Details determine the quality of POF heat shrinkable film

The details determine the quality of POF heat shrinkable film! Generally speaking, a lower density can improve the heat sealability of the film, while a higher density can improve the rigidity, impact strength and tear strength of the film, but its heat shrinkability is slightly reduced. This is mainly due to the higher crystalline melting point, which can be compensated by changing the inflation ratio or traction ratio. Experience has proved that the best resin density is 0.918～0.924. The melt index of the resin is small, the molecular weight is high, there are many entanglement points between the molecules, and the impact strength and shrinkage stress of the film are large. Generally, raw materials with a melt index (M1) of 0.3 to 1.0 are suitable. The melt index is best not to exceed 5, otherwise the shrinkage stress of the film will be significantly reduced, and the shrinkage in both vertical and horizontal directions will not be easily balanced. Specifically, according to the different packaging uses, the melt index can be divided into three categories: MIu003c0.6, suitable for shrink packaging of heavy goods and pallet goods; MI between 0.6 and 1, suitable for shrink packaging of light packaging ;MIu003e1.0, suitable for shrink packaging that does not require high strength and shrinkage. The film produced by a resin with a narrow molecular weight distribution has a low shrinkage temperature; conversely, a high shrinkage temperature. In addition, the degree of branching of the molecular chain has a great influence on the stretching characteristics of the film. It is said that mixing a resin with a degree of culture of less than 10 (MI is 0.5 to 3.0) and a degree of branching of 10 to 30 can greatly improve the stretchability of the film. The degree of branching is greater than 10, which has little effect on improving the tensile properties. And the degree of branching is equal to 10, the stretchability of the film at high temperature is very unsatisfactory. The heat shrink packaging machine uses shrink film to wrap the product or package outside. After heating, the shrink film wraps the product or package tightly, fully showing the appearance of the item, improving the product displayability, and increasing the beauty and sense of value. At the same time, the packaged items can be sealed, moisture-proof, and pollution-proof, and protect the product from external shocks. It has a certain cushioning property, especially when packaging fragile items, it can prevent the utensils from flying when broken. my country has a large population, a relatively large consumer group, and the circulation of products is relatively fast. Different products must go through certain packaging. The shrinking machine uses shrink film for packaging items, which greatly reduces the packaging cost, and the shrinking machine tightly wraps the shrink film on the surface of the item, so that it saves a lot of space both in storage and transportation. At the same time, the shrink packaging machine is sustainable and environmentally friendly packaging. At present, food packaging machinery has become an indispensable packaging machinery for food production enterprises with the continuous development of my country's market economy. Shrinking machines have also emerged from the initial disapproval to now on the packaging production line. Through a survey of nearly 20 well-known companies in beverage, daily chemical, pharmaceutical, beer and other major industries, it is found that the biggest reason for the affirmation of heat shrink packaging technology is mainly: it can reduce costs, promote sales, and increase shelf display. With the diversification of packaging forms by heat shrink packaging, it is more conducive to promotion, and it has the flexibility to adapt to different specifications, especially the small-size product cluster packaging can save nearly 10 million yuan in the medical industry heat shrinking instead of carton. Some pharmaceutical packaging companies said that because the pharmaceutical industry has relatively low requirements for external packaging, companies use heat-shrink packaging to reduce the total cost by reducing the cost of packaging materials. It is expected that in the next 3 to 5 years, with the development of heat-shrink packaging technology and the continuous improvement of heat-shrinkable film pressure capacity, in certain specifications of packaging, the cuff heat-shrink packaging machine can completely replace the carton or heat-shrinkable half-tray box. The packaging machine will have more room for development.