• Fibers and Polymers
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• v.5 no.1
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• pp.25-30
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• 2004

The present paper reports the impact of thermal treatment on the characteristics of core-sheath type hybrid technical yarns. The core-sheath type hybrid yams are prepared using DREF-III technology. Polyester and glass multifilaments are used as core components whereas the cotton and polyester staple fibers are the sheath components wrapped around the core filament with different proportions to form a hybrid structure. The thermal treatment is carried out both in dry and in wet state under relaxed condition and the thermal shrinkage, sheath-slipping resistance and tensile and bending properties of hybrid yarns have been studied. Thermal treatment markedly increases the thermal shrinkage and sheath-slipping resistance of hybrid yarns with polyester multifilament in core, but insignificant effect for yarns with glass multifilament in core. Breaking elongation of hybrid yams with polyester multifilament in core increases with treatment temperature. The hybrid yarns with glass multifilament in core are least affected by thermal treatment.

• Fashion & Textile Research Journal
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• v.17 no.3
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• pp.462-475
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• 2015

This paper investigated the characteristics of the physical properties of woven fabrics according to the yarn structure and fibre property. It was found that wicking property of woven fabrics made of sheath/core hybrid yarn were better than those of siro spun and siro-fil hybrid yarns, which was caused by platform for transport of moisture vapor by filaments on the core part of sheath core hybrid yarns. In drying property, the fabric specimen woven by PP/Tencel sheath core hybrid yarns as a warp and Coolmax/Tencel spun yarn as a weft showed quick drying property, which was caused by the sheath core hybrid yarn structure as drainage of water moisture and coolmax fibre characteristics as quick dry material. Concerning to breathability and thermal conductivity as heat transport phenomena, it was observed that breathability of fabrics woven with hybrid yarns such as sheath core and siro-fil in the warp and hi-multi filaments in the weft showed the lowest water vapor resistance, which was explained as due to for air gap in the fibres of the spun yarns to restrict the wet heat transport from perspiration vapor. Thermal conductivities of the fabrics woven with PET/Tencel siro-fil yarns in the weft and hybrid yarns such as sheath core and siro-fil in the warp revealed the highest values, which was observed as due to higher thermal conductivity of PET than PP and more contact point between fibres in the siro-fil and sheath core hybrid yarns.

• Polymer(Korea)
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• v.37 no.1
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• pp.52-60
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• 2013

Partially hydrolyzed cellulose acetate (CA) fibers were prepared by treating CA fibers in aqueous $Na_2CO_3$ solutions of various concentrations. The deacetylation of CA fibers was confirmed through FTIR spectra and WAXD patterns. The hydrolysis was confined to the surface part of the CA fiber by controlling the treatment conditions. The resultant fibers had a sheath-core structure with a sheath component of regenerated cellulose and a core of non-hydrolyzed cellulose acetate. The SEM images of the surface-hydrolyzed CA fibers, the core of which was dissolved out using acetone as the solvent, showed that the sheath thickness increased with increasing alkaline concentration, indicating an increase in the hydrolyzed fiber, i.e., regenerated cellulose. Polarized FTIR analysis of the polyimide film rubbed with velvet fabrics of surface-hydrolyzed CA fibers showed that polyimide molecules were preferentially oriented to the rubbing direction.

• Fashion & Textile Research Journal
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• v.16 no.1
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• pp.145-152
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• 2014

The usage of textile-based sensors has increased due to their many advantages (compared to IT sensors) when applied to body assessment and comfort. Textile-based sensors have different detecting factors such as pressure, voltage, current and capacitance to investigate the characteristics. In this study, textile-based sensor fabrics with sheath-core type conductive yarns were produced and the relationship between capacitance changes and applied load was investigated. The physical and electric properties of textile-based sensor fabrics were also investigated under various laminating conditions. A textile based pressure sensor that uses a sheath-core conductive yarn to ensure the stability of the pressure sensor in the textile-based sensor (the physical structure of the reaction characteristic of the capacitance) is important for the stability of the initial value of the initial capacitance value outside the characteristic of the textile structural environment. In addition, a textile based sensor is displaced relative to the initial value of the capacitance change according to pressure changes in the capacitance value of the sensor due to the fineness of the high risk of noise generation. Changing the physical structure of the fabric through the sensor characteristic of the pressure sensor via the noise generating element of laminating (temperature, humidity, and static electricity) to cut off the voltage output element to improve the data reliability could be secured.

• Macromolecular Research
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• v.16 no.1
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• pp.21-30
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• 2008

Based on the sheath-core bicomponent composite fibers with modified polystyrene (PS) and the modified polypropylene (PP), composite fibers obtained were further cross-linked and sulphonated with chlorosulphonic acid to produce strong acidic cation ion exchange fibers. The structures of the fibers obtained were characterized using Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) etc. The optimal technology of the fibers obtained is discussed. The static absorption capacity of the sheath-core bicomponent composite cation exchange fibers for $Zn^{2+}$, $Cu^{2+}$ was determined. The absorption kinetics and major factors affecting the absorption capacities of $Zn^{2+}$, $Cu^{2+}$ were studied, and its chemical stability and regenerating properties were probed. The results suggest that cation exchange fibers with better mechanical properties and higher exchange capability were obtained. Moreover, this type of ion exchange fiber has good absorption properties and working stability to various metal ions. Hence, they have higher practicability.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.1
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• pp.84-97
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• 2017

