• Fibers and Polymers
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• v.3 no.2
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• pp.80-84
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• 2002

Tension control is an important factor in producing high quality knitted products and in maintaining good processing condition. Yarn tension during knitting is subject to be affected from many elements of the machine and process parameters. Several factors including yam feeding speed, feeding angle, and needle gauge that are considered to influence on the tension variation were investigated. Yam feeding speed did not show high contribution to the tension variation but feeding angle of yam did show high correlation with the tension. No or negative correlation of the tension with needle gauge was found from the results. In order to keep well-determined process condition in the knitting manufacturing, it is strongly suggested that all knitting elements and parameters should be in the integrated control circumstance.

• Fibers and Polymers
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• v.5 no.4
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• pp.275-279
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• 2004

Yarn tension is a key factor that affects the efficiency of a ring spinning system. In this paper, a specially constructed rig, which can rotate a yam at a high speed without inserting any real twist into the yarn, was used to simulate a ring spinning process. Yarn tension was measured at the guide-eye during the simulated spinning of different yarns at various balloon heights and with varying yarn length in the balloon. The effect of balloon shape, yarn hairiness and thickness, and yam rotating speed, on the measured yarn tension, was examined. The results indicate that the collapse of balloon shape from single loop to double loop, or from double loop to triple etc, lead to sudden reduction in yarn tension. Under otherwise identical conditions, a longer length of yarn in the balloon gives a lower yarn tension at the guide-eye. In addition, thicker yarns and/or more hairy yarns generate a higher tension in the yarn, due to the increased air drag acting on the thicker or more hairy yarns.

• Textile Coloration and Finishing
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• v.20 no.3
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• pp.1-7
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• 2008

Three kinds of 135D/108F ITY were produced from raw yam 85D/72F + SDY 50D/36F with. interlacing pressure $1.5kg/cm^2$, $2.5kg/cm^2$, $3.5kg/cm^2$ respectively. 72 kinds of sized yams were manufactured from three ITYs by altering sizing speed, sizing temperature and sizing tension. The mechanical characteristics of 72 kinds of plain fabrics which were woven using the sized yam as a warp were analyzed after scouring. The initial modulus of scoured fabric responded sensitively to the sizing speed in high tension. The WT of scoured fabric recorded the. highest1n the conditions of sizing tension 30g, and air pressure $2.5kg/cm^2$ in interlacing treatment. When sizing temperature was high, the WT value appeared low, but when sizing speed was high, the WT value was much affected by air pressure in interlacing raw yam. The MIU value of fabric according to sizing tension variations increased up to sizing tension 40g, but decreased above it. The bulk density decreased up to sizing tension 30-40g, but increased above it. In addition, the bulk density decreased as sizing temperature increased.

• Fashion & Textile Research Journal
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• v.6 no.6
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• pp.765-771
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• 2004

This study surveys the warp and weft tension differences among 3 types of rapier looms and analyses the mechanical properties of worsted fabrics for garment with relation of these looms characteristics using KES-FB system. Raper is divided by two parts. In the 1st paper, the worsted fabric is woven as 5 harness satin weave using 1/40 Nm sirofil worsted warp yam and 1/30 Nm worsted weft yam by rapier looms such as FAST-R, THEMA-11-E and PICANOL-GTX respectively. The weavability is also analysed by measuring warp tension variation according to the warp position and weft tension of 3 kinds of looms. The relationship between shed amount and the warp tension is surveyed, and the relationship between end breaks and warp and weft tensions is also discussed.

• Fibers and Polymers
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• v.6 no.2
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• pp.146-150
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• 2005

In this paper, friction of air-jet textured yams is investigated. Using a friction measuring apparatus fabricated inhouse, dynamic friction forces of the yams under yarn-to-metal (YM) and yam-to-yam (YY) rubbing modes are measured. The influence of processing variables of air-jet texturing viz., overfeed, air pressure, dry/wet texturing and normal/core-and-effect texturing on dynamic friction is analysed. The results indicate that friction force increases with increasing rubbing speeds and yam input tension. YM dynamic friction decreases initially and then starts to increase at higher overfeeds. YY dynamic friction increases with increasing overfeed. YM dynamic friction decreases with an increase in air pressure while an opposite trend is observed for YY friction. Wet textured yams have higher friction than dry textured yams. Core wetted coreand-effect textured yams have higher friction than normal textured yams.

