Physical and Mechanical Properties of Bamboo Oriented Strand Board (BOSB) Prepared from Steamed Strands under Various Bamboo Species and Resin Content

Abstract

INTRODUCTION. Recent study showed that bamboos were very prospectus as raw materials for developing bamboo oriented strand board (BOSB). Steam treatment was applied to bamboo strands to improve BOSB properties. In order to reduce the resin cost, phenol fomaldehyde (PF) resin was used in this study. The effect of resin content and bamboo species on the BOSB prepared from steam strands were investigated in this study. MATERIALS AND METHOD. Strands were prepared from tali bamboo (Gigantocholoa atroviolacea Widjaja) and hitam bamboo (Gigantochloa apus (J.A & J.H. Schultes) Kurz). The strands were steamed in autoclave at temperature of 126° C and 1,4 kg/cm2 pressure for 1 hour. Then, the strands were then dried in oven at a temperature of 60 °C to reach the moisture content (MC) around 5%. Commercial phenol formaldehyde (PF) resin was used in amount of 6%, 8% and 10%. Paraffin was used in amount of 1%. The geometry strand, physical properties (i.e., density, MC, water absorption (WA), and thickness swelling (TS)), mechanical properties (i.e., modulus of elasticity static (MOEs), modulus of rupture (MOR), internal bond (IB), and screw holding power (SHP)) were evaluated. Nondestructive test (NDT) of stress wave velocity (SWV) and MOE dynamic (MOEd) parameter was also evaluated. The results were also compared with CSA 0437.0 (grade O-2) standard for OSB. RESULTS. The average value of slenderness ratio of tali and hitam bamboo strands were f 75,24, 67,74, respectively. The average value of aspect ratio of tali and hitam bamboo strands was 3,60, 3,44, respectively. The Physical and mechanical propertes of BOSB were much affected by bamboo species and resin content. BOSB prepared from tali bamboo strands showed better physical and mechanical properties compared to BOSB prepared from hitam bamboo strands. The higher the resin content applied resulted in the better the physical and mechanical properties of BOSB. Based on NDT result (sound waves velocity), the best relationship was achieved by SWV-MOR and SWV-MOEs perpendicular to the grain direction (95% confidence level). BOSB made from tali bamboo strands with 10% PF resin content had the excellent physical and mechanical properties. All the parameters measured fulfilled the requirement of CSA 0437.0 (grade 0-2) standard for OSB.

Penelitian akhir-akhir ini menunjukan bahwa bambu memiliki prospek sebagai bahan baku pembuatan Bambu Oriented Strand Board (BOSB). Perlakuan pendahuluan steam terhadap strand bambu dilakukan untuk memperbaiki sifat-sifat BOSB. Dalam rangka mengurangi biaya perekat, perekat yang telah disteam fenol formaldehida (PF) digunakan dalam penelitian ini. Pengaruh dari kadar perekat dan jenis bambu pada BOSB dari strand dicari pada penelitian ini. Strand disiapkan dari bambu tali (Gigantochloa apus (J.A & J.H. Schultes) Kurz) dan bambu hitam (Gigantocholoa atroviolacea Widjaja). Strand disteam menggunakan autoclave pada suhu 126o dan tekanan 1,4 kg/cm2 selama 1 jam. Kemudian dikeringkan dalam oven pada suhu 60 °C sampai kadar airnya di bawah 5%. Perekat fenol formaldehida (PF) digunakan pada kadar perekat 6%, 8% dan 10% serta penambahan parafin sebanyak 1% terhadap berat total bahan baku. Pengujian yang dilakukan antara lain geometri strand, sifat fisis (kerapatan, kadar air, daya serap air dan pengembangan tebal), sifat mekanis (modulus elastisitas statis (MOEs), modulus patah (MOR), internal bond (IB) dan kuat pegang sekrup (KPS)). Pengujian nondestruktif (NDT), cepat rambat gelombang suara (SWV) dan modulus elastisitas dinamis (MOEd) juga dievaluasi. Hasil pengujian dibandingkan dengan standar CSA 0437.0 (grade 0-2) untuk OSB.