(Summary description)In the printing process, printed matter is prone to inaccurate overprinting. Overprinting is the basis for achieving color reproduction, and it is also the key to ensuring print quality. When evaluating the quality of printing, the accuracy of overprinting and color standards are both important. Inaccurate images are in a fuzzy state and can be judged directly with the printed sheet. Generally, there are regular lines such as registration lines and corner lines on the printed sheets, and the overprint can be judged by comparison. Is it accurate?
From the point of view of the printing press, the paper has a strict handover relationship in the transfer process of paper feeding, regular parts, paper grippers, transfer rollers, and delivery teeth. The essence is to ensure that the paper is conveyed accurately and accurately. No paper allowe
In the printing process, printed matter is prone to inaccurate overprinting. Overprinting is the basis for achieving color reproduction, and it is also the key to ensuring print quality. When evaluating the quality of printing, the accuracy of overprinting and color standards are both important. Inaccurate images are in a fuzzy state and can be judged directly with the printed sheet. Generally, there are regular lines such as registration lines and corner lines on the printed sheets, and the overprint can be judged by comparison. Is it accurate?
From the point of view of the printing press, the paper has a strict handover relationship in the transfer process of paper feeding, regular parts, paper grippers, transfer rollers, and delivery teeth. The essence is to ensure that the paper is conveyed accurately and accurately. The phenomenon of paper out of control is not allowed, and it can be summarized in one sentence: "The paper must always be properly and firmly controlled during the paper path, so as to ensure the accuracy of overprinting."
Now focus on explaining the fault of inaccurate overprinting from a technological perspective. Inaccurate overprinting can be directly judged by the printed sheet. This inaccurate overprinting situation can be divided into three categories: 1. The position of the post-printed image is equidistant to one side. This failure is caused by the inconsistency between the image of the printing plate and the position of the paper. 2. The position of the post-printed image is unevenly deviated. It may be that the crosshairs are registered on one side and the other side is not. This inaccuracy is caused by the inconsistency between the existing image size on the paper and the newly printed image size. 3. Partial image registration is not accurate. This situation only occurs on a small area of the printed sheet, and when this type of failure is serious, paper wrinkles often appear.
There are also three reasons for the above inaccurate overprinting, namely, improper adjustment of the printing press, expansion and deformation of the paper, and improper lining of the cylinder. We also need to have corresponding solutions: 1. Operate the printing equipment according to the technical instructions; 2. Set up a special printing paper library, the printing paper should preferably be ready-made; 3. Strictly follow the technical data to replace the printing consumables (including Lining, plate film, PS plate and blanket, etc.). As long as the master printer pays attention to accumulating experience and pays attention to the operating method of the printing press, it is easy to solve the inaccuracies in the printing of printed products due to the process.
