In the printing of books and periodicals, the printed sheets printed by the lithographic sheet-fed printing press need to be folded into signatures by the folding machine; while the books and periodicals are printed in a rotary way, the folded signatures are printed at high speed. The production efficiency of printing is obvious. Therefore, when printing books and periodicals in large quantities, the printing enterprises of various books and periodicals generally adopt the rotary printing method.
Due to the limitations of the performance of the book rotary printing press, basically the minimum output of the folding output is only 16 knots. For the commonly used 32 kap specifications of books and periodicals, due to the differences in the production equipment, processes and management methods of the book printing companies, different The 32-knife wheel transfer process technology style. There are two types of 32 format, horizontal and vertical. The most commonly used is the vertical format. This article will discuss the advantages and disadvantages of the application of these commonly used rotating 32 vertical book printing processes from the aspects of quality, efficiency, and efficiency.
1 Comparison of production efficiency of lithographic and revolving books and periodicals
Use the J2205 offset sheet paper two-color printing machine (referred to as 05 machine) and J204 rotary two-color printing machine (referred to as 204) commonly used in China to print the same printed matter for comparison, for example: a printed text with a vertical format of 32, 7 printed sheets, 60g light paper, both sides are printed in two colors, the number of copies is 200,000, using the same glue binding linkage line glue binding, working time is 12 hours / shift.
1) Printing plan of lithography machine
2 sets of 05 machines, 1 folding machine, and 1 glue binding linkage line are used for printing.
â‘ The production speed of normal printing two-color on machine 05 is 7500 sheets / hour, using 32 billing unit to copy the folio printing, and two machine 05 to complete the above order requires at least 15 shifts.
â‘¡The single folding machine of the matching book folding machine needs 4 folds in half, the production speed is 5000 sheets / hour, and at least 23 shifts are required to complete the book pages.
â‘¢The production speed of the bookbinding linkage line is 32 format, and the single copy is 4000 copies / hour, and more than 4 shifts are required after binding.
It can be seen that there are a total of 27 shifts after printing and binding. From the standpoint of production efficiency, the folding time is longer than the printing time. The binding time of the binding line is the shortest, mainly to wait for the book pages to be folded. Therefore, more than 23 shifts are required to complete the above order even in a hurry in batches.
2) Printing scheme of rotary printing machine
Use one set of 204 and one set of glue binding linkage printing.
â‘ The production speed of 204 normal printing double-sided two-color printing is 18000 sheets / hour. It adopts 32-fold duplex printing and the printing is about 6.5 shifts.
â‘¡The production speed of the binding and binding line is 32 format, and the double binding is 3500 sets / hour. After finishing 2.5 shifts, a total of 9 shifts are required after printing. If there are rush times in batches, 7.5 shifts are enough. .
Compared with the above different printing schemes, the production efficiency advantages of the large-volume books and periodicals produced by the rotary transfer printing machine are difficult to catch up with. Mass printing of books and periodicals, using rotary printing has long become the preferred method for book and printing companies. In some books and periodicals printing enterprises with advanced equipment, a large number of books and periodicals are often printed on a rotary printing machine with multiple paper paths. The time used for printing can be basically synchronized with the post-press binding, and the production efficiency is higher.
If the number of books and periodicals printed is small, that is, when the short version is printed? The number of copies is less than 5,000, and the rotary printing machine will consume a certain amount of normal paper receiving and ink-balancing test machines due to its self-feeding paper roll transmission structure. The paper has far exceeded the normal number of lithographic single-sheet printing. After all, lithographic single-sheet printing can also be debugged with over-printed paper (recyclable), so lithographic single-sheet printing short books and periodicals still have certain advantages. But after the lithographic sheet printing, it also needs supporting offline folding, the production efficiency is low, resulting in too low economic benefits.
2 Conventional 32-book printing production process
Due to the limitation of the folding mechanism of the rotary printing machine and the pre-press platemaking process, when the 32-page book is printed in rotation, the output signature is folded three times, that is, the 16-sheet format, and finally it needs manual or offline The upper folding machine then folds the last fold (ie the 4th fold) to fold it into 32-fold format.
