1) Double-roll glue coating machine.
The double-roll glue coating machine is mainly composed of upper and lower glue coating rollers and glue tanks. The lower part of the lower glue coating roller is immersed in the glue tank, and the glue of the upper glue coating roller is transferred by the lower glue coating roller. When the veneer passes between the two glue coating rollers, it contacts the glue coating roller so that the glue on the roller is coated on the upper and lower surfaces of the veneer. The amount of glue coating mainly depends on adjusting the gap between the upper and lower glue coating rollers and the pressure of the upper glue coating roller. The thicker and narrower the veneer, the greater the pressure of the roller on the veneer, and the smaller the amount of glue coating; conversely, the greater the amount of glue coating. The shape and number of grooves on the roller also affect the amount of glue applied. The height of the glue liquid in the glue tank should be 1/3 of the diameter of the lower glue coating roller. Too large or too small will affect the amount of glue coating.
2) Three-roll glue coating machine.
The figure below shows the appearance of the BS3313 three-roll glue coating machine. The three-roller glue coating machine is to add a squeeze roller next to the upper or lower glue coating roller. The amount of glue applied is determined by the gap between the glue coating roller and the squeeze roller. A squeeze roller is set next to the upper glue coating roller, and the glue is supplied by the glue pump through the rubber hose, and the glue is stored in the groove formed between the glue coating roller and the squeeze roller; a squeeze roller is set next to the lower glue coating roller to supply glue from the glue tank, and the amount of glue applied is not affected by the height of the liquid level in the glue tank. Although the three-roller glue coating machine has good glue coating quality, it can only control the amount of glue applied on one side, so it is not widely used.
3) Four-roller glue coating machine.
The figure below shows the appearance of the BS3426B four-roller glue coating machine. The four-roller glue coating machine is to add a squeeze roller next to the upper and lower glue coating rollers to control the amount of glue applied on the upper and lower surfaces of the single board respectively. The linear speed of the squeeze roller is 15% to 20% lower than that of the glue coating roller, which plays a role in scraping glue, and the gap with the glue coating roller is adjustable to ensure that the thickness of the upper and lower glue layers is uniform. The upper and lower glue rollers supply glue at the same time without interfering with each other. It is not easy to jump when applying glue. It is a widely used glue coating equipment.
There are two ways to arrange the glue squeezing rollers of the four-roll glue coating machine. 1) The upper and lower glue squeezing rollers are arranged on both sides of the glue coating roller, and the glue pump supplies glue through the rubber hose; 2) The upper and lower glue squeezing rollers are both located on the feeding side of the glue coating roller, and the upper glue coating roller is supplied with glue by the glue pump, and the lower glue coating roller is supplied with glue by the glue tank below. Due to the different arrangement and glue supply methods of the rollers, their functions are also different. The former has uniform glue coating and can save glue; the latter is suitable for situations with relatively high productivity.
