After the press, everyone talks: the experience of the glue process
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In the past few years, under the guidance and great help of the superior authorities, we have carried out careful and meticulous observation and analysis of the glue-made production methods through technical personnel, and found out the general rules of the book-making process from the practice. Now we have some brief practices in the management of the binding process, and a brief exchange with the colleagues engaged in the binding work, in order to continuously improve the hot melt binding process, the correct use of hot melt adhesives, and constantly improve the quality of the book.
First, the book page before entering the machine is very important
In the bookbinding process, especially in the production of the binding line, the book page is the main raw material for the input machine. The quality of the folding quality, the correct storage method will directly affect the operation quality of the whole machine, affecting the overall efficiency. According to our on-the-spot investigation of more than a dozen binding line: more than 60% of the downtime of the perfecting machine is caused by the irregularity of the pages, even if the linkage with the throwing device will not stop, it will be Neutral operation reduces production efficiency. Therefore, in order to make full use of the equipment introduced by several million yuan, it is necessary to minimize the occurrence of downtime and neutral operation, and ensure the balanced and smooth operation of each station of the entire line.
According to this, in the processing of the book page to adhere to: 1. The cut of the book page is completely excluded from the air inside the book page, and then firmly tied with a hard wooden board, and the flat sheet is kept flat to keep the flat sheet of the book. 2. Try to avoid the appearance of thin pages. It is true that the double pages that are inevitable due to the restrictions on the printed sheets should be handled in a nested manner. When an illustration or a single page appears, it should be pasted on an adjacent book page and then bundled. This seems to increase the workload, but in the efficiency of the mechanical support (especially the binding line) is economical, the book's page error rate is also greatly reduced. Because we insist on the book before the machine is strictly in accordance with the set process. The quality and efficiency of the bookbinding products are significantly improved. For example, a recently opened 16-page and eight-print "Junior Geography", with a speed of 6,000 volumes at a speed of evenly running at an average of 1.5 hours or more, each station has no faults, no downtime and idling occur, making the entire line The operation reached a good level of the same grade of binder.
Second, the temperature of the book page should be adaptively processed in winter.
For general-scale printing companies, due to the book production cycle and factory area restrictions, it is customary to store the folded pages in unheated warehouses or outdoors. This kind of storage method has no obvious influence on the bonding effect of the bookbinding in spring, summer and autumn. If the book is stored in the warehouse or outdoor for many days in the cold winter, the bonding strength will be seriously affected. And even caused the book to be scattered. This is because the contact temperature of the glue is instantly reduced after the contact of the glue with the frozen book page, and the film is quickly solidified. It is difficult to infiltrate the pages, thereby significantly reducing the bonding effect. Therefore, in the cold season, the hot melt adhesive book must be processed, and the book page must be stored in the same environment as the binder temperature for more than 24 hours, and aging treatment is carried out to ensure the inherent quality of the book.
Third, milling back and slotting should pay more attention to
Slotted quality In recent years, rotary machines and folding machines have been widely used for printing. Binding production improves the quality of folding. The short phenomenon of some manual folding has caused the processing unit to pay attention to it, and the problem of milling through the loose pages is better solved. Any book with a flat back, a flat pull with a certain tension, and no creases on the back of the book have better slotting treatment. It is obvious that it is processed with a better performance. The glue layer of this book has a higher strength even if it is within 0.6mm, and it can be restored with a large force and the back of the book can be restored. On the contrary, there is no book for grooving, even if the glue layer is above 1mm, if you turn it hard, you can see the paper cross section and the glue layer behind the milling, and the back of the book will be creased. Such a book is generally caused by the fact that the slot machine is not properly adjusted on the small disk machine or the wire machine, and is a quality defect. In the past few years, we have controlled and modified the slotting quality of the pages behind the milling as the main monitoring focus, and solved some mechanical structures with imperfect work stations, which makes the operation of the slotting station more stable and the structure more reasonable. For example, the introduction of Warrenberg adhesive binding line, the original machine behind the slotting knife is designed with soft material, although it can avoid the damage of the slotting knife caused by improper operation, but it is not durable. Usually it takes about two hours to adjust, and each time it stops for more than ten minutes.
