Exploitation of liquefied wood waste for binding recycled wood particleboards

Abstract

Four types of industrial waste from wood processing, namely a mixed hardwood-softwood powder, pine and beech sawdust, and bark were liquefied and tested as binders for particleboards (PB) made of recycled wood. The liquefaction reaction was carried out at elevated temperature with a mixture of solvents from polyhydroxyl alcohols such as glycerine and propylene glycol, and p-toluenesulfonic acid as a catalyst. Then the liquefied woods (LWs) were characterized in terms of their suitability for PB production as a partial substitute for synthetic urea-formaldehyde (UF) resin. The standard properties of PBs such as tensile strength, bending strength and modulus of elasticity, density, moisture content, swelling after 24 h, water absorption, and formaldehyde content were measured. All tests were performed in comparison to a standard PB bonded by UF resin. It was demonstrated that the substitution of UF resin up to 20% of LW did not have a significant effect on the mechanical properties. PB made of recycled wood produced with LW possessed good mechanical properties that meet the European standard quality demands for PBs.

Influence of Urea-formaldehyde Adhesive Modification with Beech Bark on Chosen Properties of Plywood

“…With the use of bark as the adhesive filler, these negatives can be overcome. Bark in the liquefied form has been also applied as a UF modifier and tested as a binder for particleboards production (Janiszewska et al 2016) In addition to input raw materials, other key parameters that influence the final composite properties are the composition of adhesive mixtures, amount of adhesive, and the parameters of the pressing process (temperature, pressure, pressing time) (Igaz et al 2015(Igaz et al , 2016. Optimization of the pressing process can increase the manufacturing speed, decrease expenses, reduce energy, and lower emissions (Thoemen et al 2006).…”

Urea-formaldehyde microspheres as a potential additive to wood adhesive

“…Corn flour improved mechanical performance and reduced formaldehyde emissions if added to UF [5]. A substitution up to 20% UF resin was reported using liquefied wood without impairing the mechanical properties of particleboards [6]. The co-condensation of UF with furfural proved to be feasible and resulted in reduced formaldehyde emissions at the expense of significantly increasing the necessary pressing temperatures [7].…”

Bio-Based Polyurethane Composites and Hybrid Composites Containing a New Type of Bio-Polyol and Addition of Natural and Synthetic Fibers

“…Homogeneous catalysts (organic and inorganic alkalis, acids, and salts) are more active and popular than heterogeneous catalysts. Studied catalysts including acidic catalysts (hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, oxalic acid), metallic salts, alkalis (sodium hydroxide), and acidic ionic confirmed that using strong acids as catalyst in the liquefaction process can cause corrosion of metallic equipment and environmental pollution compared with an alkali catalyst, but promotes higher efficiency of liquefaction [21,25,29].…”