Volume 17 (2017): Edizione 3 (September 2017)

The present work has reported the compression properties of polyurethane-based warp-knitted spacer fabric composites (PWSF). In order to investigate the effect of structural parameters of fabric on the compression performance of composites, a series of warp-knitted spacer fabrics (WSF) with different structural parameters including spacer yarn inclination angle, thickness, fineness of spacer yarns, and outer layer structure have been involved. The produced composites have been characterized for compression properties. The energy-absorption performance during the compression process has been determined as a function of the efficiency and the compression stress obtained from compression tests. The results show that the composites based on spacer fabrics having smaller spacer yarns inclination angle, higher fabric thickness, finer spacer yarn, and larger mesh in outer layers perform better with respect to energy-absorption properties at lower stress level, whereas at higher stress level, the best energy-absorption abilities are obtained in case of spacer fabrics constructed of larger spacer yarn inclination angle, lower fabric thickness, coarser spacer yarn, and smaller mesh in surface layers.

This work investigates changes in the physicochemical properties of dry multiuse medical textiles used in surgery and as packaging material in sterilization after 0, 1, 10, 20, 30, and 50 washing and sterilization cycles in real hospital conditions of the Clinical-Hospital Centre in Zagreb. Scanning electronic microscope (SEM) was used to perform morphological characterization. Physicochemical characterization and the resulting changes in the medical textiles were monitored using Fourier transform infrared (FT-IR) spectrometer. The change in the mass of the medical textiles as a results of temperature was determined by thermogravimetric (TG) analysis. Furthermore, structural characteristics based on the changes that resulted during the washing and sterilization processes are provided. The conclusion of the conducted research on the changes in the properties of multiuse medical textiles (Cotton/PES, Tencel®, and three-layer PES/PU/PES textile laminate) in real hospital conditions is that the medical textiles do manage to preserve properties after continuous use and it is safe to use them up to 50 washing and sterilization cycles.

In this study, we used an experimental design to investigate the influence of the total draft, break draft, distance between the aprons (Clips) and production roller pressure on yarn quality in order to obtain optimum drafting conditions for polyester and viscose (PES/CV) blend yarns in ring spinning frame. We used PES fibers (1.4 dtex × 38 mm long) and CV fibers (1.6 dtex × 38 mm long) to spin a 20 Tex blend yarn of PES (70%)/CV (30%) blend ratio. When the break draft, adjustment of distance between of aprons and roller pressure is not reasonable, controlling and leading of the fibers is not sufficient for proper orientation of the fibers in the yarn structure to produce a high quality yarn. Experimental results and statistical analysis show that the best yarn quality will be obtained under drafting conditions total draft of 38, 1.2 break draft, 2.8 mm distance between of aprons and maximum pressure of the production top roller (18daN).

A test rig is described, for the measurement of temperature and resistance parameters of a Temperature Sensing Fabric (TSF) for calibration purpose. The equipment incorporated a temperature-controlled hotplate, two copper plates, eight thermocouples, a temperature data-logger and a four-wire high-resolution resistance measuring multimeter. The copper plates were positioned above and below the TSF and in physical contact with its surfaces, so that a uniform thermal environment might be provided. The temperature of TSF was estimated by the measurement of temperature profiles of the two copper plates. Temperature-resistance graphs were created for all the tests, which were carried out over the range of 20 to 50°C, and they showed that the temperature and resistance values were not only repeatable but also reproducible, with only minor variations. The comparative analysis between the temperature-resistance test data and the temperature-resistance reference profile showed that the error in estimation of temperature of the sensing element was less than ±0.2°C. It was also found that the rig not only provided a stable and homogenous thermal environment but also offered the capability of accurately measuring the temperature and resistance parameters. The Temperature Sensing Fabric is suitable for integration into garments for continuous measurement of human body temperature in clinical and non-clinical settings.

In this paper, the results of mechanical strength tests of thin conductive Ag and Au layers created on Cordura composite substrate using the thermal vapor deposition method are presented. The resistance of the conductive layers to the bending and tensile stresses was tested and changing the surface resistance of the test structures was accepted as a criterion. The layers created on unmodified and plasma-treated surfaces have been examined. As a result of the surface modification, the electrical and mechanical properties of the thin Ag and Au metal structures have been improved. The results of measurements of surface resistance changes during strength tests and SEM microscopic studies of stressed samples indicate the high mechanical strength of the electroconductive layers deposited on Cordura, which may be the basis for the application of such technology in textronics applications.

