Ruihua Yang

Comparative study of cellulase treatment on low stress mechanical properties of cotton denim fabric made by torque-free ring spun yarn

Cellulase is useful for bio-polishing cotton fabrics which enhances their aesthetic performance instead of stonewashing process. Torque-free ring spun process is a widely used technique to produce newly low-twist and balanced torque yarns with soft hand. In this paper, denim fabrics woven with torque-free ring spun yarn and conventional ring spun yarn respectively were treated with cellulase under the same condition and their fabric handle, expressed as low stress mechanical properties, such as tensile strength, bending, shearing, compression and surface performance were investigated by Kawabata Evaluation System for Fabric (KES-F). After cellulase treatment, both denim fabrics revealed better flexibility, elasticity recovery, raised shearing stiffness, fluffier and improved smoothness. While torque-free ring spun yarn made denim fabric showed a better fabric handle than conventional ring spun yarn made denim fabric.

Antimicrobial activity and mechanism of PLA/TP composite nanofibrous films

Electrospinning is conducted with polylactic acid (PLA) and tea polypheno (TP) to obtain PLA/TP composite nanofibrous films with high antimicrobial activity. An investigation of the composition, antimicrobial activity, and mechanism of these composite nanofibrous films was conducted by using infrared spectroscopy (FT-IR), inhibition zone method, fluorescence activated cell sorter (FACS), and transmission electron microscope (TEM). IR spectra results showed that TP and PLA composited well through valence bonds in PLA/TP composite nanofibrous films. Ranges of the inhibition zone for the growth of Escherichia coli (E. coli) and Staphylococcus (Staphylococcus aureus) were 3.67 and 3.71 cm in pure PLA nanofibrous films, but 5.17 and 5.67 cm in PLA/TP composite nanofibrous films, respectively. Results indicated that the antimicrobial activity of PLA/TP composite nanofibrous films were much higher than that of pure PLA nanofibrous films. Meanwhile, the antimicrobial activity against S. aureus was also slightly higher than E. coli. FACS results showed that the positive rate of PLA/TP composite nanofiber films was greater than that of pure PLA nanofibrous films, increasing from 1.45 and 0.78% to 9.26 and 6.47% against S. aureus and E. coli, respectively. The result of TEM indicated that PLA/TP composite nanofibrous films led to the death of bacteria by destroying the integrity of cell membrane.

Diameter Prediction for Electrospun Nanofibers

Models for jet velocity and fiber diameter of the electrospun fibers are given, respectively, by combing the mass conversation law with the force balance model in the electrospinning process.

Effect of heat setting parameters on some properties of PLA knitted fabric

This article reports the outcome of a study conducted for examining the effect of heat setting parameters on some properties of PLA knitted fabric. Three heat setting parameters, namely, treatment time, treatment temperature, and tension, were considered for optimizing the heat setting process with fabric shrinkage after dyeing and color yield as the evaluation factors. Experimental results revealed that lower shrinkage and higher color yield can be achieved when: (i) heat setting time = 60 s; heat setting temperature=130 oC; and tension=0%. After that, the PLA knitted fabric was treated under the optimum heat setting condition and was dyed with 1% depth disperse dye, which produced a better dyeing result. However, the handle of the heat set PLA knitted fabric, as measured by Kawabata Evaluation System for Fabric (KES-F), became stiffer and more resistant to shearing movement and had worse drape and bending recovery ability, while the appearance became fluffier and rougher.

Some physical properties of resin-treated 100% light-weight plain knitted cotton fabric

Abstract100 % cotton light-weight plain knitted fabrics were treated with resin using different concentration by conventional pad-dry-cure method so as to influence their physical properties such as wrinkle-resistant, smoothness, dimensional properties and bursting strength. After resin treatment, the wrinkle-resistant property, smoothness and dimension stability of the four fabrics were consequently improved even after simulated domestic laundering process. The experimental results were reported and discussed thoroughly.

Inner-resonance in Rotor-Spun Composite Yarn Spinning Process

In this paper, a dynamic model was proposed for the rotor-spun composite yarn spinning process. The conditions for inner-resonance were obtained, which should be avoided in the spinning process.

Fiber Reinforced Electrospun-matrix Composites

A novel strategy of producing fiber reinforced electrospun-matrix composites is presented. The new composites show a special morphology with protuberances on the surface and nanoporous structure.