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How to do front exposure in hardcover printing

The front cover is required for the hardcover printing process, and the front exposure is also called the main exposure, which forms the printed portion of the flexographic plate. The proper positive exposure and back exposure in the process of hard-box printing can produce high-quality printing plates that meet the requirements of various graphic types. Generally speaking, the lack of positive exposure will cause the bottom of the shoulders around the graphic to be brushed off, which will affect the service life of the printing plate. Excessive positive exposure will cause insufficient corrosion, which may cause paste and form waste during printing. Before conducting the frontal exposure experiment, we advocated that the operator prepare an experimental "sample" for the manufacture of flexographic plates. The "samples" should contain subtle whitening, general anti-white and solid, general graphic, subtle Lines and characters, dots and other basic printed graphic types, and a certain number of network lines (such as 150lpi) from 10% high to a higher field are reflected in the "sample". The positive exposure experiment can be performed by using a "sample" on the plate-making machine by partial concealment and repeated exposure. In the early stage, you can start from a less difficult transaction, from easy to difficult, gather experience, and fully grasp the skills of the flexible version.

In theory, the more precise the image is, the longer the positive exposure time is, but keep in mind the effect of it and back exposure. For example, the back exposure and the positive exposure are less demanding in reverse white, and the fine dot is longer in the back exposure and the positive exposure because of the shallower corrosion depth. Through the exploration and practice of general time, the plate-making operator should understand the limits of his own plate making, such as thin lines, smaller characters, dense dots and 3% of the dots can stand up, 50% of the dots are highlighted. Whether to "open up" and so on.

What should I pay attention to when washing and drying?
As the number of times of solvent application increases, the timing of brushing the plate should be properly extended; adjust the orientation between the brush and the plate according to the different plates, and then adjust the pressure of the brush and the surface of the plate; if the system is particularly fine At the outlet point, the pressure of the fine brush should be further reduced on the basis of the gauge thickness orientation to prevent the dots from being washed away. The drying temperature is about 50. c, the time is about 1.5~2 hours; should be taken out a few times during the drying process, check the appearance of the layout for solvent mottle or other burrs, use a clean cloth that can not use fiber, dip some fresh solvent, quietly scrub the version The appearance is then placed back in the drying oven for continuous drying. Post-exposure and de-bonding of the plate can greatly improve printability. The prepared flexographic plate is preferably placed for 12 hours and then tack-printed, in order to completely evaporate the residual solvent absorbed into the printing plate during the plate making process. In general, in the actual operation, the flexographic plate-making personnel must work closely with the personnel of the ink draft planning, film production and printing departments to communicate with each other and timely summarize the lessons learned in order to improve the overall level of flexographic printing.
Pharmaceutical products are related to our future sacredness, and the quality of their packaging directly affects our health. With the extensive use of high-tech in the field of printing, a variety of innovative packaging is also emerging. In the new packaging printing method, thermal handling printing technology has been implemented in the flexible packaging of medical products. It not only has the advantages of changing the printing information, and is suitable for different substrates and various irregular appearances, and the labels printed by this method also have a certain anti-counterfeiting effect. With the continuous improvement of thermal handling printing technology, the gradual progress of printing film, ink and other materials, it is certain that thermal handling printing will have a greater effect in future flexible packaging of pharmaceutical products.