Adhesives for glulam

A wide variety of adhesives may be used for glulam . Polycondensation adhesives such as melamine resin and phenol-resorcinol resin adhesives cure by splitting off water and are also called glues. Polyurethane adhesives belong to the group of polyaddition adhesives.

The adhesive bonds in glulam are extremely thin (usually approx. 0.3 mm) and offer excellent resistance to chemical influences. Modified melamine resin and phenolic resorcinol resin adhesives, which are commonly used, contain small amounts of formaldehyde. However, low formaldehyde adhesives are preferred to ensure that the expected indoor air concentrations remain well below the limits of the formaldehyde directive (so-called E1 class) for wood-based panels.

Polyurethane adhesives are formaldehyde-free. However, since formaldehyde is a natural component of wood, glulam made with polyurethane adhesive also contains small amounts of formaldehyde.

Gluing of laminated timber is carried out in the Derix Group with the melamine resin gluing system GripPro-Plus, approved according to DIN EN 301:2018. This new generation of adhesive does not contain any hazardous substances that need to be declared. With emission values of 1/10 of the permissible limits, these values correspond to those of natural wood. The finger-joints and in the production of X-LAM are partly glued with 1K polyurethane adhesives (PU).