The hot melt adhesive cools before bonding. The reasons and solutions are as follows:

(1) The use temperature of hot melt adhesive is low → increase the use temperature;

(2) The opening distance is too long → reduce the opening distance;

(3) The conveyor belt speed is too slow → increase the conveyor belt speed;

(4) The amount of glue applied is not enough → increase the amount of glue applied;

(5) The temperature of the adhered material and the environment is low → increase the temperature of the environment or the adhered material;

(6) The pressure is inappropriate → adjust the pressure.

It needs to be analyzed one by one for different reasons to obtain corresponding solutions.