• Textile Coloration and Finishing
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• v.20 no.1
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• pp.36-43
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• 2008

False twist texturing uses the thermoplastic property of synthetic yarn and produces a bulk and a stretch by giving the filament a permanent crimp. This study investigated the effects of false twist texturing parameters, disk/yarn(D/Y) and heater temperature, on the physical properties of nylon textured yarn. D/Y was a primary determinant of twist numbers of filaments and was proportionally increased with the twist numbers of filaments, resulting in an increase of crimp rigidity of the textured yarn. Heater temperature, a determinant of the heat setting of transformed filaments, was proportionally increased with the increase of crimp rigidity. Nylon 6 was partially melted at $190^{\circ}C$. This study consequently suggested the optimal parameters of nylon 6 85d/68f full-dull POY.

• Textile Coloration and Finishing
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• v.9 no.5
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• pp.1-9
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• 1997

In the single yarn spinning process by the ring spinning system, the finer the fineness of yarn and the lower the twist coefficient, the lower the breaking strength and breaking elongation. The change of yarn specific volume to yarn number agreed with Peirce's formula in the range of Ne 50 to 70, but above that range the values of the experiment are higher than that of the formula. The change of diameter of yarn to the reciprocal of the square root of yarn number agreed with Peirce's formula in the range of under 0.14, but above that value the values of the experiment are higher than that of the formula. In breaking strength variation according to twist constant of single yarn, as the twist coefficient increased, breaking strength increased. At 5.8∼6.0 of twist coefficient the maximum breaking strength was shown, but above that value breaking strength decreased. Breaking elongation also showed a similar tendency. But at 6.0∼6.5 of twist coefficient the maximum breaking elongation was shown. Also spinning tension increased as twist coefficient increased. Twist coefficient, breaking strength and breaking elongation according to the number of coils stayed almost the same. Yarn spinning tension according to the number of coils at the maximum of diameter was the lowest value. The speed of the traveller at the maximum of diameter was the highest value.

• Fibers and Polymers
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• v.6 no.1
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• pp.72-78
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• 2005

The impact of fiber friction, yarn twist, and splicing air pressure on mechanical and structural properties of spliced portion have been reported in the present paper. The mechanical properties include the tensile and bending related properties and, in the structural properties, the diameter and packing density of the splices are studied. A three variable three level facto­rial design approach proposed by Box and Behnken has been used to design the experiment. The results indicate that there is a strong correlation between retained spliced strength (RSS) and retained splice elongation (RSE) with all the experimental variables. It has been observed that RSS increases with the increase in splice air pressure and after certain level it drops, whereas it consistently increases with the increase in yarn twist. The RSE increases with the increase in both fiber friction and yarn twist. It has also been observed that the yarn twist and splicing air pressure have significant influence on splice diameter, percent increase in diameter and retained packing coefficient, but the fiber friction has negligible influence on these parame­ters. Yarn twist and splicing air pressure has a strong correlation with splice flexural rigidity, where as poor correlation with retained flexural rigidity.

• Textile Coloration and Finishing
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• v.23 no.1
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• pp.35-42
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• 2011

For high quality DTP products, it is important to optimize the parameters of media, pre- and after-treatment, ink, printer, etc. This study investigated the effect of types of fabrics(media) as a DTP parameters. Especially, the effects of media properties such as yarn twist and knitted fabric structure, on printability and color difference were examined. Two types of cotton yarn twist(830 and 1630 twist/meter) and five knitted structures of media were prepared with a single circular knitting machine. The K/S values of hard-twist samples were higher than those of normal-twist samples in every media structures. It is more effective to use the knitted fabrics of a hard-twist yarn to obtain dark color in the printing above input level value 60 where the printability improvement was most pronounced in case of plain structure. Among the five media structures a plain structure was the highest and that of corduroy was the lowest in terms of K/S values. Also ${\Delta}E$ values and lightness of the hard-twist yarn samples were smaller than that of normal-twist yarn samples when ${\Delta}E$ values were tested by using a standard of a normal twist yarn sample with a plain structure, which was increased in the case of corduroy structure.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.67-70
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• 2010

Spandex yarn requires a twisting process during winding and unwinding processes at the textile industry. The air-twist nozzle is widely used as part of the winding and unwinding. This paper describes computational approach to design the geometry of the air-twist nozzle. The nozzle has circular yarn-channel and the air-inlet which is perpendicularly connected to the yarn-channel with yarn-loading slit. The air-inlet of the nozzle is designed while measurements of the yarn-channel are fixed. The airflow inside the air-twist nozzle is simulated by using Computational Fluid Dynamic model. The Ansys CFX was used to perform steady simulations of the airflow for the air-twisting process. The vortical structure and the airflow pattern such as velocity streamline, vorticity, velocity of the air-twist nozzle are discussed. Computational results are compared with experimental results in this paper.

