Book glue binding is a necessary link in the book binding process. This process is completed well and will greatly improve the appearance of the book. If there are quality problems, the grade of the entire batch of books will undoubtedly be reduced. The bookbinding quality of glue binding workers is not enough. It also involves technology, production processes, raw material quality, workshop production environment, and even local climate conditions. Therefore, it is necessary to analyze common quality problems. And discussion.
Adhesive-bonding equipment causes quality problems
1, cover double, broken Zhang (without cover)
The double cover sheet is caused by the improper angle of the nozzle of the air blower and the amount of air blown. Adjust the blow volume first, and then adjust the angle of the blow nozzle. Generally, rigid paper requires a large amount of air, and the angle of the air nozzle is generally 20 to 40. It is appropriate. The broken sheet is generally caused by the inaccurate timing of the nozzle and the press wheel. The page cannot be completely conveyed by the pager. The suction nozzle lifts the work, and the second half of the cover is attracted to cause a broken sheet. When adjusting, loosen the fixing nut that controls the nozzle, turn the cam so that the press wheel will completely output the cover, and the nozzle will perform the second time.
2, the book is not neat
The big chuck conveys the book that has been on the cover to the receiving position, and the book is dropped after the tension is opened. Because the large chuck has a higher position than the sipper, the impact vibration occurs when the book falls, and the continuous operation of the large chuck increases the impact of the book's falling. The falling body produces a rebound force, which results in irregular book receipt. At this time, the book-receiver must be raised to reduce the impact force and enhance the sink hardness of the book-recorder.
Analysis of Common Quality Problems in Finished Products
1, wild rubber
Wild glue is the most common glue binding quality problem when binding books, and it is mainly related to the operation status of glue binding equipment. For example, the loosening of book splints, wear of running rails, vibrations generated when the book moves, etc. will generate wild glue. After the rubber wheel is worn, the diameter of the front and rear wheels is different. After the front wheel is glued, the rear rubber wheel cannot be completely smoothed, and wild glue is also produced. In addition, the technical performance (such as melt temperature, package speed, etc.) of the glue-binding equipment is unstable or does not meet the requirements. Therefore, to avoid the development of wild glue, first of all, the equipment should be fully adjusted. Parts with excessive wear should be replaced, and the hot melt adhesive temperature and input speed must be strictly controlled within the scope of technical standards. These data can be used in small quantities. After the onboard test, make the determination.
2, empty back
Airbacks have a great influence on the beauty of books, and when they are serious, they can cause pages to leave pages and pages. The generation of air back may be due to serious problems in the hot melt adhesive itself. For example, the hot glue contains many impurities and generates bubbles when it is melted. It may also be that the amount of glue applied is not uniform or the glue is uneven. The surface of the glue wheel is in poor contact with the book block, or Rubber glue wheel running parallelism caused by the difference. In addition, the squeegee rubber is too tightly contacted with the book block or the rubber is too hard, so that the already-rubbed glue may be scraped off, resulting in an empty back.
The solution is: (1) choose a good quality hot melt adhesive, can be determined after a small batch of trials; (2) adjust the machine so that the surface of the rubber wheel and the book block good contact, loosen the connecting rod nut first, Raise the height of the rubber sheet, and then loosen the nut on the rubber sheet so that the book block is in parallel with the surface of the rubber wheel. (3) Adjust the distance between the rubber and the book block so that the rubber does not come into close contact with the book block, or You can soften the rubber.
3, overflow glue, slurry width is inconsistent
Pulp is controlled by the glue-glue machine. If the poor contact between the glue board and the book block, or the poor parallelism of the glue board, it will result in inconsistent width of the glue or slurry. To overcome this phenomenon, the book block conveyed by the clip board can be fixed on the sizing position so that the brush teeth come into contact with the book block, and then the rubber nut can be loosened and the height and parallelism can be adjusted according to the position of the book block. , Tighten the retaining nuts after achieving the best results.
4, plastic hole
The first problem is the quality of the hot melt adhesive, which is similar to the air back. In addition, the unsuitable melt temperature will generate bubbles in the melter to produce a glue hole. Therefore, the temperature of the melter can be controlled. Important.
5, the cover, book back skew is not allowed
The cover transfer wheel conveys the cover to the countertop. If the delivery is insufficient or the positioning is inaccurate, the cover will be skewed. To overcome this, it is necessary to adjust the machine, first loosen the push plate transmission connecting rod fixing nut, rotate the connecting rod, lengthen or shorten the connecting rod can make the push plate forward or backward; at the same time adjust the cover and back cover parallel to the book block. The two sides push the board and the positioning of the head and leg to make it accurate so that it can be accurately sealed. It is worth noting that before adjustment, check whether the specifications of the cover are consistent. If there are any phenomena such as printing rules, sizes, and skewness, you should remove them first to ensure that the whole cover is neat and then on the machine.
6, book block up and down skew
Because the machine is not adjusted well, the clamp clamp plate fails to timely clamp the book block sucked by the suction board on the tray, or the clamping time is too early or too late to cause the book block to be tilted up and down. The distance between the clip board and the book block will also cause the book block to be tilted up and down. Therefore, it is necessary to adjust the clamping time of the slider first, and then adjust the distance between the clip boards to make it completely accurate.
7, indentation line is too deep
The indentation line is too deep to easily cause the cover to break off, and it is also easy for the cover of the cover film to produce bubbles at this position, which eventually causes the cover to foam over a large area. Just adjust the indentation knife slightly and adjust it to the proper pressure.
8, the book is too wide or too narrow
If the back is too wide or too narrow, it will cause the book to be out of square and unsightly. This phenomenon is mainly caused by the clip board is too high or too low, the book back is too high out of the back of the book width (cover book back is wider than the thickness of the book block), clip book is too low out of the back of the book is narrow (cover book back Less than book block thickness). Therefore, we must adjust the height of the clip board to avoid this phenomenon.
9, round back
The reason for the round back is that when the lift plate is not lifted into position during operation, when the book block is connected with the book block, the gap left is too wide, resulting in a round back or empty back (in the case of lack of glue). In this regard, as long as the distance between the clip board and the lift plate is adjusted, it can be avoided.
Source: "Printing Technology"