1) This production process is currently widely used by various book printing companies. The advantage is that if the pre-pressed film is not different from lithographic and rotary folding methods, there is no need for tedious revisions. The lithographic single-sheet printing machine and rotary printing The machine can be directly used universally, and even the PS version used in lithographic printing can be used on the machine after being cut and then rotated.
2) Have certain flexibility in production management and process application: application models, paper materials, etc. are not subject to excessive restrictions in advance, once a production order is placed, you can be flexible according to the existing printing press conditions and paper inventory conditions Arrange production in an orderly manner.
3) This production process, which needs to fold the last fold, is a frustrating choice for the old (or worn out) rotary presses with low folding accuracy.
4) Due to the need to fold the last one manually, the Indian enterprises will consume more precious production time and labor. The production efficiency and benefits of this pure single-unit 32 format are destined to be very low: often the number of prints The larger the size, the more obvious the existing drawbacks, so it will be used more in the printing of short editions (or complements) of books and periodicals with fewer prints.
3 The classic 32-knife double-wheel transfer printing process
At present, the minimum size of the folding mechanism of the domestic book and periodicals rotary printing machine is 16 knots, so the signatures output by folding after printing must be double 32 knots in order to meet the requirements of folding.
1) Due to the different production equipment, processes and management methods of various book printing companies, there are basically two classic methods for the production of 32-page double-copy book and wheel transfer production.
â‘ The common 32-fold double book, that is, the upper and lower book block printed sheets are exactly the same printing production process. The double-printed book is printed and printed to match the book block, which can be directly connected to the online and offline flexible binding book book, or can be cut into a single book offline book book, which can meet the flow of the linked production line. On-line production is also suitable for off-line manual production. It is currently one of the most widely used 32-format production methods in the book printing industry. In the application of books and periodicals printing companies, the biggest difference is the double-segmentation and cutting: the printing equipments with complete equipment can mostly connect the double-book cover and the double-cutting, and only the large-printed books and periodicals are divided into single Joint cutting; small-scale printing enterprises with incomplete supporting equipment, double-coated book, and finally divided into single-cutting; printing equipment with single equipment and unable to support, only double-linked with book blocks, split into single-linked Baoben, cutting.
â‘¡ In fact, it is still the production process of the 32-sheet copy, that is, the book block printing production process in which the upper and lower links each occupy half of the printed content. After printing to post-printing processing, the book block is pre-provisioned and pasted, and then cut into two half-piece book blocks, and the two half-piece book blocks are combined to form a complete book. Only after the core, can the construction method of offline books be used. This production process is mostly used when the short version of books and periodicals is printed by the rotary machine.
2) Comparison of the characteristics of the two production processes
â‘ In the process of pre-press and printing, one set of additional films and one additional set of PS plates must be output. The corresponding material cost has increased. When the number of prints is larger (more than 30,000 copies), the multi-purpose film and PS plates are used. The cost of materials accounts for a small proportion of the total production cost, generally below 5%, but the benefits of post-press processing production efficiency improvement are much higher than this consumption. This production has obvious advantages, especially in the two major processes of binding and book binding after printing, which can improve the overall production efficiency by more than 70%. It is one of the most effective means to solve the bottleneck problem of lagging binding efficiency in current book printing. It is widely used by printing companies in the printing of long-printed books and periodicals. However, in short-run printing, the unit cost of materials used is relatively large, generally accounting for more than 20 ~ 30% of the total production cost, so in short-run printing, this production process is the most unreasonable and not very Cost-effective. In addition, some high-tech printing companies use a single set of small prints to print in the form of a double copy format and directly print the double copy format. In theory, it can save a set of film, but the amount of PS version does not No reduction, still need to consume two sets of PS version, and direct sun exposure also consumes a certain amount of human resources and production time, whether the direct sun exposure process is adopted by each book printing company according to the specific circumstances.
â‘¡While the material consumption of the film and PS version has not increased, but after finishing the signatures in the post-press binding, it still needs to be cut (or divided) into two upper and lower links, and then re-matched to complete the two. Book blocks, artificial processes will add a lot, precious labor resources will be occupied more, and opportunities for hidden quality problems will be increased. This process is mostly used for manual offline operation with short prints. It is necessary to repeat the post twice (this), the efficiency is too low, and it is not suitable for the requirements of high automation production line operations.
