Evaluation standard of the hottest EVA hot melt ad

2022-08-24
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Evaluation and standard of EVA hot melt adhesive

in order to solve the quality problem of wireless adhesive binding of books and periodicals and standardize the market of using EVA hot melt adhesive, the National Printing Standardization Technical Committee organized publishing houses, adhesive material manufacturers and printing and binding units in 2005 to formally apply for and start the formulation of the national industry standard "use requirements and inspection methods of EVA hot melt adhesive for books and periodicals binding"; This year, the relevant technical data in the standard content were tested and verified, that is, the activity of "evaluation of EVA hot melt adhesive for bookbinding" was carried out. This is the first evaluation of EVA hot melt adhesive in China in the past 20 years

as the saying goes, everything is difficult at the beginning, although there are inevitably some deficiencies in the evaluation work, such as the environmental conditions in the test are not ideal, the test items are not comprehensive enough, and the test data are somewhat repeated. However, the overall situation is that the test items are basically satisfactory, the test data are basically accurate, and the results of the test work are commendable

this evaluation work has laid a scientific, quantitative and standardized foundation for the formulation of China's industry standard "use requirements and inspection methods of EVA hot melt adhesive for book binding", which is a great good thing for improving the quality of book binding in China. For this reason, on behalf of all processing enterprises of post press binding, I would like to express my heartfelt thanks for this work. The National Printing Standardization Technical Committee can not make some achievements in this test work without the strong support of the units participating in the test and the standard making. I also express my heartfelt thanks to these units and experts

at present, the quality problem of post press binding in China, especially wireless adhesive binding, is very serious, causing a very bad impact at home and abroad. Such as loose pages, falling pages, breaking and non sticking, dirty books, broken heads, etc; The problem of film covering is also very serious, and the four major problems of blistering, folding, detachment and curling have not been completely solved so far. Hardcover and horseback binding also have many problems, but they are not as prominent as wireless binding. A few years ago, binding problems accounted for more than 65% of the unqualified prints in China's quality inspection center, and wireless binding problems accounted for more than 85% of the 65% of the unqualified prints. What's more amazing is that 90% of the 80 varieties of bound books in Beijing tested by Beijing quality inspection station recently have quality problems such as loose pages, falling pages, side glue cracking and so on. There are many reasons, but in the units where these problems occur, there are many similar phenomena, that is, the first glue is not good, the second paper is not good, and the third equipment has problems. Some users can't find the reason, so they ask the rubber factory to change the rubber and claim for compensation; But the rubber seller or the rubber factory can't make a reasonable explanation or solution. In order to retain customers, it often happens to do business at a loss. In fact, the real reason is the lack of glue knowledge on both sides. Of course, due to the chaos in the rubber making and marketing market, we do not rule out the troubles brought to us by some unqualified or even illegal rubber dealers, as well as the management, use and environmental conditions in the operation of the processing plant

this time, the National Printing Standardization Technical Committee conducted numbered notarization tests on 12 kinds of glue samples from 8 glue factories. According to the test data, the viscosity, hardness, fracture elongation and tensile force of the adhesive meet the requirements of the international general standard data, and the tensile force of the pages after the book is pasted is more than 4.5 (the international standard is 4.0)

the results of this test can illustrate that the products produced by Chinese rubber factories can meet or even exceed international standards. As long as the quality of the products produced by the rubber production enterprises can be the same as that of the rubber samples sent, the quality of the rubber will be guaranteed, and the use market of the rubber will be basically stable, which can eliminate the doubts of the users. The following is a multifaceted analysis of the current quality problems

from the macro analysis

for a long time, due to the backward prejudice against the binding profession left over from history and the neglect of this process, it has caused:

1 For decades, the cultural quality of the staff engaged in this profession is now that most deformation units adopt single-chip 24 bit ultra-low noise analog-to-digital converters lower than prepress and printing. Few college students do bookbinding, but many change jobs. Or the personnel allocation is not reasonable. 1. The microcomputer controlled LCD display is reasonable. The educated and beautiful ones go to prepress, the strong ones go to print, and the rest go to binding. Now the new binding equipment is a linkage line with a high level of intelligence, and it is difficult for people who do not know the point to master the post press operation

2. Beijing Institute of printing, the largest printing institution in Asia (referring to the number of students), has no such major so far. Where did the reserve force of post press binding come from? Rely on wage earners? Who will master the advanced equipment? How to produce high-quality products? Because there is no such major, teachers are even more difficult to find

3. Few of the technical lectures of China's large-scale printing industry information conferences, science and technology seminars and large-scale exhibitions over the years involve the content of this major. It seems that the printed pages can be sold to readers for reading and use without ordering or loading

4. The price of binding is too low to be lower. Everyone tries to lower the price of binding, forcing the processing plant to buy only low-quality materials, resulting in a vicious cycle of quality decline

5. The cycle is always pressed on the post press binding process, and the delay caused by prepress and printing is added to the binding head. Working overtime for the Spring Festival can't go home, cleaning the battlefield for the last two processes. Aren't these phenomena the reasons for the quality problems in the binding process

