Analysis of the effects of heat treatment on the tensile properties of coir fibres using Minitab-18 statistical software

Abstract

Vacuum oven heat treatments were done to enhance the properties of coir fibre for improved performance in composites. Their effects on the mechanical properties of coir fibres were investigated. As received (AR) coir fibres were subjected to heat treatment temperatures of 80 oC and 160 oC for 6 hours at each temperature in a vacuum oven. The effects of the heat treatment temperature on AR coir fibres were statistically analyzed using ANOVA, F-tests, Fisher Pairwise grouping and Fisher Individual Tests for Difference of Means (FITDM) with Minitab-18 Software. This was done to determine the significance of these heat treatments on the tensile properties of AR coir fibres. Fisher Pairwise grouping and FITDM show that strength and elongation of AR coir fibres differed significantly from coir fibres heat-treated at 80 oC. The tensile strength of AR coir fibres was found to be, respectively, 49% and 24% lower than coir fibres treated at 80 oC and 160 oC. The stiffness of coir fibres (AR) was found to significantly increase after heat-treating at 160 °C, while the elongation at break of AR was 44% higher. The strength distributions obtained from the tensile test data were subjected to two-parameter Weibull statistics. AR coir fibres displayed Weibull moduli that were 16% and 56% higher than coir fibres treated at 80 oC and 160 oC, respectively. SEM was conducted on the samples to delineate the morphological changes affecting the properties of coir fibres.

Keywords

• coir fibre
• heat treatment
• vacuum oven
• tensile properties
• statistical analysis
• weibull distribution