Effect of copper based preservatives treatment of the properties of southern pine LVL

This work reports the effect of copper based preservatives treatment namely copper azole (CA-B), micronized copper azole (MicroCA) and alkaline copper quaternary (ACQ-C) on the physical and mechanical properties of southern pine laminated veneer lumber (LVL) bonded with cross-linked thermoplastic PVAc (XPVAc) or thermoset phenol formaldehyde (PF) adhesives. Three treatment procedures, pre-dip treatment of veneers, vacuum-pressure treatment of LVL and post-dip treatment of LVL were used for treatments. The preservatives retention of non-pressure treated veneers and LVL vary from 0.67 to 1.9 kg/m3 while the retentions for samples pressure treated vary from 4.0 to 9.6 kg/m3 also similar to retention for ground contact applications for solid wood. Density, water absorption, thickness swelling, flexural modulus of rupture (MOR) and modulus of elasticity (MOE), hardness, tensile shear strength, wood failure and delaminations were evaluated and no significant reduction due to treatments was observed, suggesting that such process can be used to treat LVL and therefore increase the service life of such products against biological deterioration.

► Laminated veneer lumber was made with micronized copper pretreated veneer. ► Thermoplastic and thermoset adhesive were used. ► No significant reduction on the physical and mechanical properties. ► Viable manufacturing method to increase resistance to decay.