The quality of post-press binding processing is related to the overall effect of a book. If there is a problem in the last process of the printed product, it will be abandoned beforehand, which will cause great losses and extremely bad social impact. In recent years, there have been many problems with the quality of books and magazines, especially the paperback and the hardcover books. According to the author's understanding, every time the national book quality evaluation, including several major trophies, there are non-conforming products, such as flat-loaded adhesive nails, pages, wrinkles, uneven front, uneven backs, and posts. Lines, book pages before and after the loose pages, etc.; as in the hardcover book, the floating mouth is not up to standard, the ring lining is not firmly adhered to the three sides (the lotus leaf side), the round end book is not standard, the square back is round, and the hot stamping The grain is not clear, the surface of the book shell is warped upwards, and the like. The result of each test is that the quality of the post-press binding is more than half of the reasons for all the non-conformities. If 10 non-conforming products are found, more than 6 of them are caused by the binding process, and the quality of the binding can be imagined. Severity. Of course, we can't negate that binding is a very complicated process, and the process is relatively long. It is equipped with more than a dozen processes and is equipped with more than 20 processes. One of the processes is not controlled, and finally there may be unchangeable. as a result of.
In view of the above problems, especially the current problem of glued book droppage problems. The China-India Association held a meeting to invite relevant units and experts to study and published documents to seek to resolve the quality problems of glue-booking pages. According to the author's practical experience in binding work and professional education work for many years and the knowledge of processing enterprises in the whole country every year, the reasons for the quality problems in the binding processing are analyzed here, only for the reference of quality management staff.
Insufficient enterprise management
In recent years, competition among enterprises has intensified, and various processing enterprises are desperately trying to live, increase products, and increase profits. However, they have neglected the quality problems, which are manifested in the following aspects:
There are fewer times to publicize and implement the country's various quality standards (including those in the enterprise areas), and more than a dozen standards for GB/T and CY/T after the national standard are printed, and some regions have no publicity and implementation. Less. In fact, the national standards for binding professional are the most complete in the world, and also a favorable basis for corporate rights protection. At present, many enterprises and staff responsible for the quality inspection department, quality inspectors, and even the leaders responsible for quality inspection work do not understand the contents of the national standard. Some even do not understand it. It is difficult to manage, so how is the quality? Control and improve.
The quality inspection work system is not perfect, there is no serious training and learning quality inspection work content requirements, fulfilling the due responsibilities; the quality inspection personnel also rarely carry out regular or irregular assessments, thus resulting in the actual work, only pay attention to "product inspection Control, while ignoring the "process inspection control" caused problems to detect the consequences.
Quality management is not rigorous, the system is not perfect, no inspection, good or bad, quality "eat big pot", there is no strict system and measures to ensure quality. The quality inspection personnel are not working hard and are not responsible for the production of non-conforming products.
Workers are too fluid and have frequent job hopping. Temporary workers are employed without any training, and do not know the standards and requirements for work. Enterprises are afraid of training due to work time delays, and they are afraid of job-hopping after training. Therefore, there is a lack of job training for temporary workers.
The promotion of "quality first" is less, as long as the efficiency is long live, there is no or lack of the concept of "no quality, no production", resulting in the consequences of neglecting quality.
The material market is disordered, the technical parameters are not clear, and there is a lack of understanding of material knowledge.
There are many materials for binding, especially adhesive materials, which have evolved from animals and plants to synthetic resins. In addition to some animal glue for hardcover, almost all of the other are synthetic resin-based bonding materials, the main types are: ethylene vinyl acetate copolymer (EVA) hot melt adhesive; polyvinyl acetate paper (PVAC) water-soluble instead of flour Paste; acrylic acid (PMA) water-soluble paper-plastic composite; ethylene vinyl acetate (VAE) water-soluble paper-plastic film-coated adhesive ring; polyurethane (PUR) fully enclosed flammable high-strength adhesive.
Among them, polyvinyl alcohol hot glue and polyolefin (PO) film-plastic composite glue and self-adhesive are not commonly used. The largest amount is EVA hot melt adhesive, which is used in the country for about 18,000 tons per year. The most problematic is also in the use of this glue. At present, there are more than 1400 wireless binding production lines in the country, and nearly 95% use EVA hot melt adhesive. The rest use PUR glue. In some advanced countries, the amount of PUR glue accounts for about 40%. At present, China only has about 5%. Because PUR glue has many benefits, it is the future development trend.
EVA hot melt adhesives were introduced and used in the mid-1970s. In the early 1980s, China's own manufacturing was made and matured and exported, with an annual output of more than 30,000 tons. Because EVA hot melt adhesives are easy to manufacture and the amount of use is gradually increasing, so there are more and more rubber factories. However, some rubber factory products have entered the market without testing and appraisal, resulting in quality problems in 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 glue, the market is chaotic, and there are many varieties, but the enterprises themselves can't be chaotic. If you don't want to mess with yourself, you should learn the knowledge of using glue and avoid being deceived.
2. Look at the price for the same quality, look at the quality at the same price, and don't be superstitious about foreign countries.
