelf effect. In the process of labeling, the label and container can be integrated without using adhesive, which can realize the large-scale on-line operation of goods and reduce the production cost.

At present, the application of heat shrinkable film in the domestic market mainly shows the following characteristics:

1, used for bottled beer instead of strapping rope packaging, to prevent bottled beer explosion injury;

2. It has been widely used in fast food, ceramic products, tea sets and mechanical parts.

3. It is of great significance to apply the combination of heat-shrinkable film and gas-phase antirust technology to replace antirust oil in machinery and hardware tools to enhance antirust ability.

4. Heat shrinkable film is also the patron saint of building and transportation materials. It is not only suitable for the packaging of multiple products and packaging with pallets, but also convenient for transportation and sales, easy to realize mechanization and save labor and material resources, and can partially replace the packaging of cartons and wooden cases;

5. It can be used to label various PET bottled beer and beverages, which can reduce the process of removing labels and facilitate recycling;

POF heat shrinkable film is a widely used and environmentally friendly packaging film in the market at present, which is favored by manufacturers and consumers, and has opened up the first wave of green packaging in China. POF heat shrinkable film is gradually replacing PE and PVC packaging films, taking the leading position in the packaging film market. The production process of POF heat shrinkable film is clean, and the consumption of raw materials per unit area is low, so it is an environment-friendly packaging film with development potential and market prospect.

First, the physical POF is thin and tough, with uniform thickness, good properties and soft texture. Tensile strength, tear strength, adjustable shrinkage. Because of the existence of LLDPE, it has good rubbing resistance. PE is thick and tough, with uniform thickness, good properties and soft texture. The tear strength is lower than POF, but much higher than PVC, and the shrinkage rate is poor. Rubbing resistance is not as thick and brittle as POF.PVC, with uniform thickness, poor properties and hard and brittle texture. Low strength, low shrinkage and poor rubbing resistance.

Second, cold resistance and other physical properties POF has excellent cold resistance, is not hard or brittle at -50℃, and is not easy to break, so it can be used for frozen food packaging.

Third, the cost POF has a specific gravity of 0.92, a thinner thickness of 0.012mm, and a lower actual unit cost. The specific gravity of PE is 0.92, the thickness is thinner than 0.03, and the actual unit cost is higher. The specific gravity of PVC is 1.4, the thickness is 0.02mm, and the actual unit cost is higher.

Heat shrinkable film is designed based on the principle of stretching and orientation of high-extraction molecular chain, and shaped by rapid cooling. Its physical principle is: when the ionomer 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 molecular movement, and the molecules return to their original state, resulting in contraction.