Compared with traditional labels, self-adhesive label stickers have the advantages of no brushing, no paste, no dipping, no pollution, and saving labeling time. It has a wide range of applications and is convenient and quick. All kinds of self-adhesive labels can be applied to materials that are incapable of general paper labels. It can be said that self-adhesive labels are a kind of label, and the printing of self-adhesive labels is the same as that of traditional printed matter. There is a big difference in comparison. Self-adhesive labels are usually printed and processed on the labeling linkage, and multiple processes are completed at one time, such as graphic printing, die cutting, waste discharge, cutting and rewinding. It can be seen that self-adhesive labels have higher requirements for printing technology and printing equipment, so there are several points to pay attention to when choosing self-adhesive labels:
⑴ Comprehensive consideration based on the type, grade, quality of the labeling object, the characteristics of the pasting surface, the use environment and the user’s requirements. If you want to use a label made of a transparent polypropylene sticker to be attached to the transparent bottle, it can produce a fashion feeling without a label, which can improve the grade of the product and stimulate the consumer’s desire to buy. The flexibility, shrinkage, opacity, processing characteristics and labeling characteristics of PVC film are very good, and the colors are bright, the contrast is large, it can attract people’s attention, and it has the effect of promoting and promoting products.
⑵ The surface of the film-type self-adhesive labels must 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.
⑶ The thickness of the self-adhesive label sticker must be uniform and the strength index must be qualified. The printing pressure applied during the printing process is related to the thickness of the sticker. If the thickness is uneven, the printing pressure will also be uneven, which will cause the writing or ink color of the label printing 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.
⑷ The self-adhesive label should be flat, and the rewinding tension should be even. The flatness is good, and it can be conveyed, run, registered and rewinded correctly during printing. The rewinding tension of the film should be uniform and appropriate. If the tension is too small, the film substrate will relax and the vertical and horizontal registration is not accurate; if the tension is too large, the substrate will shrink in the horizontal direction, the color registration will be unstable, and it will be difficult to print normally.
⑸ The film type self-adhesive label should also have the characteristics of corrosion resistance, aging resistance, non-fading, and small shrinkage and expansion ratio. If the corrosion resistance is poor, it is easy to age and fade, the made 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 for the labels of high-end products, try to avoid the embarrassing situation that the products have not expired and the labels are already aging (the aging of the labels includes plastic aging and ink fading). When necessary, the aging resistance test of plastic or label should be carried out to test its performance.
⑹ The purchased self-adhesive labels should also maintain good stickiness within the validity period.