Why does the Hot melt adhesive turn black after heating?

         Why does the Hot melt adhesive turn black after heating?

         The color of Hot melt adhesive generally does not change much before and after heating, but it may sometimes be black when it is found in actual use. What is going on?

         At the time of production, the hot melt adhesive generally changes in color due to the added content and components. After the production is completed, what color is the colloid at normal temperature, and there is no obvious change in the general color after heating and dissolving, but there are also many factors that will change the hot melt adhesive.

        It may be that there is too much carbide in the rubber pot, and there may be some glue remaining in the rubber pot. After many long-term work of hot melt adhesive equipment, the equipment operator did not have the awareness of cleaning the plastic pot. In the case of cyclic heating, the performance degradation of the hot melt adhesive is intensified, and it may cause more and more carbides in the pot, and the carbide hinders the performance of the glue.

        If it is not cleaned up in time, the amount of impurities may be mixed with a lot of black impurities, so the glue will easily turn black.

       Of course, it is also possible that the quality of the hot melt adhesive itself is not good, resulting in variation at high temperatures. The molecular structure variation caused by the reaction between raw materials may not only break the original characteristics of the raw materials, but also cause color changes, which may not necessarily turn black, or may become other colors.