Multistitched three-dimensional (3D) woven E-glass/polyester/nanosilica composite (MNS) was developed. Its mechanical and impact performances were characterized for particular end-use applications. It was found that the warp-weft directional tensile strength and modulus of MNS structure were higher than those of the off-axis directions. In addition, there was not a big difference between warp and weft directional bending and short beam strengths of MNS structure. The MNS structure had a small damaged area under low velocity impact load. The failure was confined at a narrow area because of multistitching and nanomaterial and resulted in the catastrophic fiber breakages in the normal direction of the applied load of the structure. The results from the study indicated that the multistitching and the addition of nanosilica in the composite structure improved its damage tolerance.

The present study examined the physical properties related to the intelligent coolness characteristics including the wearing comfort of Huvis elastic fiber (HEF) knitted fabrics. For this purpose, three kinds of covered filament yarn specimens, such as PET-HEF, Aerocool-HEF, and PET-spandex, were prepared, and their knitted fabric specimens were made using these covered yarn specimens. These knitted fabric specimens were dyed at different dyeing temperatures and times to analyze the dyeing characteristics. The moisture absorption rate, drying, and hygral expansion of the three kinds of knitted fabric specimens were measured and compared with the yarn characteristics to determine the wearing comfort of HEF knitted fabrics.

Functionalization of textile fabrics with metal oxide nanoparticles can be used to add antibacterial and moisture management properties to them. Current work focuses on the development of these properties on polyester/cotton woven fabrics by treating them with zinc oxide nanoparticles for workwear and sportswear applications. Zinc oxide nanoparticles, prepared by sol-gel method, were applied on fabric samples, which were then tested for antibacterial and moisture management properties using standard test methods AATCC 147 with Staphylococcus aureus and AATCC 195, respectively. It was found that application of ZnO nanoparticles improved both these properties with smaller particle imparting larger effects on both of them.

A series of single-hole hollow polyester fiber (SHHPF) reinforced hydrogenated carboxyl nitrile rubber (HXNBR) composites were fabricated. In this study, the sound absorption property of the HXNBR/SHHPF composite was tested in an impedance tube, the composite morphology was characterized by scanning electron microscope (SEM), and the tensile mechanical property was measured by strength tester. The results demonstrated that a remarkable change in sound absorption can be observed by increasing the SHHPF content from 0% to 40%. In the composite with 40% SHHPF in 1 mm thickness, the sound absorption coefficient reached 0.671 at 2,500 Hz; the effective bandwidth was 1,800-2,500 Hz for sound absorption coefficient larger than 0.2. But the sound absorption property of the composite deteriorated when the SHHPF content increased to 50% in 1 mm thickness. While with 20% SHHPF proportion, the sound absorption property was improved by increasing the thickness of composites from 1 to 5 mm. Compared with the pure HXNBR of the same thickness, the tensile mechanical property of the composite improved significantly by increasing the SHHPF proportion. As a lightweight composite with excellent sound absorption property, the HXNBR/SHHPF composite has potential practical application value in the fields of engineering.

The paper presents the approach to analyse of reaction forces and contact pressure for ring-traveller system in twisting machine. The theory of the ballooning yarn has been adapted for the calculation of reactions, and the motion equation is developed for traveller with two reaction forces. The components of normal reaction forces are analyzed for system with free balloon and control one. The effect of the balloon control ring is shown to be significant, reducing the reaction forces of traveller or increasing the speed of spindle. Contact pressure generated between the ring and the traveller is analyzed using Hertzian contact theory. The article also presents the recommendations for optimization of the traveller shape to increase its service life.

We investigated the effects of the combinations of patternmaking methods and dress forms on the appearance of a garment. Six upper garments were made using three patternmaking methods used in France, Italy, and Japan, and two dress forms made in Japan and France. The patterns and the appearances of the garments were compared using geometrical measurements. Sensory evaluations of the differences in garment appearance and fit on each dress form were also carried out. In the patterns, the positions of bust and waist darts were different. The waist dart length, bust dart length, and positions of the bust top were different depending on the patternmaking method, even when the same dress form was used. This was a result of differences in the measurements used and the calculation methods employed for other dimensions. This was because the ideal body shape was different for each patternmaking method. Even for garments produced for the same dress form, the appearances of the shoulder, bust, and waist from the front, side, and back views were different depending on the patternmaking method. As a result of the sensory evaluation, it was also found that the bust and waist shapes of the garments were different depending on the combination of patternmaking method and dress form. Therefore, to obtain a garment with better appearance, it is necessary to understand the effects of the combinations of patternmaking methods and body shapes.

In this paper, we investigate on the preparation of waste cotton fabric-based activated carbons by different methods. Two different kinds of carbon materials are prepared from waste cotton fabric, the structure and properties were characterized using instrumental analyses such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). It is revealed that the products prepared using one-step process are composed of macroporous carbon network , which looks like sponge-type morphology, and exhibit the high values of q_iodine (1,198 mg/g) and q_mb (235.6 ml/g), showing their potential usage as adsorbent.