Browsing by Author "Bisanda, Elias T. N."

Now showing 1 - 7 of 7
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    Effects of Sawdust Additives on the Properties of Natural Adhesive Bonded Rice Husk Boards
    (2000-09) Ndazi, Bwire S.; Tesha, J. V; Bisanda, Elias T. N.
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    Performance of Cotton-Kapok Fabric-Polyester Composites
    (Elsevier, 1999) Mwaikambo, Leonard Y.; Bisanda, Elias T. N.
    Cotton–kapok fabric, at a ratio of 2:3, has been incorporated with unsaturated polyester resin in various fibre volume fractions. The fabric was also treated with 5% sodium hydroxide with the aim of improving fibre–matrix adhesion. A simple manual lay up technique was used in fabricating the composites. A hand operated hydraulic electrically heated press was used and the composites were cured at 100°C for 60 min and post cured overnight in the oven at 80°C. Mechanical properties such as tensile strength, tensile modulus, impact strength, and flexural properties of composites not subjected to weathering conditions and weathered composites have been evaluated. Composites with untreated fibres had higher fibre volume fractions than composites prepared using treated fibres. The tensile strength of composites with untreated fibres was higher than that of composites prepared using treated fibres but had, on average, higher tensile modulus than composites manufactured using untreated fibres. The impact strength decreased with increase in fibre volume fractions for both composites, with or without alkali treated fibres. Reductions in flexural strength and moduli were observed with weathered composites. The specific strength of the composites was comparable to that of other vegetable fibre reinforced resins.
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    Production of rice husk composites from tannin based resin
    (2002) Ndazi, Bwire S.; Tesha, J. V; Bisanda, Elias T. N.; Karlssion, S.
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    Production of Rice Husks Composites with Acacia Mimosa Based Tannin Resin
    (Journal of Materials Science, 2006) Ndazi, Bwire S.; Tesha, J. V.; Karlssion, S.; Bisanda, Elias T. N.
    Rice husks are amongst the typical agricultural residues, which are easily available in huge amounts. They have been considered as raw material for composites panels’ production. However, the major hindrance in rice husks utilization for composite manufacture lies in the lack of direct interaction with most adhesive binders to form the anticipated interfacial bonds. Rice husks are highly siliceous and have poor resistance to alkaline and acidic conditions. Manufacture of rice husks composites panels having good interface bond is difficult and largely dependent on a proper understanding of the interaction between the husks and the binder. This paper presents and discusses results on the production of composites boards from a mixture of rice husks and wattle (Acacia mimosa) tannin based resin. The experimental results have shown that the ‘as received rice husks’ when blended with alkali-catalyzed tannin resin do not result in optimum composite panel properties. However, it was found that a slight physical modification of the rice husk particles by hammer-milling resulted in drastic improvements in the interfacial bond strength and stiffness of the composites panels from 0.041 MPa to 0.200 MPa and 1039 MPa to 1527 MPa, respectively.
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    Properties of Rice Husk Particleboards Bonded by Tannin Based Resin
    (Uhandisi Journal, 2002) Ndazi, Bwire S.; Tesha, J. V.; Bisanda, Elias T. N.; Karlssion, S.
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    Some Opportunities and challenges of producing bio-composites from non-wood residues
    (Journal of Materials Science, 2006) Ndazi, Bwire S.; Tesha, J. V.; Bisanda, Elias T. N.
    Plant-based composites (bio-composites) may in the future, become materials to replace polymer based composites and wood in terms of their attractive specific properties, lower cost, simple processing technologies, eco-friendliness, and ability to be recycled after use. The quality and performance of plant fibre-based composites can further be improved by adopting appropriate engineering techniques. Although plant-based fibres have these advantages, they also have some limitations. One of the serious problems of plant fibres is their strong polar character, which creates many problems of incompatibility with most thermosetting and thermoplastic matrices. Production of bio-composites with high quality and performance is therefore based on adjusting the properties of the constituents to meet the requirements of the composite material i.e. a product with consistent, uniform, predictable, and reproducible properties. Such adjustments involve creating strong interfacial bonds between the lignocellulosic substrates and the binder. Successful development of biocomposites therefore stem from a careful understanding of the influence of these adjustments on the composite properties. This paper suggests some opportunities available in producing bio-composites from non-wood resources, and the challenges that must be overcome to make this technology commercially viable. Gaps in knowledge and information required before full commercialisation of these materials are identified.