Лако-красочные материалы — производство

The viscosity of a glue mix is determined by the viscosity of the resin (mainly depending on the degree of condensation and the resin solids content) and the composition of the glue mix. If the viscosity or the degree of condensation of the resin is too low, a large portion of the resin might penetrate into the wood, causing a starved glue line. In such a case no true glue line can be formed and hence no bonding strength can be obtained. Conversely, at a too high viscosity there might be a lack of proper wetting by the adhesive of the wood surface opposite to that surface where the adhesive was applied, consequently with no or very low penetration into the word surface and hence no mechanical interlocking of the adhesive into the substrate. Poor bond strength will also be obtained in such a case.

Besides the viscosity of the adhesive resin itself, the viscosity of the glue mix also plays an important role in the final result. A higher dilution of the resin gives a higher volume to be spread and with this a better distribution of the resin on the particles or fibers, and thus better bonding strength [337]. This also saves on costs.