Effects of Silane Treatment on Physical and Mechanical Properties of Particleboards Prepared with Urea Formaldehyde
Research subject and fields:
In this study, the effect of silane on particleboard physical and mechanical properties was investigated. Silane was mixed in particleboards with two different methods. In the first method, silane was mixed with wood chips namely as a pretreatment of wood chips. In the second method, silane was mixed with urea-formaldehid adhesive. The amounts of silane used in both methods were 1 %, 2 % and 3 % of the particles based on the dry weight. Urea formaldehyde with 65 % solid content was used as adhesive. Ammonium sulfate (1 %) was added as a hardener to the used adhesive. The target density of three-layer particleboards manufactured was 550 kg/m3. The properties of particleboards evaluated include thickness swelling, bending properties and internal bond strength. Results indicate that particleboards thickness swelling values increase with the use of silane. Overall, pretreatment of the wood particles provided better mechanical properties than the addition of silane to the adhesive solution. Flexure strength and flexure modulus of particleboards were significantly improved by use of silane. Pretreatment of particles with 2 % silane yielded the best improvement of modulus of rupture and modulus of elasticity. For the particleboards prepared with pretreated wood chips with silane, the highest increase of the flexure modulus and flexure strength was 20 % and 40 %, respectively. Pretreatment of wood particles with 3 % of silane nearly doubled internal bond strength of the particleboards. Silane pretreatment can be an alternative method for the improvement of particleboard mechanical properties.