In this paper, 400 flax fibers with 10 different lengths (40 fibers at each length) are experimentally characterized (quasi-static tensile behavior) and then the results are statistically analyzed. The quasi-static tensile test results appeared to have a large dispersion, which makes it possible to measure the degree of variability in the ultimate tensile strength (UTS), failure strain, and the Young’s modulus of the fiber, at different gage lengths (10 mm to 500 mm). The variation in mechanical properties at each fiber length is established using two and three Weibull statistics based on maximum likelihood estimation (ML) and least square estimation (LS). Finally, all 10 groups for each tensile property are analyzed by one-way (ANOVA).

In this study, biocomposites fibers (flax/epoxy) with different fiber ratios were manufactured and their tensile, 3-point bending and morphological properties were characterized. The interfacial binding of fractured composite samples after tensile and 3-point bending tests were examined by scanning electron microscopy (SEM). The mechanical results revealed an increase in the composite sample manufactured by second formulation CT090 (biocomposites UD [0/90°]_s treated by NaHCO₃) compared to the different formulations studied. For example, the stress and Young’s modulus values of qua-static traction of the biocomposite CT090 treated with sodium bicarbonate are obtained to be 70.13 MPa and 1420.47 MPa, respectively. The overall test results stated that bio sodium carbonate treatment enhanced the mechanical and morphological properties of the biocomposites in this study. Finally, the experimental results were subjected to a one-way analysis of variance (ANOVA) using MINITAB software.

The knowledge of the mechanical behavior of woven fabrics is necessary in many applications, in particular, for the simulation of textile composite forming. However, in-plane shear behavior of textile performs is the most studied mechanical property, because this mode of deformation is necessary for forming on double curvature surfaces. In this paper, bias extension tests on non-crimp fabrics (NCF) have been conducted. Two different types of non-crimp fabrics were tested. Force and displacement were measured and then force displacement curves were plotted. Shear angles and normalized shear forces were determined. The shear stress was represented as function of the shear angle, and obtained curves were assigned polynomial regression equations. The derivative of those regression equations provides in-plane modulus of rigidity as a function of shear angle. The effect of small stitches on the rigidity of these fabrics was also examined.

In this work, the optimization of extraction of polysaccharides from Citrullus colocynthis curd polysaccharides (CCPs) is investigated by using the analysis of variance. For this aim, a chemical extraction method has been developed in order to be able to isolate CCPs at high level of purity. The extraction was performed by using boiling water at different extraction times (30, 60 and 120 min), extraction temperatures (50, 75 and 100°C), and a material ratio (30, 60 and 100 g/ml), for maximum polysaccharide extraction. The 3-D response surface plot and the contour plot derived from the mathematical models are used to determine the optimal conditions. The optimum extraction conditions are as follows: extraction temperature 100°C, extraction time 120 min and the ratio of water 30 ml/g. Under these conditions, the experimental final mass is 210.6 mg which is very close to the predicted value (209.46 mg) with a regression coefficient of 94.01%. In addition, the existence of the polysaccharide has been confirmed by the characterization of the galactomannan obtained from C. colocynthisis obtained by Fourier transform infrared-attenuated total reflection, IR-Raman spectroscopy and X-ray diffraction.