Four Key Factors to Consider 1. Bonding Force Between the Rubberized Surface and Adhesive In self-adhesive labels where the surface material is a film, poor adhesion between the rubberized surface and the adhesive can lead to residue or glue overflow. To improve this bonding force, it's essential to treat the rubberized surface before coating. Common methods include coating treatment and corona treatment. While corona treatment is more widely used due to its cost-effectiveness, maintaining the correct surface energy before and after treatment is crucial for consistent performance. Additionally, the water content and curing agent concentration in the adhesive significantly affect the bonding strength. These factors must be strictly controlled. Another important consideration is the cohesive strength of the adhesive. The lower the cohesive strength, the higher the risk of glue oozing out during application. 2. Adhesive Flowability and Coating Amount The flowability of the adhesive plays a major role in glue overflow. Higher temperatures enhance flowability and initial tack. In high-temperature and high-humidity environments, such as summer or rainy seasons, adhesive tends to become more fluid, increasing the likelihood of overflow. Therefore, it's vital to monitor and control temperature and humidity in storage areas, processing environments, and finished product warehouses. It’s also important to avoid using heat-resistant adhesives in unsuitable printing environments. For example, hot melt adhesives like HPWS2000 digital printing machines can withstand temperatures above 150°C, but materials like AW5209 are only suitable for temperatures below 70°C. Using them on incompatible equipment could cause issues. Similarly, screen-printed silver ink requires high infrared drying temperatures, so high-temperature resistant materials should be selected for such processes. The amount of adhesive applied also affects glue overflow. Labels with heavy adhesive coatings, such as tire labels, are more prone to overflow, even with flow inhibitors added. Seasonal variations in adhesive application are especially important for film-based materials. Winter and summer adhesives have different formulas, and mixing them can lead to problems. It's best to use materials within their intended season and avoid long-term storage to prevent quality degradation. 3. Die-Cutting Depth Control Incorrect die-cutting depth can damage the silicone oil layer, causing label misapplication, machine jams, or frequent tape breakage (commonly referred to as “broken beltâ€). If the labeling process frequently encounters broken tapes, inspecting the broken parts will often reveal that the break occurs along the die-cut line, as shown in Figure 1. Figure 1 Effect of Die-Cut Depth on Glue Overflow If the adhesive layer isn’t properly cut during die-cutting, adhesion can occur at the back of the cut area. As waste is removed, the adhesive beneath the waste edge and under the label stretches and eventually breaks. These fragments may fall onto the leading edge of the label, creating a one-sided glue overflow along the die-cut direction. Messenger Bag,Single-Shoulder Bag,Cross Body Bags,Women'S Xbody Bag NINGBO SUREWAY E-FASHION IMPORT AND EXPORT CO,.LTD , https://www.surewaybags.com
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