As the wireless glue-binding process has the characteristics of fewer processes, high processing speed, short production cycle, stable quality, low labor intensity and beautiful binding, it has been recognized by more and more users and consumers, and has gradually become the main mode of modern binding. . The wireless glue-binding process has developed rapidly in the printing of books and periodicals, but there have also been a large number of binding quality problems. Some manufacturers do not provide technical training for operators and allow them to blindly produce, resulting in the occurrence of page-off and loose-leaf pages in glue-set products. , Inclined, unbalanced books, bubbles, shorts and other fault phenomena, of which the most prominent page off, loose pages, to readers inconvenience. So, what are the factors that affect the quality of glued products? Let's talk about the author's experience.
Personnel technical quality and equipment status
First of all, the quality of glue products has a direct relationship with the technical level of operators. Before taking up the job, manufacturers must provide technical training for operators to understand the performance, operation sequence, and maintenance principles of the bookbinding machine and corresponding solutions to problems. Otherwise, it will cause certain difficulties for the improvement of product quality. Therefore, it is necessary to increase first-line personnel's understanding of new equipment, new technologies, new products, and new processes, and improve their technical and comprehensive capabilities.
Secondly, the availability of equipment is also the basic guarantee for improving the quality of rubber products. In the production process, once the equipment fails, it should be promptly eliminated, so that the machine is always in a good state of operation.
Binding process
The value of printed matter depends on the finished product that is finally bound. The quality and process of each process must obey the process requirements of binding in order to achieve the maximum benefit of the glue-binding process. First of all, the cover design must meet the technical requirements of the glued product. When making the imposition, an extra 5 to 10 mm knife is to be left at the top of the cover and at the foot of the ground. The purpose is to prevent the problem of dragging and mass shutdown due to the short cover and long book block. In addition, the precision of cutting the cover paper and the quality of the glue-binding product also have an important relationship. The size of the cut-out paper must be the same, the angle between the edge and the edge must be 90°, and the upper and lower cutting edges should be perpendicular, when cutting the cover The dimensions must be unified and there must be no ambiguity. Therefore, the quality of paper cutting is the foundation of the entire cover printing and cutting accuracy, and it is also one of the most critical links.
In addition, there are a large number of loose-page books, loose pages and loose pages related to folding, folding out of sets is too large, when the page is not in place when the page is caught, are caused by page breaks, loose pages. Therefore, no matter if it is a machine hinge or a hand-folded page, the four-folding page must be cut open and closed to prevent it from being pulled out; a folding or single page is best used to solve the problem by sticking pages, so that it can be ensured that there will be no page drop. phenomenon. Books and magazines with thick book pages and large amounts of paper are also the main reasons for page dropping and loose-leafing when the adhesive backing layer is too thin. If the milling back is too deep (more than 3mm), it will cause the front nick not to open and the page shrink phenomenon. Therefore, the operator is required to strictly control the depth of the milling back, the rotation page is controlled within 3mm, the flat page is controlled within 2.5mm, and the folding out sleeve is less than 1.5mm. When the book block is too thick, it is necessary to increase the depth of the milling back groove and increase the thickness of the back glue, which is approximately 1.2 to 1.5 mm, so that the back of the book is not easily broken and the page is dropped.
Correct use of hot melt adhesive
Now the EVA hot melt adhesive used on the bookbinder, the adhesive temperature is generally controlled between 160-180°C, the temperature of the side glue is generally controlled between 90-110°C, and must be preheated for about 2 hours before use. Make it a good liquidity.
The use temperature of hot-melt adhesives must be strictly controlled within the scope of use, not too high nor too low. If the temperature is too high, the fluidity and permeability of the hot melt adhesive will increase, but the viscosity and strength will decrease, affecting the adhesive strength of the publications; if the temperature is too low, the viscosity of the hot melt adhesive will increase, and the fluidity and permeability will be affected. Hot melt adhesives will thicken, become brittle, and have poor adhesion. Coated paper publications should use some hot melt adhesives with good quality and high viscosity because of their high tensile strength and good adhesion.
In addition, according to the local climate change, adjust the use of hot melt glue. Books and magazines that are stocked at low temperatures and in cold places should not be forced to overturn the book's back and avoid freezing and breaking. When used, it needs to be relieved indoors.
In short, in today's increasingly fierce competition in the publishing and printing industry, we must work hard on quality in order to have a foothold in our products. Therefore, it is imperative to improve the quality of our products. We must attach great importance to product quality, strengthen overall quality management, enhance employees' quality awareness, master the process parameters of each process, strictly follow the “adhesive-binding process quality requirements and test methods†for production, and improve the level of binding products. Practice, continuous exploration.
Author: Ping Shizhong
Reprinted from: Printing Technology