On the characteristics, advantages and selection p

Talking about the characteristics, advantages and material selection principles of shrink film labels

release date: Source: China print flexible packaging editor: Yu Jia browse times: 7318 copyright and disclaimer

core tip: shrink film label is more and more popular in the market because it can combine high-quality patterns and distinctive shapes. What are the characteristics, advantages, design and material selection principles and production points of shrink film labels? This article is explained in detail for reference

[China Packaging News] shrink film cover labels are becoming more and more popular in the market because they can combine high-quality patterns with distinctive shapes. What are the characteristics, advantages, design and material selection principles and production points of shrink film labels? This article is explained in detail for reference

concept and advantages

shrink film sleeve label is a kind of film sleeve label printed on plastic film or plastic pipe. It has the following characteristics:

1. The shrink film sleeve label is easy to process, the package is sealed, anti pollution, and has good commodity protection

2. The film sleeve is close to the commodity, the packaging is compact, and the commodity shape can be displayed, so it is suitable for irregular commodities that are difficult to package

3. When labeling the shrink film sleeve, there is no need to use adhesive, and the same transparency as glass can be obtained

4. The shrink film label can provide 360 ° all-round decoration for the packaging container, and can print commodity information such as product description on the label, so that consumers can understand the performance of the product without opening the package

5. The printing of shrink film cover label belongs to film inner printing (pictures and texts are on the inner side of the film cover), which can protect the imprint, and the label has better wear resistance

design points and material selection principles

1. Label design

the design of decorative patterns on film covers should be determined according to the thickness of the film. When designing the pattern, we should first make clear the horizontal and vertical shrinkage of the film, as well as the allowable shrinkage in all directions after packaging and the allowable deformation error of the decoration pattern after shrinkage, so as to ensure that the contracted pattern and text can be accurately restored

2, film thickness and shrinkage

materials used for shrink film sleeve labels should focus on three factors: environmental protection requirements, film thickness and shrinkage performance

the basis for determining the film thickness is the application field and cost factors of the label. Of course, price is not the decisive factor, because each film has its own uniqueness. Users and trademark printing manufacturers must clarify the film used and the process of the most suitable material before signing the contract. In addition, the indexes required by processing equipment and other process factors also directly affect the selection of thickness. Generally, the film thickness of the shrink film sleeve label is required to be 30 ~ 70 μ m. Of which, 40 μ m、50 μ M films are widely used. In addition, there are certain requirements for the shrinkage of the film, and the transverse (TD) shrinkage is higher than the longitudinal (MD) shrinkage. The transverse shrinkage of commonly used materials is 50% - 52% and 60% - 62%, and can reach 90% in special cases. The longitudinal shrinkage is required to be 6% - 8%. When making shrink film sleeve labels, try to choose materials with small longitudinal shrinkage

film materials

the materials for making shrink film sleeve labels mainly include PVC (polyvinyl chloride) film, pet (polyester) film, PETG (modified polyester) film, OPS (oriented polystyrene) film, etc. Its properties are as follows:

1, PVC film

PVC film is the most widely used film material at present. It has low price, large temperature contraction range and low requirements for heat source. The main processing heat source is hot air, infrared or a combination of the two. However, PVC is difficult to recycle and produces toxic gas when burning, which is not conducive to environmental protection, and has been banned in Europe and Japan

2. OPS film

as a substitute for PVC film, OPS film has been widely used. It has good shrinkage and is also conducive to environmental protection. The domestic market of this product is in short supply. At present, high-quality OPS mainly depends on imports, which has become an important factor restricting its development

3. PETG film

petg copolymer film is not only conducive to environmental protection, but also can adjust the shrinkage in advance. However, due to the excessive shrinkage, it will also be limited in use

4. PET film

pet film is an internationally recognized environmental friendly heat shrinkable film material. It 1. How to install the hydraulic universal testing machine? Its technical indicators, physical properties, application scope and use method are close to PVC heat shrinkable film, but the price is cheaper than PETG. It is the most advanced unidirectional shrinkable film at present. The horizontal shrinkage rate is 70%, the longitudinal shrinkage rate is less than 3%, and it is non-toxic and pollution-free. It is the most ideal material to replace PVC

in addition, the heat shrinkable film tube is also the material for the production of shrinkable film sleeve labels, and it can be formed at one time without stitching in production. Compared with horizontal flat film, the cost of producing shrink film sleeve labels with heat shrinkable film tubes is lower, but it is difficult to print on the surface of the tube. At the same time, the pictures and texts of the heat shrinkable thin film adjusting and loading mechanism as a horizontal moving film tube label can only be printed on the surface of the film. The relevant objects can be measured manually to ensure the normal measurement work. The pictures and texts are easy to be worn during transportation and storage, thus affecting the packaging effect

shrink film sleeve label printing

1, printing

print on the selected film. At present, the printing of shrink film cover mainly adopts gravure printing, using solvent based ink, followed by flexographic printing. With the development of flexographic printing technology, the printing color is bright and clear, which is comparable to gravure printing, and has the thickness and high gloss of gravure printing. In addition, flexo printing uses water-based ink, which is more conducive to environmental protection

2. Slitting

use a high-performance slitter to Slitter the printed roll film material longitudinally, and at the same time, process the edge of the film to make it smooth, flat and non crimping. When using the slitter, care should be taken to avoid heating the blade, because the heated blade will wrinkle the slitted part of the film

3. Suture

the longitudinally cut film is sewn in the center with a sewing machine, and the nozzle is bonded to form the film sleeve required for packaging. The material allowance required for stitching depends on the stitching accuracy and the skill of the operator. The maximum allowable amount of stitching is 10mm, usually 6mm

4. Horizontal cutting

wrap the film sleeve outside the commodity, and use the slitter to cut horizontally according to its packaging size. Under proper heating temperature, the length and width of the shrink film will shrink sharply (15% - 60%). Generally, the film size is about 10% larger than the maximum size of the commodity

5. Thermal shrinkage

heating through hot channels, hot ovens or hot-air guns. At this time, the shrink label will quickly shrink along the outer contour of the container, closely fit with the outer contour of the container, and form a label protective layer completely consistent with the shape of the container

in the production process of shrink film sleeve label, each process should be closely tested by a special detector to ensure the production accuracy

scope of application

shrink labels have strong adaptability. They can decorate and decorate the surface of wooden, paper, metal, glass, ceramics and other packaging containers. They are widely used in the packaging and decoration of food, daily chemical products and chemical products, such as various beverages, cosmetics, children's food, coffee and so on. In the field of drug labels, paper is still the main substrate, but the development of film packaging has become increasingly rapid. At present, the key to the development of shrink film labels is to reduce costs. Only in this way can we improve competitiveness and strive for greater market share