• Journal of the Korea Fashion and Costume Design Association
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• v.21 no.3
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• pp.1-11
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• 2019

This study examined the cause of the phenomenon of shrinkage in machine-embroidered fabrics, specifically those made of thin and pliable fabrics. Four woven fabrics and two knitted fabrics were selected as samples for analysis. The fabrics selected were silk organza, flax linen, polyester chiffon, cotton batiste, polyester raschel mesh, and cotton jersey. The thickness and drapability of the fabrics were observed and the shrinkage of the various types of embroidered fabrics produced using satin & step stitch techniques were measured. Moreover, the correlation between the shrinkage of the machine-embroidered fabrics and the drapability of the original fabrics was analyzed. Also, the colorfastness of six embroidery yarns was determined. The results of the study are as follows: first, the shrinkage of machine-embroidered fabrics increased at a greater rate than in embroidered knitted fabrics as compared to rates in embroidered woven fabrics. Moreover, in terms of stitch techniques, there was a greater shrinkage rate when satin stitch was applied compared to step stitch. Second, the shrinkage rate of machine-embroidered fabrics decreased when a stabilizer was fused onto the fabric. The shrinkage rate also decreased for fabrics when fused with paper stabilizer compared to those without it, and the rate decreased at a greater amount with paper stabilizer as compared to alginate film. Third, since there was a strong correlation between the shrinkage rate of the embroidered fabric and the drapability ratio of the original fabric, it was generally the case that the more pliable the fabric was, the greater the shrinkage rate was when the fabric was embroidered. Fourth, while the embroidery yarns mainly used in machine-embroidery presented an overall excellent level of colorfastness, there was slight color migration of level 4 to level 5 when using viscose rayon.

• Science of Emotion and Sensibility
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• v.24 no.2
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• pp.49-56
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• 2021

In this study, we investigated the necessary mechanical properties of conductive multifilament yarns for fabricating the electrodes of biosignal measurement pressure and stretch textile sensors using embroidery. When electrodes and circuits for smart wearable products are produced through the embroidery process using conductive multifilament yarns, unnecessary material loss is minimized, and complex electrode shapes or circuit designs can be produced without additional processes using a computer embroidering machine. However, because ordinary missionary threads cannot overcome the stress in the embroidery process and yarn cutting occurs, herein, we analyzed the S-S curve, thickness, and twist structure, which are three types of silver-coated multifilament yarns, and measured the stress in the thread of the embroidery simultaneously. Thus, the required mechanical properties of the yarns in the embroidery process were analyzed. In the actual sample production, cutting occurred in silver-coated multifilament rather than silver-coated polyamide/polyester, which showed the lowest S-S curve. In the embroidery process, the twist was unwound through repetitive vertical movement. Further, we fabricated a piezoresistive pressure/tension sensor to measure gauge factor, which is an index for measuring biological signals. We confirmed that the sensor can be applied to the fabrication of embroidery electrodes, which is an important process in the mass production of smart wearable products.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.8
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• pp.1057-1064
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• 2004

Silk, polyester, cotton, and wool fabrics were embroidered with varying stitch length of 3mm, 5mm, and 10mm to examine the difference in fabric shrinkage in terms of sewing direction, fabric thickness, cover factor, stitch length, and fiber type. Warp, filling, and bias direction of sewing resulted in no difference in fabric shrinkage. Within the samples with same stitch length, there was less fabric shrinkage in fabrics with higher fabric thickness or higher cover factor. There was larger shrinkage when sewn with longer stitch length. Comparing fabrics with different fiber types but similar fabric thickness, silk and polyester fabrics showed the smallest fabric shrinkage and wool fabrics showed the largest shrinkage. It is shown that similar fabric shrinkage between silk and polyester is due to the similarity in cover factor.

• Science of Emotion and Sensibility
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• v.26 no.3
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• pp.149-160
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• 2023

This study develops a time-varying system-based noncontact fabric sensor that can measure cerebral blood-flow signals to explore the possibility of brain blood-signal detection and emotional evaluation. The textile sensor was implemented as a coil-type sensor by combining 30 silver threads of 40 deniers and then embroidering it with the computer machine. For the cerebral blood-flow measurement experiment, subjects were asked to attach a coil-type sensor to the carotid artery area, wear an electrocardiogram (ECG) electrode and a respiration (RSP) measurement belt. In addition, Doppler ultrasonography was performed using an ultrasonic diagnostic device to measure the speed of blood flow. The subject was asked to wear Meta Quest 2, measure the blood-flow change signal when viewing the manipulated image visual stimulus, and fill out an emotional-evaluation questionnaire. The measurement results show that the textile-sensor-measured signal also changes with a change in the blood-flow rate signal measured using the Doppler ultrasonography. These findings verify that the cerebral blood-flow signal can be measured using a coil-type textile sensor. In addition, the HRV extracted from ECG and PLL signals (textile sensor signals) are calculated and compared for emotional evaluation. The comparison results show that for the change in the ratio because of the activation of the sympathetic and parasympathetic nervous systems due to visual stimulation, the values calculated using the textile sensor and ECG signals tend to be similar. In conclusion, a the proposed time-varying system-based coil-type textile sensor can be used to study changes in the cerebral blood flow and monitor emotions.