Milling and back grinding is one of the important steps in the binding process. It uses a high-speed rotating milling cutter to grind and polish the book block page into a single sheet, and then the adhesive penetrates into each page to make the books stick. A process. To complete this process, we need to start from three aspects.
1. Choose high-quality milling inserts
Milling cutters are important tools for milling and back grinding. Their quality directly affects the quality of books that are glued and bound. Therefore, the choice of milling inserts is of utmost importance. The milling cutters on the cutter head of the wireless glue machine are divided into two kinds: movable knife and fixed knife. Whether it is a movable knife or a fixed knife, the material of the cutting edge of the milling insert is very important. There are two types of milling inserts on the market for wireless glue binding: one is a common blade with high carbon steel at the cutting edge; the other is an alloy insert with a hard alloy at the cutting edge. High-carbon steel has a carbon content of 0.6% to 1.2%, and cemented carbide is an alloy material made by a powder metallurgical process using hard metals and metals of refractory metals, having high hardness, wear resistance, strength and Good toughness, heat resistance, corrosion resistance and a series of excellent performance, although the price of ordinary blades is relatively cheap, but the blade hardness, sharpness, high temperature resistance, abrasion resistance, etc. are far away from the alloy blade, so the milling cutter It is best to choose a hard alloy blade.
2. Adjust the gap between movable knife and fixed knife
The newer perfect binder, the best clearance between the movable knife and the fixed knife is 0.05mm. This gap is for the milling cutter, in addition to the milling condition is good, the milling resistance is small, the blade wear is also small, and milling When the back is polished, the back of the book has a high degree of smoothness, which is beneficial to the penetration of the adhesive and can improve the binding quality of the book.
3. There must be a certain depth when milling and back grinding
If the depth of milling and back grinding is not enough, the innermost pages will not be worn, which will affect the penetration of adhesives. In general, three-fold book milling back, polished should be 1 ~ 1.5mm, folding too many books or posts, milling back grinding depth must be increased to 2 ~ 3mm, otherwise it is difficult to break through. Of course, the depth of milling and back grinding is not as big as possible. The operation should be performed according to the thickness of the signature. If it is too large, the size of the opening will become smaller. If the cutting is still carried out according to the standard size, the phenomenon of shrinking will inevitably occur.
The above content is taken from the printing technology and digital graphic arts of Keyin Media , No. 3, 2013. For more journal content, please pay attention to the journal channel. Click on the latest journal content to enter the channel of the electronic journal .