Rayon Fabrics Research Articles

Twisted nematic liquid crystal cells with rubbed poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) films for active polarization control of terahertz waves

We fabricated a terahertz (THz) polarization converter using a twisted nematic (TN) liquid crystal (LC) cell. Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) films coated on quartz glass substrates were used as electrode layers in the TN LC cell. The PEDOT/PSS films were rubbed unidirectionally using a rayon cloth to align the nematic LC, thereby also serving as an alignment layer. The azimuthal surface anchoring strength of the PEDOT/PSS films was measured to be 5 × 10−4 J/m2 using the Néel wall method, which is similar to that of typical polymeric alignment layers. The optical constants of the PEDOT/PSS film in the THz range were also characterized using the Drude-Smith model, and the results indicated that the PEDOT/PSS films could be used both as transparent electrodes in the THz range and as alignment layers for the LC. The electro-optical properties of the fabricated TN LC cell were also investigated using a polarized visible laser and THz time-domain spectroscopic system. In particular, the transmission spectra and polarization conversion property of the TN LC cell in the THz range were theoretically analyzed based on a stratified model that considers optical anisotropy, absorption, and multiple interference. This work substantiates the advantages of TN LC cells with rubbed PEDOT/PSS films useful for THz polarization converters with electrical tunability.

Radiation Induced Grafting of Viscose Rayon Fabrics with Some Acrylic Acid Derivatives and Styrene

Radiation induced grafting of viscose rayon fabrics, consisting mainly of cellulose fibers, with some acrylic acid derivatives, namely methyl acrylate, acrylamide and acrylonitrile, and also styrene, has been studied. The resultant graft yields have been determined as a function of the applied different experimental parameters. The impact of the graft yields on the physicochemical properties of viscose rayon fabrics such as swelling, moisture absorption, tensile strength, elongation at break, crease recovery angle and also dyeing ability of the grafted fabrics, has been also studied.

Effects of washing parameters on dimensional stability of viscose rayon fabrics

Viscose rayon clothes are usually worn in summer and are soiled by many hydrophilic materials. Wet cleaning effectively removes soil from rayon fabrics and is ecofriendly; however, shrinkage of the fabric during laundering must be reduced. The swelling behaviors of commonly used rayon staple and filament fabrics during laundering have been studied. The effects on fabric shrinkage of presoaking in polyglycol solutions before washing and drying using various methods were examined. Staple and filament rayon fabrics both shrank more in the warp than in the weft direction; and in the warp direction, the staple fabric shrank greater than the filament fabric after washing. The lateral swelling of fibers, which leads to increased yarn crimp and finally to fabric shrinkage was lower in polyglycol solutions than in water and a light-duty detergent solution. The shrinkage of washed rayon fabrics after drying was greatly affected by the residual moisture in the fabrics just before drying. Shrinkage was lower at low residual moisture levels. The mechanical force used for dehydration had no effect on the shrinkage of rayon fabrics. Shrinkage was 58 % less when the staple fabric was presoaked in polyglycol solution before washing and then dried in a tumble dryer at 60 °C for 60 min compared with the shrinkage when the fabric was only washed with a light-duty detergent and dried in air. The shrinkage after seven washing cycles using the former method was 45 % less than that after seven washing cycles using the latter method.

Comparison of Bolus Materials to Highly Absorbent Polypropylene and Rayon Cloth

This study assesses the utility of a highly absorbent polypropylene and rayon cloth (HAPRC) as a bolus material in radiation therapy. A comparison of various bolus materials used clinically at our center to the test bolus material, water-saturated HAPRC, was conducted. The reproducibility of the physical density was assessed by computerized tomography (CT) scanning the water-saturated HAPRC on a uniform density block phantom on multiple occasions, allowing the cloth to dry fully between subsequent CT scans. The cloth was found to have a consistent physical density between 0.8 and 1.0 g/cm3. To evaluate the dosimetric impact of the various bolus materials, metal oxide semiconductor field effect transistor dosimetry measurements were performed for a 6 MV treatment beam on the anterior surface of an anthropomorphic thorax phantom. The ability of the bolus material to conform to an irregular surface was assessed by CT scanning the various bolus materials overlaying the nose of an anthropomorphic head phantom and another irregularly shaped test object. The HAPRC conforms well to irregular contours and is relatively inexpensive compared to Superflab and thermoplastic sheets. Before implementing the material into the clinical setting, an appropriate process for laundering the material should be determined, for hygienic reasons.

