Different adhesives are used after printing (top)

In the modern binding process, different types of glue are often used for different requirements. What kind of glue is used under what circumstances? This is a question that puzzles many people. In this article, we will discuss the use of different types of glue. I hope that through the introduction of this article, I will be able to help everyone in the future.

Nowadays, the more common adhesives are animal adhesive materials, starch adhesive materials, casein adhesive materials, natural resin adhesive materials, cellulose adhesive materials, and synthetic resin adhesive materials. Below we introduce separately.

First, animal bonding materials:

(1) bone glue

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The main component of bone glue is a protein that is insoluble in water. Another form of protein that becomes a protein after it is heated is called gelatin, which is soluble in hot water and has adhesive properties.

performance:

The plastic film of bone glue is very strong and elastic after being formed, which is determined by the long molecular chain of bone glue. This long molecular chain can change its own arrangement without breaking, so it produces a very good elasticity. If an appropriate plasticizer is added during use, the elasticity of the film can be increased.

However, bone glue is not water resistant, and water will cause the rubber layer to expand and lose its bond strength. Its corrosion resistance is also not good. When the water content in the glue reaches 20% or more, it is easily deteriorated. High temperature and high humidity can also cause changes.

Usage:

It has good bonding performance, high bonding strength, less moisture, quick drying, low cost, and easy to use. In particular, the adhesive and dipped packaging shells can achieve good results.

Bone glue is best for pasting book shells, which can avoid or reduce unevenness of the book case.

(2) Gelatin

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The raw materials for making gelatin are high-quality fresh animal hides, leg material and bones.

performance:

Gelatin composition is similar to bone glue, but the purity is relatively high and the colloid is transparent. Gelatin melt temperature and coagulation temperature are slightly different from bone glue.

Usage:

The use of gelatin is basically the same as that of bone glue. However, due to its relatively high price and price, it is generally used only in some high-grade books and special processed objects.

Animal glue features:

In general, the adhesive properties of animal glues are good, easy to dry, and the price is relatively cheap, which is very popular among users. However, when using this kind of glue, only add water to heat and melt the glue to use, there are shortcomings such as embrittlement after drying, so use some additives to change some properties of the glue in order to achieve better results .

Such as:

Glycerol can effectively prevent the adhesive layer from becoming brittle after drying.

Carbonic acid and other preservatives can prevent moldy deterioration.

Whiteners such as titanium dioxide can improve the color of glue.

Urea can increase the drying speed of the film at room temperature.

A small amount of terpineol (or silicone liquid, tributyl phosphate, etc.) can eliminate air bubbles in the glue. $Page break $

Second, starch-based adhesive materials

Starch-based binders refer to binders made from starch extracted from seeds, stems, tubers, etc. of plants.

(1) gluten slurry

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The gluten slurry is the gluten slurry obtained by kneading the glutinous rice flour and the wheat flour (flour) with water or the gluten pulp obtained by fermenting the flour paste.

performance:

The gluten slurry binder has the advantages of fine texture and pureness.

Usage:

It is commonly used for bonding paper and paper on adhesive paper reels, as well as wrapping corners for book covers, book letters, and book blocks.

(2) flour paste

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The main ingredient of the flour paste is starch. Stapling paste is mainly wheat flour paste, glutinous rice flour paste.

Features:

There is a certain degree of cohesive strength, enough to bond paper, cardboard, cardboard, woven fabric, etc., and can be modulated into different viscosities according to the requirements of the adhered object. However, the sticky paste of the flour paste sticks easily after being damped, and when the temperature is high and the humidity is high, the flour paste is easily fermented, enzymes are generated, and corruption occurs. The paste after fermentation has a sour smell, surface blisters, long green hair, and the viscosity is greatly reduced, affecting the normal bonding process.

Usage:

The adhesive strength of flour paste is not high, suitable for paper, cardboard and paper and paper paste, can also be used to stick the general cover, ring lining, pulp back and other processing, not bonding bonded materials with high strength requirements.

Such as:

Single and double pages, liners, paperbacks, paperback covers, paperbacks, etc.

(3) Dextrin

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Dextrin is a kind of binder made from starch by acid or heat treatment or by the action of starch mold.

Features:

Compared with starch, it has high viscosity, fast drying, good transparency, and it is not easy to put away for a long time. Dextrin is easily soluble in hot water, slightly soluble in cold water, and has good adhesive properties.

Dextrin and paste have the same fluidity and penetration ability, can be infiltrated, diffused, and have good bonding effect after being wetted. Dextrin has many advantages, and there are many types of packaging, ranging from small to large, easy to use. very popular.

Usage:

Suitable for bonding paper, fabrics and other absorbent objects. It is worth mentioning that the use of dextrins in the confrontation of cardboard is quite extensive.

Starch-based binders can also be used in combination with other synthetic resin binders to change their properties and achieve better bonding results.