Bubbles in the melt will affect the adhesive effect.

The first type:

The glue contains moisture, and the moisture is vaporized at high temperature and mixed into the glue, and because the glue is relatively viscous, it is difficult for the water vapor to float to the surface and release.

The second type:

Before using the hot melt adhesive, there are other chemical components mixed in. The former reacts with the currently used hot melt adhesive to release a certain gas and also generate bubbles.

The third type:

The amount of glue in the glue pot is too small, and air enters the delivery port together with the glue liquid, and the glue flows out together with the air.

If there are bubbles in the glue due to the above three reasons, you can solve it as follows:

The first type:

Find out the reason for the moisture in the glue, whether it is because of the high humidity in the glue tank or because the hot melt glue itself has moisture. If the glue tank is relatively humid, dry it before putting the hot melt glue in. If there is moisture on the surface of the hot melt adhesive, it needs to be dried before use.

The second type:

Before using different brands of hot melt adhesives, it is recommended to clean the glue tank first, in order to avoid chemical reactions of hot melt adhesives prepared with different raw materials. But generally the same application, the same type of hot melt adhesive, the raw material configuration is not much different, but because the amount of hot melt adhesive melted each time is large, a little difference in composition may also cause crosstalk, if the impact is large, It is recommended to refill the hot melt adhesive after cleaning the glue tank before use.

The third type:

Some products do not apply much glue, but the glue machine has a large capacity. Sometimes, in order to avoid waste, only a few pieces of hot melt glue are placed in the large-capacity glue tank. When the hot melt adhesive is completely melted into a liquid, the glue and air will enter the glue delivery port together, and it seems that the same volume of glue is applied, but because the glue flows out with air bubbles, the amount of glue applied does not actually reach the product. demand, so that it affects the paste effect.