Properties of Plastic Bonded Agricultural – Waste Composites, I: Charcoal and Wood-Dust Separately Bonded Composites

Abstract

Eleven (11) composites, are unfilled and five each filled with varying contents of charcoal and wood dust separating bonded with melted spent thermoplastics have been compounded and their compressive strength, density, specific gravity, percentage shrinkage and percentage absorption determined.Composite density ranges (0.83-0.94)g/cm 3 , compressive strength from (6.92-16.14)n/mm 2 , percentage shrinkage from (1.01-4.76)% and percentage water absorption from (1.75-15.75)%. These results suggest that these composites (i) meet the allowable American standard for test and measurement (ASTM) for ceramic floor and wall tiles in compressor strength (0.2-22.1)minimum, % shrinkage (maximum 15%) and water absorption (maximum 16%) (ii)are appreciably strong compare to the gmelina-wood/cement composite and (iii) if comprehensively examined, composites may be useful in the building industry for the manufacture of tiles and boards and even compete favorably with the wood cement composites. Keywords: Compressive strength, % shrinkage, % absorption, thermoplastic,tiles. I. Introduction The reinforcement of inorganic matrices for improved structural integrity with linigocellulose fluids materials is an old option. Inorganic builders such as Portland cement have been used in building elements. Example of the different types of inorganic bonded wood composite industrially produced are magnesium bonded composite panel (1,2). They are used as particle partitioning, cladding, wall lining and paneling and roofing of floor base (3-5) The use of cement builder in the production of particle boards has aroused interest lately probably because of the shortage and increase in the price of synthetic resin and the desire of develop boards that are suitable foe the exterior applications. The needed raw materials (cement and wood) are readily available in developing countries and the production technology is relatively simple. The cement bonded particle boards is reported (2, 6-8) to have better resistance to impact loading when compared with asbestos board stiffer than the unbound with a bond strength that increase progressively with period of exposure to structural weathering. One of the many problems with cement bonded particle is that of which relates to the weight of the board. Commercially, the board is manufactured within the density range of 1100-1300kg/m 3 and with cement wood ratios ranging between 2.75 -3.00 cement to 1.00 of wood on weight basis (9). The large quality of cement per unit weight of wood employed in the board manufacture makes the resultant board to be heavy. It has been noted that the characteristically high density of the board is a possible limitation to the boards use particular in the areas where weight saving is essential. Deppe (10) noted the need for research effort directed towards finding ways of reducing density of the board while at the same time improving the strength of the board.This need is the aim of the present work. The sale of pure water in plastic sachets without effective management of the sachet after the consumption of the water contains has resulted in environmental pollution caused by the non-biodegradable spent purer water sachet particularly in our cities in this country. In an attempt to control the menace, the spent sachet has been used as a binder in the production of particle boards separately consisting of charcoal and wood dust. The compressive strength, % absorption and % shrinkage of the composites are reported in this write up. EXPERIMENTAL Materials spent pure sachet were collected from restaurants, washed and sun dried. Filters: (a) Charcoal was bought at the Erekesan market Akure, washed, sun dried, crushed and sieved with endecotte sieve into an appropriate particle size and stored at 105