• Textile Coloration and Finishing
• /
• v.27 no.2
• /
• pp.132-141
• /
• 2015

Fall-arrest systems(maximum arrest force and allowable free-fall) have been widely applied to provide a safe stop during fall incidents for various industrial activities. Fabric structure affects on the mechanical properties of shock energy absorber. The object of this study is to perform the basic research for the evaluation of the capacity of fall arrest energy absorber in relation to the different interlace yarn density. In this work, pack style energy absorber was prepared by weaving 10 types(Interlace yarn density used high tenacity PET 1000D : 60, 59, 58, 57, 56, 55, 54, 53, 52, 51). The paper presents the results of theoretical investigations of the performance of adjustable absorber during fall arrest. Dynamic load tests based on the EU fall protection equipment standard(CE : EN355:2002) were conducted. Results showed that the maximum arrest force by dynamic load test of energy absorber was satisfied with global standard(below 6,000N). Also, Maximum allowable free-fall of energy absorber showed below 1.75m.

• Fibers and Polymers
• /
• v.7 no.3
• /
• pp.317-322
• /
• 2006

Reduction of yam hairiness by nozzles in ring spinning and winding is a new approach. Simulation of the airflow pattern inside the nozzles provides useful information about actual mechanism of hairiness reduction. The swirling air current inside the nozzles is capable of wrapping the protruding hairs around the yam body, thereby reducing yam hairiness. Since production rate of winding is very high and the process itself increases yarn hairiness any method to reduce the hairiness of yarns at this stage is a novel approach. A CFD (computational fluid dynamics) model has been developed to simulate the airflow pattern inside the nozzles using Fluent 6.1 software. In this study, both S- and Z-type nozzles having an axial angle of 500 and diameter of 2.2 mm were used for simulation studies. To create a swirling effect, four air holes of 0.4 mm diameter are made tangential to the inner walls of the nozzles. S- and Z-twisted yams of 30 tex were spun with and without nozzles and were tested for hairiness, tensile and evenness properties. The total number of hairs equal to or exceeding 3 mm (i.e. the S3 values) for yam spun with nozzle is nearly 49-51 % less than that of ring yams in case of nozzle-ring spinning, and 15 % less in case of nozzle-winding, while both the yarn types show little difference in evenness and tensile properties. Upward airflow gives best results in terms of hairiness reduction for nozzle-ring and nozzle wound yams compared to ring yarns. Yarn passing through the centre of the nozzle shows maximum reduction in S3 values.

• Textile Coloration and Finishing
• /
• v.18 no.5 s.90
• /
• pp.61-71
• /
• 2006

This paper addresses the factors hindering the image quality of lines in inkjet printed on polyester fabric as printing media. Lines were printed onto different types of polyester fabrics in warp and filling directions. Line image quality including line width, edge blurriness, and edge raggedness was assessed. The effect of capillary wicking on line image quality of printed spun polyester fabric is discussed. The factors on the image quality include printing position(top of the yam or between the yarn), printing direction(warp or filling), yarn structures(filament or spun), thread size(yam or fiber), finishing, and ink properties(evaporation rate). More than 30% differences in image quality results were observed by changing the printing location on the spun polyester fabric. The best results of the image quality were obtained with the printed plain and spun polyester fabrics. The fiber sizes may affect capillary size; therefore, the image quality can be dissimilar. Types of finishing materials and inks greatly improve the line image quality on spun polyester fabrics.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.11
• /
• pp.1757-1764
• /
• 1997

The geometric and elastic models based on the unit cell have been proposed to predict the geometric characteristics and the engineering constants of plain and satin woven composites. In the geometric model, length and inclined angle of the yarn crimp and the fiber volume fraction of woven composites have been predicted. In the elastic model, the coordinate transformation has been utilized to transform the elastic constants of the yarn crimp to those of woven composites, and the effective elastic constants have been determined from the volume averaging of the constituent materials. Good correlations between the model predictions and the experimental results of carbon/epoxy and glass/epoxy woven composites have been observed. Based on the model, the effect of various geometric parameters and materials on the three-dimensional elastic properties of woven composites can be identified.

