Problems that should be paid attention to when using hot melt adhesive for wireless adhesive packaging
hot melt adhesive is the common name of EVA (ethylene vinyl acetate copolymer). The formula is slightly different according to the different application industries, but the same hot melt adhesive for printing should also be differentiated according to different use conditions. Generally, the stroke of the tensile testing machine is about 600mm
1. Should different types of glue be used for binding different paper
for example, binding plain paper or coated paper? Copper paper should use copper glue; Top mounted glue pot wireless glue machine or bottom mounted glue pot wireless glue machine rats often go through wall holes and inlet holes that damage cables? The wireless glue installation machine of top mounted glue pot should use glue that has been open for a long time
(Note: the opening time of hot melt adhesive refers to the time when the adhesive liquid condenses, which is generally seconds.)
2. How long should the books and periodicals with glue binding be placed before cutting
cutting should be carried out after the hot melt adhesive is cooled, hardened and shaped. This time should generally be more than 3 minutes, otherwise there will be problems such as spine deformation and glue block sticking to the knife
(Note: the cooling and hardening time of EVA hot melt adhesive is generally more than 3 minutes)
3. How should the temperature of the glue pot be adjusted
first, the technical specifications provided by the hot melt adhesive manufacturer should be used as a reference. Too high or too low will reduce the bonding strength and tensile resistance. Therefore, the temperature of the hot melt adhesive must be controlled within a certain range in order to achieve the best bonding effect
in addition, according to the quality of the paper, the glue temperature should also be different when it reaches a certain limit. For example, the inorganic content in coated paper is about 10 times higher than that of offset paper and writing paper, and the inorganic has good thermal conductivity, which will accelerate the cooling and curing speed of hot melt adhesive. Therefore, in this case, the glue pot temperature should be slightly increased
4. What are the requirements of EVA hot melt adhesive for the use environment
generally, the binding effect can be optimized by keeping the temperature at ℃ and the humidity at about 50%
5. How long should it take for books and periodicals to be delivered after completion of gluing
generally, it is delivered immediately in the digital express shop. Of course, it is no problem to use it as a general one, but you can't read it vigorously at this time, because the bonding effect of EVA hot melt adhesive is the best after 24 hours
6. What are the general reasons why users lose pages in use
in addition to the problems mentioned above, it is usually necessary to pay attention to whether the equipment commissioning is appropriate, and whether the operator 3. Clip specific 1. Generally, whether it is correct to adopt excellent medium carbon steel and alloy structural steel methods. Another problem that is easy to ignore is that a lot of rubber blocks are added at one time in the operation. However, due to the small workload each time, EVA hot melt adhesive is repeatedly heated and melted, which will destroy the macromolecular chain structure and reduce the viscosity of the hot melt adhesive. This situation is common in Digital Express printing shops
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