In addition, due to the softness of the board and the rapid wear, the depth of the book slot is different and the beginning is different before and after the board is adjusted and installed. To ensure a more consistent slotting, it is necessary to frequently adjust and replace the backing plate, which increases the downtime and seriously restricts the performance of the mechanical performance. After analysis and research, we have changed the backing plate to cemented carbide material. After precise adjustment, the groove depth can be accurately controlled to about 1.2mm, and it will not be replaced for long-term use. We have installed an alloy backing plate since October 4, 1999. It is produced in two shifts per day at a speed of 6,000 copies. It is still in normal use and has received excellent results. The slotting knife of the disc binder is on the same cutterhead as the milling cutter. Although it is difficult to adjust the uniform and orderly groove shape due to the limitation of the mechanical structure, as long as the correct adjustment is made carefully and carefully, the machine is kept. Speed balanced operation, can also open a more ideal trough shape, produce quality books. In short, no matter which type of machine is used to produce the glue book, the correct processing of the slotting directly affects the quality of the book, which is one of the important links that should be controlled in the binding process.
Fourth, the correct use of different stations of the rubber wheel
An adhesive book with beautiful appearance and reliable quality, in the production process, can not ignore the correct adjustment of the two front and rear rubber rollers. Each type of binding machine is equipped with at least one set of rubber furnaces, and each set of rubber furnaces has two rubber wheels for the running book. We adjusted the two rubber wheels in such a way that the first rubber wheel is adjusted to make a slight contact with the book after the slotting, so that the glue can be poured into the book slot with a large pressing force, so that The glue tank is filled, but the back of the book cannot be deformed. The relative gap between the second rubber wheel and the book book should be adjusted according to the thickness of the book. The paper condition should be adjusted according to the ideal thickness of the glue layer. In this way, we adjust the front and rear rubber wheels to produce various books. Both the thickness of the cut and the thickness of the back of the book are basically the same, which ensures the flatness and beauty of the book.
Fifth, the correct choice and use of hot melt adhesive
When cleaning the hot melt adhesive after melting in the winter, it was found that the hot melt adhesive used was extremely brittle after freezing, and immediately made a film in the refrigerator at various price points in the factory. Freezing test. The test results were: only two were not brittle after 4 hours of freezing at minus 2 °C. When we inquired about a large rubber factory, the other party did not have this test. It's hard to imagine that a book made with this glue won't spread on a cold winter, at the very least, there is no guarantee that it won't be scattered. In particular, the readers of the textbooks are mostly rural students, and their reading environment in winter is below zero. According to this, we must carry out strict inspection on each brand and batch of hot melt adhesive entering the factory. Only the glue that is qualified for each indicator can enter the workshop. In this way, the quality of the glued product is ensured. The indicators we control mainly include the following:
(1) Low temperature resistance. We have designed a temperature-controlled freezer with a temperature control error of +/-1 °C and a temperature range of -10-10 °C. The hot melt adhesive is made into a certain strip, placed on a curved frame of the freezer, and subjected to a bending test after being kept at a predetermined temperature for 30 minutes. It is a good product that does not break at -1 °C. At present, we are working on designing an automatically controllable low temperature performance tester to make the measurement results more objective and scientific.
(2) Fatigue strength. This is an indicator of the number of times the rubber layer is resistant to bending. It ensures that the book will remain intact after repeated readings. First, the hot melt adhesive is made into a rubber strip as specified, and then tested on a fatigue strength meter (self-made) at a predetermined temperature.
(3) Specific gravity. After comparative tests, we found that the specific gravity of the rubber with a specific gravity greater than 1 is lower than that of the hot melt adhesive with a specific gravity less than 1. In addition, the greater the specific gravity of the hot melt adhesive, the greater the weight of the single adhesive when the adhesive layer is the same, which will significantly increase the production cost. The specific gravity can be measured in accordance with the relevant adhesive measurement method. In practice, we often use the "water bleaching" method for qualitative determination: the glue with a specific gravity greater than 1 will sink to the bottom of the water, and the rubber with a specific gravity of less than 1 will float on the surface. This method is simple but fast and effective.