The reasons why the adhesive for flexible packaging does not dry may involve many aspects. The following are some of the main reasons:
1.The ambient humidity is too high: Glue needs water to evaporate during the curing process. If the ambient humidity is too high, the water in the glue will evaporate slowly, which will affect the curing effect. Therefore, when using glue in an environment with high humidity, it is easy to appear dry.
2.The ambient temperature is not high enough: Glue curing requires a certain temperature support. If the ambient temperature is not high enough, the glue molecules move slowly, the curing speed will slow down, and even cause the glue to not dry. Therefore, in an environment with low temperature, special attention should be paid to the curing conditions of the glue.
3.The glue composition is not suitable or mixed unevenly: For two-component or multi-component glue, if the components are not mixed evenly or the proportion is not right, the glue will not react fully, thus affecting the curing effect. In addition, if the glue composition itself is not suitable for the current application scenario, it may also not dry.
4.Insufficient curing time: Glue needs a certain amount of time to complete the curing process. If the curing time is too short, the glue may not be completely cured. Therefore, when using glue, you need to ensure that enough curing time is given.
5.Substrate problems: Improper surface treatment of the substrate or excessive differences in thermal shrinkage between substrates may also affect the curing effect of the glue. For example, if there are impurities such as oil, moisture or dust on the surface of the substrate, it will affect the adhesion between the glue and the substrate, resulting in the glue not drying.
6.Equipment or process problems: During the composite production process, if there are problems with the equipment or process, such as failure of the mixing pump, leakage of the glue head, and excessive air humidity in the glue tank, it may affect the mixing and curing effect of the glue.
In view of the above reasons, the following measures can be taken to solve the problem of soft packaging glue not drying:
1.Adjust the environmental conditions to maintain appropriate humidity and temperature.
Select the appropriate glue ingredients and ensure that the mixing is uniform and the proportion is correct.
2.Extend the curing time to allow the glue to fully cure.
3.Strengthen the surface treatment of the substrate to ensure that the substrate is clean, dry and free of impurities.
4.Regularly check and maintain the equipment to ensure that the equipment is in good condition.
5.Improve the production process, optimize the mixing and gluing process, and reduce the generation of impurities and bubbles.
In short, the reasons why the soft packaging glue does not dry may involve multiple aspects, which need to be comprehensively analyzed and corresponding solutions taken according to the specific situation.