Advice on Quality Control of Binding Process

Over the past few years, with the help of the guidance and assistance of the superior authorities, we have carefully observed and analyzed the glue production methods through technical personnel, and have learned from the practice the general laws of bookmaking by glue-binding techniques. We are now in the glue processing process management practices, experience and colleagues engaged in binding work for a brief exchange, in order to continuously improve the hot melt glue processing technology, the correct use of hot melt adhesives, and constantly improve the quality of glue books.

First, book pages before entering the machine is very important

In the binding process of books and periodicals, especially in the production of binding lines, the pages are the main raw materials for the input machines. The quality of its folding, the correct storage method will directly affect the overall operation of the machine, affecting the overall efficiency of the play. According to our field survey of more than a dozen glued-link lines, more than 60 percent of the failures in the glue-binding machine were caused by non-standard pages. Even if the linkage lines with discarded devices do not stop, they will also cause Neutral operation reduces production efficiency. Therefore, to make full use of the equipment introduced by several million yuan, it is necessary to minimize the occurrence of shutdown and neutral operation and ensure the smooth and balanced operation of the entire station.

Based on this, we must insist on the handling of the pages: 1. The book pages cut the air in the pages of the book and then firmly bound it with a hard board. The flat yards keep the pages flat. 2. Try to avoid the appearance of thin pages. The two pages that are inevitably constrained by the printed sheets should be dealt with in a nested manner. When illustrations or single pages appear, they should be pasted on adjacent pages and then bundled. This seems to increase the workload, but it is economical in terms of the operational efficiency of the machinery (especially the glue-adjustment linkage line), and the book-layout error rate of books and books is also greatly reduced. Because we insist on the book pages before entering the machine strictly in accordance with the set process. Make the binding product quality and work efficiency have been significantly improved. For example, a recent 16-eight-print eight-junction "Junior Middle School" operates at an average speed of 6,000 volumes per hour and averages no more than 1.5 hours in each station. There is no downtime and no air running phenomenon, making the entire line The operation reached a good level of the same order glue order.

Second, the temperature of the book should be adapted to the winter

In general-scale printing companies, because of restrictions on the production cycle of books and the area of ​​factory buildings, it is customary to store the folded pages in a warehouse without heating or outdoors. This storage method has no obvious effect on the glue-bonding effect of rubber-bound books in spring, summer, and autumn. If the adhesive-bonded sheet is stored in a warehouse or outdoors for several days in the cold winter, the bond strength will be seriously affected. , even causing books and magazines to loose pages. This is because after the glue is brought into contact with the frozen book, the surface temperature of the glue is instantaneously reduced, and it rapidly solidifies. It is difficult to infiltrate the page, which significantly reduces the bonding effect. Therefore, processing hot melt adhesive books and periodicals in the cold season must ensure that the pages are stored for more than 24 hours in the same environment as the gluebinder's ambient temperature for aging treatment to ensure the inherent quality of glue books.

Third, milling back and slot should pay more attention

In recent years, rotary machines and folding machines have been widely used in printing. Binding production improves folding quality. The phenomenon of partial hand-folded shorts has caused the processing units to pay more attention, and the issue of milling through pages has been solved. The author for a "old bound" professional habits, had in Beijing Xidan Book City, observed reading 60 different thickness, different format of books, and use the factory in the quality of books to monitor the experience of methods, look at the quality of glue books, in None of the 60 books contained loose pages due to milling backs. Where the back of the book is flat, with a certain pull pull, the books that do not appear to be creased on the back of the book are all well grooved. It is obvious that the book is processed with a better-performing co-motive. The book's adhesive layer has a high strength even if the book back is less than 0.6mm, and opens with a greater force, so the back of the book can still be restored to its original shape. On the contrary, books that have not been grooved, even if the adhesive layer is more than 1 mm, can see the cross section of the paper behind the milling and the glue layer, and the back of the book is creased. This kind of book is generally caused by the incorrect adjustment of the slotting mechanism on the small-sized disc machine and the line machine, and it is a kind of quality defect. In the past few years, we have controlled and modified the slotting quality of the pages behind the mill as the main monitoring focus, which has solved some of the mechanical structures that are not fully completed, and has made the operation of the slotting station more stable and the structure more reasonable. Such as the introduction of the Warrenberg adhesive binding line, slotted knife back plate original machine design is a soft material, although it can prevent the slotting knife damage caused by improper operation, but it is not durable. Usually two hours or so to adjust once, more than ten minutes each stop.