• Textile Coloration and Finishing
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• v.11 no.6
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• pp.18-23
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• 1999

PET POY(pre-oriented-yam) were treated by false twister to high bulky. False twister have many processing parameters velocity ratio(VR), belt cross angle$(\theta)$, 1st heater temp. and K(twisting tension/untwisting tension). we analyzed the effect of properties of textured polyester yam on processing condition. Initial modulus, thermal stress, No. of snarl is decreased by 1st heater. In VR=1.97, Dry and wet shrinkage is increased but is decreased by 1st heater in VR=1.564. K/S and cristallinity tend to increase by decreasing VR.

• Fashion & Textile Research Journal
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• v.1 no.2
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• pp.166-172
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• 1999

An experimental investigation has done for studying the changes of physical properties of the air-jet textured polyester yarn. Through the experiments of polyester 85/72 drawn yarn and 50/36 partially oriented yarn doubling' the following results are obtained. The tenacity of textured yarn decreased as the number of tension rings increased when the nozzle diameter was 1.2 mm. In the case when the tension ring was not used during the texturing process, the tenacity of textured yarn decreased as the nozzle diameter increased. But this tendency changed according to the number of tension rings used, the diameter of the nozzle, and yarn take-up speed. Breaking elongation decreased as the number of tension rings increased from one to four and the take-up speed increased at diameter 1.2 mm of the nozzle. The higher the diameter of the the nozzle the higher the breaking elongation until 1.4 mm. The number of interlacing went down as the diameter of the nozzle increased and the take-up speed of the yarn increased. The higher the number of tension rings, the lower the number of interlacing.

• Structural Engineering and Mechanics
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• v.82 no.5
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• pp.611-628
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• 2022

Energy-dissipative rocking (EDR) columns are a class of seismic mitigation device capable of dissipating seismic energy and preventing weak-story failure of moment resisting frames (MRFs). An EDR consists of two hinge-supported steel columns interconnected by steel dampers along its height. Under earthquakes, the input seismic energy can be dissipated by plastic energy of the steel dampers in the EDR column. However, the unrecoverable plastic deformation of steel dampers generally results in residual drifts in the structural system. This paper presents a proof-of-concept study on an innovative device, namely self-centring energy-dissipative rocking (SC-EDR) column, aiming at enabling self-centring capability of the EDR column by installing a set of shape memory alloy (SMA) tension braces. The working mechanism of the SC-EDR column is presented in detail, and the feasibility of the new device is carefully examined via experimental and numerical studies considering the parameters of the SMA bar diameter and the steel damper plate thickness. The seismic responses including load carrying capacities, stress distributions, base rocking behaviour, source of residual deformation, and energy dissipation are discussed in detail. A rational combination of the steel damper and the SMA tension braces can achieve excellent energy dissipation and self-centring performance.

• Textile Coloration and Finishing
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• v.16 no.1
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• pp.5-9
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• 2004

This research surveys the threadline instability on the belt texturing machine according to the 1st heater temperature, draw ratio and velocity ratio. the threadline instability to the time, which is called surging phenomena, is analysed with variations of draw ratio and velocity ratio. In addiction, the surging phenomena is investigated with the variation of the untwisting tension and false twist mechanism on the belt texturing machine. The breaking strain, modulus and yam unevenness of the DTY along the yarn length are measured and analysed with the surging phenomena which is due to untwisting tension variation on the threadline according to the draw ratio, 1st heater temperature and velocity ratio.

• International Journal of Control, Automation, and Systems
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• v.4 no.6
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• pp.763-768
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• 2006

The two-for-one(TFO) twister is precision machinery that twists fibers rapidly under constant tension. Since the quality of the twisted yarn is directly deteriorated by faults of the twister, such as the distortion of the spinning axis, bearing abrasion, and tension irregularity, it is important to detect faults of the TFO twister at an early stage. In this research, a new algorithm is proposed to detect faults of the TFO twister and their causes, by measuring the vibrations of the TFO twister and obtaining frequency components with a FFT algorithm. The TFO twister with faults showed increased vibrations and each fault generated vibrations at different frequencies. By analyzing changes of characteristics of vibrations, we can determine faulty twisters. The proposed fault detection algorithm can be implemented cheaply with a signal processor chip. It can be used to find when to repair a faulty TFO twister without much loss of yam on-line.