Discussion on post press processing mode of the ho

2022-09-21
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A few years ago, digital printing was still a new thing, which was far from commercial production. There was a big gap between the quality of digital printing and people's requirements, and the production efficiency was also very low. It was difficult to carry out on-the-job training to meet people's needs. However, in recent years, the speed of change and development of digital printing has completely exceeded people's imagination. Today, the production efficiency of digital printing has been greatly improved, and the range of printing materials is becoming wider and wider. The printing quality and effect of some printed materials have to be amazing. Digital printing has indeed become the most attractive way of printing

however, from the perspective of bookbinding and post press processing, there are still some problems that cannot be ignored in the post press processing of digital printing. This paper attempts to explore the post press processing mode of digital printing, in order to provide some references for readers

consider post press processing from prepress design

prepress design will contribute to the successful completion of digital printing post press processing. In digital printing, the quality of prepress design has a great impact on the cost of post press processing. Because the paper specifications used in digital printing are limited, and a large number of digital prints are printed on one side, in addition to the prepress design of digital printing to strive to make the most effective use of paper, the following factors should also be considered

1. Paper thread direction

if allowed, try to make the thread direction of the paper consistent with the back direction of the finished book. Due to the particularity of the combination of the color material on the surface of digital printing paper and the paper, if the page is folded in the horizontal direction, the image is easy to break at the fold. Therefore, the pre press design of digital printing should take into account the post press processing technology

2. Image position on the print sheet

usually, many digital prints design the image in the middle of the print sheet, but when post printing processing is carried out after printing, it is found that doing so wastes a lot of time and money. For example, make a size of 6 inches × The 9-inch image is designed to be 8.5 inches in one page × In the middle of the 11 inch printing sheet, the four sides of the printing sheet need to be cut when cutting; However, if the image is placed on a corner (such as the upper left corner), it only needs to cut both sides, which saves the post press processing time and reduces the printing cost. However, if the other two sides of the image are bleeding designs, it is still necessary to cut all four sides of the printed sheet

key points of binding and post press processing

only by carefully designing and arranging printing at the beginning can we ensure the harmony between printing and post press processing. In production, the following points should be noted

1. Folding

because the ink pigment on the digital print only attaches to the paper surface, folding processing is prone to fracture. Therefore, it is best to press creases before folding processing

2. Lamination

lamination processing on the surface of digital printing, especially after printing a large area of the field, will help to protect the printing in post press processing, especially when cutting or packaging. It may not be beneficial to cover the double-sided printed matter on one side, because the uncoated side may be more prone to the phenomenon of printing pigment peeling due to friction in the subsequent processing

3. Horse riding binding

horse riding binding is a good choice for most digital printed materials, especially suitable for the binding of thinner books such as guides, pamphlets and brochures. This binding method is economical and practical, and can be carried out online with other processing methods. It can carry out the post press processing of page matching, folding, binding and online cutting at the same time, which can provide a guarantee for the rapid delivery required by digital printing

4. Flat binding

when designing flat binding books, first of all, pay attention to leaving enough binding space between the binding opening and the text. For example, when the line hole ratio of O-type spiral line is 3:1 (meaning there are 3 holes per inch), at least 3/8 inch blank should be left; When the line hole ratio is 2:1, at least 1/2 inch of blank space should be left. This blank refers to the distance between the stapling opening and the nearest line hole edge

in order to clarify the specific location of flat binding processing, designers had better understand the changes of actual printed paper after digital printing from post press processors before digital printing processing, which is particularly important for digital printing. Most computer design programs do not consider the small changes in the thickness of the paper after printing. In digital printing, the color material printed on the surface of the paper will cause the thickness changes of the printed sheet. When Binding dozens of digital printed sheets, the cumulative thickness changes may make the binding size carefully calculated by the computer meaningless. Therefore, it is necessary to master the sample sheet change parameters of the actual production paper after digital printing, so as to accurately measure the book thickness in the printing design and ensure that the appropriate binding size can be obtained in the post press processing

5. Wireless adhesive binding

like the wireless adhesive binding processing of offset printing, the cutting amount of binding should also be considered for the wireless adhesive binding of digital printing. In addition to leaving 1/8 inch milling allowance on the back of the book, 1/8 inch cutting allowance should also be left on the other three sides of the book. In addition, a 1/4 inch gluing area should be left at the lower part of the book cover to prevent glue from seeping into the next book during binding. Wireless adhesive binding processing also requires that the printing of bleeding cover should be a little larger than the size of the text

