473. How to prevent animal adhesive layer from becoming brittle?
A: The adhesive layer of animal glue is likely to become brittle after drying, and an appropriate amount of glycerol can be added during use to give the film a certain degree of flexibility. Add proper amount of glycerin, and mix it with the glue until it can be used.
474. What is the cause of deterioration of animal glue?
A: Animal glue is a kind of adhesive material with weak moisture resistance. When it is wet or when the temperature is high, it will appear moldy and deteriorating, and it will also affect the strength of bonding.
475. How to prevent and solve the deterioration of animal plastic moldy B>?
Answer: First, control the temperature and humidity in the operation room; Second, add appropriate amount of preservatives in the glue, such as carbolic acid. There are two ways to add preservatives: one is to add appropriate amount of preservatives to the water, and after the work is completed, the rest of the glue is mixed and mixed uniformly; the other is to sprinkle the preservative on the surface of the remaining glue after the work is completed. Control gum fluid is not deteriorated.
476. What caused the darkening of animal glue?
A: The glue in animal glue is a light brown translucent body. The higher the purity of gelatin, the lighter the color is, and the better the transparency, but the temperature of the glue is too high during use, and it will not be cleaned up or fixed for a long time. Repeated heating of the glue solution will cause the color of the glue solution to become darker and the colloids to deteriorate.
477. How to prevent animal glue from becoming darker and colloids deteriorate?
Answer: There are two ways to prevent animal glue from darkening and degrading colloid. First, the amount of glue stored should be added according to the required amount. It should not be too much, and it should be used with the increase. The plastic pot should be cleaned on time. The general situation is six months. Must be cleaned once; Second, when the glue has turned dark brown, but has not yet affected the viscosity, can be appropriate to incorporate some brighteners, such as titanium dioxide, etc., adding brighteners, stirring in advance with water until the dilution is uniform After being incorporated into the glue, the gel color is uniformly lightened to prevent the appearance of the book after smearing.
478. How to speed up the drying of animal glue?
A: When the humidity in the operation room is high or the glue is not easy to dry, a small amount of urea can be added properly, which can increase the drying speed of the film in the room.
479. What are the causes of air bubbles when using animal glue?
A: The amount of bone glue used in animal glue is larger, and more animal glue is used in the machine shell. Due to the rolling of the rubber roll in the glue liquid, the glue liquid is turbulent and unstable. After the air is stored in the glue liquid, bubbles are generated. This phenomenon usually occurs. Do not apply this phenomenon by hand when applying the machine.
480. How to prevent and eliminate bubbles in animal glue?
Answer: To prevent and eliminate air bubbles in the glue when using the machine casing to apply glue, add a small amount of liquid crystals of germanium or silicone, tributyl phosphate, etc.
481. What is starch-based adhesive material?
A: Starch-based adhesive materials refer to adhesives made from starches extracted from seeds, stems, and tubers of plants. Different types of starches can be extracted from different plants, including wheat, glutinous rice, and corn. .
482. What are the types of starch-based adhesive materials?
A: Starch-based adhesive materials include gluten, flour, and dextrin.
483. What is gluten slurry? How to make?
Answer: The main ingredients of gluten slurry are glutinous rice or wheat. There are two methods to make it. One is to grind the seeds of glutinous rice or wheat into fine powder (ie, flour), knead it into noodles with water, and then continue to use water. Rubbing and washing, remove the mixed protein in the noodle, make a starch slurry, heat and dilute the starch slurry with water, and then dilute it to become a gluten slurry adhesive; the other is to ferment and heat the flour to make a paste and then ferment it.
484. What characteristics of gluten slurry are suitable for bonding work materials?
A: The gluten paste adhesive has the characteristics of fine texture, pure and soft, and is often used for the compounding of enamel, enamel and rice paper, and the binding cover, bookmarks, draws, and corners of book blocks.
485. What is flour paste?
A: The main components of flour paste are glutinous rice and wheat starch. There are two ways to make it: one is to stir the flour evenly and then heat it to a sticky material with a certain viscosity; the other is to add a little water to the flour and stir it evenly, and then use a kind of cementitious material obtained by boiling and boiling. .
486. What are the characteristics of flour paste?
A: Flour paste is one of the longest-running and most common traditional bonding materials in bookbinding processing. Its use has been gradually reduced in recent years. Its characteristics are wide source, simple production, low cost, easy to use, tasteless, and non-toxic. You can add water to adjust its viscosity and thickness.
487. How to use flour paste?
A: The adhesive strength of flour paste is generally applicable to the stickiness of paper, cardboard, fabric and paper, and can also be used for the processing of general covers, ring linings, pulp backs, etc., and materials with high bonding strength requirements are not suitable. If the fermentation phenomenon occurs during normal use, do not throw it away. Use it in pulp or blended with unfermented paste, or use it after gluten washing. The flour paste can also be mixed with some other synthetic resin cold glues. For example, it can be used in combination with PVAC for good adhesion.
488. What is dextrin?
A: Dextrin is a kind of adhesive made from starch by acid or heat treatment or by amylase. Compared with flour paste, dextrin has high viscosity, fast drying, good transparency, long shelf life and is not easy to corrupt.
489. What are the characteristics of dextrin?
Answer: Dextrin is easily soluble in water and has good adhesive properties. It is suitable for bonding porous objects such as paper and fabrics. It has the same fluidity and penetration ability as flour paste, can penetrate and spread when wet, and has good adhesion effect after drying. Dextrin has many advantages, and it has a small amount to a large number of various packaging forms. It is convenient to buy. popular.
490. How to make dextrin?
A: There are many kinds of ingredients for making dextrins, and there are certain requirements for the proportion (see Table 1). There are two ways to make it: The first is to first mix the glutinous rice flour into cold water and stir it into a slurry. Add the wheat flour to the alum and cold water and mix it until it becomes a slurry. Mix the above two kinds of pulp and mix well and add phenol to continue stirring. Uniformly, then pour 100°C boiling water into the mixture slurry, add water and stir to make a paste. Add appropriate amount of flavor to continue to make the dextrin; the second method is to blend all the ingredients (except the fragrance) together. , Stir evenly after heating (while stirring and heating), to 100 °C above dextrin products finished, each stirring must be uniform, can not have any particulate matter.
491. What is natural resin adhesive material?
A: Most of the natural resin adhesive materials are made of resin material flowing out from the cut of bark on the stem of a certain tree species. Stapling uses this adhesive material, which is mainly used as an adhesion aid in hot stamping.
(author/Wang Huaizhu)
Printing Technology - Publishing and Commercial Printing
Fenghua Jade Motor Co., Ltd. , http://www.chinapestrepeller.com