Bookbinding process technology operation

Bookbinding technology refers to the use of hot-melt adhesives to bind book-bound bookbinding methods without using wires or wires. The glue-binding process flow is for inserting the cover of the backside glue on the backside of the book core milling backing groove. Due to the stable quality of glued products, low error rate, short production cycle and light labor intensity, it is the development direction of the binding process. According to the actual operation of our factory, if we can attach importance to the following aspects, the effect will be better.

First, the correct choice of hot melt adhesive

The main material for glue-binding EVA hot melt adhesive is a solid, fusible polymer that does not require solvents, does not contain water. The hot melt adhesive is a solid at room temperature, and it heats the flux to a certain degree and becomes a fluid with a certain viscosity. It is mainly composed of EVA resin, thickened polymerized rosin, terpene resin, viscosity-adjusted microcrystalline wax, and antioxidant di-tert-butyl p-cresol. There are many types of hot melt adhesives on the market, and their performance is not the same. Hot melt adhesives should be divided according to the speed of different glue-binding machines when used. There are three types of low-speed glue, medium-speed glue and high-speed glue. Low-speed glue is set at about 2000 copies per hour, and medium-speed glue is set at about 2000-4000 copies per hour. , high-speed binding more than 4000 hours / hour or so. The open time of the hot melt adhesive for the low speed machine is 1520 seconds, the open time of the hot melt adhesive for the medium speed machine is 510 seconds, and the open time of the hot melt adhesive for the high speed machine is 27 seconds. The curing time of the hot melt adhesive is 35 minutes. Hot melt adhesive opening time and curing time are closely related to the speed of glue binding. Therefore, it should be selected according to the type and performance of hot melt adhesive. In the selection, it should also be noted that the glue-binding product is different from the paper, and the hot-melt adhesive also has the difference between the coated paper and the general paper. Therefore, the hot melt adhesive must be selected appropriately. Different papers have different surface finishes, and they require different permeability, infiltration and thermal conductivity.

Second, glue book binding imposition, pull mouth, mark mark

Binding book binding on the machine before the printing of the large version and the wire hand door, saddle stitching, lock line set on the machine printing of the spelling version is somewhat different, glue book binding book sticker layout should be relaxed at the door 23mm, which is used for the plastic backing and milling, because the trimmed part of the book block is to be milled and the top page is also milled into a single page in order to guarantee the glue. penetration.

Book seal for Lekou products, in the glue before the book should be cut out in the knife on the machine to pull the mouth, pull the mouth should be the size of the external incision to relax 23mm, so that the product can be adjusted after milling book book and product standards .

The book is pasted on the labeling mark and put in the binding production. In addition to marking the back of the book, the sticker mark of the glue book should also be marked in the space of the book. The back of the book should be milled and all the marks on the back of the book must be marked. Milling, such as adding a mark to a new part of the book's Tiantou, will allow the book with the cover to be further examined before the upper three-machine knife is cut.

Third, rubber bookbinding book book core with the finishing

The processing of the book block before it is glued into the glue book is a process that can not be ignored in the glue-binding process. The flatness and tightness of a well-designed book have a direct impact on whether or not the bookbinding product line can function properly. It also has a direct impact on the quality of the finished book. If the book is not affixed, it is not strapped, and it is not compacted. , Turned into the milling back, pull the groove, then the quality of this semi-finished product is bound in the bookbinding machine after the clamp is bound to be uneven, milling cutter is not in place, the depth of the book back trough is not good enough, glue after the There will be a lot of quality problems such as off-page, loose-leaf, empty-back, wrinkled back and so on, so the finishing of the book is very important. Finishing is to put a good book with fluffy, loose, tied, bundled, put a certain number of books on the strapping machine, the end of each bundle of books with a hard sheet of wood as a pad plate, pad size and size should be Match the size of the stickers, start the strapping machine, compact the loosened book, and then tie it with a string, in order to stiffen the solidified back, use polyvinyl alcohol glue after compaction and binding. Thinly brush the back of the bundled book. After the polyvinyl alcohol glue to be brushed is dry, the bundling rope is released. Each book is then cleared and then transferred to the glued book.

Four, book block with paste after milling, drawing slot

Milling back and pulling groove are the key steps for glue binding. Milling back is to cut back the book block of the good book along the setting part and cut it into a single page. The back of the book can't be cut into bevels. The groove is the back of the book block that is milled and cut. The undulating groove is deeply drawn and deepened to increase the permeability and contact area of ​​the hot melt adhesive to the book block, so that the pages can be closely adhered. According to the thickness of the paper, the thickness of the book is determined by the thickness of the paper. The depth of the cutting is defined by the number of folded layers of the book. Take 52 g of 60 g paper as an example. The depth of the three-pass book block is 1.52 mm, and the four-fold book block is 23mm. Groove depth is generally controlled between 0.8-1.5mm. If the paper is thick and the fiber is poor, you can pull it deeper, and vice versa. The deepest shall not exceed 1.5mm, and the shallowest shall not be less than 0.8mm. The shape of the pulling groove shall be a ∧ type, and the angle shall be approximately 60°. The distance between two adjacent grooves is generally 35mm, and the concave may be properly adjusted according to the condition of the paper. The distance between slots, the general situation 64 book core can pull 46 slots, 32 books can pull 68 slots, 16 books can pull 810 slots, 8 book core can pull 1012 slots, if milling back Depth and depth of the groove can not meet the requirements, will affect the penetration of glue, resulting in page breaks, loose sheet quality defects, in the inspection of milling back, the depth of the groove is appropriate, but also to check before entering the glue The quality of semi-finished products in the process of matching, bundling, compaction, etc., must also be checked.

