How to prevent the unglued English Print Books off the page, unglued phenomenon?

How to prevent the unglued English Print Books off the page, unglued phenomenon?

Those affected by the climate environment is small, the seasonal books printed and distributed in the province, on the premise of ensuring the quality of EVA hot melt adhesive and milling back grinding quality, you can use the wireless binding process, and this kind of books print large, tight time, do not use wireless binding, difficult to complete the task of publishing books.

Correct selection and use of adhesives

Taking EVA hot melt adhesive as an example, this paper introduces how to choose and use adhesive correctly.

1. Select high quality EVA hot melt adhesive

First, appearance inspection. Visual inspection of EVA hot melt adhesive, good texture granular (or flake) EVA hot melt adhesive should be bright, translucent, flake EVA hot melt adhesive with two hands folded back and forth should not have a large deformation, granular EVA hot melt adhesive with a small hammer percussion should not be too large deformation.

Second, smell discrimination. After opening the package, the smell of EVA hot melt adhesive with good texture is light. After heating, there will be no pungent odor, no smoke, and it will not turn yellow or black quickly.

Third, elasticity identification. EVA hot melt adhesive can be divided into high temperature adhesive, medium temperature adhesive and low temperature adhesive, printing enterprises can choose according to their equipment. Generally speaking, high temperature glue is harder than medium temperature glue, and medium temperature glue is harder than low temperature glue. High temperature glue with good quality teeth when biting, there is a certain elasticity, the higher the elasticity, the better. However, the elasticity of medium and low temperature glue is not obvious, and it is difficult to distinguish.

Fourth, cold and heat detection. Cold detection is mainly to put EVA hot melt adhesive in the environment of -10 ~ -20℃, after a period of time, observe its toughness change, test whether it can adapt to the cold in winter; Thermal detection is mainly to put it in the environment of 40 ~ 50℃, to see how the degree of curing changes, can adapt to the heat of summer.

Fifth, price comparison. Generally speaking, the price of good quality EVA hot melt adhesive is relatively high, where the EVA hot melt adhesive is obviously lower than the market price, when buying must be careful.

In addition, the printing enterprise is when the choose and buy can also be combined with their own equipment and operator's work habits take a small amount of purchase, and to carry on the strict test, when it is necessary to do destructive test (such as cold, high temperature aging test, etc.), whether its stability in line with the production needs, determine the quality and then buy in large quantities; Especially for those printing enterprises that have used a certain brand of EVA hot melt adhesive, determine the reliability of the product after use, and do not change at will because of the price, otherwise the hardship must be their own.

2. Use EVA hot melt adhesive correctly

(1) Control the operating temperature

The use temperature refers to the viscosity, viscosity, fluidity of EVA hot melt adhesive is very suitable for book bonding temperature, generally 130 ~ 180℃. The operator must strictly control the operating temperature according to the label of the manufacturer.

(2) Control the action time

The action time of EVA hot melt adhesive includes opening time, curing time and cooling and drying time. Opening time refers to the time when EVA hot melt adhesive can be glued on the adhesive. Curing time refers to the solidification time after EVA hot melt adhesive is applied and bonded, which is almost 7-15 seconds. The cooling and drying time refers to the time of cooling and shaping after the book bonding and waiting for cutting. This time is also very important. It is not the EVA hot melt adhesive on the back of the book can be cut immediately after curing, but it can be cut after cooling and drying thoroughly.

Control the back milling and grinding link

1. Select quality milling blades

The milling cutter on the cutter head of the wireless rubber machine is divided into two kinds of movable knife and fixed knife. Whether it is movable knife or fixed knife, the material of the cutting edge of the milling blade is very important. Although the price of ordinary blades is relatively cheap, but blade hardness, sharpness, high temperature resistance, wear resistance and so on are far from the alloy blade, so the best choice of milling blade hardness alloy blade.

2. Adjust the gap between the movable knife and the fixed knife

Generally new wireless binding machine, the best gap between the active knife and the fixed knife is 0.05mm, this gap for the milling cutter, in addition to the milling state, milling resistance is small, the wear of the blade is small, and milling back polishing the back of the flatness is high, conducive to the penetration of adhesives, can improve the quality of books.

3. Milling back grinding should have a certain depth

In general, three folding books milling back, grinding should be 1 ~ 1.5mm, folding too much or a set of books, milling back grinding depth must be increased to 2 ~ 3mm, otherwise it is difficult to play through. Of course, milling back grinding depth is not the greater the better, according to the thickness of the book to operate.

Change the traditional method of prepress lithography

To prevent wireless binding books off the page, the emergence of ungummed phenomenon, but also must change the traditional prepress method, the traditional "four fold spell" to "three fold spell", that is, the traditional fold 4 fold into a post to fold 3 fold into a post. This is because folding too little will affect the later process, and labor time; Fold too much will appear inside and outside the dislocation of the page number (commonly known as "crawling page") and figure eight folds, but also make the paper layer increase, thickening, milling back grinding to bring difficulties.

Fully consider the influence of climate and environment

EVA hot melt adhesive is a kind of chemical polymer, which will be affected by the climate environment and change, such as aging, brittle, etc., that is to say, the smaller the climate change, the smaller the probability of book peeling and gluing. Based on this inference, small countries are really more suitable for wireless binding this process, because its land area is not large, the north and south latitude difference is very small, limited by the impact of climate and environment. However, the big countries are not the same. To take China as an example, the North and South latitudes span nearly 50 degrees, a distance of about 5500 kilometers, and it is a continental monsoon climate, different regions have their own different climate characteristics, temperature and humidity are very big difference. In such a climate environment, it is difficult to ensure that the day long EVA hot melt adhesive does not change.

So is our country inappropriate to use wireless glue this technology? Not really. We can use it selectively. For those affected by the climate environment is small, the seasonal books printed and distributed in the province, on the premise of ensuring the quality of EVA hot melt adhesive and milling back grinding quality, you can use the wireless binding process, and this kind of books print large, tight time, do not use wireless binding method, it is difficult to complete the task of book publishing. And the national distribution of books, especially with the collection of books, or the use of the traditional "lock line + binding" binding as well.