Plywood bonding is a rather complex production process, for which special presses and thermostats are used. Thin layers are glued on top of each other so that the fibers of one sheet are perpendicular to the fibers of the next.
Two types of adhesive compositions are used for gluing layers in production:
- glue based on urea-formaldehyde resins. It is originally natural and eco-friendly and it is preferably used with regard to hygiene. In this way, plywood of the FK brand is made.
- glue based on phenol-formaldehyde resins. It forms a strong and high-quality connection of layers but volatile phenols in its composition are quite toxic. Plywood of the FSF brand is produced with such an adhesive composition.
If it is necessary to use a high-quality connection of plywood parts, it is recommended to choose the type of glue with which it is made. Glue based on phenol-formaldehyde resins is water resistant and is not damaged by microorganisms. If it is required to obtain a colorless seam, the use of combined urea-formaldehyde glue is recommended.
There are widely known cases when other types of glue are used, for example, glue based on PVA, polyurethane, epoxy resin, but for fine work completely natural compositions can also be used - albumin or casein.
Each composition has its own characteristics and disadvantages and it is necessary to choose the right one according to those characteristics that are important for a specific purpose.