Fifth, preheating of hot melt adhesive

The hot melt adhesive should be preheated before use. When it is preheated, the solid hot melt adhesive is poured into the preheated glue pan, heated at a temperature of about 160-200° C., preheated for about 12 hours, and the heating temperature is reached. After the liquidity is good, hold the preheated hot melt adhesive into a plastic tank with a machine of 160-180°C for normal start-up. The heating temperature of the hot melt adhesive is closely related to the fluidity and adhesive strength of the adhesive. Therefore, when the hot melt adhesive is heated, the temperature must be strictly controlled. The heating temperature should not be too high or too low, and the temperature range should be strictly controlled within the technical parameters provided by the manufacturer. General hot melt adhesive heating temperature and sizing temperature should be controlled in the range of 170-180 °C. If the temperature is too high, the fluidity is very good, and the permeability to the pages is also strong, but the bond strength will decrease; the temperature is too low, the bond strength will rise, but the fluidity of the glue will decrease, and the pages will not be firm. Adhesion, limb removal, loose-leaf quality problems. If the hot-melt adhesive temperature exceeds 200°C, the hot-melt adhesive may be carbonized and cracked. Hot melt adhesive should not be put for a long time, try to avoid repeated melting and solidification.

Sixth, the glue on both sides of the back and back of the book block

The glue glue is glued on both sides of the back and back of the book block. After the book block is milled back and grooved, the hot melt glue can bind the book page to the book page. The binding between the book block and the cover becomes a Book. The adhesive has the difference between adhesive and side adhesive. Their fluidity, opening time, and curing time are all different. The adhesive temperature should be controlled at 170-180°C, and the thickness of the adhesive glue is generally controlled at 0.62mm. The layers should be uniform and thin on the backsheet can affect the bond strength. Thickness on the backsheet can increase the cost. The length of the adhesive should be slightly shorter than the cover size of 12mm. If it is too long, it will cause the remaining glue to accumulate mechanical transmission components, causing it to malfunction. If it is too short, it will cause the back of the book and the feet to become empty, which will affect the quality. When the upper side glue between the book block and the cover is used, the side glue must be a hot melt adhesive with good flowability, long open time and curing time, and high bonding strength. The temperature of the side glue is controlled at about 160-180°C. The width of the glue is generally about 46mm, and the fuller the glue on the side, the better, and requires a firm bond in order to ensure the quality of the book and the cutting requirements. Do not use gum as a side glue, otherwise it will make the book cover on the cover line, affecting the quality of the product.

VII. Causes and elimination of common breakdowns of bookbinding

(a) book degumming, loose leaflet

1 The depth of the book block milling back is not enough, and the book page is not completely milled into a single page, which causes the degumming and loosening of the book, and the depth of the milling back should be increased.
2 The distance between the knife and the depth of the knife should be adjusted by improper distance between the pulling groove and the depth of the pulling groove.
3 hot melt adhesive temperature is too low, glue liquidity and permeability caused by the book degumming, loose pages, the hot melt adhesive should be heated to about 170-180 °C.
4 book back hot melt adhesive over-filled caused by degumming books, loose pages, should control the thickness of adhesive, generally controlled between 0.62mm.
5 If the hot melt adhesive is used improperly to cause the degumming and loose-leaf of the book, the hot-melt adhesive matching the model and season should be selected.

(B) The book is not square

1 The use of an unsharpened milling back tool causes the back of the book to be out of squareness, and the sharp milling back knife should be replaced.
2 The adhesive on the adhesive does not cause the back of the book to be square, and the gluing mechanism should be adjusted to make the adhesive glue even.
(3) Improper setting of improperly established institutions causes the back of the book to be incorrect and should be adjusted to the established type.
4 book stickers and finishing are not square back caused by the book is not square, should be organized to ensure that the quality of the book posted.

(3) The cover is not even, and the cover line is obvious

The excessive amount of 1 side glue causes the cover to be uneven, and the cover line is obvious. The amount of side glue should be controlled.
If the temperature of the 2 side glue is too low, the uneven side coating causes the cover to be uneven and the cover line is obvious. The temperature of the side glue should be increased, and the temperature is generally controlled at about 160°C to 180°C.

(4) Inaccurate cutting size of books

1 The cutting size of the book is inaccurate, and the dimensions of the three-side cutter must be adjusted.
In short, as long as we continue to grope and sum up experience from practice, conscientiously understand the material's performance, master the appropriate process parameters, and strictly operate on the process, we can obtain satisfactory glue-binding products.