Analysis and Solution of the Causes of Bookfold Ruffle

The quality problems that appear in book pages after books binding are common in printing houses all over the country, and now it has become a difficult problem in processing and binding. The overall quality of books is not good. In recent years, the quality of books has become more serious. The relevant departments have also Many studies have been carried out to create favorable conditions, but so far it has not been resolved because of many reasons. Let's talk about the causes and solutions of the wrinkles and hilly wrinkles that appear after the books are bound.

1, the impact of humidity on the page folds

Paper contains a certain amount of moisture, which can guarantee the flexibility and peace of mind of the paper. Approximately 7% of the water content is reasonable, and if this is exceeded, the paper may become brittle, damp or deformed. Now that the quality of book paper is getting better, the grammage is getting higher and higher. If the production shop does not pay attention to the specification of humidity, it will cause serious losses. At present, there are more than 100,000 bookbinding factories in the country, and the conditions are good (about 1/10 of them). The temperature and relative humidity of the production workshop can also be guaranteed. If the conditions are poor, it cannot be guaranteed. Some processing plants also paid attention to scientific management and put piles of book pages, signatures and semi-finished book blocks. Some piled on the wall, some piled on the ground (without paper table), and some were placed near the heating. Once these paper products are wet or dry, the moisture inside the paper is damaged and the pages are hydrocarbon-like. To the Lord, the pages sent were flat and flat. After the phase of the whole book, there was a hill-like fold. The publishing house was greatly dissatisfied. These are all due to management problems. Therefore, management personnel must take seriously, strengthen scientific process management, re-arrange facilities, rational layout, ensure reasonable temperature and relative humidity in the workshop, and prevent the paper from being damaged.

2. Too many sheets when designing layout or imposition

When the pages are folded, the more errors are, the more errors are, and the higher the number of overlaps, the greater the possibility of wrinkling. This is due to the fact that the air in the overlapping signatures is not released. . For a long period of time, it has been specified that there should be up to four percent discounts and that air be vented. However, in the past, the weight of the book block paper used in the past was usually about 52 g/m2, and now the book core paper was mainly made of offset paper of 65 g/m2 or coated paper of 80 g/m2. As the weight of the book block paper is increased and the thickness is increased, if the four-fold or three-fold reduction is still carried out according to the original regulations when using thin paper, problems will certainly arise. In this regard, the departments engaged in the design of publishing houses and printing houses must pay attention and can no longer operate according to the old regulations, nor should they think that the number of employees is more than the number of workers. In fact, this does not take into account the quality of the processed products. Because there is no production without quality, the relationship between quantity and quality must be made clear. This will never change.

In light of these circumstances and the fact that the weight of paper has increased, the revised national industrial standard CY/T27-1999.3 clearly states in 3.1.2 that a maximum of 40% off for papers up to 59g/m2; 60g/m2 to 80g/m2 for most papers Folding 3 fold; 81g/m squared paper up to 20% off. The main provisions ensure that the pages of the bound book are free from or less wrinkled. However, according to the understanding of printing factories all over the country, many units still do not pay much attention to this issue, and some are blindly pursuing production and are not implementing national industry standards. As a result, books are bound more folds, dead folds, and products are not. The serious consequences of the pass.

3, machine folding is not equipped with broken knife

The folded folding roller of the folding machine is now equipped with a book-folding seam breaking knife device, which breaks the passage of the book passage into a regular pattern through the transmission of the sheet and the transmission of the folding roller. The small mouth, in order to discharge the air inside the book, to prevent the book from processing due to stress caused by dead folds. However, it is understood that there are a large number of folding machines in factories across the country. When using a folding machine, because of fear of inaccurate cutting of the broken knife (not accurately marked on the crease line), the broken knife device will be unloaded. If you don't use it, this is extremely bad. Breaking the knife is not allowed to adjust and master the technical problem of the folding machine. It is not necessary to remove the breaking device because the technology is not convenient. As a result, all the signatures inevitably appear to be wrinkled. This phenomenon of technology, otherwise can not guarantee the quality of the unit's products.

Now the commonly used H660-type four-fold bar-knife hybrid folding machine, on the third fold no break device (folio four fold) should be modified to solve the four fold signature without a broken knife caused There are wrinkled quality problems.

4, manual folding does not break

CY/T27-1999.3's 3.1.1 also stipulates that tri-fold (referring to paper of more than 6g/m2) and signatures of more than three percent shall be marked to exclude air. This is also to ensure that the folds are not wrinkled. Hand-folded four-fold (50g/m2 and below paper) or hand-folded three-fold (60g/m2 to 80g/m2 paper) should be scraped on the third-to-last fold of the signature to exclude the signature. The air is inside to prevent wrinkles, but now there are many units who know that they should break when they fold the pages manually. However, blindly pursuing production is not to break. The final book binding is very serious and can not be remedy. This practice is extremely undesirable. The factory should seriously implement the national standard and it should not be ignored.

5. Improper process processing

In addition to the above reasons, it is also important that the process is reasonable. Bound books or this book, is inseparable from the adhesive, and now the binder for binding more water-soluble, these adhesives contain a lot of water inside, especially cold glue, are almost all water-soluble, adhesive water content On paper, it has a certain effect on the paper. Some pages are wrinkled and deformed after being glued, so the viscosity of the glue must be reasonable and appropriate. Some factories use adhesives that do not have enough viscosity to make up for them with multiple amounts of water, causing the pages to become soaked with water that causes them to deform and wrinkle. The adhesive used in general circumstances, should be the viscosity of the most suitable low limit, the amount is less and even prevail, this will ensure that the book is firmly bonded, but also allows the book page is not submerged and ensure the flatness of the book. Which kind of adhesive should be used should also be noted that there should not be any random inappropriate. Because there are many types of adhesives available today, some are suitable and some are not. Selection must be based on the texture of the adherend and the required viscosity for proper selection and deployment.