Development of a Cassava Pelleting Machine

A cassava pelleter comprising of a feed hopper, screw conveyor, barrel, 4hp electric motor, extrusion plate and a pelleting knive was designed and developed using standard and locally sourced materials. The performance test analysis indicates that its pelleting capacity is 80.46 kg/h with an eciency of 80.31% at an optimum operational speed of 250 rpm. The pelleting capacity increased with the mass of pre-conditioned cassava while the eciency of the pelleter decreased with increase in mass of pre-conditioned cassava in some cases. The estimated cost of the machine was 32,350:00.Keywords: cassava, pelleting capacity, screw conveyor, feedstock, pelleting machin

Production of Manual Metal Arc Welding Electrodes with Local Raw Materials

Manual arc welding using flux coated electrodes is carried out by producing an electric arc between the base metal and a flux covered metal electrode with electric current that depends on the type of electrode, material, welding position and the desired strength. The composition of flux coated electrodes is complex and a variety of coatings were used to cater for different types of welding applications. However, in all cases, the coating is formulated to satisfy three major objectives: to form fusible slags, to stabilize the arc and to produce an inert gas shielding during welding. In the research carried out, several flux samples of various local raw materials were collected, their chemical compositions were determined and the results utilized in producing manual metal arc electrodes. The electrodes produced were used to carry out welds on mild steel sections. The basic characteristic test criteria for determining the performance of any electrode were carried out. The samples of the weld metals were analyzed to determine the homogeneity of the chemical composition as a result of the flux coating, welding rod, and base plate materials. It was observed that manganese based flux covered electrode (a local electrode) with tensile strength of 585.8 N/mm2 was able to compete effectively with titanium dioxide based electrode (a foreign electrode) with tensile strength of 606.7N/mm2. This research work therefore, highlights the need to maximize the use of local raw materials aimed at reducing the cost of importation and thereby help in conserving scarce foreign exchange

Factors That Improve the Impact Responses of Ukam Plant Fibre Reinforced Composite

Natural fibres around us have mechanical properties capable of making them compete effectively with synthetic fibres in the development of fibre reinforced composites. Synthetic fibres (such as glass fibres) and resins (such as polyester resin) have long been used in the development of structural components for car bodies, boat buildings, house and aircraft constructions. This project is concerned with the preparation of cashew nut shell liquid resin (natural resin) and the collection of Ukam plant fibres (natural fibres) and using them in the development of fibre reinforced plastic composites. Factors that improve their impact responses were considered in the development processes. These are fibre volume fractions, fibre treatment, fibre length, fibre orientation and the application of additives. Fifty different test specimens which involved the synthetic and the natural composites were developed using the hand lay-up method. The specimens were subjected to pendulum or notched Izod impact tests using ASTM D256 impact testing machine. The results of the impact tests show that: (1) Natural composites can withstand impact strengths like the synthetic ones, (2) Impact response of composites improves when the five factors indicated above are taken into consideration in composite development. Among these factors, the introduction of 20% by resin weight of additives yielded the best impact response for both natural and synthetic composites. For example at 40% fibre volume fraction, the natural composite test sample with additives developed an impact response of 86.4kJm-2 against 78.9kJm-2 impact response of the natural composite test sample without additives. This optimum impact response improvement was also observed with synthetic composite test samples with values of 96.5kJm-2 and 94.8kJm-2 for samples with additives and without additives respectively. From these results, it is obvious that structural components such as car bumpers could be developed from natural composite

Comparison of Cashew Nut Shell Liquid (CNS ) Resin with Polyester Resin in Composite Development

Natural resins can compete effectively with the synthetic ones in composite development. In this research, cashew nuts were picked and processed for the extraction of the resin content. The resin (natural resin) so obtained was mixed with cobalt amine (accelerator), methyl ethyl ketone peroxide (catalyst) to develop two sets of composite specimens – specimens without fibres and specimens reinforced with glass fibres. This method of sample specimen development was repeated with polyester (synthetic) resin. Compressive and tensile strength tests conducted proved that composites developed with cashew nut shell liquid (CNSL) resin were comparable to those developed with polyester resin. In the results, CNSL has an ultimate compressive strength of 55MPa compared to that of polyester resin with an ultimate strength of 68MPa. The result of tensile strength proved cashew nut shell liquid resin (with ultimate strength of 44MPa) to be better than polyester resin with 39MPa as ultimate tensile strength. This means that natural resins could be a better substitute for the synthetic ones when the required quantities of fibers (reinforcements) and fillers are used in the fibre-reinforced plastic composite developments.KEYWORDS: CNSL resins, polyester resins, composite development, strength test