Prepress processing of low-grade printing paper

Recently, a batch of printing jobs are using lower grade papers, and there are phenomena such as flounces, tight edges, and wrinkles on the paper. The surface of the paper is rough and the black filler floats on the surface of the paper. Paper often appears during the printing process. Defects caused by paper feeding, due to paper defects caused by printed products appear defective, waste, not only seriously affect the progress of the work, resulting in a great waste of raw materials, but also affect the quality of printed products:

After repeated practice and active exploration, we have solved the problem of unstable quality of printed products when using low-grade printing paper through the following methods during the course of our work. That is, according to the problem of uneven quality of paper, paper is selected according to A, B, and C (A: printing paper, B: proofing paper, C: other paper), and the selected A-grade product is taken as Printing paper on the machine, and then deal with from the following three aspects.

l, for non-plastic deformation, an appropriate increase in paper drying time, and the paper shop's temperature and humidity and the printing plant's temperature and humidity consistent, on the machine before the paper stored in the printing shop for 3 to 5 days, so that the paper contains The trend of water balance is to prevent phenomena such as image ghosting caused by the sheet's lotus leaf. In doing so, the physical properties of the paper can be kept as stable as possible, achieving the requirements for printing on the machine.

2, for plastic deformation, in the state of close to the ideal pressure, only the water does not under the ink, so that the machine on the press in the state of the press under the air run twice, with the help of the pressure between the blanket cylinder and the impression cylinder to make the paper reach The maximum deformation, so that in the actual printing operation, the difference between the size of the first color printing graphics and the theoretical size and the difference in the same direction tends to zero, to enhance the stability of the overprint accuracy of printed products.

3. For the paper-transformation, install a static elimination device on the paper-feeding section and the paper-receiving section of the offset press to eliminate paper static electricity and absorb debris from the paper to prevent paper dust and paper hairs from attaching to the plate and eraser. Cloth, to eliminate the sticky dirt and other problems that are difficult to solve, to eliminate the paper due to electrostatic adhesion and double-sheet, Zhang Zhang and other transport failures.