Genyang Cao

Examination of the dyeing properties of pigment printing fabrics in a water-ethanol mixed solvent.

We examined the dyeing properties of pigment printing fabrics in a water-ethanol mixed solvent. SEM, infrared spectroscopy, XRD, and rheological studies were carried out to understand the results. The K/S values of all pigment printing fabrics initially increased prior to a subsequent decrease, as can be observed from SEM images of the fabric surfaces. Viscosity tests indicated that variations in the dyeing performance in the mixed solvent could be mainly attributed to the quality of the thickener. Through examination of the rheological properties of the NaAlg paste and the IR spectra of the NaAlg membrane, ethanol appeared to weaken the hydrogen bonds between the NaAlg chains and water molecules, leading to more compact and disordered NaAlg chains. As the rubbing fastness remained relatively constant upon increasing the colour depth of the printing fabrics, this indicated the potential for broadening the application range of such a system.

Unidirectional torsion properties of single silk fibre

The unidirectional torsion properties of silk fibre were investigated on a purpose-built single fibre torsion tester. The torsional fracture angle and the number of cycles of torsion at breaking were recorded, and the effect of the gauge length and pretension together with the torsion speed on the torsion properties of single silk fibre was investigated in detail. Scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis and a tensile tester were used to understand the morphology, structure and tensile properties of silk fibre after torsion deformation. SME photos show that silk fibre exhibits a ribbon-like profile after torsion, and fracture tends to occur at both ends of the silk fibre, where a larger number of twists can be observed. The crystallinity calculated from XRD spectra of silk fibre increases from 26.11% to 34.10% after torsion. The breaking stress and strain decreases slightly with an increase in the gauge length. The breaking cycle increases linearly with an increase in the gauge length, while the actual torsional fracture angle decreases gradually at the same time. The torsional fracture angle together with the breaking cycle decreases gradually as the pretension increases. The fracture angle together with the breaking cycle increases with an increase in the torsion speed. Understanding the unidirectional torsion properties of single silk fibre will benefit its further application in specific areas where the fibre will be subject to frequent torsion and deformation.

Effect of anti-creasing component on properties of two-ply cotton yarn

Durable press finishing is a common process used to impart wrinkle-free properties to cotton fabrics through the crosslinking of cellulose macromolecules. Unfortunately, this process results in a loss of fabric strength and decreases the durability of garments. If the content of crosslinked fibers is reduced in the fabrics, their strength would be retained to a greater extent. In addition, hydrophilic property, permeability, and quality of fabrics could be improved. In the past, researchers primarily focused on the strength of the whole fabric. In this study, single cotton yarns were treated with formaldehyde-based N-methylol finishing agents. Subsequently, they were plied together according to different proportions, and then further cured at a certain temperature. The tensile strength, elongation at break, breaking time, work of rupture and bending rigidity were used to investigate the effects of the treatment on the mechanical properties of cotton yarns. Wrinkle recovery angle was used to evaluate the anti-creasing property of the yarns. The results suggest that when the yarns are plied together in different proportions, their mechanical and anti-creasing properties change with the treatment to which they have been subjected as well as with their blending proportion. Moreover, a reduced anti-creasing yarn proportion decreased the amount of formaldehyde released. This study will guide further development of environmentally friendly anti-crease processing methods.

Electrochemical Pigment Coloring of Wool Fabrics

Green processing technology has been examined extensively in the area of textile coloring, because it is usually highly efficient, environmentally friendly, and energy conserving. Herein, a novel pigment coloring technology by electrochemical modification of wool fabric surfaces is reported. This technology exhibits superior color properties with higher efficiency and lower energy and chemical consumption than the conventional cationic pretreatment coloring method. The pigment-colored wool fabric was characterized to investigate its surface morphology and roughness, K/S value, and rubbing fastness (dry and wet) under a variety of experimental conditions. The mechanism of electrochemical pigment coloring technology has been revealed, and the color properties of the fabrics have been fully investigated. Optimized technological parameters, including voltage, coloring time, and electrolyte concentration, have been determined for further application of this promising technology. Electrochemical pigment coloring has great potential for commercialization as it results in superior color performance with less pollution, higher efficiency, and lower input consumption compared with other methods.

High Infrared Blocking Cellulose Film Based on Amorphous to Anatase Transition of TiO2 via Atomic Layer Deposition

A high IR-blocking cellulose film was designed based on an amorphous to anatase transition of TiO2 using atomic layer deposition (ALD). This transition was realized at 250 °C, at which the cellulose is thermal stable. Optimized ALD condition of 250 °C and 1200 cycles give us an excellent heat insulator, which could significantly reduce the enclosed space temperature from 59.2 to 51.9 °C after exposure to IR lamp for 5 min.