Incorporation of phenol-formaldehyde-based black liquor as an adhesive on the performance of plywood

Abstract

Background and Objectives: Adhesives are one of the most important ingredients in plywood industry. Black liquor (BL), a liquid comprising waste from the pulping process, was used to reduce adhesive consumption in plywood production. The characteristics of BL and properties of phenol-formaldehyde-based black liquor as an adhesive on the performance of jabon (Anthocephalus cadamba Miq.) plywood were investigated. Materials and Methods: Adhesive mixes were prepared using phenol-formaldehyde (PF) with the seven kraft BL-based adhesive added (0, 5, 10, 15, 20, 25 and 30% (w/w). Three-ply panels were produced at glue spread of 180 g cm–2, then pressurized at 10 kg f cm–2 at a temperature of 140ºC for four minutes (PF-BL plywood). The physical and mechanical properties of PF-BL plywood were analyzed according to Standard Nasional Indonesia (SNI) and Japanese Agricultural Standard (JAS). Results: The crystallinity of BL was 25.88%, mean while methanethiol (CAS) mercaptomethane, ethanedioic acid (CAS) oxalic acid, methanethiobis-(CAS) 2-thiapropane, phenol 2-methoxy-CAS guaiacol, phenol 2,6-dimethoxy-CAS 2,6 dimethoxy phenol were the dominant of chemical components in BL. Jabon plywood bonding with PF-BLadhesiveup to 30% of BL addition, met the SNI and JAS standards. The best treatment for PF-BL plywood was reached at 15% of BL addition. Conclusion: Up to 30% BL addition can be used to reduce PF resin in order to produce PF based plywood. BL was a potential material for decreasing the use of PF-based adhesive for plywood.