The quality of the post-press binding process is related to the overall effect of a book. If there is a problem in the last process of the printed product, the previous efforts will be abandoned. Seriously, it will cause great losses and very bad social impact. In recent years, there have been many problems with the quality of book binding, especially the problems with paperback wireless bound books and hardcover books. According to the author's understanding, every time the national book quality evaluation, including several Grand Prix products, there are unqualified products, such as paperback glued staples, pages, wrinkles, uneven front mouth, uneven back of the book, perforation, and post Lines, loose pages in front and back of book blocks, etc .; another example is that the floating mouth in the hardcover does not meet the standard, the ring is not firmly adhered to the three sides (lotus leaf edge), the round back is not standard, the front opening of the square back is round, and the hot stamp Unclear lines, upward warping of the book case surface, etc. The result of each test is that the quality problem of post-press binding accounts for more than half of all the causes of non-conformance. If 10 non-conforming products are detected, more than 6 of them are caused by the binding process. It is conceivable that the quality of the binding problem Severity. Of course, we can't deny that binding is a very complicated process, and the process is relatively long. There are more than a dozen processes in the flat and more than 20 processes in the precision. One of the processes is not well controlled, and finally there may be unchangeable. as a result of. In view of the above problems, especially the seriousness of the current page-gluing problem. The China Printing Association convened a meeting to invite relevant units and experts to study, and issued a document to seek to solve the quality problem of the pages that are glued out. According to the author's practical experience in bookbinding and professional education for many years and the understanding of processing enterprises throughout the country every year, here is an analysis of the causes of quality problems in bookbinding processing, for reference only by quality management staff. Insufficient enterprise management In recent years, competition among enterprises has intensified, and various processing enterprises are desperately striving for more jobs, more products, and more benefits, but they have neglected the quality problems, which are specifically reflected in the following aspects: The number of publicity and implementation of various national quality standards has been reduced (including those in enterprise areas). For the dozens of standards after GB / T and CY / T in the national standard, some regions have not been publicized and implemented at all. Less. In fact, the national standards of the binding profession are the most complete in the world, which is also a favorable basis for enterprises to protect their rights. Now many enterprises and the staff, quality inspectors responsible for the quality inspection department, and even the leaders responsible for the quality inspection work do not have a deep understanding of the contents of the national standard, and some do not even understand it. Control and improve. The quality inspection work system is not perfect, there is no serious training and learning of the quality inspection work content requirements, and the due responsibilities are fulfilled; the quality inspection personnel are rarely carried out regularly or irregularly. Therefore, in actual work, only the "product inspection" Control â€, while ignoring the“ process inspection and control â€causes problems only to be aware of the consequences. The quality management is not rigorous, the system is not perfect, the inspection is not the same, and the quality is the same. There is no strict system and measures to ensure the quality. The quality inspection personnel are not able to work effectively and are not responsible for the production of unqualified products. Worker mobility is too large, and job-hopping is frequent. Temporary workers go to work without any training and do not know the work standards and requirements. The enterprise lacks job training for temporary workers because it fears that training will take up work time and delay production, and secondly, it will change jobs after training. Propaganda of "quality first" is less, as long as the efficiency is long lived, there is no or lack of the concept of "no quality without production", resulting in the consequences of neglecting quality only by quantity. The material market is turbulent, the technical parameters are not clear, and there is a lack of knowledge of materials. There are many binding materials, especially adhesive materials, from animals and plants to synthetic resins. Except for some animal glues for hardcover, synthetic resin adhesive materials are almost all used. The main types are: ethylene vinyl acetate copolymer (EVA) hot melt adhesive; polyvinyl acetate paper (PVAC) water-soluble instead of flour slurry Paste; Acrylic Acetic Acid (PMA) water-soluble paper-plastic composite adhesive; Ethylene Vinyl Acetate (VAE) water-soluble paper-plastic composite film-coated adhesive ring liner; Polyurethane (PUR) fully enclosed flammable high-strength adhesive. Among them, polyvinyl alcohol hot glue and polyolefin (PO) film-plastic compound adhesive and stickers are not commonly used. The largest dosage is EVA hot-melt adhesive, the annual national consumption is about 18,000 tons, and the most problematic is also in the use of this adhesive. At present, there are more than 1,400 wireless binding production lines nationwide, and nearly 95% of them use EVA hot melt adhesives. The rest uses PUR glue. Some advanced countries use about 40% of PUR glue. China currently has only about 5%. PUR glue has many benefits and is the future development trend. EVA hot-melt adhesives were introduced and used in the mid-1970s. In the early 1980s, our country made them ourselves. Now they are mature and exported, with an annual output of more than 30,000 tons. Because EVA hot-melt adhesives are easy to manufacture and gradually increase in usage, there are more and more glue factories. However, some glue factory products enter the market without testing and identification, resulting in quality problems in the processed books and periodicals. This is the second cause of quality problems, so how do we identify and use it? The following points are for reference only: 1. There are many manufacturers of rubber, the market is chaotic, and there are many varieties, but the enterprise itself cannot be chaotic. If it is not chaotic, it is necessary to learn the knowledge of using glue to avoid being cheated. 