These two common double-book production processes can basically meet the production requirements of common book printing processes, such as flat binding, glue binding, plastic wire ironing, saddle stitching and so on.
4 Efficiently come and go to fight the production process of Shuanglian 32 format
In the printing of books and periodicals, there are both long and short versions, and even the number of prints with different numbers of prints in the same variety. How to properly arrange production is a substantive problem for each book and printing company. .
After exploration, the advantages of the above two production processes are innovatively combined, that is, the new process of making full use of the printing efficiency of the rotary machine and adapting to the requirements of short-run printing-Come and go, that is, come and go The production process of Lian 32 format has been logically promoted in production. Compared with the traditional double-printing process: this method requires only one set of film, a set of materials, and no additional printing volume to complete the double-printing. It is suitable for the printing of long and short editions of books and periodicals.
1) Coming up and down to spell the double vertical 32 format, the essence is that when matching the book signature into the book block, half of the same signature is to be turned around to match the signature, with a large 32 open, finished 216 × 148mm, 6 printed sheets, perfect binding The binding method and the rotary machine come and go and spell 32 open double books as an example:
â‘ Posts 1 (P1-16) and 12 (P177-192), 2 (P17-32) and 11 (P161-176) ... 6 (P81-96) and 7 (P97-112) Combination: Two mixed signatures with the same parts and different directions are combined into two identical book blocks, that is, the 32-sheet double-folding.
②If the rotary machine determines to print with 880mm wide web, the imposition requirement is head-to-head or ground-to-ground imposition, the upper link printing width is 216 × 153mm, the lower link printing width is also 216 × 153mm, and the two links are pre-intermediate If the saw-edge is 4mm, the blank page of the upper link must be the same as the blank page of the lower link? If necessary, the blank page of the upper link is allowed to be larger than the blank page of the lower link. The requirement, that is, the blank space is 2mm, basically has little effect on the suitability of printing, and can also meet the requirements of various production operations after printing.
③If the roll paper is printed with 890mm width, the imposition requirement is still head-to-head imposition? Or ground-to-ground, the upper and lower linkage printing width is unchanged, it is still 216 × 153mm, and the cut edge reserved between the two linkages is 4mm. No change, but the corresponding blank space of the two pages should be changed to 4.5mm.
â‘£ When the cover is imposition, you must also make a double-up in a round-trip manner. Except when the cutting edge is 4mm between the two sets, the amount of empty space on the page of the core of the official document should also be the same, otherwise accidents are easy to occur, namely Low-level errors that do not match the cover and the core of the official document can happen unexpectedly.
⑤ When spelling back and forth method 32 open double version, it is necessary to pay attention to adding the relevant necessary quality monitoring logo, confirm that when the double method is used in the double method or the middle cut is two copies and then the copy, you can also check whether it is on the back label. There are common unqualified post-press processing projects such as wrong posts, multiple posts, few posts, inverted posts, and missing posts.
⑥ Fully consider the production requirements and quality standards of book printing. According to the requirements of national quality standards, in terms of folding, the qualified product allows the tolerance between adjacent page numbers ≤4mm, and the tolerance between page numbers of the whole book ≤7mm. The author believes that even if there is a 2mm tolerance in the material specification width, the folding There will be 1 ~ 2mm error, which is more than enough for qualified products. From the long-term actual production random inspection, the folding tolerance between adjacent page numbers can be controlled between 2mm and only a small deviation between 3mm, and the position error of the entire book page is basically controlled at 5 ~ 6mm. There is no difficulty, and it can also meet the printing requirements of ordinary books and periodicals
⑦Can meet the construction requirements of the linked production line. In the paperback (offset binding) linkage line, the short version processing advantages brought by the 32-fold process can be more reflected.
2) The specifications of the rotating web material are required to be consistent. To understand from the quality requirements of book printing: the position error of adjacent page numbers does not exceed 4mm, and the position error of page numbers of the entire book does not exceed 7mm (the author believes that it should refer to the requirements of the copybook core position). This process design is to match the specifications and characteristics of the material with the suitability of post-press processing. This is the first condition related to the successful completion of the 32-fold double copy. If the size of the material to be printed is too wide, the folded signatures will be of different lengths after printing, which will cause considerable trouble for the use of signatures to mix and match reverse copies. The signatures of different lengths will be mixed. After matching, there may be quality problems due to the position error of the page number of the signature.
