Adhesives are one of the main materials for book binding. The selection of binders has a direct bearing on the quality of the book's processing. When used properly, the finished books are firm and flat. Otherwise, they may cause serious quality problems.
Binder A substance that bonds two objects together is an important material that is indispensable in binding. Some books such as wireless glue books are all bound together with adhesives. There are many problems in many areas of the country due to improper use of adhesives or unreasonable use. For example, three sides of the hardcover book ring village are not sticky (flash), the warpage of the book shells is uneven, and the wireless glue book is missing pages. The inequality at the end of leaking plastic and book back rubber buildings is extremely serious. Unqualified products appear and the society reflects a great deal and it should attract attention from all sides.
Based on these circumstances, I will introduce the type, performance, and use of binders for use by our peers.
First, synthetic resin binder Synthetic resin, also known as synthetic resin, is a monomer by the party or polycondensation resin. Synthetic resin adhesives are widely used, convenient, and a wide variety of adhesive materials. There are mainly the following for book binding.
1. Polyvinyl acetate (PVAC) bonding material Polyvinyl acetate is a polymer that is polymerized from vinyl acetate monomers. According to different polymerization methods, it can be divided into two types: emulsion type and solution type. The type of emulsion used for binding is milky or white plastic because of its color and whiteness.
1 Performance of Polyvinyl Acetate PVAC is a milky white viscous liquid that is slightly acidic. It can dissolve in many organic solvents, and can resist dilute acid, dilute alkali, not be afraid of pests and bites, not mildew, and harmless to human body. The PVAC cured adhesive layer is a colorless transparent body that does not cause contamination on paper, etc., and is an aqueous solution, so it is easy to wash, and its viscosity can be arbitrarily adjusted. Easy to use. The PVAC adhesive layer has good toughness after drying, and the cutting does not damage the blade. It is very suitable for binding. This kind of glue has many advantages, but the disadvantage is poor water resistance and poor heat resistance. However, as long as you take care of its performance without any influence, it is the longest time to use (bookbinding has been used for more than 20 years), the most A popular and popular synthetic resin adhesive material.
2PVAC Adhesives Indicators The quality indicators for PVAC adhesives currently produced in China are: milky white thick liquids with no obvious particles in the body: solids content 50%±2%: viscosity 1 to 2 microns; pH 4 to 6: The validity period is generally one year (keeping it safe for one and a half years).
Use of 3PVAC Adhesives PVAC adhesives are used extensively and are particularly well suited for the bonding of porous materials such as paper, fabric, cardboard, leather, wood, and the like. Use the following points when using:
A. The binder with the required viscosity can be prepared before use by using cold water (not lower than 0°C) or hot water (not higher than 36°C). The more water is added, the lower the viscosity is, and stir evenly when adding water.
B. Can be used for single and double-sheet paper, paste back, sticky book back system, package cover (flat) and other adhesive use, have a good stick to the effect.
C. can be mixed with flour paste, carboxymethyl cellulose, etc. to increase the consistency of the fluid and reduce costs.
D. During winter use, care should be taken to prevent cold and summer heat protection. Do not store and use it below O°C and above 36°C for a long period of time. Otherwise, limbs will deteriorate and precipitate. In order to prevent cold, suitable amount of dibutyl phthalate can be added.
E. After using the remaining glue should pay attention to the seal (especially after the open bucket) is not in contact with the air, the plastic surface is best to pour some cold water, to avoid the dry knot hardness to achieve a waste.
F. paste book shell is best not this glue. Because PVAC is a water-soluble binder, the drying speed (same as the rough surface paste) is slow, the penetration is strong, and it is not easy to set. After the paste, the book shell will be deformed due to moisture penetration and delay the drying time. Injustice.
After the G.PVAC adhesive is mixed with the 504 glue, the adhesive PVA coating cover and ring liner paper have a very good effect.
The drying of PVAC adhesive depends on evaporation of water. The drying speed is directly related to temperature and relative humidity, and the drying speed is relatively slow: if it is used in a linkage production line, drying equipment such as far-infrared rays, high-frequency dielectric heating, etc. needs to be added. Drying temperature can not be too high.
2. Polyvinyl alcohol (PVA) bonding material Polyethylene acid binding agent is a white flocculent or powdery polymer compound that dissolves in water and is a clear, colorless, viscous liquid after melting.
1 PVA adhesion properties PVA properties are determined by the structure and degree of alcoholysis of polyvinyl acetate. When the degree of alcoholysis reaches 99% to 100%, a highly crystalline polymer can be obtained, and its water resistance is excellent; when the degree of alcoholysis is 87% to 89%, it is easily soluble in water; when the degree of alcoholysis decreases, The solubility of water is reduced again. The PVA with a high degree of polymerization has a large molecular weight, a good film forming property, a high viscosity, and a strong viscosity, but has poor water solubility. The degree of polymerization is divided into high, medium and low categories, ie, 500 to 700 is a low degree of polymerization: 700 to 1500 is a medium degree of polymerization: 1500 to 2000 is a high degree of polymerization. For binding PVA binders, it is necessary to consider both the degree of polymerization and water solubility.