Analysis of Main Factors Causing Back Stuck

The glue-binding process has the advantages of simplicity, high quality, stability, and high efficiency, and thus has been rapidly developed in the book printing industry in recent years. However, in the process of popularization, many manufacturers have appeared in varying degrees of quality problems in the use of hot melt adhesives, and have paid a heavy price for this.

1. Cover paper is too bad

"A person has a face and a book has a skin." The cover of the book must use good quality paper, but the key lies in the choice of the booker.

2. The direction of the cover paper is not correct

When choosing the cover paper, the printing factory must use the standard format paper with the direction of the paper silk and the vertical of the spine, especially those with special editions and cover plates in the form of links, and try to ensure that the heads, feet, or tails In order to ensure the consistency of the paper on each cover.

3. The inner leaflet is not compacted before packing. Each book has many printed sheets, many signatures, and the book core is too loose.

After the internal leaflet page is folded, it must be tied with a 10mm thick high-density board to compact the spine of the book, especially the folds folded by the folding press of the offset press. However, avoid excessive length of bundled clipboard (size of clipboard larger than open size 10mm) and the spine at the back of the booklet, avoid irregularities at the spine of the booklet, and avoid the edges of the edge of the book (A side) and spine (B side) to avoid Ladder shape when handling.

4 milling cutter wear, not sharp

The groove cutter and the groove of the groove are worn away, the gap is too large, the milling cracks, the back of the glue is loosened, and the thickness of the book back increases.

(1) Mechanic personnel ground milling slotting knife Before using the new milling slotting knife, first use Whetstone to turn the tip of the knife to R=2mm. To avoid the tip of the cutter head, the slot at the bottom of the slot is too small, so that the bottom of the slot is not filled with glue.

(2) Whether it is Martini or Warrenberg rubber binding linkage line, the slotted bottom plate, which is matched with the milling cutter, is mostly organic plate or nylon plastic plate. This type of base plate is poor in toughness and intolerance. High temperature, quick wear. Once in continuous production, the front edge will be worn out due to heat. If the gap between the milling cutter head and the bottom plate of the milling groove is too large (should be less than 0.10mm), the slot that is milled out will become a tear. groove".

1 The surface of the slot is fluffed and the adhesive is not strong. It must be always worn and often changed. The same applies to milling back knives.

2 At the bottom of the trough groove, the bottom of the trough is cracked, with a little confetti, and the cracking gap is filled with glue. The roots of the book pages are not firmly bonded.

3 tortoises are likely to cause the loose end of the book endorsement, and the thickness of the book after back gluing is increased, commonly known as "bigger." Processing method: replace the bottom plate of the milling groove with steel plate, weld a hardness alloy strip that is consistent with the angle of the milling groove knife (60°) at the edge of the steel plate, and form the upper and lower blades with the milling slotting knife. Such milling is thorough and durable.

5. Lateral glue bar protrusion, increased spine space

Whether it is the glue-binding linkage line or the glue-bonded disc stand-alone machine, the brush side glue is completed through the extrusion of the outer side surfaces of the two copper wheels. The width of the glue on the upper side of the glue binding machine is the thickness of the copper wheels on both sides. Because the two copper wheels are too smooth on both sides, the distance between the two sides of the copper wheels is too small to support the spring tension of the two copper wheels. There is often no upper side glue in the range of 3 to 4 mm, but outside the width of the side rubber wheels. A rubber bar with irregular height and width was used. The solution is as follows:

(1) With the principle of easy hanging of glue, the outer rounds of the two copper side rubber wheels are knurled (rhombus). Parallel to the axial rolling groove.

(2) Adjust the clearance between the top scraper of the side rubber bracket and the top surface of the copper wheel to zero, and use a spatula to clean the yellow adhesive layer of the top surface of the copper wheel heated and burned. The rubber squeezed from the side of the copper wheel is prevented from accumulating on the top surface of the copper wheel. With the centrifugal action of the continuous rotation of the copper wheel, a high-low, wide and irregular glue bar L is left at the spine at 4mm.

6. Three-sided knife jack pressure adjustment from the spine is not reasonable

Rubber-bonded line three-pronged knife with random matching 32 and 16 open, with dovetail, jacking plate with wood pressure plate. Some operators do not need to trim, and only replace the two specifications of the pressure plate that comes with the machine. This is not appropriate. Different jacks should be used according to the printed sheets (book thickness) of the book being drafted.

The height of the three-faced knife each time the book is cut is limited. The fewer printed sheets each time the book is cut, the more copies are printed and the more copies are printed. If each book carries one of the five factors mentioned above, the more cuts each time it takes, the greater the chance of a spine break and vice versa, and the less chance of a spine break. If you cut 8 books at a time, the height of each book cover is 1mm, and the height of the second glue bar is 2mm. The 8mm spine of the 8 volumes is 16mm higher than the back of the book. When the cuts are made, the pressure plate is dropped first and the pages are locked. The back of the book is vacant, so that the back of the book must be cracked when it is cut. Responses:

(1) According to the trial cut, gradually reduce the number of books per cut

(2) Take the random pressure plate as the base body. First, under the premise of handling the above five factors, according to the thickness of the book that is often cut, the thickness of the book is divided into 3 to 4 types of platens. The production of these types of pressboards is based on the size of the open (32 and 16 open) sizes, and each type produces 3 to 4 blocks of 5 to 10 mm thick wood, with a length less than the open size of 6 to 8 mm and a width less than the open size of 10 to 20 mm. According to the experience of the classification of 3 to 4 types of books, two layers of 3mm thick Liaoyang paperboard were glued on the self-made wooden board and fixed on the random tape base body with wooden screws. When bonding the two Liaoyang paperboards, the spine should grow the self-made wood boards at 3mm and 6mm respectively, and when it is cut, it will be plastically bent after being subjected to the force, forming different slopes with the height of the spine to compact the side glue mouths and The height of the book is back, and it avoids wrinkling of the book when it is cut. According to the thickness of the back of the cut book, replace the plate with different bevels.

7. Three-sided edge grinding failed

If a worker wants to do good, he must first sharpen his tools. Trim edge grinding is very important, it is related to whether the glue-binding line can really play its maximum effectiveness. Responses:

(1) Select a high-precision grinding machine. Now many of the entire paper cutters and plastic trimming three-sided knives are mostly carbide knives, so the grinding of the blades is critical. In addition to the choice of high-precision grinding machine type, it is best to use a machine with two sharpening heads, one to install white steel jade grinding wheel grinding body, one to install green silicon carbide grinding wheel grinding carbide cutting head.

(2) After grinding, it must be ground with a grinder or fine whetstone, and then use sycamore wood board or foam plastic board to wipe off the residual grinding debris at the edge of the knife to prevent cutting edge damage.

8. Three-sided knife edge adhesive, cleaning is not timely

When the three-faced knife is cut, the angle between the back of the blade body and the cutting surface of the book must be 5° to 10° (this angle is formed by the cutter body manufacturer during production and processing). Due to the continuous operation of the glue-binding linkage line, on the one hand, the distance of the conveyor belt is too short, the back glue of the book is too late to completely solidify, and on the other hand, the knife body itself generates heat, so that the hot melt adhesive can easily adhere to the back of the cutter body, so that the back angle of the cutter body is zero , Increased friction, easy to cause the book spine incision, the back of the book break and so on. The countermeasures are as follows:

(1) Spray silicone oil

(2) Install hot melt cleaner

(3) Clean the blade manually.

9 book paper thickness, fold more, high width at the edge of the head width, hollow large

If the book block is made of thick paper, the plates will be opened in small increments during plate making. This will reduce the number of folds in the folded folder.