3) Precautions for this process
â‘ It is suitable for the construction requirements of the 32-sheet double-book booklet with the binding method of flat printing, perfect binding, plastic thread ironing and other binding methods with the printed sheets as whole printing sheets or 0.25, 0.50, 0.75, but it is not suitable for saddle stitching and hardcover books And other binding methods. Due to the mixed imposition of the head and the foot of the book signature, due to the influence of domestic materials and equipment, the cumulative error of each process of printing is large, which is not suitable for books and magazines with high requirements such as registration or fixed position logos and patterns. Printing, this is its most regrettable place.
â‘¡The imposition is basically the same as the conventional spelling, except that half of the printed pages in the entire book post of the Come and Go double-linked book are spelled in the upper link in the binding order, and the other half is placed in the lower link, counting from the countdown The order of the printing and printing is arranged, and the upper and lower links must adopt the head-to-head (or ground-to-ground) spelling method. The layout imposition should be centered in the paper width in principle. Whether to leave a 3 ~ 4mm split cut between the two signatures is determined by the process operation requirements of each production unit. The author believes that when the paper is suitable, the 3 ~ 4mm split cut is reserved between the two signatures It is helpful to ensure the quality of the binding and cutting, no matter how many printed sheets are the thickness of the book block, in the production line of the glue binding production line, it is necessary to reserve the double split cutting edge, even if the double book After cutting the finished product without cutting, it can also reduce common defects such as cutting heads and wrinkles.
â‘¢When using the rotary double paper path printing, the bookmark imposition should consider the crawling between pages. It is strongly recommended to use the pre-press desktop electronic layout technology process, according to the thickness of the paper, fine-tune the amount of crawling between pages, to ensure that the folding has sufficient registration accuracy, especially for books and periodicals with certain layout requirements. , If you have a positive and negative book line layout, you should pay attention to adopt it. Manual imposition is more difficult to accurately adjust the crawling between pages.
â‘£ Maintain the accuracy of folding and folding of the rotary printing machine. This is the key to whether the printing process can be carried out smoothly. The requirement is that the error of positive and negative registration is less than 0.5mm, and the folding error is less than 1mm. , Bookmarks should be served evenly.
⑤When collating after printing, please note that half of the signatures are to be reversed. The normal collation process will get two identical book blocks. This is a completely different requirement from the usual construction, and it is also a spelling. The essence of the new technology of the 32K double-link. It is necessary to strengthen and improve the technical quality and work responsibility of post-press operators, carefully debug the production equipment, and increase the inspection strength of collated signatures and book blocks. This is a special new process, and the feedback from the production practice shows that there is a greater chance of errors in the collating process, and it is necessary to adapt and strengthen management in place. This relationship comes when the new process can be obtained. Effective application.
â‘¥According to the condition of post-press processing equipment, it is possible to flexibly choose the single or double mode package book. Under the premise that the binding equipment and technology can meet the quality requirements, the linkage production line can be used to match the stickers and the double package book should be used as much as possible. To improve production efficiency.
5 The application prospects of this process
To put it simply, the combination of the top and bottom of the book signature is just a simple reverse search of the ordinary work mode. Although there are certain management risks, the effective reduction of production costs has brought about an increase in benefits. The process of 32-fold double-combination has been a mature production process abroad. It is just a start-up in China. There are not many printing enterprises that dare to promote and apply it. The main reason is that they are afraid of binding errors after printing.
On the premise of overcoming existing difficulties and satisfying the necessary product quality, we make use of the existing production conditions and change the original conditions without changing the equipment usage status, new cost, quality requirements and new labor resources. With a fixed conventional thinking mode, you can seek breakthroughs in market competition with your heart. Through various innovations, timely introduction of new technology, people-oriented, and new management concepts to deal with. Everything is difficult at the beginning, and when you get used to it and get used to it, it will become natural and solve the bottlenecks that are currently plaguing the low efficiency of post-print binding in short-run production, and strive to achieve a substantial new breakthrough.
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