1. The height of the paper stack. As the stack height increases, the error in the cut size increases. Because the paper stack is too high, the pressure of the paper press is correspondingly increased, and the shear resistance of the paper stack is large, thereby increasing the bending deformation of the paper stack, and the cut paper will appear longer at the upper part of the stack and shorter at the lower part. Therefore, it is best to control the height of the cut paper stack below 100mm.
Second, the shape and sharpness of the cutter. When using the double-blade carrier knife, the friction force and cutting force of the paper stack on the beveled surface of the carrier knife are reduced, and the cutting accuracy is improved. The blade is sharpened, the cutting resistance of the object to the cutting knife is small when cutting, the wear and power consumption of the machine are small, and the cut product is neat and the incision is smooth. On the other hand, if the sharpening blade is not sharp, the cutting quality and cutting speed will decrease, and it is easier to pull out the paper on the top of the paper stack when cutting, resulting in the inconsistency of the upper and lower cutting edges.
Third, the pressure of the paper stack. The paper press must be pressed tightly along the cut line of the paper. As the pressure of the paper press increases, the possibility of the paper being pulled out from the paper press is small, and the cutting accuracy is high. The adjustment of the pressure of the paper press should be adjusted according to the type of paper to be cut, the cutting height and the sharpness of the sharpening blade.
Fourth, the type of paper. When cutting different types of paper, the pressure of the paper press and the sharpening angle of the blade should be adapted to it. The correct presser pressure should allow the cutter to cut straight into the stack of paper. It is generally believed that when cutting soft and thin paper, the pressure of the paper press should be higher. If the pressure is relatively small, the paper on the top of the paper stack will be bent and deformed, and the deformation of the upper layer of the paper stack will be large. When cutting hard and smooth paper, the pressure of the paper press should be smaller. If the pressure is too high, the blade will easily deviate to the side with less pressure during cutting. The paper after cutting is short at the top and long at the bottom. When cutting hard paper, to overcome the cutting resistance, the sharpening angle of the cutter should be larger. Otherwise, due to the thinness of the sharpening edge, the shear resistance of the paper cannot be overcome, resulting in insufficient cutting at the bottom of the paper stack, which affects the quality of cutting.
Fifth, the water content of the paper. As the water content in the paper increases, the shear resistance decreases and the cutting accuracy increases. At the same time, when the water content of the paper is large, the friction coefficient is large, and the part of the paper stack to be cut is difficult to move from the inclined surface of the knife, squeezing the cutting knife and affecting the accuracy of cutting. The optimum moisture content in the paper is about 7% to 8%.
6. The state of the paper cutter. The parallelism and height of the cutting blade and the worktable, the verticality of the cutting blade and the worktable, the parallelism of the working surface and the cutting line of the pusher, and the verticality of the worktable are of great significance to ensure the cutting quality. When installing and maintaining the paper cutter, these parts should be adjusted accurately so that the blade and the blade are opposite to each other, and the paper should be cut according to the specified requirements. The above factors that affect the quality of cutting a single sheet of paper are also factors that affect the quality of books and periodicals.
Seven, binding methods are different. The difference in thickness between the front of the book block and the back of the book is different. For the book block to be cut on three sides, the thickness of the front opening and the back of the book should be basically the same. The greater the difference between the two, the worse the cutting accuracy. The cutting height should be adjusted according to the paper quality, binding method and the thickness of the book.
For a paperback book with a cover, the glue layer in the back of the book should be moderately dry and wet. If the back of the book is not dry enough, the glue will overflow and adhere to the side knife when cutting; if the back of the book is too dry, the side knife will quickly become dull when cutting. Both situations make cutting difficult.
