Fabrication process optimization of hemp fibre-reinforced polypropylene composites

Abstract

Natural fibre-reinforced composites have attracted great research and economic interests because of their outstanding ‘green’ characteristics compared with glass fibre-reinforced composites. It is very important to understand the processing effect on the natural fibre-reinforced composites mechanical properties because of the natural fibre degradation characteristics. Optimizing the fabrication process, especially the compounding process, is effective to achieve the optimal properties of the composites. In this research a natural fibre, noil hemp fibre, was applied to reinforce polypropylene with internal mixing process. The influence of compounding parameters, such as mixing temperature, mixing time and rotor speed, on the mechanical properties (tensile strength, flexural strength and impact strength) of the noil hemp fibre/polypropylene composites was investigated using orthogonal method and the evidence of thermogravimetric analysis test of fibre and the observation of fibre dispersion in resin. The range analysis and variance of analysis demonstrated that the mixing temperature has significant effect on the three mechanical properties, mixing time has minor influence on the tensile and flexural strengths, and rotor speed mainly affects the impact strength. The thermogravimetric analysis test of noil hemp fibre and the fibre dispersion in resin show that a combination of low mixing temperature, short mixing time and high rotor speed of compounding process is helpful to achieve certain fibre dispersion without serious thermal degradation of fibre. Noil hemp fibre/polypropylene composites with the best comprehensive mechanical properties could be obtained at 165℃ for 12 min with rotor speed 50 r/min.

Characterizing the Mechanical Properties of Fused Deposition Modelling Natural Fiber Recycled Polypropylene Composites

“…According to literature, the surface finish of fiber reinforced polymer composites becomes progressively more abrasive and dull with increasing fiber content [11,12]. This relationship was largely observed in harakeke, and to a lesser degree in hemp composites during this investigation.…”

Fused Deposition Modelling of Natural Fibre/Polylactic Acid Composites

“…In addition to a less viscous composite exiting the nozzle, the lower melting temperature may help with fusing the already solidified layers to the hot layers by melting them together more effectively. Controlling the melt rheology has also been shown to be the most practical way to reduce fibre breakage and achieve better fibre distribution [17,18].…”

Parametric analysis of mechanical properties of bagasse fiber-reinforced vinyl ester composites

“…[26][27][28][29][30] They mostly used the Taguchi technique with analysis of variance (ANOVA) to optimize the fabrication process parameters and to find out the percentage of contribution (significant). [31][32][33] In this context, an initial attempt was conducted on bagasse fiber reinforced vinyl ester composites to evaluate their mechanical properties as function of fiber length, fiber content, fiber diameter, sodium hydroxide (NaOH) concentration and NaOH treatment duration using Taguchi and ANOVA techniques. The main objectives of this attempt were to fabricate the composite specimens based on Taguchi's experimental design; to understand the influence of fabrication process parameters on mechanical properties of composites; to optimize the fabrication process parameters; to analyze the results using ANOVA to know the percentage of contribution of each parameters on mechanical properties of composite and also to develop a multi-variable non-linear regression equation to predict the tensile and flexural strength of composite.…”