Effect of strand dimension and specific pressure on the performance of strandboards made from Tali bamboo (Gigantochloa apus (JA & JH Schultes) Kurz)

Bamboo is a lignocellulosic material that has the potential for substituting wood and wood-based materials. Tali bamboo (Gigantochloa apus (JA & JH Schultes) Kurz) has long been used in Indonesia as a traditional material for housing construction, woven products, and handicrafts. It is a promising raw material for a biocomposite product, such as strandboards since it is abundantly grown and widely planted in Java, Bali, Sumatera, and Kalimantan. This research aimed to determine the physical and mechanical properties of bamboo strandboards (BSB). Homogenous unidirectionally bamboo strandboard (BSB) with the dimension of 30 cm x 30 cm x 1.2 cm and a target density of 0.75 g/cm3 were fabricated in a laboratory using adhesive mixture of 7% (resin solid) phenol formaldehyde (PF) based on the strand dry weight, and 1% of paraformaldehyde based on PF weight. Three different strand dimension, i.e. 75, 100, and 150 mm in length, 25 mm in width, and 0.5 − 0.8 mm in thickness, were used to produce BSB. The BSB mats were hot-pressed at 150°C for 6 minutes with specific pressure of 25 kg/cm2 and 30 kg/cm2. Results revealed that strand dimension and specific pressure significantly influenced the physical and mechanical properties of tali BSB, with the exception of moisture content and density. BSB manufactured from longer strand had the lowest thickness swelling, water absorption, and width expansion of 2.37% and 23.30%, and 1.64%, respectively. The highest internal bond and MOE were found in BSB prepared from 150 mm long strand and specific pressure of 30 kg/cm2 (0.89 N/mm2) and 10779.80 N/mm2, respectively. All physical and mechanical properties of BSB manufactured in this study conformed with the Japanese Industrial Standard for Particleboard (JIS) A 5908-2015.