2. The same quality depends on the price, the same price depends on the quality, don't be superstitious about foreign countries. 3. It is best to understand the proportion of glue components and the contents of technical parameters (now the glue factory does not write ingredients to replace with font size), the quality of glue ratio directly affects the quality of glue. 4. Pay attention to the following 5 key points and 9 precautions when using EVA hot melt adhesive: ☟ 5 key points Melting point: also known as the softening point of the glue, it must be ≥82 ℃; Opening point: 6000 ~ 8000 / h, generally 5 ~ 11s; Surface curing point: generally 7 ~ 16s; Cooling and melting point: ≥3min; Glue temperature: the technical parameters must be based on the tolerance of ± 5 ℃, special conditions ± 10 ℃ (refers to the excessive environment when the temperature in the working room is too high or too low). 9 notes (1) To understand and master the various types of EVA hot-melt adhesives and related technical performance, because the melting point (softening point), opening point (to-be-tack time), surface curing point, use temperature of different types of EVA hot-melt adhesives All are different, and it is necessary to strictly distinguish the changes in the glue due to the difference in area, temperature, humidity, etc. (2) The solid EVA hot melt adhesive must be preheated by a qualified preheating device before being used. After the preheating temperature is qualified, it can be used in the working glue pot before use. The preheating time should not be less than 2 hours. Put the glue block directly into the working glue pot. (3) The glue storage in the preheated glue pot should be appropriate, and the amount of glue storage should be measured according to the amount of processing and the length of boot time. Too much rubber storage causes the colloid to melt and aging repeatedly, and too little rubber storage will cause normal production to proceed due to waiting for melting. (4) The entire process of bonding, clamping and holding the book block and cover must be completed within the opening time of the hot melt adhesive. If the machine is shut down for more than 20 seconds during normal operation, the glue and the glue should be applied according to the operating speed. Take out the book block and do not continue to use it. (5) The glue temperature after melting should be strictly controlled within the range of technical parameters. (6) The preheated glue pot and working glue pot should be cleaned regularly to ensure the cleanness of the glue pot, to prevent the precipitation of impurities in the glue liquid and affect the accuracy of the glue temperature, or even cause accidents. Normal continuous production of preheated glue pots Cleaned once every three months (one quarter), the working glue pot is cleaned every two weeks or at any time to ensure the smooth progress of safe production and prevent carbonized smoke, pulverization and fire. (7) During the long-term repair period of the wireless perfect binding equipment, the glue pot should be closed to prevent the glue from repeatedly melting after repeated heating and aging and deterioration causing waste. (8) When changing the type of glue, try to clean or keep as little glue as possible. Different types of glue should never be mixed with each other. (9) When more than two types of paper and grammage appear in a book, the glue model should be used on the principle of "climbing up and down". It is appropriate to take care of strong paper and heavy weight. Analysis of manifestations and causes of quality problems in wireless glue binding Nearly all paperback books processed in China in recent years have used the wireless binding method. Because this method has many characteristics and is suitable for modern processing needs, it occupies the top of all books and periodicals. Due to the large amount of processing, there are also many quality problems. Now we will put forward several quality problems in production and analyze them for reference in the actual work of peers. Page off Refers to the separation and shedding of pages when the pages are read after processing. There are two types of page breaks, one is broken pages, and the other is dropped pages. Reason analysis ↓ (1) Breaking off the page: a. When the temperature is too low in the working room or the storage site of the finished product when the weather is cold or placed outside in the open air; b. The glue fluid often turns and melts repeatedly to cause the colloid to age and become brittle and deteriorate; Excessive rosin; d. The coating is uneven and the grooves are not parallel to the milling back. (2) Shedding pages: a. The milling groove is too shallow, the groove distance is too large; b. The fold seam runs empty when folding; c. The book is not shocked before the cover of the package, there is a shrinking phenomenon; d. Pure paper wool The paper dust has not been removed, the slot is blocked, and the glue cannot penetrate; e. Improper use of glue or aging and deterioration of the glue; f. Adhesive is attached to the edge of the clip board, and the front and back pages are pulled off; g. (Or placed outside in the open air on hot days); h. The paper quality of books and periodicals is not good, and the fibers on the surface of