Microwave-assisted coating of silver nanoparticles on bamboo rayon fabrics modified with poly(diallyldimethylammonium chloride)

Silver nanoparticles were coated on bamboo rayon fabrics (fabrics made from filaments of dissolved and regenerated bamboo pulp fibers) modified with poly(diallyldimethylammonium chloride) (PDDA) under microwave radiation. The silver nanoparticle coated bamboo rayon fabrics modified with PDDA were characterized by fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, atomic force microscope and scanning electron microscope. Color properties, ultraviolet (UV) protection, softness and contact angle of the silver nanoparticle coated bamboo rayon fabrics were evaluated. The results show that PDDA is successfully modified on the bamboo rayon fabric. Compared with the bamboo rayon fabrics without PDDA modification, more silver nanoparticles are coated on the bamboo rayon fabrics modified with the PDDA. In addition, the bamboo rayon fabric modified with PDDA is evenly covered with silver nanoparticles. The silver nanoparticle coated bamboo rayon fabric modified with PDDA shows the excellent UV protection with UPF of 223.88 and the hydrophobic property with contact angle of 127°. PDDA modification improves the adhesive strength between silver coating and bamboo rayon fabric.

Use of Squid as an Alternative to Human Skin for Studying the Development of Hit Marks on Clothes

The development of latent skin impressions on a variety of fabrics (cotton, rayon, polyester, nylon, and acrylic fabrics in five colors; white, black, yellow, blue and red) has been studied. Squid soaked in artificial sweat solution or de-ionized water was used as an alternative to human skin to make skin impressions on the fabric. A piece of squid was subjected to a constant force, to transfer the skin components onto the fabric. The fabrics bearing the skin impressions were treated with various reagents such as ninhydrin, 1,8-diazafluoren-9-one (DFO), 1,2-indanedione/ Zn (1,2-IND/Zn), Amido black and Hungarian red, to know the most effective method for developing the skin impressions on the fabrics. Comparing the sensitivity of the reagents, stronger development was observed from the impressions made with the artificial sweat soaked squid than the de-ionized water soaked squid. These results show that the development quality of the latent hit mark is influenced by the sweat, as well as other skin components. Also, the development efficiency of the reagents varied depending on the chemistry, color and texture of the fabric. Therefore, before the development of skin impressions on the evidence fabrics, it is suggested to perform a preliminary experiment with different methods on a similar fabric to decide the most sensitive method.

Radiation Induced Grafting of Acrylic Acid onto Viscose Rayon Fabrics and Its After-Effects

Radiation induced grafting of various polymers with different monomers proved to be an attractive means to modify the physical or chemical properties of polymeric materials or textile fabrics. In the present work, radiation induced grafting of viscose rayon fabrics, consisting mainly of cellulose fibers, with acrylic acid monomer has been carried out. The grafting yields have been thoroughly studied as a function of different applied experimental parameters. The impact of the graft yield on the physical properties of the fabrics such as tensile strength, elongation, swelling, moisture absorption, crease recovery angle and also the dyeing properties of the fabrics has been studied. The effect of increasing the contact time of the fabric and monomer solution, at room temperature, after stopping irradiation has been studied in detail as well as the effect of temperature on the irradiated samples also after stopping irradiation. The best grafting yield was obtained on irradiating viscose rayon fabric in methanol-water solvent containing acrylic acid monomer, at a dose 20 kGys, then heating for 7 hours at 80℃ and finally keeping the samples at room temperature for about 20 hours. That treatment significantly increased the final graft yield.

