Experience of the hottest binding process 1

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Over the past few years, with the care, guidance and great help of the superior competent department, through the careful observation and analysis of the binding production mode by the technicians, we have found out the general law of binding process making books from practice. Now we will have a brief exchange with our colleagues engaged in binding work on some practices and experiences in the management of binding process, in order to continuously improve the hot-melt binding process, correctly use hot-melt adhesive, and constantly improve the quality of binding books. 1、 The page arrangement before entering the machine is very important. In the binding process of books and periodicals, especially in the production of binding linkage line, the page is the main raw material input into the machine. The folding quality and the storage method will directly affect the operation quality of the whole machine and the overall benefit. According to our field survey of more than a dozen binding linkage lines: more than 60% of the downtime of the binding machine is caused by the non-standard pages. Even if the linkage line equipped with a waste disposal device will not stop, it will reduce the production efficiency due to neutral operation. Therefore, in order to make the equipment imported with millions of yuan give full play to its benefits, it is necessary to minimize the occurrence of shutdown and neutral operation, and ensure the balanced and stable operation of all stations of the whole line. Accordingly, we should adhere to the following in the treatment of pages: 1. After the air in the pages is fully removed from the cutting edge of the pages, bind them firmly with hardwood, place them horizontally and stack them to ensure that they can be used in a predictable situation. The most stringent experimental conditions should be selected to keep the pages flat. 2. Try to avoid thin pages. Double pages that are unavoidable due to printing restrictions should be handled in a nested manner. When illustrations or single pages appear, they should be pasted on the adjacent pages, and then bundled. This seems to increase the workload, but it is economical in terms of mechanical support and operation efficiency (especially the binding linkage line), and the page matching error rate of books and periodicals is also greatly reduced. Because we insist on treating the pages before entering the machine strictly according to the set process. The binding product quality and work efficiency have been significantly improved. For example, a recently processed 16 folio eight print edition of junior high school geography, with a speed of 6000 copies per hour, runs evenly for an average of more than 1.5 hours, and each station has no failure, shutdown and idling, so that the operation of the whole line has reached a better level of the binding line of the same grade. 2、 In winter, it is necessary to deal with the temperature adaptability of the pages. Due to the limitations of book production cycle and plant area, general scale printing enterprises are used to storing the folded pages in the warehouse without heating or outdoors. This storage method has no obvious effect on the bonding effect of bound books and periodicals in spring, summer and autumn. In cold winter, if the pages stored in the warehouse or outdoors for many days are immediately glued, it will seriously affect the bonding strength and even cause scattered pages of books and periodicals. This is because the surface temperature of the glue decreases instantly and solidifies rapidly after the glue liquid contacts the frozen book pages. It is difficult to infiltrate the pages, thus significantly reducing the bonding effect. Therefore, when processing hot-melt binding books and periodicals in the cold season, the pages must be stored for more than 24 hours in an environment with the same ambient temperature as the binding machine, and aging treatment should be carried out to ensure the internal quality of binding books and periodicals. 3、 Back milling and slotting should pay more attention to the quality of slotting. In recent years, rotary machines and folding machines are widely used in printing. Binding production improves the folding quality. The short position phenomenon of some manual folding has attracted widespread attention of processing units, and the problem of milling impervious loose pages has been better solved. Out of an "old binding" professional habit, the author once observed and read 60 books of different thicknesses and sizes in Beijing Xidan Book City. Zhao Ming, the deputy general manager of the company, told the reporter that he used the empirical method of monitoring the quality of books in the factory to read the quality of bound books. Among the 60 books, there was no loose pages caused by milling back. All books with flat backs, flat backs with a certain tension, and no creases on the backs have better slotting, which is obviously processed with linkage machines with better performance. Even if the adhesive layer of this kind of book is within 0.6mm, the back of the book also has high strength. With a larger force, the back of the book can still be restored to its original shape. On the contrary, for books without slotting, even if the adhesive layer is more than 1mm, if you turn it over with a little force, you can see the paper section and adhesive layer behind the milling, and there are creases on the back of the book. Such books are generally not properly adjusted and used on small disc machines and self threading machines. Common fault 7: the slotting mechanism after the sample is broken, which is a quality defect. Over the past few years, we have taken the slotting quality of the book pages behind the milling as the main monitoring focus to control and transform, which has better solved some of the imperfect mechanical structures of the station, making the operation of the slotting station more stable and the structure more reasonable. For example, the imported Wallenberg binding linkage line, the original design of the back plate of the slotting knife is made of soft materials, which can avoid the damage of the slotting knife due to improper operation, but it is not durable. Generally, it needs to be adjusted once in about two hours, and the machine will be shut down for more than ten minutes each time. In addition, due to the soft and fast wear of the backup plate, the depth and beginning of the book slot are different before and after the adjustment and installation of the backup plate. To ensure a more consistent slotting, it is necessary to adjust and replace the backup plate frequently, which increases the downtime and seriously restricts the play of mechanical efficiency. After analysis and research, we now change the slotted back plate to cemented carbide material. After precise adjustment, the slotting depth can be accurately controlled at about 1.2mm, and it will not be replaced after long-term use. Since October 4, 1999, we installed and used an alloy rear backup plate, which is produced in two shifts at the speed of 6000 copies per hour every day. Up to now, it is still in normal use and has received excellent results. The slotting cutter of the disc binding machine is on the same cutter head as the milling cutter. Although it is difficult to adjust the uniform and orderly slot type due to the limitation of the mechanical structure, as long as the correct adjustment is carried out carefully and carefully to maintain the balanced operation of the machine speed, it can also open a more ideal slot type and produce books and periodicals with qualified quality. In short, no matter which type of machine is used to produce binding books, whether the slotting treatment is correct or not directly affects the quality of books and periodicals, which is one of the important links that should be well controlled in the binding process. 