Publication Printing and Quality Inspection (II)

2) Cover Color Difference Cover color includes two aspects: on the one hand, the color of the cover of each book in the book is inconsistent; on the other hand, the cover colors of different editions of a single book are inconsistent. The consistency of the color of the book cover needs to be solved from the aspects of the cover sheet printing and the printer ink balance. The color difference problem of a single book is mainly solved by the ink balance of the printing press.
3 Stapling 1) Page number error standard stipulates that: the page center point shall prevail, the allowable error of the page number between two pages is not greater than 4mm, and the allowable error of the whole page page position is no more than 7mm. Under normal circumstances, low-weight paper will not have such problems, 70g/m2 or more paper is easy to appear in the four-fold, which need to be changed before the printing by changing the hand or "needle" approach to solve.
2) There are many reasons for uneven book backs caused by uneven books, empty backs, round backs, and vacuoles. For example, uneven milling, shrinking of books, improper sizing, improper dragging, uncomfortable cutting pressure, and improper specification of finished products. . Empty back and round back are mainly caused by too little or too much gum. Cavitation is caused by bubbles in the glue or by backfilling the book. Cavitation can be solved by controlling the temperature of the glue solution.
3) Overfilled rubber, wild glue, and open glue are prone to overflowing in the seals 2 and 3 of the finished book, which is mainly caused by excessive glue on the cover. Wild glue is mainly due to the loss of control of the application of glue and the non-standard operation in the glue-binding process. The glue is mainly caused by the poor adhesion, thickness, and poor uniformity of the sealant and the book block adhesive layer.
4) Hardcover Case Warpage Hardcover book case is made of hard cardboard and soft cover. The quality of the sample book may be very good at the time, but after a while the book case warps. The quality of the paperboard itself, including the production of materials, storage conditions, processing methods, etc., will affect the quality. In addition, adhesives, soft covers, etc. will also have an impact on quality; in order to solve the above problems. In material selection, we must strictly control the quality, select good quality and hard-to-change paper analysis boards, and require the binding factory to heat-press the cardboard before and after gluing, to evaporate water and enhance its stability. When selecting the adhesive, select the adhesive with low moisture content and strong adhesive force. When selecting the cover material, it is appropriate to use stripes, and the stripes are not easy to warp.
5) Hardcover book lining and wrinkled paper before and after the book block are very sensitive to moisture, easily absorb moisture and make the paper lose its smoothness. If you do not have a good grasp of hardcover book lining lining technology, then the lining of the back cover of the bookcase of moisture is relatively large, it is easy to make the inside and back of the book block due to moisture absorption and deformation. Once the paper surface is absorbed and deformed, it will show obvious unevenness, that is, it will be difficult to restore the original flatness after drying. In order to prevent the moisture absorption and deformation of the inner pages of the book block, in addition to requiring the adhesive or paste to be thin and uniform when the ring liner is attached, the cover must be closed with a correspondingly-sized film to prevent moisture. Penetrate into the book block, and then carry out the flattening process so that the ring liner is flat and tight, so as to better guarantee the bookbinding quality. However, some binders place the film side of the coated white paper with the film facing the bookcase. This is not correct. This will prevent the adhesive from sticking to the white paperboard, but it will not provide moisture protection.