In the summer, do not dry rubber spilling, lifting? Is the glue right?
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Last week, I shared with you the reasons and countermeasures for the phenomenon of summer self-adhesive film loosening and printing and flowering. Today, we would like to ask experts to talk about the summer self-adhesive glue spilling and lifting, and how to deal with it.
Hot melt adhesive & water gel
The high temperature season will significantly enhance the fluidity of the adhesive. The melting degree of the hot melt adhesive is about 75 ° C. The higher the temperature, the more obvious the fluidity of the hot melt adhesive.
Acrylic latex (hereinafter referred to as water gel) has a certain absorption of water, and the higher the temperature, the more active the molecule is. In the case of high temperature and high humidity, the water gel is the most active, and the fluidity is also the largest.
Due to the nature of the self-adhesive glue, the self-adhesive material has an adjustment to the glue in terms of the amount of coating and the formulation of the glue in the summer and winter production.
However, each type of glue has its range of application and viscous performance. In a high-temperature, high-humidity environment, the overflow phenomenon occurs due to the fluidity of the self-adhesive glue.
Due to the different nature of the glue, its performance is also different. Therefore, the points of attention when storing, transporting, and processing the self-adhesive materials should also be different depending on the type of glue.
Hot melt adhesives should be avoided as much as possible to allow the glue type of material to be processed and labelled in a higher temperature environment, even during transportation or use.
Hot melt adhesives in higher temperature environments will become more and more thin as the temperature becomes higher and higher, the viscosity will become lower and lower, the cohesive force will become smaller and smaller, and the possibility of overflowing glue will become more and more. The bigger.
Case Studies
Case 1
A company in Shanghai processes hot-melt adhesive paper materials in the summer, with ambient temperature and humidity of 36 ° C and 85%, respectively. When the printing material is unwound, a rubber yarn is found on the end surface, and the glue roller of the paper width is continuously accumulated with glue, and the phenomenon of waste labeling during die cutting is serious.
Move the materials in this warehouse to another company, and after one day in the warehouse with temperature and humidity control, when the processing is also carried out in the printing workshop with the same temperature and humidity control, the unwinding and drawing phenomenon is weakened, and the die cutting and discharging are also No longer with the standard.
Case 2
A toy exporting company in Guangzhou uses a hot melt adhesive label attached to the toy. The shipping method is container shipping. During the two-month shipping process, almost all of the labels were lifted up to varying degrees during the summer through the equator.
Reason: Summer shipping is going to pass through the equatorial high temperature area, and the temperature inside the container is close to 68 °C. The hot melt is near the edge of the melt and the viscosity is reduced causing the label to warp.
Action: Change the hot melt adhesive to water gel and the problem is solved.
Summer and winter cannot be mixed
In summer, the adhesives of hot melt adhesive materials and some adhesive thickened and gram-adhesive adhesive materials, such as tire label hot-melt adhesives, should pay special attention to controlling the storage environment and the temperature and humidity of the processing site. . The higher the temperature and humidity, the greater the influence on the material, and the more problems such as overflowing during printing.
Since the self-adhesive material is made at the time of production, the glue formula of different seasons is adjusted. Therefore, the self-adhesive label processing manufacturers should not use materials in the wrong season in principle. Do not put the self-adhesive materials purchased in the summer for winter processing, and do not use the self-adhesive materials used in winter for summer processing.