• Textile Coloration and Finishing
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• v.20 no.1
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• pp.28-35
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• 2008

Texturing is the process of including a characteristic of a natural fiber in a synthetic fiber. The most common method of it the false twist texturing. Nylon textured yarn is primarily manufactured by the disk type. The major process parameters or the disk type false twist machine ratio, disk/yarn, and heater temperature. This study therefore investigated the effects of false twist texturing, especially speed and draw ratio, on the physical properties of nylon textured yarn. The increase of speed was proportional to the increase of unwinding tension, which could reduce the production efficiency by elevating the tension affecting to fiber during the process. In addition, the increase of speed was inversely proportional to the increase of crimp rigidity of nylon textured yarn. Draw ratio was proportionally increased with the increase of tenacity and the reductions of fineness and elongation, showing the influence or draw ratio to the ultimate physical properties of textured yarn.

• Textile Coloration and Finishing
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• v.12 no.2
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• pp.89-95
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• 2000

Effect of twist-setting time, temperature and cylinder layer for the physical properties of the twist yarn were investigated by separated 9 layer from yarn cylinder. Obtained results were as follow. Shrinkage of the yarn in middle layer shows high value with heat-permeation and in inner's shows low value because of cylinder hardness. And then yarn thermal shrinkage in outer layers shows more or less high value because twist yarn in the outer layer sets more faster. Concerning to the difference on the yam physical properties among cylinder layers, the changes on physical properties shows significant differences from the 7th layer to the last one. Linear density, T.P.M and initial modulus decreases but snarl index increases.

• Fibers and Polymers
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• v.7 no.2
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• pp.213-216
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• 2006

The effect of cashmere yarn twist, knitted fabric density, and cashmere properties on pilling rates of cashmere knitted fabric is investigated in this paper. The experimental results show that yarn twist and fabric density have little influence on pilling rates of cashmere knitted fabric for yarn 38.4 tex/2 when yarn twist varies from 234 T/m to 272 T/m, and the fabric density is 9.7, 10.7, and 11.2 yarns/inch, respectively. The length of cashmere fiber, in particular less than 7.5 mm, is responsible for the pilling rates of cashmere knitted fabric based on optimal scaling regression analysis.

• Fashion & Textile Research Journal
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• v.12 no.4
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• pp.500-507
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• 2010

In this study, physical properties were studied by using latent stretching yarn in order to develop the texturing yarn technique for super bulky yarn, which is better in bulkiness and handle than natural wool and also adds property of synthetic fiber to natural wool. In order to obtain textured conditions by analysing basic properties for manufacturing DTY yarn with super bulky property, DTY 50d/12 after spinning latent yarn spined POY 80d/12 was obtained under the two conditions of (i) false twist(T/M) level 3 in DTY texturing and (ii) draw ratio level 4 in draw texturing. For DTY texturing yarn, Elongation rate increased as the heat treatment time and temperatures increased. In addition, shrinkage became higher as false twist was higher, so that elongation rate became lower. When annealing became longer in time and higher in temperature, initial modulus increased. In addition, as the count of false twist increased, the initial modulus showed higher values. For draw texturing yarn, under the conditions of heat temperature 180 and heating time 30 minutes, shrinkage rate in draw ratio 1.55 and 1.6 draw ratio was 7%, and that in 1.65 and 1.7 draw ratio was 8.5%. High draw ratio samples' tenacity was much influenced by heating time and temperature, but low draw ratio samples' tenacity was influenced not by treated time, but by treated temperature.

• Textile Coloration and Finishing
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• v.22 no.3
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• pp.282-291
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• 2010

Digital textile printing(DTP) is becoming more important because the production trend of textile printing goods is adapting to small-lot multiple items. Recently enhanced use of DTP is closely connected with production of high value-added products in fashion industry, which is also appropriate for quick response system(QRS). Quality of DTP depends on pre-treatment, after-treatment, ink, media, printer, etc. One of these parameters, Selection of good media is very important to obtain high quality of DTP products. Especially, the effects of media on printing quality of DTP according to yarn twist and structure of knitting fabric were examined in this study. Two types of yarn twist of 830 t.p.m and 1630 t.p.m for cotton knit were used and five types of media structures were knitted with single circular knitting machine. First, MIU, MMD, SMD's values are closely related with surface roughness of sample as well as printing quality. The hard twist samples were higher values than normal twist samples in the same media structure. In case of SMD, the values increased from plain to corduroy types. Second, aspect of line sharpness, line area, and line width values of hard twist samples decreased from plain to corduroy than those of normal twist samples. Third, line deviation values of hard twist samples, blurriness of line, also decreased than those of normal twist samples.