3. It is best to understand the composition ratio of the rubber and the various contents of the technical parameters (now the rubber factory does not write the ingredients with the font size instead), the quality ratio of the rubber directly affects the quality of the glue.
4. Pay attention to the following five key points and nine precautions when using EVA hot melt adhesive:
5 key points
Melting point: also known as the softening point of the glue, must be ≥ 82 ° C;
Open point: 6000~8000/h, generally 5~11s;
Surface curing point: generally 7~16s;
Cooling and melting point: ≥ 3min;
Glue temperature: The tolerance of the technical parameters shall be ±5 °C, and the special case shall be ±10 °C (refer to the over-standard environment when the temperature in the working room is too high or too low).
9 precautions
(1) To understand and master the various models and related technical performances of EVA hot melt adhesives, because the melting point (softening point), open point (to be stuck time), surface curing point, and use temperature of different types of EVA hot melt adhesives They are all different, and it is necessary to strictly distinguish the changes in the glue due to the difference in area, temperature, humidity, etc.
(2) Solid EVA hot melt adhesive must be preheated before use. After preheating temperature is passed, it can be used in the working glue pot. The preheating time is not less than 2 hours. The rubber block is placed directly into the working glue pot.
(3) Preheating the glue in the rubber pot should be appropriate. Depending on the amount of processing, the length of the boot time is a measure of the amount of glue stored. If the amount of glue stored is too large, the colloid will be repeatedly melted and aged and deteriorated. If the amount of glue is too small, it will cause normal production due to waiting for melting.
(4) Complete the whole process of sticking, clamping and supporting the book block and cover during the opening time of the hot melt adhesive. If the machine is stopped for more than 20 seconds during normal operation, it should be glued and glued according to the running speed. The book block is taken out and cannot be used any more.
(5) The glue temperature after the melt glue should be strictly controlled within the scope of use of the technical parameters.
(6) Preheating the glue pot and working glue pot should be cleaned regularly to ensure the cleaning inside the glue pot, prevent the precipitation of impurities in the glue liquid and affect the accuracy of the glue temperature, and even cause accidents. Normally continuous production of preheating rubber pots Clean up once every three months (first quarter), work the rubber pot every two weeks or at any time to ensure safe production smoothly, to prevent carbonization, smoke, powder and fire.
(7) The wireless binding equipment should be closed during the long-term repair period to prevent the colloid from being repeatedly melted and aging and degraded after a long time of heating.
(8) Try to clean or leave less glue when changing the type of glue. Different types of glue should not be mixed with each other.
(9) When more than two kinds of paper and gram weight appear in a book, the type of rubber should be used in the principle of “carrying up and not going downâ€, taking care of the paper and the weight is good.
Analysis of the Forms and Causes of Quality Problems in Wireless Adhesive Ordering
In recent years, almost all of the paperback books processed in China use the wireless binding method. Because this connection method has many characteristics and is suitable for modern processing needs, it accounts for the first method of all books and magazines. Due to the large amount of processing, there are many quality problems, and several quality problems appearing in production are proposed and analyzed for reference in the actual work of the peers.
Drop page
Refers to the separation of the pages of the book when the book is processed and turned over. There are two types of page breaks, one is to break the page, and the other is to drop off the page.
Cause analysis↓
(1) Breaking off the page: a. When the weather is cold, the temperature in the working room or the storage finished site is too low or placed outside the open air; b. The glue often repeats melting to cause the colloid to age and become brittle and deteriorate; c. Inferior or in-gel composition Excessive rosin; d. uneven coating, non-parallel milling back grooves.
(2) falling off the page: a. the milling groove is too shallow, the groove distance is too large; b. the folding seam is empty when folding; c. the book before the cover is not shocked, there is a shrinking phenomenon; d. pure paper hair The paper scraps are not removed and the slots are not permeable; e. improperly glued or glued and deteriorated; f. The adhesive board is attached to the edge of the bookboard, and the front and back pages are pulled off; g. The temperature of the finished stack is too high, and the humidity is too high. (Or placed outside the open air on a hot day); h. Book paper is not good, after the glue, the paper surface fiber is pulled off.
Unrecognizable book
It means that the book is cut into a book and the back of the book is not flat. The back of the book and the written edges are not clear.
Cause analysis↓
a. The air in the signature is not excluded (no binding after folding); b. The book is not shocked and neat; c. The clamping force of the bookboard is too large, the back of the book is deformed; d. The adjustment of the rubber roller is improper, the amount of glue applied Too much, the glue layer is too thick; e. The adjustment of the plate and the clamping position is improper; f. The slope of the book board is too large, the back of the book is slanted and skewed; g. The adhesive cover is not finished in the opening time. The adhesive is pre-cured and the back of the book is not flat; h. When the book is cut, the pressure is too large or the specification of the book is not appropriate, and the book backing is not completely cooled and shaped.
Rouge root
After the book is cut, the upper and lower ends of the front and back pages are broken by the cover to reveal the rubber marks.
