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Fibreboard from exotic raw materials. I. Hardboard from rice straw pulps

1975; Wiley; Volume: 25; Issue: 9 Linguagem: Inglês

10.1002/jctb.5020250903

0375-9210

Fardous Mobarak, Abd‐Alla M. A. Nada, Yehia Fahmy,

Lignin and Wood Chemistry

Abstract The suitability of rice straw for hardboard making was studied. Both the mechanical and semichemical pulping methods were investigated. It was found that addition of a relatively high amount of resin (2–3 %) is essential if hardboard—comparable to average commercial samples made from wood—is to be made from mechanically prepared rice straw pulp. Mild chemical treatment of the mechanical straw pulp by sodium hydroxide at optimum conditions, however, enabled the amount of resin added to be reduced and improved the bending strength and water resistance of the board considerably. Treatment with calcium hydroxide or sulphuric acid was, generally, less successful. This was accounted for by changes in pulp chemical composition. On the other hand, when the straw was first subjected to mild chemical pretreatment followed by the mechanical defibration, many fines were formed and the resulting semichemical pulp was not suitable for hardboard.