At present, handbags and paper bags are widely used in the packaging of clothing, food, leather shoes, gifts, tobacco and alcohol, medicines and other commodities. Some handbags and paper bags have to go through many processing procedures, such as offset printing, gold printing, silver printing, bronzing, film covering, indentation, folding, bonding, punching, punching, threading and so on. Cheng Jian
In order to make handbags and paper bags more exquisite and meet the requirements of customers, what points should be paid attention to in the production of printed handbags?
1. Adjust the printing pressure
Handheld paper bags often use 250 ~ 400 g/m2 white board paper, which is thick and puts forward strict requirements for the adjustment of printing pressure. During adjustment, the center distance between the printing plate cylinder and the rubber cylinder remains unchanged, and only the center distance between the impression cylinder and the rubber cylinder needs to be adjusted. When printing a whiteboard with a basis weight of 250 ~ 450 g/m2, the center distance of the photosensitive drum can be increased by 0.20 ~ 0.40 mm In addition, due to the poor smoothness of the surface of the whiteboard paper, the density is far less than that of the coated paper, so it is necessary to pay attention to increasing the printing pressure accordingly. In order to adjust the printing pressure, the thickness of the rubber roller liner can also be increased or decreased.
2. Adjust the paper feeding part of the offset press
When printing white board paper, coated paper, cardboard and kraft paper, due to the heavy weight of paper, the air volume of paper suction nozzle and paper blowing nozzle in the paper conveying part should be increased accordingly. The paper separation nozzle should be replaced with a rubber ring with larger diameter and thicker thickness; The compression spring of the paper drawing gauge can be replaced with a larger diameter model to achieve the purpose of feeding paper stably without swinging. When printing whiteboard paper, the gap between the two controllers of the offset press should be increased accordingly, and the distance between the paper pressing tongue of the side gauge and the front gauge and the paper feeding board should also be increased. Prevent multiple pieces of whiteboard paper from being stuck between the impression cylinder and the rubber roller, resulting in "paper jam" failure. The distance between the double control wheel and the paper feed roller should not be less than 2 sheets of paper or more than 3 sheets of paper, otherwise the arched paper will stop when it passes; Or two pieces of paper pass through the surface of the controller, but the power supply of the controller does not touch the electric shock, so the purpose of controlling the two pieces of paper cannot be achieved. In addition, the dust or insulation on the surfaces of the two electric shock surfaces of the double control wheel, the paper feed roller and the power control place should be cleaned up in time to prevent the double control system from failing.
Step 3 prevent your back from getting dirty
Handbag printing often has a full version of the field, which is easy to cause dirty back. Therefore, the original barrel ink should be selected as far as possible, and some debonding agents and anti-sticking agents should be added appropriately, without adding 6# ink blending oil and drying oil in hot weather.
In addition, it can also be solved by powder spraying. However, it should be noted that powder spraying will affect the surface gloss of printed matter, pollute the environment, and wear and stain the paper receiving part of offset press.
Pay attention to the correct arrangement of printing color sequence. In order to avoid the dirty back caused by paper collision when the imprint is not dry, the text version and line version should be printed first, and then the field version should be printed.
4. Arrange the printing color order
When arranging the printing color sequence, besides rubbing your back, you should also pay attention to the following points.
(1) Print halftone first, and then print lines and fields. When there are four-color overprinted halftone images, characters, field patterns and lines on the handbag, in order to ensure the accuracy of overprinting and reduce the influence of paper stretching, halftone should be printed first, then lines and fields should be printed, and recognition should be given priority.
(2) Print dark color first, and then print light color. Because of the weak hiding power, light-colored ink is slightly inaccurate and imperceptible when placed in the back for overprinting, and the overprinting effect is better.
(3) If the water content of whiteboard paper, cardboard, kraft paper, etc. is large. Is uneven, uneven wrinkling, poor surface strength, resulting in powder and hair loss, you can first print a blank water to solve the quality accident in monochrome printing.