Self-adhesive stickers have the advantages of no brushing, no paste, no drowning, no pollution, and saving labeling time compared with traditional stickers. All types of adhesive stickers can be applied to materials that are not suitable for general paper labels. It can be said that self-adhesive labels are a kind of universal label, and self-adhesive labels are printed with the traditional printed matter. There is a big difference in the ratio. Self-adhesive labels are usually printed on the label-driven engine, and multiple processes are completed at once, such as graphic printing, die-cutting, waste disposal, cutting and rewinding. Visible, self-adhesive labels on the printing process and printing equipment have higher requirements, so choose adhesive stickers should pay attention to several points:
(1) According to the type, grade, quality of the labeling object, the characteristics of the paste surface, the use environment, and the user's requirements. If a label made of a transparent polypropylene adhesive label is applied to a transparent bottle body, it can produce a non-labeled fashion sense, which can improve the grade of the product and stimulate consumers' desire to purchase. The PVC film's flexibility, shrinkage, opacity, processing characteristics, and labeling properties are all very good, and the colors are bright, contrasting, attract people's attention, and have the effect of promoting the promotion of goods.
(2) The surface of the film adhesive label must be smooth, dense, uniform in density, uniform in color and good in light transmittance, so as to ensure uniform ink absorption of the film and small color difference in the same batch of printed products.
(3) The thickness of self-adhesive labels should be uniform and the strength index should be qualified. The printing pressure applied during the printing process is related to the thickness of the sticker. If the thickness is not uniform, the printing pressure is not uniform, which may result in a deep or shallow ink on the sticker print. If the film strength is too poor, the film tension during the printing process is difficult to control and will have a great impact on die cutting and waste disposal.
(4) Self-adhesive labels should be flattened and the rewinding tension should be even. The flatness is good, and the correct conveying, running, registering and winding can be done when printing. The rewinding tension of the film should be even and appropriate, such as the tension is too small, the film substrate is loose, and the longitudinal and transverse overprinting is inaccurate; if the tension is too large, the substrate shrinks laterally, the color registration is unstable, and it is difficult to print normally.
(5) Membrane adhesive labels must also have the characteristics of corrosion resistance, aging resistance, no fading, shrinkage, and low expansion ratio. If the corrosion resistance is poor, it is easy to age and fade, then the label made is not durable, and it will also affect the sales and use of the product. If the ratio of shrinkage and expansion is large, the overprinting accuracy during printing will not only be affected, but also the label will be deformed during use, affecting the sales and use of the product. In particular, the labels of high-end goods should be avoided as far as possible, and the embarrassing situation that the labels have been aged (the aging of the labels including plastic aging and ink fade). If necessary, aging tests should be conducted on plastics or labels to check their performance.
(6) The self-adhesive stickers that are purchased must also maintain good adhesion within the validity period.