$page break $from the analysis of the communication between the publishing house and post press processing

now there are more than five phenomena in the publishing house, namely, there are more short editions, more wireless binding, more special and special processing products, more new materials and new designs, and it is required to publish books quickly, with short cycle and high quality. From the perspective of publishing, it is to think of good books and publish more books, so that readers can be satisfied in terms of content, genre, design, material selection and factory processing. However, in the production process, sometimes the desired effect is not achieved, and some of the previous efforts are even wasted

there are many reasons for this. For example, in recent years, many publishing house art editors are newcomers, most of whom are college students, with cultural knowledge, but many laymen, lack of business knowledge and practical experience, and there are few opportunities to leave the factory. Some of them have an understanding of prepress and printing, but they have too little understanding of the complexity of post press binding processing (because universities do not have this discipline), and there are often inconsistencies between expectation and effect, When problems are found, there are some blind suggestions, especially some American editors who can't put down the shelf and refuse to consult and communicate with the binding teacher, so as to obtain 2) the accuracy indicators of environmental parameters in the working chamber of the climate box (such as temperature, humidity, salt fog sedimentation rate, etc.) are practical knowledge of the results of detection in the empty state

in the past, the processing factory was the God of the publishing house, but now the publishing house has become the God of the factory. Even if there are some varieties of unreasonable design or inappropriate materials, the factory knows that it does not meet the requirements of process processing, and dare not raise more opinions, lest the publisher be unhappy, deduct wages or refuse to work. Now it is difficult for printing houses to make money, especially for binding processing. This year is a low profit year, and some booksellers are disrupting the market. Life is very sad

1. The problem of work price

the endless decline of work price results in:

① purchasing cheap and inferior materials, resulting in the decline of product quality

② extend working hours, lower workers' income, force the loss of skilled workers, recruit workers everywhere, and the technical level cannot be improved. At the same time, it threatens social security and harmony. Some small non-standard processing plants use their own advantages to lower prices in order to compete. Make publishing units reduce wages endlessly, resulting in a vicious circle of quality decline

2. As long as the book is published quickly, regardless of the rationality of the processing cycle, the printing and packaging processing of books and periodicals needs a certain processing cycle, and only within a reasonable processing cycle can we ensure that the processing quality meets the ideal requirements. However, at present, this condition is basically not guaranteed, and the time given by the publishing house to the processing plant often takes up a lot of time. It is understood that pressing manuscripts can take as little as one month, or as much as two months or even longer, squeezing out the time for post press processing. When they are sent to the publishing department, they will need books for manuscript delivery, regardless of the feasibility of the processing cycle, such as: ① the drying time between printing and film coating; ② Drying time between four-color printing and binding; ③ Natural flattening and setting time after hardcover book processing; ④ The time of publishing and delivering books should be counted as part of the processing cycle

3. Art editing and design problems

① improper material selection

△ the front opening is also folded with paperboard for cover material (above 250g/m2), resulting in uneven front opening and broken folding opening

△ the book block paper is too thin, and the cover paper is too thick and hard. The strength of the two is very different, and the tension is not equal, resulting in the leakage of the rubber sole of the first page, etc

△ the ring lining is made of coated paper, causing wrinkles and lining spitting after lining sweeping

△ the selection of hardcover cover cover is inconsistent with the printed pictures and texts, resulting in the inability of hot stamping

② improper design

△ no allowance will be made for the box line on the back of the book

△ the book is thin, the back is narrow, and the words on the back are large

△ the bleeding line of the front mouth is required to be neat

△ the paper is thick and has many folds, resulting in zigzag folds and unevenness after cutting the front mouth

△ when making up, there is no difference in the packaging method, and the error in the center of the edition is large, which makes it impossible to process

△ if there are jigsaw pages, no part will be left for the milling back. The cover behind the wrapped book is often shorter than the book block, exposing the book back glue. Dirty books and dirty bands affect the appearance quality

△ wireless binding only cares about reducing the cost, regardless of the processing difficulty and processing effect, regardless of the difficulties of readers, resulting in unevenness and inability to read

△ in order to make the books firm, the factory is unreasonably required to thicken the adhesive layer, which makes it impossible to browse (mixing thickness and strength into the same concept)

△ thick hardcover books are rounded to make a square back, causing the front mouth to become rounded and protrude outward to form a split round, which affects the appearance quality

△ thick hardcover round endorsement without bobbin paper material, resulting in distortion, relaxation, deformation, etc. after processing

the above is mainly caused by not knowing the post press binding process and blindly seeking to reduce costs

4. Some suggestions for the Publishing Department of the publishing house

establish a work style of sticking to the end, and communicate more with all processes of the printing plant, especially the binding process. Learn more about the process technology of various processes in the factory, especially the college students who are new to the publishing house, and gradually become experts. We should understand the quality standards of prepress, printing and post printing, especially the national quality standards, and reasonably require the factory

5. Some suggestions for us editor design

① express the design form according to the quality and value of books

② select the packaging materials according to the book content and the object of use

③ according to the feasibility of factory processing, achieve the consistency between expectation and processing effect

④ consider the processing feasibility in the design, so that the work can achieve the ideal design and perfect processing effect

$page break $analyze from the internal reasons of the binding enterprise

in addition to the adverse factors caused by the outside world, the main problems of the binding quality are caused by the internal reasons of the processing unit, such as management, personnel quality, etc

1. The production consciousness of scientific management cannot keep up with the needs of modern development

① the temperature and humidity control of the plant is not up to standard

② the layout of plant equipment is not standardized

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