The details determine the good or bad of the POF heat shrinkable film
edit：admin Time：2018-07-20 17:40:22
The details determine the good or bad of the POF heat shrinkable film. In general, the lower density can improve the thermal compatibility of the film, and the higher density can increase the rigidity, impact strength and tear strength of the film, but the thermal shrinkage of the film is slightly decreased. This is mainly due to the higher melting point of crystals, which can be compensated by changing blowing ratio or traction ratio. Experience shows that the optimum resin density is 0.918 to 0.924.
The melt index of resin is small, the molecular weight is high, the entanglement point between molecules is more, and the impact strength and shrinkage stress of film are large. The raw material with a melt index (M1) of 0.3 to 1 is suitable. The melt index should not exceed 5, otherwise the shrinkage stress of the film will be significantly reduced, and the longitudinal and horizontal shrinkage is not easy to be balanced.
Specifically, according to the different packaging uses, melt index can be divided into three categories.
MI<0.6, suitable for heavy goods and pallet goods shrink packaging;
MI is between 0.6~1, suitable for shrink packaging of light package.
MI>1.0, suitable for shrink packaging with low strength and shrinkage requirements.
The films produced by resins with narrow molecular weight distribution have low shrinkage temperature; otherwise, the shrinkage temperature is high. In addition, the branching degree of the molecular chain has great influence on the tensile properties of the films. It is said that the tensile properties of the films can be greatly improved by mixing resins with a degree of culture less than 10 (MI 0.5-3.0) and a degree of branching of 10-30. The degree of branching is greater than 10, which has little effect on improving tensile properties. While the branching degree is equal to 10, the tensile properties of the film at high temperature are very unsatisfactory.
Heat shrinkable packaging machine is wrapped in the outside of the product or package by shrinking film. The shrinkable film is wrapped up by heating to wrap the product or package. It can fully display the appearance of the goods, improve the product's display, and increase the beauty and the sense of value. At the same time, the articles after packaging can be sealed, moisture-proof, anti pollution, and protect the goods from the external impact. It has a certain buffer, especially when the packaging is fragile, it can prevent the wares from breaking and flying.
China has a large population, a large number of consumers, the circulation of products is relatively fast, different products have to go through a certain packaging. The contract machine uses the shrinkage film to pack the goods, which greatly reduces the packaging cost, and the shrinkage machine is tightly wrapped in the exterior of the goods, so that it saves space greatly in both storage and transportation. At the same time, the thermal shrink packaging machine is a sustainable environmental protection package.
At present, with the continuous development of the market economy in China, food packaging machinery has become an indispensable packaging machinery for food production enterprises. Through the investigation of nearly 20 famous enterprises in several major industries, such as beverage, daily chemical, medicine and beer, it is found that the biggest reason of heat shrinkable packaging is that it can reduce cost, promote sales and increase the effect of shelf display.
As the heat shrinkable packaging makes the packaging form diversified, it is more conducive to the promotion, and has the flexibility for different specifications, especially the small size of the product cluster packaging in the medical industry heat shrinkable replacement paper box can save nearly ten million yuan. Some pharmaceutical packaging enterprises say, because the requirements of the pharmaceutical industry are relatively low, so the use of heat shrinkable packaging is more to reduce the cost of packaging materials to reduce the total cost.
It is expected that in the next 3~5 years, with the development of heat shrinkable packaging technology and the continuous improvement of the bearing capacity of heat shrinkable film, the cuff heat shrinkable packer can completely replace cartons or heat shrinkable semi - pallet boxes in a certain specification of packaging. The heat shrinkable packer will have greater development space.