• Journal of Fashion Business
• /
• v.6 no.6
• /
• pp.1-11
• /
• 2002

The attractiveness of the textile fabrics are generally judged by visual or tactile evaluation methods. Since the surface of the textile materials are so diverse that the visual factors such as optical properties or luster of the fabrics are not easily measurable. While most of the cotton fabrics are not so much lustrous, calendering process could impart the cotton fabric better luster. Also, the general grade silk-like polyester fabrics resemble silk fabric with some limit in terms of luster properties. One of the interesting fabrics showing subdued luster is the velvet fabrics with dark shade. In this study, the luster related properties are examined using some image analysis methods. Yarn models based on the fabric weave types were developed to further investigate the effect of fabric crimp shapes due to weave on the optical properties or luster of the fabrics.

• Fashion & Textile Research Journal
• /
• v.5 no.1
• /
• pp.53-58
• /
• 2003

The stretch fabrics were made by the use of PTT[Poly(trimethylene terephthalate)] fibers and changes in their physical properties were analysed. Tenacity and elongation of D-1(PTT DTY) yarn were 3.32 g/d and 50.4%, respectively, while these of D-2(PTT+CDP DTY) yarn were 2.46 g/d and 32.1%, respectively. The tenacity of PTT-1 and PET-1 fabrics was similar, but the elongation of PTT-1 and PET-1 fabrics was 75% and 44%, respectively. Thus, the elongation of PTT-1 fabric was two times higher than those of PET-1 fabric. In addition, the elastic recovery at 20% elongation of PTT-1, PTT-2 and PET-1 fabric was 85.0%, 80.5% and 60.0%, respectively, indicating that so PTT-1 fabric showed better elastic recovery. The light, wash, and abrasion fastness of PTT-1 and PTT-2 fabrics were above Grade 3, Grade 4-5, and Grade 4-5, respectively. Therefore, there was little effect of substance on the fastness.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.28 no.1
• /
• pp.19-24
• /
• 2014

Silk has always been one of the most favored textile materials. Fully degummed silk fiber (i.e., silk fibers without sericin) shows better luster than raw silk fiber (with sericin); it is also softer. On the other hand, raw silk fiber feels cooler because of the presence of sericin, making it useful as a textile for the summer season. Recently, partially degummed silk has attracted researchers' attention because it provides better luster, feel, and dyeing properties. However, the partial degumming of silk is very difficult because it results in inhomogeneously degummed fiber. In the present study, silk yarns were degummed with surfactant aqueous solutions and the effects of each surfactant on the degumming ratio, crystallinity, and homogeneity of the degummed silk yarn were examined. The degumming ratio and crystallinity index of silk yarn varied depending on the type of surfactant. On the whole, anionic surfactants resulted in higher degumming ratios and better homogeneity than nonionic surfactants.

• Textile Coloration and Finishing
• /
• v.13 no.2
• /
• pp.49-49
• /
• 2001

Interlace texturing is very useful method to make compound yarns for new synthetic fabrics. In this study, we make the compound yarns for peach skin fabric by interlace texturing method. This study surveys relationship between physical properties of interlace textured yarns and process conditions such as air pressure, yarn tension and take-up speed. Nip density, tensile properties and multi-step shrinkage of the various specimens were discussed with process conditions.

• Proceedings of the Korean Fiber Society Conference
• /
• 1994.10a
• /
• pp.11-11
• /
• 1994

A new theoretical fabric shear model has been presented and a quantitative study has been conducted on the shear properties of polyethylene(terephthalate)(PET) fabrics of four different fabric densities and five different weight reduction. The fabric shear properties were measured with KES-F handle measurement system. From the theoretical and experimental studies, following results can be summarized : 1) The fabric shear behavior is strongly dependent on the fabric density and free volume available for the constituent yarns and their filament. 2) Shear hysteresis at the small shear angle(2HG) is dependent more on the yarn tensile properties than on the fabric structure. 3) Shear hysteresis at the shear angle, 5(2HG5) is dependent more on the interaction between two crossing yarns which is directly related on the fabric structure than on the yarn tensile properties.

• Carbon letters
• /
• v.26
• /
• pp.107-111
• /
• 2018