At present, most small and medium-sized enterprises in the country generally do not have air-conditioning equipment. Most of the measures are to sprinkle some water near the machines to increase air humidity. For non-network printing products that do not require high printing quality, you can use the spray cylinder to spray water on the edge of the paper and then print on the machine. When the air humidity in the workshop is high, the cut paper is best covered with a plastic cover to prevent the moisture from getting too long. If it is the printing of the second printing, you can use the method of borrowing lines to compensate for the image's contractility.

4 o'clock overprint processing advice:

1, try to use cross-filament when printing. The paper has horizontal and vertical threads. During the papermaking process, the papermaking department, because the pulp (vegetable fiber) flows vertically to the moving screen, the fibers are suddenly accelerated, and most of them are linked together along the direction of movement of the screen, forming what we call Vertical and horizontal wire. The plant fibers in the paper are all hollow translucent tubes. We can say vividly that the length direction of the fibers themselves is what we call longitudinal warp, and the direction of the fiber and fiber gaps is transverse warp. The experimental results show that the condensing force of the fiber itself is greater than the binding force (mainly hydrogen bonding force) between the fibers. After the paper is wet, the telescopic extension in the longitudinal direction is smaller than that in the horizontal direction, which is approximately 1:2. Therefore, overprinting more accurate products must take into account the paper's vertical and horizontal deformation. Therefore, when printing, make the longitudinal twist direction of the paper parallel to the axis of the drum, and the same batch of printing paper should be consistent in the direction of the strand.

2, overprint water (commonly known as water pressure). In the case that printing paper is not well understood, in order to prevent the paper from elongating in printing, a method of overprinting the water once may be used to adapt the paper to the printing requirements and then start printing the color. This method does not solve overprinting. Have a certain role.

3, control the printing plate surface moisture. The moisture content of the printing plate is a key factor in controlling the retractability of the paper. The moisture of the plate is transmitted to the paper through the blanket. The greater the moisture content of the plate, the greater the retractability. Therefore, it is better to control the moisture content of the layout, especially when printing 80 g of offset paper.

4, using a pull machine to lengthen the printing plate. Generally monochrome machine in the third, four-color printing process, two-color machine in the second printing process, the image of the paper has a longer stretch, resulting in overprinting is not allowed. This is due to the fact that the PS plate material has good ductility and can be stretched by the plate-pulling machine so that the image of the plate plate and the image on the paper are stretched in a balanced manner so that the overprint is correct.

In general, there are many methods to solve the problem of over-printing and un-calibrated processes. It is generally possible to solve the problem by strengthening the discussion and management of the printing process.