Requirements and Control of Hot Melt Adhesive in Automatic Disc Binder Machine

In the glue-binding production process with the automatic disk-type gluebinder, the hot melt adhesive as a bonding material and the glue binding machine as a bonding device are a contradictory unity. Poor mechanical adjustment, poor performance, no matter how good the use of hot-melt adhesives does not contain a good book; Similarly, the standard of hot-melt adhesives can not reach, no matter how good the machinery can not contain a good book. With the increase in the use of automatic disc machines, operators will have accumulated more experience in mechanical repairs and adjustments. However, the production of hot-melt adhesives is not in the hands of its users, and users have uncertainties about the performance and standards of hot-melt adhesives used. In the existing glued production state, the quality of the hot-melt adhesive purchased from the outside is directly related to the quality and benefit of glue-set production, directly affecting the services and responsibilities to users. Before the use of bookbinding hot melt adhesives and testing standards have not been formally promulgated, the following points are available for your reference:
1. The production of hot melt adhesive must have a certain quality stability.
Hot-melt adhesives are special materials for the blending of polymer materials. The branding, performance, molecular weight of the synthesized materials, and the working conditions for the blending stage are all directly related to the performance of each batch of hot-melt adhesives. Guarantee the stability of the quality performance of each batch of hot melt adhesive, enable the operator to form a concept in the work, produce the adaptability of the standardized equipment control and production operation management, and will not cause the production operation due to the instability of the quality of the hot melt adhesive. Disturbance with device regulation, while affecting the binding production efficiency and the quality of the fixed product.
2, hot melt adhesive must have a certain viscosity.
The hot melt adhesive has a good viscosity, and can make the adhesive layer evenly reach each page (including the positive number and the penultimate page) with firm bonding. Whether the viscosity is appropriate or not can be seen in the glue book production if the adhesive layer after the glue stick is substantially uniform or not. In the production of hot melt adhesives, the size of the viscosity mainly depends on the content of primary tackifier resin. The main sticky resin content is high, the viscosity is large, and the cohesion force is large, then the synthetic hot melt adhesive has strong adhesive force, and vice versa. In general, its content must not be lower than tackifying resin. Small viscosity hot melt adhesive, after passing through the glue stick, the back of the book will appear obvious one side of the glue more than one side of the glue, the binding of the page is a good one side bad phenomenon.
3, hot melt adhesive must have a certain permeability, wettability, fluidity.
The permeability, wettability, and fluidity of hot-melt adhesives mainly depend on the amount of tackifier resin and adjustment material added in the production of hot-melt adhesives and its own performance. If the tackifier resin material or brand is used improperly, the hot melt adhesive will have poor aging resistance; if the adjustment material is selected with a low grade, its melting point and low temperature resistance to brittleness will be significantly worse. Only by selecting appropriate tackifying resins and adjusting materials and combination ratios, the hot melt adhesive has certain permeability, wettability, and fluidity, which can make the binding of the book pages firm and the glue liquid is level, beautiful, and not after passing through the supporting mechanism. Cavitation, no empty glue.
4, have a certain curing time.
The curing time of the hot melt adhesive is crucial to ensure the bonding effect between the cover and the inner document core and the leveling and angle setting of the book back. In the actual operation of rubber glue binding, the glued book is solidified before it reaches the receiving table, and the back of the book should have a good shape. It is required that the setting time of hot melt adhesive should not exceed 10 seconds.
In the production of hot melt adhesive, its melt viscosity, fluidity, permeability and curing time are contradictory. Among them, one indicator is strong, and other indicators are correspondingly weak. According to the different needs of different regions, seasons, different equipment, and different types of processed products, different types of hot melt adhesives that can be used in the bookbinding machine are produced.
With the realization of “multi-color printing and high efficiency”, the printing cycle becomes shorter. The printing rate of 15,000 to 60,000 sheets/hour makes it possible for water produced on the printing plate to be rapidly absorbed by the paper produced in the printing condition with water, and it is difficult to discharge to the outside atmosphere under the laminating flow conditions. . When the content album with the larger moisture content passes through the glue-binding production line, the environmental conditions on the glue-binding machine are obviously higher than the temperature of the printing and printing product storage and circulation environment and the humidity is small. This difference in temperature and humidity will cause the moisture in the album to volatilize. The brief process of making the book block through milling and back grooving and gluing not only leaves fiber plush and paper powder particles on the edges of the book, but also causes the moisture content of the paper to evaporate. When its water vapor meets with the liquid phase of the molten hot melt, it causes a slight crust on the surface of the molten glue before it is glued. Also due to evaporation of moisture in the text album, the temperature of the absorbed heat or air temperature, which can be referred to as providing heat energy, is reduced, and the molten rubber wave is brought into contact with the cooled cold air and the iron rubber wheel in the glue wheel to make the glue liquid. Instantaneous drop of temperature results in the intensification of the surface crust on the glue liquid, which affects the fluidity and initial viscosity of the hot melt adhesive, and reduces the permeability and adhesive force to the pages.
Raising the back part of the milling cutter by 0.05mm, the application of the brush behind the milling cutter and the opening of the baking lamp can improve this state and improve the glue binding effect. (Yang Chunming) (From "China Packaging News")