Author
E. O. Onuorah
E. O. Onuorah
Journal of Tropical Forest Science
Vol. 17, No. 4 (October 2005), pp. 497-507
Published by: Forest Research Institute Malaysia
Stable URL: http://www.jstor.org/stable/23616587
Page Count: 11
Viewing page 497 of pages 497-507
Abstract
The potentials of oil palm (Elaeis guineensis) stem and / or mixed tropical hardwood sawmill residues for making dry-formed resin-bonded medium density fibreboard (MDF) and / or wetformed hardboard were investigated. Chips/fibrous strands of 15 to 25 mm length by 4 to 7 mm thick with variable widths of < 15 mm were digested into pulp using 1.5% NaOH at material:liquor ratio of 1:3.5. The cook lasted 90 min at 25 °C, pH 10.5 and 0.45 MPa. Pulp yields were high (86—88%) and screen rejects were at acceptable levels (1.76—4.11%). Boards were made either as 9.53 mm thick MDF (SG = 0.7, resin content = 7%) or 3.175 mm thick hardboard [SG = 0.8 of either two smooth surfaces (S2S) or screen meshed back (S1S)]. Boards were sampled and conditioned at 20 ± 2 °C and 65 ± 2% relative humidity, and tested in accordance with ASTM D 1037—90. Ten replicates were used for each test for each product. MDF made from tropical hardwood sawmill residues had higher modulus of rupture (MOR) than those from oil palm or mixed furnish. S2S hardboards had higher MOR and modulus of elasticity (MOE) than S1S. S1S hardboards had higher internal bond than S2S hardboards. The MDF and different hardboards had acceptable properties. Kemampuan batang kepala sawit (Elaeis guineensis) dan/atau sisa kilang papan daripada campuran kayu keras tropika menghasilkan papan gentian berketumpatan sederhana (MDF) secara pembentukan kering dengan ikatan resin dan/atau papan gentian keras secara pembentukan basah dikaji. Serpai/lembar bergentian berukuran 15 mm—25 mm panjang, 4 mm—7 mm tebal dengan pelbagai lebar yang tidak melebihi 15 mm dihadamkan untuk dijadikan pulpa menggunakan 1.5% NaOH dengan nisbah pepejal:cecair sebanyak 1:3.5. Campuran dimasak selama 90 min pada 25 °C, pH 10.5 dan 0.45 MPa. Hasil pulpa tinggi (86—88%) dan bahan ditolak selepas saringan adalah pada tahap yang boleh diterima (1.76—4.11%). Papan dijadikan MDF setebal 9.53 mm (SG = 0.7, kandungan resin = 7% atau papan keras setebal 3.175 mm [SG = 0.8 sama ada mempunyai dua permukaan licin (S2S) atau permukaan belakang berjaringan skrin S1S)]. Papan disampel dan disimpan dalam keadaan 20 ± 2 °C dan 65 ± 2% kelembapan relatif. Papan kemudiannya diuji berdasarkan piawai ASTM D1037—90. Sebanyak 10 replika digunakan untuk setiap ujian bagi setiap papan. MDF daripada sisa kilang papan yang mengandungi kayu keras tropika mempunyai modulus kepecahan (MOR) yang lebih tinggi daripada papan daripada kelapa sawit atau papan daripada bahan bercampur. Papan keras S2S mempunyai MOR dan modulus kekenyalan (MOE) yang lebih tinggi daripada papan S1S. Papan keras S1S mempunyai ikatan dalam yang lebih tinggi daripada papan keras S2S. MDF dan papan keras berlainan memiliki ciri papan yang memuaskan.
Journal of Tropical Forest Science © 2005 Forest Research Institute Malaysia
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