6. Wireless binding hardcover

believe it or not, wireless binding hardcover processing is also an important post press processing method in digital printing and binding. The key of hardcover technology is how to firmly bond the book block and hard case to produce books that can be preserved for a long time. Although the cost and time-consuming of wireless binding hardcover seems to be a little out of proportion to the digital printing facing the short edition printing market, some post press binding enterprises have prefabricated hardcover cases of different colors, styles and sizes commonly used in digital printing hardcover for digital printers to choose. Therefore, wireless binding hardcover has also become a common binding method in digital printing

integrated post press processing solution

the quality and speed of digital printing make it more attractive and become one of the increasingly widely used printing methods. Most digital printing products almost need post press binding processing to become practical printing products, and most post press processing processes can be applied to post press processing of digital printing

at present, the main post press processing equipment of digital printing includes folding machine, double loop binding machine, plastic loop binding machine, wireless adhesive binding machine, horse riding stapler and page matching machine. Among them, folding machine, wireless adhesive binding machine and riding stapler can be divided into floor type and desktop type, but usually riding stapler is floor type. There are two types of page dispensers, vertical and horizontal, most of which are vertical

with the rapid development of digital printing, manufacturers equipped with post press processing equipment for digital printing are also increasingly active, such as Heidelberg, mailer Martini, MBO, MBM, Baum, DUPLO, spiel associates, standard finishing, urg, southwest plastic binding, James burn international, Powis Parker, rosback, GBR, Brackett, GBC, best graphics, Riso and ab Dick

it should be clearly pointed out that not all printers or post press processors can control the post press processing of digital printing. If the enterprise has rich knowledge of digital printing, even if Huang Rongxun takes out various national certified quality certificate code printing knowledge, understands the particularity of digital printing, and has a variety of post press processing equipment, with strong production and processing capacity and rich post press processing experience, then post press processing of digital printing will no longer be a difficult job

choose the right hot melt adhesive for wireless binding

wireless binding has many advantages over traditional binding processes such as iron wire binding, sewing, horse riding binding and so on: the spine of books bound by wireless binding is flat and beautiful; Easy to open, flatten and read; It is not limited by thick books, and thick books can be bound. The hot melt adhesive used for wireless binding has fast curing speed, which is especially suitable for use on high-speed binding linkage machine, which improves the binding speed and shortens the publishing cycle. Moreover, the hot melt adhesive is non-toxic, solvent-free, and has a small odor. It is an environmental friendly product

most of the hot melt adhesives used in wireless binding are EVA (ethylene and vinyl acetate copolymer) hot melt adhesives. At present, there are many domestic manufacturers of EVA hot-melt adhesive, many models of hot-melt adhesive produced, and the performance is not the same. Therefore, when using hot-melt adhesive in the binding process, we should reasonably select the appropriate hot-melt adhesive according to the actual situation. Only in this way can we ensure the smooth binding work and produce high-quality binding products

1. select hot melt adhesive according to the speed of the binding machine

the binding machine used for wireless binding is divided into low-speed machine, medium speed machine and high-speed machine according to the different speed. The hot melt adhesive is also divided into three types according to the binding speed, namely, low-speed adhesive, medium speed adhesive and high-speed adhesive. The low-speed binding speed is about 3000 copies/hour, the medium speed binding speed is about 8000 copies/hour, and the high-speed binding speed is about 10000 copies/hour

the opening time and curing time of hot melt adhesive are also closely related to the binding speed

the opening of hot melt adhesive Jinan new era Gold Testing Instrument Co., Ltd. has produced experimental machines for several 10 years. The release time refers to the time when the hot melt adhesive is painted on one adhesive (such as the back of a Book) and then bonded with another adhesive (such as the cover). The opening time of hot melt adhesive used on low-speed machine is 15 ~ 20 seconds, medium speed machine is 5 ~ 10 seconds, and high-speed machine is 2 ~ 7 seconds

the curing time of hot melt adhesive refers to that after the cover and book block are bonded within the specified time, they can be cut at the same time when they reach all the required mechanical properties after a certain period of cooling. This cooling time is called the curing time. If the hot melt adhesive has not been cooled and cured, it will be cut, which will deform the back of the book. When cutting, the hot melt adhesive is easy to stick to the blade, affecting the quality of the book. The curing time of hot melt adhesive varies according to the model. The curing time of hot melt adhesive is generally 3 ~ 5 seconds. The curing speed of the hot melt adhesive used in medium and low-speed machines is slower, and the curing speed of the hot melt adhesive used in high-speed machines is faster, and the curing time is ≤ 4 seconds. For high-speed linkage machine, it is also necessary to determine the curing time of the hot melt adhesive used according to the length of the conveyor belt

therefore, in order to ensure the binding quality of books, different hot melt adhesives should be selected according to different machine speeds when using, and they cannot be used indiscriminately

2. Choose hot melt adhesive according to the paper

there are many kinds of paper used for binding books, and the thickness and quantity of paper are also different, such as coated paper, offset paper, book paper, etc. When binding, you should choose the corresponding hot melt adhesive for different types of paper. Because the surface finish, permeability, wettability and thermal conductivity of different papers are different. Coated paper has high surface finish, poor wettability and fast heat conduction, When choosing hot melt adhesive, you should choose high-grade hot melt adhesive with high viscosity (the melt viscosity is generally about 5000ma.s180 ° C, good adhesion, good permeability and high tensile strength. The viscosity of hot melt adhesive used in offset paper and book paper should be lower and the fluidity should be better. When there are inserts in the bound books, that is, when different types of papers are mixed, it should be based on the standard of paper adhesive with higher quality

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