• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.8
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• pp.1315-1322
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• 1997

Ramie is one of the traditional fabrics in Korea, and very comfortable fabric for summer clothes because it has a high moisture-absorbing and transporting property. Futhermore ramie is very popular and Koreans prefer its handle for summer clothes. The kansan ramie has better quality as fibers and can be weaved as fine fabrics which are famous as kansan Fine ramie. Even though the good quality of kansan ramie has known widely, very few research work have been carried out on kansan ramie in the field of textile science. In this study, the analysis of the physical and chemical characteristics of Hansan ramie was conducted by using two different kinds of Hansan ramie: Hansan Fine ramie and kansan Coarse ramie. In addition, the same experiment was held on the one kind of chinese ramie to be compared with those of Hansan ramie. The following results were obtained from this experimental study. By the analysis of chemical composition of ramie, the similar chemical composition (a -cellulose: 83∼85%, pectin substances: 2.81∼ 3.01%) were found from all of the ramie fabrics used in this study. It has shown that Hansan coarse ramie has the highest toughness value and wrinkle recovery angle among the samples used in this study. From the result of KES-F system, it was found that Hansan Coarse ramie which is composed with the thicker yarns has the highest value on the bending properties, 2HG and surface properties. The primary hand value was also calculated by KN-203 LDY and value of Koshi was shown as the order of kansan coarse ramie> Chinese ramie> kansan fine ramie, and Hansan fine ramie had shown the highest Numeri and Fukurami value among the 3 samples used in this study.

• Fashion & Textile Research Journal
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• v.1 no.3
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• pp.288-295
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• 1999

This study was conducted to examine the fatigue phenomenon of mechanical properties in tencel fabrics by repeated washing & shear and tensile deformation. The obtained results are as follows. After performing repeated shear tensile deformation, RT of tencel showed higher increase rate than that of cotton and rayon, whereas its WT and EM was a smaller decrease rate than that of them. This means that tencel's resistance to tensile deformation was the greatest. In the repeated washing and shear tensile deformation, tencel's 2HB, 2HG and 2HG5 showed a remarkable increase rate. In terms of deformation frequency, the greatest change rate appeared at the time of 1000 cycles of repeated shear tensile deformation and 15 times of repeated washing. In the hand value and THV, KOSHI showed a higher increase rate for tencel than for cotton and rayon in both repeated washing and shear tensile deformation, and NUMERI showed a higher increase rate. In the THV the change rate of rayon and cotton could be rarely seen but for tencel, it decreased. tencel's change rate of thermal insulation value by materials was 1.08%, and it increased as the washing frequency increased, compared to the grey fabrics, whereas the change rates of cotton and rayon were 0.74% and 0.22%, respectively. The qmax decreased in the order of cotton>tencel>rayon as the washing frequency increased.

• Fashion & Textile Research Journal
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• v.5 no.3
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• pp.267-272
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• 2003

Tactel(Nylon66) union fabrics were woven with the specification of 70d/34f nylon as warp for sport wear jacket. Weft yarn has three types; 100% cotton yarn, nylon core-spun yarn and nylon-polyurethane covering yarn as weft. Fabric structers were plain, twill and satin weave structure with the air jet loom. The mechanical properties of 8 fabrics were measured with KES-F and primary Hand Values and Total Hand Values were calculated. The results of the study were as follows: 1) There was little difference among LTs of N/CM fabric groups. RT of the fabrics with CM100's was bigger than that of fabrics with CM80's, resulting that the fabrics with CM100's have better formability. In terms of weaving structure, twill fabrics have shape deformation. 2) In comparison of RTs with weft yarn type, RT of N-PU covering yarn was the highest, followed by Nylon core-spun yarn and cotton yarn. Thus, the fabric with N-PU covering yarn has better stability of shape deformation. 3) Stretch yarn could express an excellent silhouette formation and twill and satin structures were better structure to make curvature on human form. 4) 2HG/G value of nylon core-spun fabrics was larger than that of N/C fabrics, but the silhouette formation of N/C fabrics was excellent. 5) The RC of N/PU was the highest, followed by N/P, and N/CM. 6) Koski of N/PU fabrics was the highest, Numeri of N/PU and N/Co-I were relatively higher than the others. THVs of N/CM-IV and N/CO-II were lower than the others, resulting that, twill structure was better than plain structure for a sport wear uses.

• Journal of the Korea Fashion and Costume Design Association
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• v.10 no.2
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• pp.125-138
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• 2008

For physical and hand property evaluation of fabrics, the knitted fabrics from 11 types of machines knitting fancy yarns, boucle (M1), knot (M2), snarl (M3), and slub (M4), tamtam (M5), tubular (M6), fur 1 (M7), bead (M8), fur 2 (M9), fur 3 (M10), and ladder (M11) yarns, were prepared with 7-10 G plain stitch. Washing test and pilling test had also been carried out. For hand properties by objective sensibility evaluation, 17 items of sir mechanical properties using KES-FB (Kawabata Evaluation System) had been measured. Then hand values of knitted fabrics were calculated with a calculation formula, namely KN-402-KT. Finally the total hand values were obtained through KN-301-WINTER. As a result of physical properties and objective evaluation for machines knitting fancy fabrics, most of them shrank in the direction of wale and course after the washing test, in which their shrinkage rate had a maximum of 3.5%. Therefore, the washing test indicated that the shrinkage ratio of knitted fabrics had a minor change. The results of the pilling test are mostly 4-5th grade, and all of the machines knitting fancy fabrics showed good results in the pilling resistance. In hand properties and objective sensibility evaluation, twisted fancy yarns, such as boucle (M1), knot (M2), snarl (M3), and slub (M4), were superior to bonding rigidity (B) and shear rigidity (G). The surface property between course and wale differs in all samples and course direction is tougher than wale direction. FUKURAMI (fullness and softness) of all samples have high values, besides NUMERI (smoothness) of tamtam (M5) and boucle (M1), which were rather good. Most samples except fur 1 (M7) had low KOSHI (stiffness) value. The total hand value (THV) of twisted yarns was low. This study proves that manufacturers, who plan knitting yarn products and knit fashion, can apply these data to develop machines knitting yarns and knits that fit the consumers' demands.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.7
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• pp.805-811
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• 2012

The reliability based design optimization (RBDO) approach requires high computing cost to consider uncertainties. In order to reduce the design cost, the single loop single vector (SLSV) approach has been developed for RBDO. This method can reduce the cost in calculating deign sensitivity by elimination of the nested optimization process. However, this process causes the increment of the instability or inaccuracy of the method according to the problem characteristics. Therefore, the method may not give accurate solution or the robustness of the solution is not guaranteed. Especially, when the function is concave, the process frequently diverges. In this research, the concept of the conjugate gradient method for unconstrained optimization is utilized to develop a new single loop single vector method. The conjugate gradient is calculated with gradient directions at the most probable points (MPP) of previous cycles. Mathematical examples are solved for the verification of the proposed method. The numeri cal performances of the obtained results are compared to those of other RBDO methods. The SLSV approach using conjugate gradient is not greatly influenced by the problem characteristics and improves its convergence capability.