Textile Research Journal

The microscopic structure of muka (fiber aggregate extracted from harakeke) (observed using light microscopy and scanning electron microscopy) from six selected cultivars of harakeke varied, and this may explain the differences perceived by weavers, and that different end uses are preferred for various cultivars. The dimensions of ultimate fibers ranged from 10.1 μm (Takaiapu) to 12.8 μm (Paretaniwha) in average-transverse-width and 3735 μm (Takirikau) to 4751 μm (Makaweroa) in length. The cultivars prized for muka (e.g. Arawa, Makaweroa) had the longest and finest ultimate fibers. The transverse-section shapes of fiber aggregate bundles varied among the cultivars. Tapamangu and Takaiapu had fiber bundles that were more uniformly shaped than the other cultivars studied, and Takirikau had a high yield of fiber aggregate bundles. Paretaniwha differed from the other five cultivars studied having an average number of narrow, non-uniformly shaped fiber aggregate bundles per unit width.

The cut resistance of three high-strength yarns under tension-shear loading conditions was measured by pressing a knife blade transversely at a constant rate against a yarn gripped at its ends. The load-deflection relation and the energy required to cut through the yarn were determined for Kevlar (aramid), Spectra (polyethylene), and Zylon (polybenzobisoxazole, or PBO). The cut energy and strain to initiate cutting were highest for Zylon, least for Kevlar, and depended on the slicing angle, the sharpness of the blade, and the pre-tension in the yarn. The dependencies are explained by changes in failure mode of the fibers within the yarn. The test provides input needed for computational simulations of ballistic response of fabrics to sharp fragments and should be useful in designing slash-resistant gloves and clothing.

Spin finishes, including lubricants, emulsifiers, antistatic agents, and wetting agents are used to facilitate the manufacturing and processing of textiles. Autoxidation of ten spin finish components was studied by subjecting them to air and heat over time. Chemical changes were observed visually and evaluated using UV/Vis spectroscopy, viscosity measurements, and Fourier Transform infrared (FTIR) spectroscopy. Yellowing occurred for HCO-16, TMP, wetting agent, coconut oil ethoxylate, and coconut oil. Changes in solubility were observed for wetting agent. Significant changes in viscosity were measured for CO-16, HCO-25, anti-static agent, and wetting agent. Finally, changes in FTIR spectral ratios were observed for CO-25, HCO-16, CO-16, and antistatic agent. Chemical changes observed were consistent with autoxidation of spin finish components.

Spider silk has attracted considerable interest in the last 10 years, because it shows a unique combination of high strength, high elongation and extreme fineness. After a general overview about known tensile properties of the different types of spider silk, the tensile properties of Araneus diadematus cocoon silk are characterized based on experimental data of five different cocoons. It is shown that A. diadematus cocoon silk has a completely different stress-strain behavior in comparison with dragline silk of the same spider species. In the second part of the study, the elastic modulus, yield strength and visco-elastic hardening were examined to determine whether they can be controlled independently of each other. It is proved that the experimental stress-strain curves can be represented effectively by just four independent parameters. Moreover, the yield region is not independent of the hardening zone. Further research on the morphology and structure of cocoon and dragline threads will be required to understand the different stress-strain behavior of both fibers.

It has recently been shown that liquid ammonia treatment (water-based process) is very effective in improving the wrinkle recovery, dimensional stability, and resistance to abrasion of the all-linen fabrics. In this study the changes in the fine structure were characterized by measuring the crystallinity and sorption properties of the linen fabrics. In addition, the effect of liquid ammonia on the surface properties of the linen fibers was investigated. X-ray analysis showed that liquid ammonia treatment did not significantly affect the ratio of crystalline and amorphous regions, but a partial recrystallization occurred in the crystalline part, resulting in mixed cellulose I and III lattices in the linen substrates. Although the moisture regain and iodine sorption capacity of the treated linen substrates increased, water retention values, however, were decreased significantly by the intracrystalline swelling treatment.

Control technology is being applied in different industries including textiles. The use of open loop control in dying machines and closed loop control in the let-off motion mechanism of looms are conventional. In this study, a weft yarn tension controller was implemented in a single nozzle air-jet loom for controlling the weft yarn tension variations during weft insertion. The effective parameters on weft yarn tension were introduced by studying the weft yarn equation of motion. Experimental results show that the mechanical brake force has the major effect on weft yarn tension. Thus, the required actuator was designed on the basis of the mechanical brake being controlled by a stepper motor. The PID (proportional + integral + derivative) controller was used to control weft yarn tension. The fabric samples were woven with and without controlled weft yarn tension and their physical properties were measured. The results show that control of the weft yarn tension decreased the coefficient of variation (CV%) of the physical properties of the fabric considerably.

The consumer is demanding more variety and personalization in apparel products. Personalization includes creating clothing that not only takes into account of variations in size, but also variations of the body shape itself. The traditional grading method is the current standard sizing system in the apparel industry. It starts with a base size which is then proportionally graded to create a multiple set of sizes. Although it caters for a limited number of sizes, this method does not include variations in body shape. In our research, we have developed a method of individual pattern making by modifying a traditional draping system so that it can be used in conjunction with modern three-dimensional modeling techniques. Individualized pattern making means customized pattern making for individuals. This method uses a five-step draping process. The steps are: (1) defining the surface shape; (2) setting grainlines; (3) fitting the fabric to the surface shape; (4) cutting of the three-dimensional surfaces; and (5) developing the three-dimensionally fitted fabric into a two-dimensional pattern. Our fitting process prevents or controls buckling when the limit angle of a fabric’s ability to conform to a surface is exceeded. We do this entire process using computed geometrical models, rather than physically. Therefore we believe it has the potential to be more efficient and simple than other techniques. When we used this method to make a pattern for a tight skirt, we easily created complex curved lines automatically using this development method. When test subjects compared our skirt with a traditionally designed skirt, approximately 80% of the subjects indicated a preference for our skirt. Although this paper focuses on patterns made for dummies, our future research will focus on fitting to real human body shapes.

Southern Regional Research Center (SRRC) is participating in a multi-year area-of-growth study of selected cotton cultivars. We report here the moisture data (water of imbibition and moisture regain) on cottons from the 2001 and 2002 crop years, and compare them in terms of maturity properties and micronaire.