Tensile shear strength of natural wood decorative plywood from lesser known Sungkai (Peronema canescens) tree

Abstract

Sungkai (Peronema canescens) small logs has been harvested from a private sungkai plantation (Sabahpuri Nursery Sdn Bhd) in Telipok, Sabah. The logs were then rotary peeled to 0.6mm thick and made into 4’ x 4’, 3 plies Urea Formaldehyde (UF) plywood with Acacia Hybrid wood used as the core veneer (1.2 mm thick) at a local plywood facility; Cymao Plywood Sdn Bhd in Sandakan. Remaining dried veneer were brought back to University Malaysia Sabah for further study. Laboratory scale 3 plies plywood (Sungkai-Acacia, Sungkai-Seraya) were made using the same source of UF resin and veneer, and used for comparison studies. Commercial 3 plies Nyatoh plywood were also used as control samples. The samples were then tested according to Japanese Agricultural Standard for Plywood 2003 (amended: 2008) Tensile Shear Strength of Type II Natural Wood Decorative Plywood. All of the samples pass the Tensile Shear Strength (TSS) minimum standard of 0.7 N/mm2 in untreated condition or even after hot and cold water immersion treatment. The untreated mill samples of Sungkai-Acacia plywood perform the best with mean TSS = 1.74 N/mm2, SE = 0.05 while Nyatoh shows the lowest mean tensile shear strength with 1.06 N/mm2, SE = 0.07. Further statistical analysis shows there was no significance difference between Sungkai mixed plywood group samples. However, Sungkai mixed plywood samples shows a significant difference (p < 0.05) with superior strength when compared to commercial Nyatoh plywood samples. If these criteria met the final requirement for the end use of the veneer, then the potential of Sungkai as an alternative or supplemental raw material is something worth given due consideration.