Static and dynamic mechanical properties of cotton/epoxy green composites

A study on the effect of alkaline treatment on the mechanical properties of cotton fabric reinforced epoxy composites is presented in this paper. One hour treatment of cotton fabric was performed using three different concentrations of sodium hydroxide (NaOH) solution. 1% NaOH treated fabric reinforced composites exhibited maximum improvement in tensile strength. It was concluded that the said NaOH concentration improves interfacial adhesion between the cotton fabric and epoxy resin. Moreover the morphology of the fracture surface, evaluated by scanning electron microscopy (SEM), indicated that surface treatment can yield better adhesion between the fabric and matrix, demonstrating the effectiveness of the treatment. The dynamic mechanical analysis (DMA) results revealed that alkali treated (1% and 3% NaOH) fabric composites exhibit higher storage moduli and glass transition temperature (Tg) values as compared to the untreated fabric composites. However, for all the composite specimens, the storage modulus decreased with increasing temperature (25 -100 degrees C). Tg values of 50.9, 56.7, 52.8 and 37.7 degrees C were recorded for the untreated and (1%, 3% and 5%) treated composites, respectively. The tan delta values decreased for all the composites with increasing temperature, indicating enhanced interactions between the polymer matrix and fabric reinforcement.Yüzüncü Yıl Üniversitesi - 2015 VMYOBO6

A STATISTICAL APPROACH FOR OBTAINING THE CONTROLLED WOVEN FABRIC WIDTH

A common problem faced in fabric manufacturing is the production of inconsistent fabric width on shuttleless looms in spite of the same fabric specifications. Weft-wise crimp controls the fabric width and it depends on a number of factors, including warp tension, temple type, fabric take-up pressing tension and loom working width. The aim of this study is to investigate the effect of these parameters on the fabric width produced. Taguchi’s orthogonal design was used to optimise the weaving parameters for obtaining controlled fabric width. On the basis of signal to noise ratios, it could be concluded that controlled fabric width could be produced using medium temple type and intense take-up pressing tension at relatively lower warp tension and smaller loom working width. The analysis of variance revealed that temple needle size was the most significant factor affecting the fabric width, followed by loom working width and warp tension, whereas take-up pressing tension was least significant of all the factors investigated in the study

Study of dynamic compressive behaviour of aramid and ultrahigh molecular weight polyethylene composites using Split Hopkinson Pressure Bar

In this paper, high strain rate compression properties of aramid and ultrahigh molecular weight polyethylene composites in the out-of-plane direction are tested at room temperature on a Split Hopkinson Pressure Bar apparatus. Tests were conducted on composites reinforced with woven or Uni-Directional (UD) fabrics made from aramid or ultrahigh molecular weight polyethylene as well as on composites reinforced with hybrid reinforcement. The strain rate is varied in the tests by changing the projectile shooting pressure. Four different pressures 2, 4, 6 and 8 bar were selected to change the strain rate. Stress-strain and energy absorption behaviour of eight type of samples were noted. Hybrid samples showed better performance in the energy absorption compared with other samples

Optimization of Knitted Structures for E-Textiles Applications

The findings of this research attempt to evaluate the electrical and compression features of electrically conductive yarns (ECY) as well as the structure of sensor systems, such as single jersey and double jersey knit designs, for healthcare applications and wearing technologies. The tensile properties and electrical properties of conductive yarns were optimized basis of the findings. Owing to the knit-tuck stitches arrangement, which gives density to the fabric, the double lacoste, popcorn, and milano ribs were proven to have adequate compressive resilience. The developed knitted structures kinds of sensors were noticed and may easily be applied to global smart socks manufacture as well as other technologies

Effect of silica particle loading on shape distortion in glass/vinyl ester-laminated composite plates

International audienc

Effect of Surface Treatment on Stiffness and Damping Behavior of Metal-Metal and Composite-Metal Adhesive Joints

In aerospace and automotive applications, composite materials are used as a major structural material along with metals. Composite-metal and metal-metal joining are very crucial in such structures. Adhesive bonding is commonly used for this purpose. Since such structures are exposed to varying temperatures and dynamic loads, it is essential to investigate the response of such joints under thermomechanical loading. Though various studies have been reported in the literature to assess the thermomechanical properties of composites, adhesives, and their joints, the effect of the surface treatment of metals and composites on the improvement in the thermomechanical behavior of the joints has not been reported. The metal and composite surfaces were modified using chemical etching techniques. The interaction between adhesives and adherends was studied using the DTMA technique in compression mode. Anodizing treatment on aluminum alloys improved the stiffness properties of metallic joints to 36% and decreased the damping to 23%, while chemical treatment on composite and metal adherends increased the stiffness of composite-metal joints to 34% and reduced the energy dissipation to 20%

Study of dynamic compressive behaviour of aramid and ultrahigh molecular weight polyethylene composites using Split Hopkinson Pressure Bar

In this paper, high strain rate compression properties of aramid and ultrahigh molecular weight polyethylene composites in the out-of-plane direction are tested at room temperature on a Split Hopkinson Pressure Bar apparatus. Tests were conducted on composites reinforced with woven or Uni-Directional (UD) fabrics made from aramid or ultrahigh molecular weight polyethylene as well as on composites reinforced with hybrid reinforcement. The strain rate is varied in the tests by changing the projectile shooting pressure. Four different pressures 2, 4, 6 and 8 bar were selected to change the strain rate. Stress-strain and energy absorption behaviour of eight type of samples were noted. Hybrid samples showed better performance in the energy absorption compared with other samples. © SAGE Publications

Effect of silica particle loading on shape distortion in glass/vinyl ester-laminated composite plates

International audienc

Effect of Cellulosic Material and Weave Design on Comfort Performance of Woven Fabrics

Availability, simplicity of processing, biodegradability, sustainability, and compatibility with human skin in terms of moisture management and temperature regulation, cellulosic fibers are preferred for clothing. In this study four (04) different cellulosic yarns (cotton, bamboo, viscose, and tencel) and two weave designs (1/1 plain and 2/2 warp rib) were used to develop eight (08) woven fabrics with equal thread densities, and their volume porosity %, air permeability, thermal resistance, water vapor permeability index, and moisture management properties were compared. The results showed that tencel fabrics showed the highest water vapor permeability index and overall moisture management capability (OMMC) values, whereas cotton fabrics had the highest values of volume porosity %, air permeability, and thermal resistance. Furthermore, the 2/2 warp rib weave design showed higher values of volume porosity %, air permeability, and thermal resistance in comparison with 1/1 plain woven fabrics, while the water vapor permeability index and OMMC values were higher in 1/1 plain woven fabrics. Moreover, the statistical significance of both factors (cellulose material and weave design) on different results was also analyzed