감즙 염색에 의한 레이온직물의 염색성과 기능성

The results of the analysis of dyed rayon fabrics treated with persimmon juice by padding are as follows. Rayon fabrics were dyed repeatedly with persimmon juice by a padding mangle for the development of dyeability. The merits of padding-based dyeing were easier color reproduction (versus traditional hand dyeing) of hard to obtain colors and color fastness to light and laundering. The add on weight increased with the number of padding times, and the color of the dyed fabrics had red-yellow colors with low brightness and high chromatic colors. Properties of fabrics treated with persimmon juice were: <TEX>$2^{nd}$</TEX> level of light resistance, <TEX>$4^{th}-5^{th}$</TEX> perspiration fastness levels, rubbing fastness, and <TEX>$3^{rd}-4^{th}$</TEX> washing fastness levels. Dyed fabrics exposed to UV light have a deep yellow-red color that increased lightness and darken when exposed to sunlight. Rayon fabrics of a treated premordant indicated strong yellow colors, especially fabrics with Fe mordant indicated greenish red-yellow colors. The direction of the weft and warp increased and improved water-repellent qualities that increased with the number of dyeing padding times and persimmon juice; however, there was less anti-crease resistance. In addition, fabrics had good antibacterial activity and deodorization.

Comparison of biodegradation of low-weight hydroentangled raw cotton nonwoven fabric and that of commonly used disposable nonwoven fabrics in aerobic Captina silt loam soil

The increasing use of synthetic disposable nonwoven products generates a large amount of non-biodegradable solid waste. In an effort to enhance the use of raw cotton in nonwoven wipes applications, this study compares the biodegradation of low-weight nonwoven fabrics (around 50 g/m2) made of mechanically pre-cleaned raw cotton, rayon, polypropylene (PP), and polylactic acid (PLA) in a Captina silt loam soil. The biodegradation rates of raw cotton and rayon fabrics were fitted to the first-order kinetics model with half-life values of 12.6 and 7.6 days, respectively. The slightly faster disintegration of cellulose structure for rayon was confirmed by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) spectra, and distinct morphological changes in the fiber (cracks and breakage were prevalent in raw cotton, whereas the thinning and merging of fibers occurred in rayon) were observed during their biodegradation. PLA and PP nonwoven fabrics exhibited no weight loss during the burial periods studied, but showed some evidence of oxidation in ATR-FTIR spectra. The breaking and burst strengths of PLA fabric decreased by 45% and 23% of the original strengths, respectively, while neither significantly decreased in PP fabric. The results suggest that mixing raw cotton or rayon low-weight nonwoven wastes with surface soil provides an alternative disposal method, but this land application could not be recommended for PLA and PP nonwoven wastes.

English

This study attempted to focus on the performance evaluation of 100% viscose rayon fabric in terms of strength, whiteness and hydrophilicity or absorbency after scouring and bleaching with two different alkalis such as NaOH and Na2CO3. This work was carried out with 100% viscose rayon knitted fabrics. A single stage scouring and bleaching process of the fabric was adopted using NaOH and Na2CO3 with varying concentrations and at the same processing conditions. The result obtained in this study indicated a great loss in strength with NaOH as compared to that with Na2CO3. Both the alkalis were found to be more or less equally efficient in terms of improved absorbency and whiteness.

Comparison of Bolus Materials vs Highly Absorbent Polypropylene and Rayon Cloth

Bolus materials are tissue equivalent substances used to modify the depth of maximum dose. Currently at the Stronach Regional Cancer Centre several types of bolus materials are used, such as superflab, thermoplastic and dental wax. Bolus materials are intended to lie flush to the skin; however, this is not always possible due to the anatomy of the area to be treated and the type of bolus material used. The bolus material to be evaluated is a highly absorbent polypropylene and rayon cloth. This study is to determine the effective use of a highly absorbent polypropylene and rayon cloth as a tissue equivalent material. The study will investigate and compare the densities, cost and practical use of a highly absorbent polypropylene and rayon cloth and currently used bolus materials. It was hypothesized that an absorbent polypropylene and rayon cloth will absorb and retain water, as well as conform and lie flush to a patient's contour. Bolus materials will be CT scanned to determine their respective densities. Materials requiring water will be scanned dry and wet (with specific volumes of water poured on them ie. 100, 200, 500 ml). Each bolus material will be scanned on a thorax phantom with an irregular contour to assess stand-off of the bolus from the phantom's external contour. A tangent breast plan will be generated according to our clinical practice. This treatment plan will include two opposing 6 MV open beams, followed by a number of inverse planned segments to increase dose homogeneity within the breast. Dose distributions of these treatment fields will be calculated on each CT scan with various bolus materials. At the time of CT simulation, five measurement points will be identified. The treatment plan will be delivered to the phantom with each type of bolus material and saturation level if applicable. Skin dose measurements will be performed using the Best Medical mobile MOSFET system at the five measurement locations determined at CT. Comparison will be made between the skin dose measurements and the skin doses indicated in the planning system at five different locations for each bolus material. Pending.

