Film labels have many advantages, such as beautiful appearance, abrasion resistance, water resistance, corrosion resistance, not easy to be torn, good transparency, etc. They are now widely used in daily chemicals, electronics, wine, food, medicine, health care products and other industries. , When choosing film raw materials, it is necessary to select films with qualified physical and chemical indicators.
1. According to the comprehensive consideration of the type, grade, quality of the subject matter, the characteristics of the pasted surface, the use environment and the user’s requirements, if a label made of a polypropylene film with good transparency is attached to a transparent bottle, it can produce no label. Fashionable feeling can improve the grade of goods and stimulate consumers’ desire to buy. PVC film has very good flexibility, shrinkage, opacity, processing characteristics and labeling characteristics, and the colors are bright and the contrast is large. It can attract people’s attention and has the effect of promoting and promoting products.
2. The surface of the film should be smooth and dense, uniform in density, consistent in color, and good in light transmittance to ensure uniform ink absorption and small color difference of the same batch of printed products.
3. The film thickness must be uniform and the strength index must be qualified. The printing pressure applied during the printing process is related to the film thickness. If the film thickness is uneven, the printing pressure will also be uneven, which will cause the writing or ink color of the printed matter to be dark or light. If the film strength is too poor, it will be difficult to control the tension of the film during the printing process, which will have a great impact on die cutting and waste discharge.
4. The film should be flat and the rewinding tension should be even. The flatness of the film is good, and it can only be conveyed, run, registered and rewinded correctly during printing. The rewinding tension of the film must be even and appropriate. The substrate shrinks horizontally, the color register is unstable, and it is difficult to print normally.
5. The film must have the characteristics of corrosion resistance, aging resistance, non-fading, low shrinkage and expansion ratio, such as poor corrosion resistance, easy aging, and fading, the label will not be durable, and it will also affect the sales and use of the product. If the shrinkage and expansion ratio is large, it will not only affect the overprint accuracy during printing, but also deform the label during use, which will affect the sales and use of goods, especially the labels of high-end goods. Try to avoid the unexpired goods. As for the embarrassing situation of aging labels (label aging includes plastic aging and ink fading, etc.), when necessary, the aging resistance test of plastics or labels should be carried out to test their performance.
6. The purchased film should be within the validity period and not be damp.