Main machines of plywood production: gluing

Although the enormous advances in artificial intelligence and automation, peoples still need to lay up the veneers by hand. Plywood factories have to employ many workers to pave plywood panels. Because the veneers are too fragile, they are not flat, not particularly flexible and often split. All these reasons make it very hard to achieve the automation of plywood lay-up. Though any company achieves the automation, the waste of wood will be huge; this is imaginable nowadays.

In the laying up process, there are three main machines used: Plywood gluing machine, glue mixing machine, and veneer paving machine. Plywood gluing machine is used for painting the glues on the veneer surface; three gluing methods are corresponding to three different machine, we will mention them in the following text. Glue mixing machine is used because of the solid content in the glue is not evenness, we should keep the uniformity of the glue to make the glue distribution one plywood be uniform. Veneer paving machine is made up of two parts: a paving platform and cutting head.

There are three different plywood gluing machine: Roller glue spreader, glue spraying machine, and glue extruding machine. The principle of glue spreader: veneer go through the gap between the roller above and the roller below, then the glue is painted on the surface of the veneers. Comparing with the other two gluing machines, glue spreader has the advantage of simple structure and low cost, but this method can not well control the glue quantity, and if the veneer is not flat, it might be damaged by pressure.

The gluing method of spraying machine: the veneers are transmitted through a rain curtain made by glue, then the glue falls on the upper surface of veneer, this type gluing method can only glue on one surface, and the requirements of glue will higher than roller glue spreader.

The principle of glue extruding machine is something like glue spraying machine: the veneers are transported under a glue extruding machine by conveyor, and the glue is squeezed on the veneer. Comparing with the glue spraying machine, this machine requires the glue with a semi-liquid condition, and the viscosity should be high. The advantage of this machine is uniform gluing.