Originally, the problem was that the machine was not adjusted, and how the bookback paper was milled back in the same way as the number of folds, so that the thin and brittle book block placement was cut. When the machine originally collocated 70 grams of offset paper 32 to open 4 fold book blocks, the milling back volume was about 3mm. Because the book block paper is thick and full of toughness, there is no crack in the back of the milling. When the book is converted into bookbinding book 16 for the three-fold book block, the 60-gram paper is brittle, and when there is a wear gap between the fixed plate and the movable guard plate on the milling-back cutter plate, the two plates are Did not fully support the bottom of the book block to prevent deformation. In this case, if the amount of back-milling is large, it will inevitably cut the position of the outer book block core. After finding out the reason, the fault is not difficult to eliminate. However, it is difficult to accomplish the role of pinching the bottom of the book block by fixing the worn-out dents and the sides of the movable guard plate. For the urgency of urgent production, we reduced the height of the book holding board by about 1mm, and then reduced the milling back load by 1mm. Cracking phenomenon, to ensure the quality of glue.
The generation and elimination of the fault, according to the author has some enlightenment: that milling back should be able to mill the book block "in the folded sheet" principle, in the neat book conditions to reduce the amount of milling back to reduce the milling back knife And cutting knife wear, and reduce the lower part of the book block on the fixed plate and the movable guard inside the friction. In addition, the "two board" spacing should also be adjusted. That is, the book block can pass smoothly between the fixed plate and the movable guard plate, and there is a slight sense of slight resistance. In this way, the lower part of the book block does not generate large tremor friction between the “two plates†during the work of the milling back cutter head, thereby reducing the wear of the inner edges of the “two plates†corresponding to the cutting edges to ensure the quality of the milling back.