This work contributes two novel modified Taguchi techniques to the optimal parametric setting for minimum water absorption in epoxy composites. Taguchi method, using ASTM standards was applied with factors (initial weight, final weight, length, sample thickness and time of immersion) and four levels in the experimental design. The analysis of variance (ANOVA) evaluates the significance and individual contributions of the parameters. The optimal parametric setting was A1B4C3D4E1 (initial weight, 2.61 g; final weight, 2.69 g; length, 62.73 mm; thickness, 3.88 mm; time, 15.65 hrs). The ANOVA identifies time and length as dominant parameters (98.98 and 1.02 % contributions, respectively). Taguchi-Pareto analysis found only factor-level from the time and length parameters economical to optimality. The Taguchi-ABC analysis revealed the individual weights and contributions of the factor-level irrespective of its initial groupings. The new Taguchi techniques highlighted the importance of time and length of sample in obtaining minimum water absorption of composites.

Wear rate appraisals are currently indispensable on agro-waste filled composites for brake pads as they predict the expected lifespan of the materials. However, existing wear rate models are inaccurate as predictions omit the inflationary cost of the materials. In this paper, the idea is to account for the inflationary cost of the materials and adjust that into a pseudo wear rate model. The wear rate of agro-waste fillers in an organic matrix to create brake pads under dry sliding wear experiments was considered. Five composite specimens were fabricated in cylindrical specimen height of 14.5 mm and varying diameters of 8, 10, 12 and 15.5 mm and the material wear loss was measured. The 8, 10 and 12 mm diameter specimens revealed that the composite with the best and worst wear resistance were the wear rates of 0.6, 1.4, 1.73 mm3/Nm, and 3.07, 3.54, 4.19 mm3/Nm, respectively. The 15.5 mm diameter specimen showed lower wear rates of 2.13 and 2.14 and 1.56 mm3/Nm than commercial brake pad’s 2.58 mm3/Nm. The pseudo wear rate model predicts the impact of the independent variable i.e. inflationary cost, opportunity cost, time, and sample size. The utility of this effort is to assist the composite manufacturers to take cost-effective decisions and design optimisation can be accomplished to lower the cost of composite products.

In this attempt, which is a second part of discussions on tapped density optimisation for four agricultural wastes (particles of coconut, periwinkle, palm kernel and egg shells), performance analysis for comparative basis is made. This paper pioneers a study direction in which optimisation of process variables are pursued using Taguchi method integrated with the Pareto 80-20 rule. Negative percentage improvements resulted when the optimal tapped density was compared with the average tapped density. However, the performance analysis between optimal tapped density and the peak tapped density values yielded positive percentage improvements for the four filler particles. The performance analysis results validate the effectiveness of using the Taguchi method in improving the tapped density properties of the filler particles. The application of the Pareto 80-20 rule to the table of parameters and levels produced revised tables of parameters and levels which helped to identify the factor-levels position of each parameter that is economical to optimality. The Pareto 80-20 rule also produced revised S/N response tables which were used to know the relevant S/N ratios that are relevant to optimality.

The diffusion parameters of orange peel epoxy composites are important elements in composite structure in that they explain how fast water and other fluids can diffuse through the composites as a sign of integrity test. In this article, we defined the optimal parametric settings for diffusivity parameters of orange peel epoxy composites. The Taguchi optimisation method used obtained an optimal parametric setting of P4Q4R1 in experiments conducted for three and seven days, respectively. The analysis of variance revealed significant contributions made by the initial and final weights, while the thickness parameter was found to be less significant. A variant of the Taguchi method called Taguchi-Pareto was introduced, which also underscores the thickness parameter as not economical to optimality. The specifications and dimensions obtained by Taguchi method or its variant may be useful design engineers when contemplating on how to reduce diffusivity and water uptake of composites.

Environmental concerns are being intensified in composite manufacturing ventures, using agricultural fillers as strategic materials to improve environmentally-conscious performance. In this investigation, which is the first part of a series of papers, four agricultural wastes (particles of coconut, periwinkle, palm kernels and egg shells) were studied for their tapped density optimisation behaviour, being tested independently of matrices. The manual tapping method with measurements applied in successive taps of the cylinder containing the particles against solid surfaces and the experiments were carried out in the laboratory. Taguchi?s method of the ?lower-the-better? (LB) quality characteristic was used in this investigation to describe the performance of the experiments. The optimal parametric settings for the particles of coconut, periwinkle, palm kernels and egg shells were found to be P2Q4R4S4, P3Q4R1S4, P2Q3R1S4 and P1Q4R2S4, respectively. The optimal results would help in attaining good reinforcing fillers with better tapped density properties. The method of mean response investigation showed that either of geometric and quadratic methods of means could be used where the LB quality characteristic is required.

Despite the potentials of dual reinforced particulate polymer composites to produce outstanding composite with enhanced wear properties, scholars have devoted insignificant attention to them. This paper introduces five diverse epoxy composites prepared in dual reinforcement blends. Using a mixed design L16 orthogonal array, Taguchi's parametric optimization was conducted with some ratios between the wear parameters as a novel way of revealing the influence of their interrelatedness in the optimization process while the statistical modelling of the wear responses was pursued. Analysis of variance was also conducted as well as regression analysis. With experimental tests on the DIN abrasion tester, the (10OPP,15CSP)% composite obtained an optimal parametric setting of A1B2-3C3D1E4. The (10PKSP,15CSP), (10PSp,15ESP), (10OPP,15PSP) and (5PKSP,20ESP)% composites obtained optimal parameter settings of A3B2C3D3E2, A3B1-3,C3D1E4, A3B2C2D1E4 and A3B2C4D3E3, respectively. The correlation plots between the experimental and predicted values of the wear process and determination coefficient indicate a high level of accuracy of the models in predicting the wear behaviour of the composites.

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Abstract. There is paucity of data relating to the free swell properties of composite reinforcement materials in outdoor applications despite the widely-debated need for more investigations in this area. In this paper, a comparative performance analysis of three optimisation models -Taguchi method, simplex algorithm and Taguchi-simplex method -is pursued. We used experimental data of 0.600 mm particulate coconut shell with the theories behind L27 (3 11 ) orthogonal arrays, to achieve our aim for the Taguchi method. The simplex algorithm required modelling the free swell problem as the objective function subject to parametric constraints defined by the factors and their respective levels. For the Taguchi-simplex method, the S/N ratios and the optimal parametric setting of the Taguchi method were used to model the objective function and the new constraints that the simplex algorithm optimised. Parameters include initial and final volumes of coconut shell particulates (CSPs), mass of water, volumes of CSPs and water as well as mass of CSPs. The optimised initial and final volumes were 10 and 34 cm 3 (Taguchi), 20 and 34 cm 3 (simplex) and 16.6 and 24.82 cm 3 (Taguchi-simplex). The optimal masses of water were 141.54, 146.81 and 89.12 g while the volumes of CSPs and water were 152, 152 and 106.4 cm 3 , and the mass of CSPs were 12.07, 12.07 and 6.28 g for Taguchi, simplex and Taguchi-simplex methods, respectively. Confirmatory test validated the results. In conclusion, the optimum parametric setting of the Taguchi-simplex method was the best.