In the field of printing and packaging, we all feel a new printing method - flexographic printing. Flexographic printing has unique flexibility, economy and is beneficial to the protection of the environment. At present, offset printing is more popular in China, and gravure printing has occupied a large market in the packaging industry. Flexographic printing is often used in cosmetic packaging box printing plants.
In the printing process, one of the key indicators that people often pay attention to is overprint, because the waste caused by inaccurate overprint often accounts for a large proportion of the total waste. Although flexographic printer manufacturers have provided a good foundation for accurate overprint in the process of design and processing, and the automatic monitoring system also provides guarantee for accurate overprint, the technical level and proficiency of operators also have a great impact on the overprint accuracy. If some adjustments can be made to facilitate overprint when designing ink drawings, it can greatly reduce the difficulty of printing and reduce the scrap rate. The simplest way is to use anti white words as much as possible when designing the original ink draft, or excavate between the two colors to form an anti white outline. You can also cover the third kind of slightly thicker dark outline at the edge of the overprint of the two colors. For the printing of finer prints, trap technology can be used. The amount of trap depends on the accuracy of the printer The quality of paper used for printing and the level of operators. Trapping processing is easy to realize on the computer. If there is no computer, there is only ready-made color separations. You can use a special trapping processor to input the value of trapping amount, and the machine will automatically produce a film that has been trapped. If there is no trapping processor, a transparent spacer can be placed between the color separation film and the copy film and exposed with a single point light copying machine, and films with similar effects can also be obtained.
When the printing factory makes resin plate and puts the flexographic plate on the plate making machine for front exposure, in order to ensure the quality of the fit between the film and the flexographic printing surface, the plate making machine is equipped with a vacuum pump to pump vacuum. At the same time, the side of the film close to the flexographic plate must be rough (frosted), so as to prevent bubbles remaining between the film and the flexographic plate from affecting the quality of the flexographic printing surface, The pressure strip used for pressing the edge of film and flexo should also be one with indentation and transverse air conduction.
