Pet heat shrinkable film is a new type of heat shrinkable packaging material. Because it is easy to recycle, non-toxic, tasteless, good mechanical properties, especially in line with environmental protection, pet has become an ideal substitute to replace polyvinyl chloride (PVC) heat shrinkable film in developed countries.
definition
Ordinary polyester is a crystalline polymer. After special processing, ordinary PET film can only obtain a thermal shrinkage of less than 30%. In order to obtain polyester film with higher thermal shrinkage, it must also be modified. In other words, in order to prepare polyester film with high thermal shrinkage, polyethylene terephthalate, an ordinary polyester, needs to be copolymerized. The high thermal shrinkage of PET film modified by copolymerization can be as high as 70%.
Characteristics of heat shrinkable polyester film: it is stable at room temperature, shrinks when heated (above glass transition temperature), and more than 70% heat shrinks in one direction. The advantages of heat shrinkable polyester film packaging are: ① close to the body and transparent, reflecting the commodity image. ② Tight packing, good dispersion resistance. ③ Rainproof, moisture-proof and mildew proof. ④ No recoverability, with certain anti-counterfeiting function. Heat shrinkable polyester film is often used in convenience food, beverage market, electronic and electrical appliances, metal products, especially shrinkable labels. Because with the rapid development of PET beverage bottles, beverage bottles such as coke, Sprite and various fruit juices need pet heat shrinkable film as heat sealing labels. They belong to polyester, are environment-friendly materials and are easy to recycle.
In addition to being used as a shrink label, heat shrinkable polyester film began to be used on the outer packaging of daily commodities. Because it can not only protect the packaging items from impact, rain, moisture and rust, but also make the products win users with beautifully printed outer packaging. At the same time, it can well show the good image of the manufacturer. More and more packaging manufacturers use printing shrinkage film to replace the traditional transparent film. Because the printing shrinkage film can improve the appearance grade of the product, is conducive to the advertising of the product, and can make the trademark brand have a deep impression in the hearts of consumers.
Properties of pet shrink film
Unitization
This is one of the characteristics of shrink film packaging. With the strong winding force and retraction of the film, the product is compactly and fixedly bound into a unit, so that the scattered small parts become a whole. Even in an adverse environment, the product has no looseness and separation, and there is no sharp edge and viscosity, so as to avoid damage.
Primary protective
Primary protection provides the surface protection of the product, forming a very light and protective appearance around the product, so as to achieve the purpose of dust, oil, moisture, water and theft prevention. It is particularly important to wrap film packaging to make the packaged articles bear uniform force and avoid damage to the articles caused by uneven force, which can not be achieved by traditional packaging methods (binding, packaging, tape and other packaging).
Compression fixity
With the help of the retraction force after the stretching of the winding film, the products are wound and packaged to form a compact unit without occupying space, so that the pallets of the products are tightly wrapped together, which can effectively prevent the mutual dislocation and movement of the products during transportation. At the same time, the adjustable tensile force can make the hard products close to each other and tighten the soft products, Especially in the tobacco industry and textile industry, it has a unique packaging effect.
Cost saving
The use of winding film for product packaging can effectively reduce the use cost. The use of winding film is only about 15% of the original box packaging, about 35% of the heat shrinkable film and about 50% of the carton packaging. At the same time, it can reduce the labor intensity of workers and improve the packaging efficiency and packaging grade.
