Pre-press processing of heat shrinkable film labels

Pre-print processing of heat shrinkable film labels Release time: 2018-11-13 　　 As a heat shrinkable film label, during the printing process, shrinkage deformation is inevitable, sometimes even more serious, and in different directions and positions The shrinkage and deformation may be different. Therefore, how to design the shrinkage deformation error of graphics and bar codes before printing is the difference between making heat shrinkable film labels and other printed materials. 1. The pre-printing treatment of heat shrinkable film theoretically believes that to obtain good printability on plastic film, the surface tension of the film should be higher than that of the ink, and the surface should have a certain degree of roughness to form an adsorption force. .　　 The polyolefins in the plastic film, such as PP and PE film, are non-polar polymer materials with stable chemical properties, low surface tension, lower than the tension of the ink, and poor adhesion to the ink. Although the surface tension of some films is equal to or higher than that of the ink, their surface is smooth, and the surface without pores is small. At the same time, the opening agent, antistatic agent, anti-aging agent, etc. added in the synthetic resin of various films will also affect The surface properties of the film make its printability worse. Therefore, there are some printability problems in most shrink films at present. Therefore, in order to improve the printability of the film surface, the surface of the film with poor printing performance must be pretreated to increase the surface tension and surface adsorption. Commonly used methods include corona treatment, plasma treatment, chemical treatment, coating treatment and so on. 2. To determine the size of the label image and text, first determine the heat shrinkable film label based on the thickness of the shrink film, the horizontal and vertical shrinkage rate of the film, the allowable shrinkage rate in all directions after packaging, and the allowable deformation error after the image and text shrink and deform. The size of the image and text on the upper side to ensure that the image and text after shrinkage and deformation can be accurately restored. 3. The graphic design of the heat shrinkable film label The graphic design of the heat shrinkable film label needs to consider the appearance of the container. The designer of the pre-press department needs to correct some parts of the label and try not to place the key image Places with high shrinkage. In addition, you can also cooperate with the container manufacturer to make the density of the container appropriate. Whether it is in a smaller size or a larger size, it can provide the correct shrinkage rate. Printing process: 　　 At present, the printing of heat shrinkable film labels mainly adopts gravure printing, using solvent-based inks, because the gravure printing plate has high precision, the printing quality of gravure printing on the film is the best among all printing, and the ink layer has a strong three-dimensional effect. , Rich graphics and text levels. Moreover, the printing plate has a high printing resistance rate, which is suitable for long-run work, and the print volume of the label is often relatively large, so gravure printing is more suitable. However, the gravure printing is complicated, the cycle is long, the cost is high, and the pollution is easy. The second is flexographic printing. With the development of flexographic plate making and printing technology, the printing colors are bright and clear, with the thick and high gloss of gravure, and the flexo printing mostly uses water-based inks, which is beneficial to environmental protection. Therefore, environmental protection requirements are improved. Plate printing will have greater applications. In addition, offset printing and digital printing also have a certain range of applications to meet the specific needs of customers. The heat-shrinkable film label is not as popular as the self-adhesive label under the advantage of a large number of shares, because it does not have too many difficult obstacles to overcome, and is not enough to attract the curiosity of the printing industry; in addition, the overall level of heat-shrinkable labels is low. The limitation in market expansion and process development is also the reason for its poor popularity. However, judging from the current application status of heat shrinkable labels, this kind of label will be used more and more, but the form will not change, only the material will be improved, and it will be more environmentally friendly, and the future trend will be environmentally friendly. Direction development. Previous: There are two ways to use process heat shrinkable film labels