the paper are pulled off after sticking. Uneven back Refers to the fact that the back of the book is not flat after being cut into books, and the angle between the back and the writing is indistinguishable. Reason analysis ↓ a. The air inside the book signatures is not excluded (there is no bundling after folding); b. The book is not shocked and tidy; c. The clamping force of the book clip board is too large and the back of the book is deformed; d. The glue roller is not adjusted properly and the amount of glue Too much, too thick glue layer; e. Improper adjustment of the support plate and clamping place; f. The slope of the lower book plate is too large, and the back of the book is knocked and skewed; Cause the adhesive to solidify the back of the book in advance; h. Excessive pressure of the catty when cutting the book or inappropriate specifications of the book pressing template, and the back of the book has not been completely cooled and set. Gelatin root After the book is cut, the upper and lower ends of the front and back pages are pulled off by the cover to reveal the glue marks. Reason analysis ↓ a. The cover paper is too hard and thick, the book block paper is too thin and soft, the strength and tensile strength of the two are very different, and the front and back pages are broken; b. The reading pressure is too shallow to play the role of reading crease. Slotted rubber exposed Refers to the dark ink coated paper glue bookbinding slot paper offset marks and coating is pulled off by the glue exposed. Reason analysis ↓ a. The strength of the glue for dark coated paper is too high or the amount of glue is too large; b. The slot is too wide, too deep, and the amount of glue penetration is too much; c. The texture of the coated paper is not good, and the coating does not bond to the paper base prison. Eyelet on one end (or both ends) of the back of the book Reason analysis ↓ a. After folding, the signatures are not tied or punched; b. The air inside the signatures is not excluded, the folding edges are too thick, and the books are not parallel; c. Because the books are not parallel, the width of the back of the book is not equal, causing the book to be clipped The clamping degree of the board is not parallel, the folded edge is tight, the loose edge clip is not loose or can not be clamped, the stopper of the rubber wheel is not uniformly coated (the front end is not coated with glue); d. Three sets of glue (glued Rollers, patch rubber rollers and rubber rollers) are not adjusted properly, and are not arranged in a trapezoidal sequence; e. After the book back glue is applied, the cover support station is not completed within the opening time, resulting in the appearance of stalactites (perforations) in the book back glue; f . Improper adjustment of the supporting plate; g. The rubber roller does not work. Spilled plastic pull cord, dirty with dirty book, Reason analysis ↓ a. There is no glue breaking device or the glue breaking device does not work; b. The cover length is shorter than the book block length, which causes the hair glue to be exposed; c. The amount of glue applied is too large and too thick. Squeeze out. Exit line Refers to the ridge of the book bulging, the angle between the back of the book and the surface of the book is indistinguishable. Reason analysis ↓ a. The spine indentation of the cover book is too large or too small; b. The cover of the package is too loose; c. The clamping force of the clamping part of the support is too large (too tight); d. The wear gap between the clamping part and the support plate Too large; e. Too much glue applied to the back of the book. After tightening, it is squeezed and overflows on the spine causing a gang line. Broken head After the book is cut, the upper and lower ends of the book back are damaged. Reason analysis ↓ a. The back of the book is not completely dried and shaped; b. The length of the conveyor belt of the linkage line is not enough to reach the cooling and hardening point of the back of the book; c. The pressure or pressure of the book is not appropriate; d. The vertical lines of the cover paper; e. The book cutter is not broken Head device; f. The angle α of the cutter is too large or the cutter is worn. After the book is folded, there is a wrinkle on the edge or the next page Reason analysis ↓ a. There is too much air storage in the book block, and the last one is not compacted; b. The amount of side glue is too large and the glue layer is too thick and overflows, causing the paper to absorb too much moisture and deform; c. The adjustment of the pressure of the catty pressure or the book template is not appropriate. ; D. The book is too loose to compact. After the book is cut, there are wrinkles in the figure Reason analysis ↓ The main reason is that the air inside the signature is not excluded. Such as a. When the machine folds, the folding roller or feed roller is not adjusted properly with the gauge or the two are not parallel. The vertical angle of 90 ° is not formed; b. The slitting knife is not installed or the gap between the slitting cutters is too large; c. The length of the slitting knife of the second and third folds (four-folding) is too small, and the air in the signature is not exhausted; d .The folded signatures are not tied flat. The front of the book is uneven after cutting Reason analysis ↓ a. The air inside the book signature has not been excluded. It swims in the book. When the book is cut, the air is released, and the curved pages are stretched out. The front cut of the fold edge is uneven. If there is too much air It will form a zigzag wrinkle when there is less air, and the front mouth will be uneven); b. The folding has a phenomenon of creases. The above 11 wireless binding quality problems manifestations and causes analysis content is for user reference only, because there are too many solutions, they are not described one by one, please understand. Hair Styling,Hair Styling Wax,Hydrating Hair Gel,Hair Styling Color Wax Pomade DELIN HAIR COSMETICS , https://www.hairstylingwaxfactory.com