No abstract

The search for innovative solutions for the reuse of solid residues has intensified with growing environmental issues and the increasing cost of most raw materials, leading to the design of eco-friendly composite materials, such as wood-plastic composites (WPCs). These materials combine the stability of wood fibres with the durability of plastic, allowing for a wide range of applications, whilst simultaneously offering the possibility of utilising waste products from the forest/wood industry and recycled plastic. Waste products that otherwise incur cost for disposal therefore become a sustainable material resource for new products. Natural fibres offer a number of advantages over synthetic fibres and are seen as a ''green'' alternative to other reinforcements. Commonly, the fibrematrix adhesion in WPCs is improved by using compatibilisers that bond to the polar wood fibres and the non-polar polymer matrix. However, the problem with these is that good dispersion is not always achieved as it depends on the adhesion properties of three individual components in the WPC, which might lead to poor mechanical properties of the WPC. The ability of the atomic force microscope (AFM) to create 3D images of topography and various interaction forces with molecular resolution made it a valuable tool for the analysis of adhesion properties in WPCs.

Physical properties are major characteristics that validate biomaterials' adaptability to commercial utilization. The moisture content, density, swelling, and shrinkage within male and female Borassus aethiopum were assessed. Green and dry moisture content, and density were tested with the oven-dry method while swelling and shrinkage were evaluated using the water-saturation test and oven-dry methods respectively. Unlike moisture content, density decreased towards the crowns and radially from the peripheries to their cores. Directional swelling decreased as: Radial > Tangential > Longitudinal. Volumetric swelling was greatest at the core of the base (6,99 %) but at least at the periphery within the middle of the male (2,89 %). However, the female recorded much swelling at the core of its mid-portion (6,23 %) and least (4,01 %) at the crown periphery. Directional shrinkage decreased identically as the male variety while the volumetric shrinkage for both varieties was not consistent. The peripheries had less moisture content, better dimensional stability and density (which influences wood strength) at the butt than those of the core indicating the peripheries would maintain its original dimension and strength when subjected to environmental changes and be more viable for structural works than the core.

ABSTRACT:The study was carried out in a furniture industry in Ghana, to identify some of the hazards, lost in revenue due to hazards and hazard control. Questionnaires were administered to workers of which 60% had adequate knowledge about hazards management; 50% had experienced minor injuries; 80% had knowledge on the use of Personal Protective Equipment, and 100% had access to good medical care provided by the Management. The results further indicated that unavailability and low usage of personal protective equipment (PPE) increase the risk of getting involved in accidents.It was recommended that Management should be committed to the training of their workers on the use of safety tools. Factory Inspectorates should increase the number of times they visit these industries to ensure safety. Procedures for providing safety against accidents are therefore very relevant, hence encouraged through safety committees.

Chemical force microscopy (CFM) was used to characterise the surface of pine and beefwood with atomic force microscopy (AFM) tips coated with different compatibilisers. With the resulting force images, potential binding sites for compatibilisers, used in wood-plastic composites (WPC) to enhance adhesion between two relatively incompatible phases, were localised and quantified. Tips were coated with two commercially available polymers namely ethylene vinyl alcohol (EVOH) and polyethylene-grafted maleic anhydride (PE-g-MA). It could be observed that the interaction forces between the EVOH coated tip and the wood surface was highly species sensitive, whereas adhesive forces measured between the PE-g-MA coated tip and the wood surface were comparable for both wood species. The force maps show that wood species differ in the distribution of functional groups, and the force histograms show that the frequency distribution of the adhesive forces varied for the two wood species. The adhesive force maps clearly show a difference between wood/compatibiliser systems, and the differences can be related to the chemical composition of the wood species. The results confirm that not all compatibilisers are equally suitable for all wood species and these results were confirmed by mechanical tensile tests of WPC systems in a related study.