Water vapor and thermal transmission properties of high emotional garments are important to evaluate wear comfort; in addition, the measuring methods of these properties are also critical for breathable and warm suit fabrics. In this study, the water vapor and thermal properties of composite yarn fabrics made of CoolMax, Tencel, and Bamboo fibers with filaments were measured and compared according to the measuring method. Water Vapor Transmittance (WVT) of the fabric woven by the sheath/core composite yarn in the warp direction was the highest due to the small staple fiber volume in the sheath/core yarn structure and high air voids in the sheath/core yarn fabrics. This property was also the highest in fabrics woven by bamboo staple yarns in the weft direction, and was the lowest on hi-multi filament fabrics. However, water vapor resistance ($R_{ef}$) of these fabrics by KSK ISO 11092 showed the opposite results to the water vapor transmittance method ($CaCl_2$ method); in addition, its correlation coefficient was low. The correlation coefficient between $R_{ef}$ and the drying rate was 0.719; therefore, the measurement mechanism of $R_{ef}$ is analogous to the drying property measurement. The thermal conductivity of the fabrics woven with compact staple yarn showed a high value; however, the hi-multi filament fabric showed low thermal conductivity. Therefore, fiber characteristics affect thermal properties more than yarn structure. The correlation between thermal property and moisture transport was also low. This study showed that: water vapor transmittance was active at the loose yarn structure, dry heat transport was vigorous at the compact yarn structure, and heat transport was affected more by fiber characteristics than yarn structure. In conclusion, sheath/core composite yarns were relevant to the high absorptive cool suit along with siro-fil and CoolMax/Bamboo staple yarns that were relevant to the heat diffusive cool suit.

• Textile Coloration and Finishing
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• v.21 no.3
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• pp.37-42
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• 2009

The low melting PET yarn has sheath/core structure: sheath portion consists of low melting point PET and core portion is regular PET. Dyeing properties of fabric made from low melting PET yarn were investigated at different dyeing temperatures. It was found that the exhaustion yield on the low melting PET fabric was higher than on regular PET fabric. The total K/S value of the dyed low melting PET fabric increased as heat setting temperature increased above $150^{\circ}C$ because the sheath portion of the low melting yarn melted. Although fastness to light of the low melting PET fabric was similar to regular PET fabric, fastness to washing was inferior to regular PET fabric by 1 grade.

• Textile Coloration and Finishing
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• v.15 no.4
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• pp.65-72
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• 2003

Poly(ethylene-co-vinylacetate) (EVA) microspheres were prepared by a thermally induced phase separation. Poly(vinyl Alcohol) (EVAL) microsphere with Core-Shell Structure were synthesized by a saponification on sheath of EVA microspheres. The size of EVA core/EVAL shell microsphere was decreased from $4.09\mu{m}\;to\;2.55\mu{m}$ by partial saponification of $NaOH/Na_2SO_4$/methanol(2 : 1 : 1 by weight) at $60^\circ{C}$ for 4h to produce a saponified surface layer of about 60% of original radius. In this process, the surface layer of EVAL microsphere was dissolved partially and morphology of surface was not showed. Add-on of cotton and silk printed with EVA core/EVAL shell microsphere was increased and that of printed PET was decreased. In case of EVA core/EVAL shell microsphere, Hand of cotton and silk printed was flexible and fullness.

• Textile Coloration and Finishing
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• v.26 no.4
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• pp.311-321
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• 2014

In this study, Aftertreatment properties of PCM/Nylon sheath/core fabrics have been determined. Especially, the relationship between finishing property and content including of PCM ratio. Samples of PCM/Nylon fabrics were monitored, separately, with 2% o.w.f solutions of each of the berberine chloride, cetylpyridinium chloride(CPC), benzyldimethylhexadecyl ammonium chloride(BDHAC) and dodecyltrimetyl ammonium bromide(DTAB). Various temperatures and liquor ratio and pH conditions were also studied to optimize aftertreatment properties. Berberine chloride finished sample showed the good color fastness. Cetylpyridinium chloride(CPC) finished sample showed very effective antibacterial properties against Staphylococcus aureus and Klebsiella pneumoniae.

• Fashion & Textile Research Journal
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• v.14 no.6
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• pp.1024-1031
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• 2012

The thermal bonding PET fabrics were produced through high temperature steaming (HTS) of low melting PET yarn as warp and composite fancy yarn containing low melting PET yarn as weft. The low melting PET yarn of sheath-core structure consisted of a regular PET in core portion and low melting PET in sheath portion. The composite fancy yarn consisted of regular PET yarn as inner part and effect part and low melting PET yarn as binding part. This study was carried out to investigate the melting behavior of thermal bonded PET fabric, the effect of HTS on the thermal bonding, mechanical properties, and dyeing properties. The melting peak of low melting PET yarn showed two melting peaks caused by sheath-core structure. Almost the entire thermal bonding of the fancy PET fabrics containing low melting PET yarn has formed at $200^{\circ}C{\times}3min$ of HTS. The tensile strength in warp and weft direction of the fancy PET fabrics slightly decreased as temperature of HTS increased. The total K/S value of the fancy PET fabrics decreased slightly to $180^{\circ}C{\times}3min$ of HTS, while increased slightly above $200^{\circ}C{\times}3min$ of HTS. The changes in the hue angle ($H^{\circ}$) of the thermal bonded fancy PET fabrics dyed with disperse dyes hardly ever happened.