POF heat shrinkable film has its uniqueness in each film
edit：admin Time：2018-07-20 17:40:29
The shrinkable film label is a new type of label which is printed on plastic film or plastic tube. It mainly includes PE, PVC, PET and other common heat shrinkable film types.
1) shrink film sleeve label processing is convenient, packing is sealed, anti pollution, good protection for goods;
2) Shrinkage film cover is suitable for irregular commodities which are difficult to pack because it is close to commodities, compact in packaging and can display the shape of commodities.
3) when the label of the shrink film label is applied, it is not necessary to use adhesives and obtain the same transparency as the glass.
4) the shrinkable film label can provide a full range of 360 degrees to the packaging container, and can print the product information on the label, so that the consumer can understand the performance of the product without opening the package.
5) the printing of shrink film sleeve labels belongs to film printing, which can protect the imprinting effect and label wear resistance is better.
Shrinkage film sleeve is a kind of thermoplastic film which is stretched and directed in the production process, and is heated and contracted in the use process. In order to ensure the accurate reduction of patterns, characters and barcodes on the container, the transverse and longitudinal shrinkage of the material and the permissible deformation errors in all directions after the contraction should be taken into account before the design of the surface pattern.
Because it belongs to the category of heat shrinkable film, its material, characteristics and so on are not different from the general heat shrinkable film, but the printing is more exquisite.
Design points and material selection principle 1, label design
The design of the decorative pattern on the film sleeve should be determined according to the thickness of the film. When designing the pattern, it is necessary to make clear the transverse and longitudinal shrinkage of the film, and the allowable deformation error after shrinkage of all directions after packaging and the contraction of the decoration pattern, so as to ensure the pattern after contraction and the text can be accurately reduced.
2, thin film thickness and shrinkage
The material used to shrink the label of membrane covers three factors: environmental requirements, film thickness and shrinkage.
The determination of film thickness is based on the application area and cost factors of the label. Of course, the price is not a decisive factor, because each film has its uniqueness, and the printing plant of the user and the trademark must be clear about the process of the film and the most suitable material before the contract is signed. In addition, the required index and other process factors directly affect the selection of thickness. The thickness of the film is usually 30~70 micron m, of which 40 m and 50 m are used. In addition, there is a certain requirement for the shrinkage of the film, and the transverse (TD) shrinkage rate is higher than that of the longitudinal (MD) shrinkage. The transverse shrinkage of common materials ranges from 50% to 52% and 60% to 62%, which can reach 90% under special circumstances. The longitudinal shrinkage rate is 6% to 8%. When making shrink film labels, we should try to choose materials with smaller longitudinal shrinkage.
The materials for making the shrinkable film cover are mainly PVC (polyvinyl chloride) film, PET (polyacrylic) film, PETG (modified polystyrene) film and OPS (oriented polystyrene) film. The properties are as follows:
1, PVC film
PVC film is the most widely used thin film material at present. Its price is extremely low, the temperature shrinkage range is large, the heat source is not high, the main processing heat source is hot air, infrared or the combination of the two. But PVC is difficult to recover, and toxic gas is not conducive to environmental protection when burning. It has been banned in Europe and Japan.
2, OPS film
As a substitute for PVC thin films, OPS films are being widely used. It has good shrink performance and environmental protection. Now the product is in short supply in the domestic market. At present, the high quality OPS film is also mainly dependent on imports, which has become an important factor restricting its development.
3, PETG film
PETG copolymer membrane is not only beneficial to environmental protection, but also can pre adjust shrinkage. However, due to the excessive shrinkage, it will be limited in use.
4, PET film
PET film is an internationally recognized environment-friendly heat shrinkable film material. Its technical index, physical properties, application range and use method are close to PVC heat shrinkable film, but the price is cheaper than that of PETG film. It is the most advanced unidirectional shrinkage film at present. The transverse shrinkage rate of the film is 70%, the longitudinal shrinkage is less than 3%, and it is nontoxic and pollution-free. It is the ideal material to replace the PVC film.
Nowadays, there are many enterprises that make use of shrinkage film to make products, such as packaging bags to make products by using shrinkage film, and the golden dragon color printing is one of them.
In addition, the heat shrinkable film tube is also a material for producing shrink film sleeve labels, and it can be molded at one time without sewing. Compared with horizontally flattened thin film, the cost of heat shrinkable film sleeve label is relatively low, and printing on tube surface is difficult to achieve. At the same time, the graph and text of the heat shrinkable film tube label can only be printed on the surface of the film. It is easy to wear and tear in the process of transportation and storage, which affects the whole packing effect.
