17 Tips for Thin Paper Printing at a Printing Factory

Many printing companies often suffer from printing failure due to lack of experience when printing thin paper (sheets below 40 g/m2). The author has accumulated some experience in this area and shares it with everyone.

(1) It is best to store the paper for about 3 months before use, so that the moisture content of the paper can be even and the wrinkles during printing can be avoided.

(2) The paper must be cut neatly.

(3) When paper is punched, it can reduce the wrinkling and cracking of the paper during the printing process and ensure the stability of the paper feeding.

(4) The paper must be loose when it is on paper to prevent double sheets, multiple sheets, skew and other faults.

(5) If the paper is wrinkled on both sides of the dragging part during printing, but no abnormality is found after checking the paper feeding mechanism and force, the paper is generally caused by the uneven moisture content of the paper. At this time, the paper needs to be cut. To the temperature of 50 °C in the baking room baking 7 ~ 8 hours or placed in the wet room dehumidification 2 ~ 4 hours.

(6) Thin paper is easily stretched and deformed in the printing process, so it is not suitable for accurate overprinting.

(7) The printing pressure should be controlled between 0.15 and 0.20mm, and the printing pressure should be balanced.

(8) The suction force of the delivery nozzle should be uniform, and the rubber band should be replaced when necessary; the suction nozzle of the paper should be strong, but it should not be too large, and the size of the blowing force should be moderate.

(9) It is very important to adjust the height of the presser foot. It is necessary to ensure that the presser foot and the separation nozzle have sufficient distances to avoid the occurrence of double sheets, multiple sheets, enthalpy or confusing paper.

(10) The time for the paper to reach the front gauge should be appropriate, and it should not be fast or slow, and the timing of the side gauge, presser foot, and tooth decay should be accurate.

(11) If the paper is always wrinkled in a particular position during printing, it is generally caused by improper adjustment of the equipment, such as uneven pressure on the impression cylinder, unstable feeding, and arching when the paper reaches the front gauge. The presser foot lifts slowly. If the wrinkling always occurs on one side of the paper trailing edge, one of the cranilies on the side of the impression cylinder can be relaxed to stretch the paper at the moment of impression.

(12) When the equipment is used for a long time, it is prone to cracking of the paper. This is mainly caused by the elongated delivery chain and the cracking of the paper by the tusks. As long as the chain is properly tightened, the problem can be eliminated.

(13) The printing speed should be properly controlled according to the technical level of paper, equipment and operators.

(14) When the paper with particularly high transparency is printed, the paper will transmit the light from the photoelectric controller, causing the photoelectric controller to detect no paper, so that the printing machine cannot start up normally. At this point remove the photoelectric controller, printing will be able to proceed normally.

(15) In the dry season, thin paper is prone to static electricity, resulting in uneven delivery. Installing a static eliminator can avoid this problem. The power of the static eliminator can be as low as 250W.

(16) The paper should not be piled up too high. If it is too high, it may cause the paper pile to be uneven and cause difficulties in paper feeding.

(17) The amount of fountain solution should be controlled within the minimum range. Over-contouring will cause curling of the paper, resulting in difficulty in the delivery of the paper.