The adjustment of the sheet feeding device of the sheet-fed offset printing machine can be said to reflect the basic skills of the operator. It includes the stacking operation, the understanding of the working mechanisms and components of the paper feeding, and the accurate adjustment of the relationship between them. In a sense, the quality of the paper conveying device directly affects the quality and output of the printed matter. Paper stacking operation In the preparation work before paper feeding, one of the most important manual operations is stacking paper. The stacking work is generally divided into several steps: knocking (pressing), shaking, and adjusting (bumping): The paper's gripper, trailing edge (rear mouth) and side rule edge are knocked into equal and fan-shaped stiff and hard creases through the front or back, which is called knocking (pressing) paper. Its main purpose is: (1) Improve the strength of the grip edge and side gauge edge, and increase the contact stress with the positioning part. (2) Improve the flatness of the paper to ensure that the paper is fed properly. (3) Improve the hardness and looseness of the trailing edge of the paper, so that the paper is easy to be blown loose and sucked up, avoid sucking up multiple sheets, and also allow the printed paper to be collected. (4) In the process of monochrome overprinting, overprinting errors occur due to the expansion and contraction of the paper, which is sometimes compensated by knocking on the paper. The correct way to knock paper is: First of all, we must pile up the papers, choose the mouth, and stand well. Secondly, one hand picks up a stack of paper with paper corner twisting (beginners can match the twisting paper with both hands), and the other hand taps the edges of the paper with the palms of the hands (must not use the palm or fingers). With both hands, knock all the way to the center of the mouth regularly. After knocking on one side, then tap on the other side. It is required that the width and lightness of the creases on both sides are the same. The thin paper creases are properly elongated and the pressure is heavier; the thicker paper folds are slightly wider and shorter and the pressure is lighter. When knocking the side of the side gauge, be sure to distinguish the position of the side gauge (ie, the operating surface or the transmission surface). Shaking the paper is a method of twisting a stack of paper, shaking with both hands, so that there is air between each paper and each paper. The purpose is to eliminate the sand, paper scraps and other debris in the paper, in order to facilitate the paper (hit). The whole paper is a manual process to arrange the scattered white paper, semi-finished products or finished products. The whole paper makes the paper tidy, which is an important means to ensure cutting and normal paper feeding. After knocking (pressing) and straightening (bumping) the paper, the stacks are stacked on the stacking table of the paper conveyor according to certain requirements, which is called loading or stacking. The purpose is to ensure that the paper is transported properly and positioned accurately. After knocking and stacking the stacked paper, it is in a free state, that is, there is no resistance between the papers (excluding gravity); the surface of the paper is flat; the front and side openings of the paper are flush. Generally thinner uncoated paper and single-sided coated paper should be knocked. Double-sided coated paper (coated paper), whiteboard paper, bond paper and other papers with good stiffness cannot be knocked. Sheets printed on four-color machines are generally not knocked. [Related Links]: For the web offset press, the manual operation of the paper feeding device mainly includes two aspects: one is to manually pass the paper, which means that the process of the paper tape passing from the paper roll to the printing part through the guide mechanism is manually completed, and the other It is to replace the new paper roll in the middle of printing. The specific manual operation steps are: (1) Send the paper roll to the proper paper loading position, and then use the clamping mechanism to clamp the paper roll and raise it to a certain height. (2) Peel off the unusable paper layer on the paper roll. (3) Place a square (black or silver) square on the position of the new paper roll joint, and attach double-sided tape. (4) Raise the new paper roll to the working height. When the old paper roll printing reaches a certain diameter, the new paper roll will be accelerated. When the speed of the new paper roll is the same as the old paper roll, the double-sided tape will stick the Paper roll. (5) The computer controls automatic paper change, the electronic tracker transmits signals, and the paper cutter cuts the tape. Interactive Dog Toys,Dog Toys,Small Dog Toys,Pet Dog Toy Yangzhou Eco Pi international trading Co.,Ltd , https://www.eco-pi.com
Paper stacking operation of adjustment of paper separation mechanism