Optimization technique is mainly used to find out the optimal value of control factors which yield the best response variables. In the case of more than one response variable, the optimization process using the Taguchi approach will give a different set of optimal level for each response variable. Consolidating Taguchi method with grey relation analysis will give optimal levels of control factors for all response variables. In the present study, multi-response optimization based on Taguchi-grey relational analysis was conducted to maximize tensile strength, breaking extension and air permeability of cotton woven fabrics. Cotton woven fabric parameters such as weft yarn count, weave structure, weft yarn density with three levels, and twist factor of the weft yarn with two levels were used as control factors. Using full factorial design, 81 experiments will be conducted. Whereas, using the Taguchi approach and L₁₈ orthogonal array in particular, these experiments will be reduced to 16 experiments. Using Taguchi-grey relational method, optimal combination of the control factors which yield the best-woven fabric properties under study were obtained.

In this experimental study, we investigated the effects of spandex filament drawing ratio and weave structures on the properties of cotton/spandex woven fabrics. One-way analysis of variance was used to explore the significant effects of the independent variables on the fabric properties. A regression analysis was also used to derive regression relationships between each of fabric properties and spandex filament drawing ratio. Our findings show that the spandex drawing ratio and structures of the woven fabrics significantly affect the physical and mechanical properties of the cotton/spandex woven fabrics. Cotton woven fabrics containing spandex show higher contraction, crease recovery, and flexural rigidity with increasing spandex drawing ratio, whereas the rest of fabric properties decreases with the increasing drawing ratio. Because of higher contraction and then higher weight, thickness, and cover factor of cotton/spandex fabrics, unexpected results of fabric air permeability and breaking elongation were detected.

Fiber-reinforced materials are widely used in many industrial applications including civil engineering, automotives, marine, aviation, etc. This is due to their high strength to weight ratios compared to metal structures. One of the major applications of composites is the structural components for automotives such as bumpers, fenders, hoods, door panels. For such applications, impact strength is required since it is directly related to the passenger safety requirements. Sandwich structures are extensively used in automobiles; the understanding of their behaviors under impact conditions is extremely important for the design and manufacturing of these engineering structures. In this study, 27 types of woven fabrics were produced using polyester fibers as warp threads with different structure parameters such as weft yarn material, picks densities, and weaving structures to be used as skin layers and nonwoven fabric was used as core layer. The sandwich composite specimens were prepared using the said woven fabrics with two types of thermoset resins and fabricated via the hand lay up method. The impact properties of the sandwich specimens produced were evaluated to choose the best samples performance to be used in automotive applications. It was found that the impact properties are strongly affected by woven fabric structure parameters and the resin properties.