Requirements and control of hot melt adhesive for

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Requirements and control of automatic disc binding machine for hot melt adhesive

in the process of binding with automatic disc binding machine, the hot melt adhesive as adhesive and the binding machine as adhesive are a pair of contradictory unity. Poor mechanical adjustment and poor performance. No matter how good the hot melt adhesive is, it can't pack a good book; Similarly, if the standard of hot melt adhesive is not met, no matter how good the machine is, it will not produce a good book. As the time of using automatic disc machine increases, the operator will accumulate rich experience in mechanical maintenance and adjustment. However, the production of hot melt adhesive is not in the hands of its users, who are uncertain about the performance and standard identification of the hot melt adhesive used. In the existing binding production state, the quality of hot-melt adhesive purchased from outside is directly related to the quality and benefit of binding production, and directly affects the service and service to users. Before the use and testing standards of hot melt adhesive for book binding were formally promulgated, the following suggestions were made for your reference:

1. The production of hot melt adhesive should have a certain quality stability

hot melt adhesive is a special material mixed with polymer materials. The brand, performance, molecular weight of the synthesized materials and the provision and control of working conditions in the blending stage are directly related to the performance of each batch of hot melt adhesive. To ensure the stability of the quality and performance of each batch of hot melt adhesive can enable the operators to form a concept in their work and produce the adaptability of standardized equipment control and production operation management. The instability of hot melt adhesive quality will not cause discomfort in production operation and equipment control, which will affect the constant binding production efficiency and binding product quality

2. The hot melt adhesive must have a certain viscosity

the hot melt adhesive has good viscosity, which can make the adhesive layer even and firmly bond each page (including the positive and penultimate pages). Viscosity appropriate or not in the binding production can be seen through the uniform glue bar after the back of the book is basically uniform. In the production of hot melt adhesive, the viscosity mainly depends on the content of main adhesive resin. If the content of main adhesive resin is high, the viscosity is large, and the cohesion is large, the adhesive force of the synthesized hot melt adhesive is strong, otherwise it is small. Generally, its content shall not be lower than that of tackifying resin. For the hot melt adhesive with low viscosity, after passing through the uniform glue stick, there will be obvious phenomenon of more glue on one side and less glue on the other side of the back of the book, and the bonding of the pages will be good while bad

3. The hot melt adhesive shall have certain permeability, wettability and fluidity

the permeability, wettability and fluidity of hot melt adhesive mainly depend on the addition amount of tackifying resin and regulating materials in the production of hot melt adhesive and their own properties. If the tackifying resin material or brand is improperly selected, the aging resistance of the hot melt adhesive will be poor; If the grade of the adjusting material is low, its melting point and low-temperature embrittlement resistance are obviously poor. Only by selecting the appropriate tackifying resin and adjusting the material and combination proportion, the hot-melt adhesive can have certain permeability, wettability and fluidity, which can make the book pages firmly bonded and the glue liquid smooth, beautiful, without bubbles and empty glue after passing through the supporting mechanism

4. A certain curing time is required

The curing time of

hot melt adhesive is very important to ensure the bonding effect between the cover and the text block, as well as the flatness and angle setting of the back of the book. In the actual operation of disc binding production, the bound book will solidify before reaching the book receiving desk, and the back of the book should be well shaped. It is required that the setting time of hot melt adhesive shall not be greater than 10 seconds

in the production ratio of hot melt adhesive, the melt viscosity, fluidity, permeability and curing time are contradictory. One of the indicators is strong, while the other indicators are weak. According to the different needs of different regions, different seasons, different equipment and different processing categories, different types of hot melt adhesives suitable for disc binding machines should be produced

with the realization of "printing multi-color and high efficiency", the printing cycle becomes shorter. The printing rate of 15000 ~ 60000 sheets/h makes the water on the printing plate quickly absorbed by the paper for the printed matter produced under the working conditions of water printing, and it is difficult to discharge and dehumidify to the outside atmosphere under the circulation conditions of lamination and stacking. When the text album with large water content passes through the binding production line, the environmental conditions on the binding machine are obviously higher than the temperature and humidity of the printing, storage and circulation environment. This difference in temperature and humidity will inevitably lead to the evaporation of water in the text album. After the short process of milling back, slotting and gluing, the book block not only leaves fiber plush and paper powder particles at the edge of the page, but also causes the volatilization of the water contained in the paper. The design of the hydraulic system is all mechanical design. When its steam meets with the molten hot melt film blowing machine, which is widely used in various industries, it causes slight scaling on the surface of the molten rubber before it is loaded on the rubber wheel. Also, due to the evaporation of water in the text album, the temperature of the absorbed heat or the air that can be said to instigate the light to turn on to provide thermal energy is reduced. The molten rubber wave contacts the cooling cold air and iron rubber wheel on the upper rubber wheel, which makes the temperature of the glue drop instantly, resulting in the aggravation of the skin on the surface of the glue, which affects the fluidity and initial adhesion of the hot-melt adhesive, and reduces the permeability and adhesion to the page

raise the back part of the milling cutter by 0.05mm. The application of the brush behind the milling and the opening of the drying lamp can improve this state and improve the binding effect. (yangchunming) (from China Packaging News)


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