High humidity usually occurs in spring. Hot melt adhesive is placed in the warehouse without protection, it is easy to be invaded by moisture, and it is easy to foam when applying glue, causing the glue to be empty, and the adhesion is uneven and unstable.
In fact, the surface of the hot melt adhesive has many small holes, which can absorb the same fine particles and water. If the air is kept moist, the water vapor on the colloid will not disappear, and the water will be carried into the melting tank of the equipment. After the hot melt adhesive is mixed with water, it will keep air bubbles during the melting process. This is because the water in the glue is vaporized, and the gas is continuously released from the glue, thereby forming bubbles on the surface of the glue. If you don't wait for all the gas to escape, the bubbles will adhere to the substrate along with the glue. Air bubbles occupy the original volume space of the glue. Where there is no glue, the total amount of glue will be reduced, aerosols or more serious failures will occur, and the bonding effect will be reduced.