4、 Correctly use the upper rubber wheels of different stations. A binding book with beautiful appearance and reliable quality can not be ignored in the production process, and the correct adjustment of the front and rear rubber wheels can not be ignored. Each type of binding machine is equipped with at least one set of glue ovens, and each set of glue ovens has two rubber wheels to glue books running. We adjust and use the two rubber wheels in this way: adjust the first rubber wheel to slightly contact the slotted book, so that the glue liquid can be poured into the book slot with a large extrusion pressure, so as to fill the glue slot, but not squeeze the back of the book. The relative gap between the second rubber wheel and the book should be adjusted according to the thickness of the book, and the paper condition should be adjusted according to the ideal thickness of the rubber layer, so as not to squeeze the rubber on both sides when supporting. We use this method to adjust the front and rear rubber wheels to produce various books and periodicals. The thickness of the cutting edge and the thickness of the back of the book are basically the same, which ensures the flatness and beauty of the bound books. 5、 Choose and use hot melt adhesive correctly. When we cleaned the hot melt adhesive after melting outdoors last winter, we found that the hot melt adhesive used was very fragile after freezing. We immediately made films of five brands of hot melt adhesive at various prices in the factory and carried out a simple freezing test in the refrigerator. The test results showed that only two kinds did not break after freezing at minus 2 ℃ for 4 hours. When we telephoned a large rubber factory for this index, the other party did not have this inspection. It is hard to imagine that books made of this glue will not be scattered in cold winter. At least, there is no guarantee that they will not be scattered. Our factory is located in North China, where the weather temperature is below zero for at least a hundred times a year, and most users of our books are also in this area. Especially for the readers of textbooks, most of them are rural students, whose reading environment temperature in winter is below zero. Therefore, we should strictly inspect the materials and mechanical functions of all kinds of castings on the 3.1 testing machine for each brand and batch of hot melt adhesive entering the factory in accordance with the rules of the response specification. Only the adhesive with qualified indicators can enter the workshop. This ensures the quality of binding products. The main indicators we control are as follows: (1) low temperature resistance. We have designed a temperature controlled freezer with a temperature control error of +/- 1 ℃ and a temperature measurement range of -10-10 ℃. The hot melt adhesive is made into a certain adhesive strip, which is placed on the bending frame of the freezer, and the bending test is carried out after 30 minutes of constant temperature at the specified temperature. Those that crack continuously at -1 ℃ are qualified products. At present, we are beginning to design an automatic low temperature resistance tester to make the measurement results more objective and scientific. (2) Fatigue strength. This is an index to detect the bending resistance of the adhesive layer, which can ensure that the books can remain intact after repeated reading. First, the hot melt adhesive is made into adhesive strips according to the regulations, and then tested on the fatigue strength tester (self-made) at the specified temperature. (3) Specific gravity. Through comparative tests, we found that the comprehensive properties of adhesives with a specific gravity greater than 1 were lower than those of hot-melt adhesives with a specific gravity less than 1. In addition, the greater the proportion of hot melt adhesive, the greater the weight of single adhesive when the adhesive layer is the same, which will significantly increase the production cost. The specific gravity can be determined according to the relevant adhesive determination methods. In practice, we often use the "water drift" method for qualitative determination: the glue with a specific gravity greater than 1 will sink to the bottom of the water, and the glue with a specific gravity less than 1 will float on the water. Although this method is simple, it is fast and effective. (4) Aging resistance. The hot melt adhesive that is easy to age will obviously scorch and change color in the process use, which will bring inconvenience to the normal operation of the process. The second is that in the use of books, due to the rapid aging speed, there will be quality problems, which will affect the service life of books. This index can be measured according to the national standard, but it takes a long time. The simpler way is to treat the rubber sample at a higher temperature, and the change of the rubber with poor aging resistance is very obvious. In the process management, we strictly limit the amount of glue added to the glue furnace at one time, so as to minimize the time of glue in the glue furnace and avoid the aging of hot melt glue. In our production practice, the glue temperature used in winter is generally 1~15 ℃ higher than that in other seasons, and is controlled between 180~185 ℃, so that the viscosity of the glue is less than 4000mpa · s. In order to make the glue maintain good wetting performance on the page. In the normal use of hot melt adhesive, we generally control a higher temperature within the aging critical temperature, which is not only to maintain good wettability, but also to greatly reduce or even eliminate the wire drawing phenomenon of gluing. It reduces or avoids the processing time of each station fault caused by glue winding, which is conducive to improving the production efficiency of the whole machine. Many effective methods of using hot melt adhesive correctly have been studied and discussed by many experts and masters who are committed to the study of bookbinding technology. At present, the national standard of hot melt adhesive for books and periodicals has not been formulated, and the manufacturers and users of hot melt adhesive do not have a perfect standard to follow. This problem needs to be further discussed. We are continuing to explore the rules of hot melt adhesive process, and do various tests of selecting and using adhesives. We are willing to explore a simple hot melt adhesive testing method with you, for the development of binding technology and the improvement of binding book quality

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