The working principle of the glue applicator

1) Double roller glue applicator.

Its appearance is shown in the figure. The double-roller glue applicator is mainly composed of upper and lower glue rollers and glue tanks. The lower part of the lower glue roller is immersed in the glue tank, and the glue of the upper glue roller is transferred by the lower glue roller. When the veneer passes between the two glue rollers, it contacts the glue roller so that the glue on the roller is coated on the upper and lower surfaces of the veneer. The amount of glue mainly depends on adjusting the gap between the upper and lower rubber rollers and the pressure of the upper rubber roller. The thicker and narrower the veneer, the greater the pressure of the roller on the veneer, the smaller the amount of glue applied; on the contrary, the larger the amount of glue applied. The shape and number of grooves on the roller also affect the amount of glue applied. The height of the glue liquid level in the glue tank should be 1/3 of the diameter of the lower glue roller, too large or too small will affect the amount of glue.

2) Three-roll gluing machine.

The figure below shows the outline drawing of the BS3313 three-roll glue applicator. The three-roller gluing machine is to add an squeezing roller beside the upper or lower squeezing roller. The amount of glue applied is determined by the gap between the squeezing roller and the squeezing roller. A rubber squeezing roller is provided next to the upper rubber roller. The rubber pump supplies glue through a hose, and the groove formed between the rubber roller and the rubber squeezing roller is used to store glue; a rubber squeezing roller is provided next to the lower rubber roller to supply glue from the glue tank. The amount of glue is not affected by the height of the glue tank. Although the three-roll gluing machine has good glue quality, it can only control the amount of glue applied on one side, so it is not widely used.

3) Four-roller glue applicator.

The figure below shows the outline drawing of the BS3426B four-roll glue applicator. The four-roll gluing machine is to add a squeezing roller next to the upper and lower glue rollers to control the amount of glue on the upper and lower surfaces of the veneer. The linear speed of the squeezing roller is 15% to 20% lower than that of the rubber coating roller, and it plays a role of scraping the rubber, and the gap with the rubber coating roller is adjustable to ensure the uniform thickness of the upper and lower rubber layers. The upper and lower gluing rollers supply glue at the same time, and they do not interfere with each other, and it is not easy to jump when gluing. It is a widely used gluing equipment.

There are two arrangements for the squeezing rollers of the four-roll glue applicator. 1) The upper and lower squeezing rollers are arranged on both sides of the glue roller, and the glue pump is supplied with glue through the hose; 2) The upper and lower squeezing rollers are located on the feeding side of the glue roller, and the upper glue roller is supplied by the glue pump. , The bottom glue roller is supplied with glue from the glue tank below. Due to the different arrangement of rollers and different ways of supplying glue, their functions are also different. The former has uniform glue application, which can save glue; the latter is suitable for higher productivity.