• Fibers and Polymers
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• v.7 no.1
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• pp.79-84
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• 2006

This paper deals with the grey fabric deformation during relaxation. It investigates the effect of twist direction and twist liveliness on the 2/2 twill weave woven fabric distortion, during relaxation This experimental work shows that twist liveliness increases the natural tendency of the twill weave woven fabric to skew. In addition when the twist direction of the warp and weft is opposite to each other the bias curling occurs too.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.11
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• pp.1033-1037
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• 2005

We have studied on the effect of the operation voltage according to the reverse twist for the different fringe field switching (FFS) structure. The FFS structure with a vertically patterned edge of the pixel electrode (VPP) has lower operation voltage comparing to the one with a horizontally patterned edge of the pixel electrode (HPP). The reason is like that the number of the pattern of the pixel edge for the VPP structure is one third comparing with the HPP structure and thus, there is small reverse twist area for the VPP structure. Actually, the reverse twist disturbs the twist of LC near adjacent active area, result that LCs near there have the unstable dynamics. That is, the operation voltage increases as the reverse twist area increases. Therefore, it is very important to design pixel electrode with a small reverse twist region for the FFS mode.

• 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.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.

• 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.

• Fashion & Textile Research Journal
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• v.8 no.3
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• pp.363-369
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• 2006

In this the study, Lyocell fabrics for blanket were developed to get high value added goods for elder and Infant. Therefore, the purpose of the study was determine the effect of twist per inch on the physical properties of developed fabrics, including compression property and abrasion resistance on the process for making Lyocell combined yarns. For comparison, commonly used cotton blanket was used. The results were as the follows: 1) Dimensional changes of Lyocell fabrics was in -3% which value was pretty stable, and antistatic property was very good with 10V of electric propensity voltage which means there was no static electricity at all. Pilling property of Lyocell fabrics showed 3 grade which was good and air permeability and moisture vapor transmission rate of Lyocell fabrics were higher than those of cotton fabric and keeping warmth rate of Lyocell fabrics was about 50% which means it very warms. 2) Twist per inch of Lyocell combined yarns increased with tensile strength and elongation of Lyocell fabrics. 3) Twist per inch of Lyocell combined yarns increased with decreasing thickness reduction rate and therefore, compression property of those was pretty good. Specially, compression property of Lyocell fabrics made with yarns of 3.9TPI was better than those of cotton fabric. 4) Twist per inch of Lyocell combined yarns increased with abrasion resistance of Lyocell fabrics.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.243-252
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• 2015

The present study, to examine the effect of the exercise for weight control, compares the difference of the heart rate and energy expenditure by sex during Twist exercise. Twenty eight adults (male 14, female 14) were carried out Twist exercise for 7 minutes and 14 minutes. During performing the exercise program, to perform HR and related variables were measured for 7 minutes and 14 minutes. Through a twist exercise treatment and the following results were obtained. 1. Females had slightly higher, without statistical significance, number of heart beat, minimum heart rate, maximum heart rate, and average heart rate than male had for both 7 minutes and 14 minutes of Twist exercise. 2. In the case of energy consumption, significant differences did not appear until 7 minutes to perform Twist exercise. On the other hand, the energy consumption for 14 minutes of performance was significantly higher in male than in female (p<.05). However, energy expenditure for the period per minute per unit weight (kcal/min/kg) showed no difference. 3. If more than 30 minutes duration were preformed the Twist exercise, males were expected to consume significantly higher than females (p<.05). To consume calories for the 10,000 step walk of, it would be required about 76 minutes for Twist exercise time without distinction of sex. Through the above findings, twist exercise is a form of aerobic exercise for obesity prevention and weight control, as well as it might be beneficial to practice and maintain the health and physical fitness with offering a variety of exercise opportunities in the public.

• 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.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.81-98
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• 2003

The purpose of this study is to closely examine kinematic characteristics by jump phase of Li Xiaopeng motion in horse vaulting and provide the training data. In doing so, as a result of analyzing kinematic variables through 3-dimensional cinematographic using the high-speed video camera to Li Xiaopeng motion first performed at the men's vault competition at the 14th Busan Asian Games, the following conclusion was obtained. 1. It was indicated that at the post-flight, the increase of flight time and height and twisting rotational velocity has a decisive effect on the increase of twist displacement. And Li Xiaopeng motion showed longer flight time and higher flight height than Ropez motion with the same twist displacement of entire movement. Also the rotational displacement of the trunk at peak of COG was much short of $360^{\circ}$(one rotation) but twist displacement showed $606^{\circ}$. Likewise, Li Xiaopeng motion was indicated to concentrate on twist movement in the early flight. 2. It was indicated that at the landing, Li Xiaopeng motion gets the hip to move back, the trunk to stand up and the horizontal velocity of COG to slow down. This is thought to be the performance of sufficient landing, resulting from large security of rotational displacement of airborne and twist displacement. 3. It was indicated that at the board contact, Li Xiaopeng motion made a rapid rotation uprighting the trunk to recover slowing velocity caused by jumping with the horse in the back, and has already twisted the trunk nearly close to $40^{\circ}$ at board contact. Under the premise that elasticity is generated without the change of the feet contacting the board, it will give an aid to the rotation and twist of pre-flight. Thus, in the round-oH phase, the tap of waist according to the fraction and extension of hip joint and arm push is thought to be very important. 4. It was indicated that at the pre-flight, Li Xiaopeng motion showed bigger movement than the techniques of precedented studies rushing to the horse, and overcomes the concern of relatively low power of jump through the rapid rotation of the trunk. Li Xiaopeng motion secured much twist distance, increased rotational distance with the trunk bent forward, resulting in the effect of rushing to the horse. 5. At horse contact, Li Xiaopeng motion makes a short-time contact, and maintains horse take-off angle close to vertical, contributing to the increase of post-flight time and height. This is thought to be resulted from rapid move toward movement direction along with the rotational velocity of trunk rapidly earned prior to horse contact, and little shave of rotation axis according to twist motion because of effective twist in the same direction.

• 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.