Cause analysis↓
a. The cover paper is too thick and thick, the book core paper is too thin and soft, the strength and tension of the book are very different, and the front and back pages are broken; b. The pressure of the scroll is too shallow to read the crease.
Slotted bottom
Refers to the dark ink ink offset paper glue book slot at the paper offset mark and the coating is pulled off the primer.
Cause analysis↓
a. The strength of the dark coated paper is too high or the amount of glue is too large; b. the groove is too wide, too deep, and the amount of glue is too much; c. The texture of the coated paper is not good, and the coating is not bonded to the paper base. prison.
There are holes at one end (or both ends) of the back of the book
Cause analysis↓
a. After the fold, the signature is not tied or the punching knife is not installed; b. The air in the signature is not excluded, the fold is too thick, and the book is not parallel; c. Because the books are not parallel, the width of the book is not equal, resulting in a book The clamping degree of the plate is not parallel, the edge of the folded edge is tight, the edge of the burr is loose or not clamped, and the back of the rubberized wheel is not evenly deformed (the front end is not coated with glue); d. Three sets of glue (gluing) The roller, the rubber roller and the rubber roller are not adjusted properly, not in a trapezoidal arrangement; e. After the adhesive is applied, the adhesive cover is not completed in the open time, resulting in the presence of stalactites (eyes) in the book adhesive; f The adjustment plate was improperly adjusted; g. The rubber roller did not work.
Overflowing glue, dirty with dirty books,
Cause analysis↓
a. No glue breaking device or glue breaking device does not work; b. The length of the cover is shorter than the length of the book block, causing the backing of the hair book to be exposed; c. The amount of glue is too thick and too thick, and the glue is clamped after being hit. Extrusion.
Outbound line
Refers to the ridge of the book, the back of the book and the surface of the book are not distinct.
Cause analysis↓
a. The cover of the cover is too large or too small; b. The cover of the cover is too loose; c. The clamping force of the clamp is too large (too tight); d. The wear gap between the clamp and the support plate Too large; e. The back of the book is too much glue, squeezed and spilled over the spine to create a line.
Breaking the head
It refers to the damage of the upper and lower ends of the book after cutting the book.
Cause analysis↓
a. The back of the book is not completely dry and shaped; b. The length of the conveyor belt is not enough, and it does not reach the cooling and hardening point of the book backing; c. The pressure of the pressure or the pressure board is not allowed; d. The vertical paper of the cover paper; e. The cutting machine is not broken. Head device; f. cutter angle α is too large or the cutter is worn.
Wrinkles on the top or bottom of the booklet
Cause analysis↓
a. The air in the book block is stored too much, the last one is not compacted; b. The amount of side glue is too large, and the glue layer is too thick to overflow, so that the paper absorbs too much moisture and deforms; c. The pressure of the pressure or the pressure of the book is not adjusted properly. ;d. The book is too loose to be compacted.
The book has a figure-eight wrinkle in the book page.
Cause analysis↓
Mainly the air in the signature was not excluded. Such as a. When the machine is folded, the folding roller or the feed roller is not properly adjusted with the gauge or the two are not parallel. No vertical angle of 90°; b. no ripper or ripper is too large; c. second, third fold (four fold) rupture knife length is too small, no air is discharged from the signature; d After the fold, the posts are not tied and flattened.
After the book is cut, the front mouth is uneven
Cause analysis↓
a. The air in the signature memory is not excluded, swimming in the book, when the book is cut, the air is released, and the sheet with the air bent is stretched and the front slit of the folding edge appears uneven (if the air is stored more) The formation of the eight-character wrinkles, the presence of less air will appear in the front of the mouth); b. folds have creases and empty.
The above 11 types of wireless binding quality problems and reasons analysis content are for the user's reference only, because the solution content is too much, not here, please understand.
Article source address: http://
Outdoor aluminum furniture is suit for outdoor patio usage for a long time. The material is 1.2mm , 1.5mm or 2.0mm thickness aluminum frame with powder-coated.
Secure and comfortable structure, simple design but elegance, is popular option for customer. Aluminum frame is welded and polished in meticulous style. Gently angled backs and wide arms encourage restful lounging. The industry`s best high-performing fabrics encase the thick, double-wrapped foam cushions.
· Traditional forms with a spacious, inviting scale
· Rust-resistant powder-coated aluminum frame.
· Comfortable 30 density cushion foam.
· Secure tempered glass for dining table and coffee table.
· Waterproof fabric for cushions.
Outdoor aluminum furniture with high quality and long time guaranty.
If you have any questions, please contact with us directly. Outdoor Aluminum Furniture are produced by Golden Eagle Outdoor Furniture Co.,ltd with High Quality and Good Appearance. Welcome you to visit our Factory for any inquiry, please send mail directly to us.
Aluminium Garden Furniture,Lawn Aluminium Garden Furniture,Outdoor Aluminium Garden Furniturel,Garden Aluminium Garden Furniture
Golden Eagle Outdoor Furniture Co., LTD. , https://www.gepatio.com