In addition, due to the softness of the plate and rapid wear, the depth and depth of the book slot before and after the installation of the plate are different. To ensure that there is a more consistent slotting, frequent replacement of the slats is required, which increases downtime and severely restricts the exertion of mechanical performance. After analysis and research, we are now changing the slats of the groove to cemented carbide materials. After accurate adjustment, the groove depth can be accurately controlled to about 1.2mm, and it will not be replaced after long-term use. We installed an alloy back plate on October 4, 1999, and produced it in two shifts per day at a speed of 6,000 pieces per hour. It is still in normal use and has received excellent results. The slitter knife of the bookbinding machine is on the same cutter as the milling cutter. Although it is more difficult to adjust the uniform and regular groove shape due to the limitation of the mechanical structure, it is only necessary to carry out the correct adjustment carefully and maintain the machine. The balanced operation of speed can also be used to create a better groove type and produce qualified books and periodicals. In short, no matter which type of machine is used to produce plastic staples, whether or not the slotting process directly affects the pros and cons of the quality of books and periodicals is one of the important links that should be controlled in the glue-binding process.

Fourth, the correct use of different stations on the rubber round

A book with beautiful appearance and reliable quality, in the production process, can not ignore the correct adjustment of the front and rear two rubberizing wheels. Various types of glue binding machines are equipped with at least one set of glue ovens, and each set of glue ovens has two rubber wheels for coating the running book. We adjust the two rubber wheels in such a way that the first rubber wheel is adjusted to a slight contact with the book after the slotting, so that the glue liquid can be poured into the book slot with a large squeezing force so that The tank is full, but the back of the book cannot be deformed. The relative distance between the second rubber wheel and the booklet must be adjusted according to the thickness of the booklet. The condition of the paper sheet should be adjusted according to the desired thickness of the adhesive layer. We used this method to adjust the front and rear rubber wheels and produce various publications. Both can make the cutting thickness and the thickness of the book basically no difference, to ensure the smooth and beautiful appearance of the rubber books.

Fifth, the correct choice, use hot melt adhesive

When we cleaned outdoor hot melt adhesives last winter, we found that the hot melt adhesives used were vulnerable to embrittlement after freezing. Immediately at the factory price, five brands of hot melt adhesives were used to make films in refrigerators. Perform a simple freezing test inside. The result of the test was that there were only two types of brittle fractures after freezing at minus 2°C for 4 hours. When we questioned the indicator for a larger rubber factory, the other party did not have this test. It's hard to imagine that books made using this kind of glue won't page in the cold winter. At the very least, there's no guarantee of non-leaving. Our factory is located in North China. At least one hundred of the weather is below zero in the year. Most of the books we produce are in this area. In particular, readers of textbooks are mostly rural students. Their winter reading environment is below zero. Based on this, we strictly inspect every brand and batch of hot melt adhesives entering the factory, and only qualified plastics for each index can enter the workshop. In this way, the quality of the bookbinding 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 made of a certain strip, placed in the freezer curved rack, temperature 30 minutes at the specified temperature, bending experiment. Not broken at -1 °C for qualified products. At present, we are working on designing an automatically controllable cryogenic performance tester to make the measurement results more objective and scientific.

(2) Fatigue strength. This is an indicator of the resistance to bending of the adhesive layer, which ensures that the book remains intact after multiple readings. First, the hot melt adhesive was made into strips according to regulations, and then tested at a prescribed temperature on a fatigue strength tester (homemade).

(3) Specific gravity. We have conducted comparative tests and found that the specific gravity of the rubber with a specific gravity greater than 1 is lower than that of a hot melt with a specific gravity of less than 1. In addition, the greater the specific gravity of the hot melt adhesive, the greater the weight of the single-use adhesive when the adhesive layer is the same, which will significantly increase the production cost. The specific gravity can be measured according to the relevant adhesive measurement method. We often use the “float” method for qualitative determination in practice: plastics with specific gravity greater than 1 will sink to the bottom of the water, and those with specific gravity less than 1 will float on the surface of the water. This method is simple but fast and effective.