The high cost of powerful, large-stroke, high-stress artificial muscles has combined with performance limitations such as low cycle life, hysteresis, and low efficiency to restrict applications. We demonstrated that inexpensive high-strength polymer fibers used for fishing line and sewing thread can be easily transformed by twist insertion to provide fast, scalable, nonhysteretic, long-life tensile and torsional muscles. Extreme twisting produces coiled muscles that can contract by 49%, lift loads over 100 times heavier than can human muscle of the same length and weight, and generate 5.3 kilowatts of mechanical work per kilogram of muscle weight, similar to that produced by a jet engine. Woven textiles that change porosity in response to temperature and actuating window shutters that could help conserve energy were also demonstrated. Large-stroke tensile actuation was theoretically and experimentally shown to result from torsional actuation.

In this work, fiber distribution through the cross-sections of compact yarns and their packing density values was investigated to provide a better understanding of the internal structures of compact yarns produced by different compact spinning systems, since there is no information available so far regarding their internal structure. The results of packing density analysis indicated that compact yarns had nearly 15—30% higher packing density values compared to that of the conventional ring spun yarns. Also, the packing density values of compact yarns produced by three different compact yarn spinning systems, namely Rieter K44, Suessen Elite and Zinser Air-Com-Tex700, revealed that there were no significant differences among these systems in terms of yarn packing density values.

In this study, electromagnetic shielding effectiveness of some weft-knitted structures is investigated. For this purpose, weft-knitted structures are produced using copper wire/cotton incorporated yarns. Conductive yarns are produced by yarn-folding machine. Four knitted constructions (plain knitting, weft in-laid plain knitting, 1X1 rib, and weft in-laid 1X1 rib) are formed into knitted structures with conductive yarns by using 7G flat knitting machine.Electromagnetic shielding values of test samples are determined by a coaxial test fixture relating to ASTM D4935 test standards. Measurements are made in the frequency range of 27 MHz-3 GHz. The effect of conductive content, stitch density and fabric construction parameters are investigated considering the electromagnetic shielding performance of weft-knitted structures. Test results show that weft-knitted structures investigated in this study have 10-40 dB shielding effectiveness under the frequency of 500 MHz.

In this work, a 3D computer aided designing (CAD) system is developed for solid modeling and visual simulation of warp knitted structures on Silicon Graphics workstations. In the first part, a three-dimensional cylindrical and uniform solid yarn model is developed, such that its central axis is a space curve, using non-uniform rational B-spline (NURBS) surfaces to achieve a true 3D solid representation of warp knit loops and structures. This yarn model is then used to create single warp knit loops and fabrics. The necessary data for empirical loop models are obtained from experimental work. This paper describes the methodology and mathematics used to create the yarn and loop models. Some examples of warp knit fabrics are generated on a computer using the empirical loop models, and these images are compared with real warp knit fabric pictures for visual evaluation.The general aim of CAD systems is to provide fast, easy designing and realistic simulation of structures on a computer screen to enable manufacturers to assess their designs before actual knitting. However, even the recent computer aided design (CAD) systems and simulation programs in warp knitting can only provide two-dimensional representations of warp knit structures [ 1, 2, 3, 11, 12, 14, 1 S, 19], This presentation is limited from the perspective of a designer and customer, since fabrics are neither pictures nor drawings. Besides, designers and customers want to predict comfort, drape, and handling characteristics of the fabrics as well as the aesthetic aspects of the design. Therefore, most of them still prefer to make their decisions by seeing physical samples rather than 2D computer images. If three dimensional models can be created on the computer screen, however, designers and customers will have much more realistic and adequate representation of structures. This will also enable them to manipulate the models (e.g., zooming, rotating, scaling, etc.) and consider other aspects of fabrics as well as aesthetic ones. In fact, there is a general trend toward three-dimensional modeling in all fields that parallels advances in computing hardware and software. However, applying 3D modeling concepts to textiles is an even more difficult task than in other fields due to the complexity of the structures. Yam Model NURBS CURVES AND SURFACESIn this work, a yam is represented in two different forms, a simple form and a solid form. In the simple form, a yam is represented by some 3D space curves, specifically cubic non-uniform B-spline (NURBS) curves. A spline curve is a continuous curve that is composed of several polynomial segments [5]. The parametric equations of a cubic curve have the following form (Figure 1 a): FIGURE 1. Mapping a parametric curve (a) and surface (b) to object space [5].

It is well known that yarn produced using the compact spinning technique, which has been introduced as one of the best spinning innovations of this century, has superior yarn structure and quality, especially in terms of hairiness and strength. However, there are different compact spinning systems on the market from different manufacturers and information concerning the favorable and unfavorable properties of each would be of great interest. In this study, we compared the properties of yarn spun on the three main compact spinning systems commonly used today. To maintain impartiality it was preferable to refer to these three systems as system A, system B, and system C instead of using their trade names. It was found that system B seemed to be more suitable for finer yarns whereas system A generally gave better results for medium to coarse counts.