감즙 염색에 의한 레이온 직물의 역학적 특성

For development of dyeability, the rayon fabrics were dyed repeatedly with persimmon juice by padding mangle. The merit of padding-based dyeing was easier color reproduction over traditional hand dyeing where various colors and color fastness to light and laundering are hard to obtain. We evaluated the mechanical properties and hand value by Kawabata Evaluation system for dyed rayon fabrics. The results obtained from this study were as follows. With the increase of repeating padding times of dyeing, the linearity load-extension curve and tensile energy per unit length of the rayon fabrics were increased, but the tensile resilience of fabrics were decreased. The value of shear stiffness and shear hysteresis were increased. Also compression resilience and linearity of compression thickness were increased. The rayon fabrics dyed with persimmon juice had shown the thickness and weight increase as the number of padding increase. As repeating times of dyeing with persimmon juice were increased, among the 6 hand values, the item of koshi(stiffness) and Hari(anti-drape stiffness), fukurami(fullness and softness) were increased. while Shinayakasa (flexibility with soft feeling) and Shari(crispness) were greately decreased. The amount of coated persimmon juice on the surface of the fabric was gradually increased as the padding times of dyeing.

Bamboo Rayon-ZnO Nanoparticles Composite as Multifunctional Textile Materials

In the current study, an acrylic acid grafted bamboo rayon fabric was utilized as a substrate to immobilize ZnO nanoparticles. The bamboo rayon-ZnO nanoparticles composite was prepared by the treatment of swollen grafted fabric with ZnCl2 followed by conversion of Zn2+ ions into ZnO nanoparticles. The modified product was characterized and then evaluated for antibacterial activity against gram-positive and gram-negative bacteria as well as durability of their antibacterial activity after washing. The product showed antibacterial activity against both types of bacteria which was found to be durable till 40 washes. The modified material also showed improved UV protection. The product can be claimed as semidurable multifunctional textile material.

Study on effect of chemical impregnation on the surface and porous characteristics of activated carbon fabric prepared from viscose rayon

In this study, synthetic viscose rayon fabric has been used for preparing activated carbon fabric (ACF), impregnated with different concentrations of <TEX>$H_3PO_4$</TEX>. The effect of <TEX>$H_3PO_4$</TEX> impregnation on the weight yield, surface area, pore volume, chemical composition and morphology of ACF were studied. Experimental results revealed that both Brunauer-Emmett-Teller surface area and micropore volume increased with increasing <TEX>$H_3PO_4$</TEX> concentration; however, the weight yield and microporosity (%) decreased. It was observed that samples impregnated at <TEX>$70^{\circ}C$</TEX> (AC-70) give higher yield and higher microporosity as compared to <TEX>$30^{\circ}C$</TEX> (AC-30). The average pore size of the ACF also gradually increases from 18.2 to 19 and 16.7 to <TEX>$20.4{\AA}$</TEX> for <TEX>$30^{\circ}C$</TEX> and <TEX>$70^{\circ}C$</TEX>, respectively. The pore size distribution of ACF was also studied. It is also concluded that the final ACF strength is dependent on the concentration of impregnant.

빠르게 안정화된 레이온직물의 특성에 미치는 초음파세척 및 화학전처리 영향

본 연구에서는 <TEX>$350^{\circ}C$</TEX>에서 4 min 이내로 빠르게 등온 안정화공정을 통해 얻어진 레이온직물의 화학조성, 물리적 특성, X-선 회절 패턴, 열안정성 그리고 직물 형상에 미치는 초음파세척 및 화학전처리의 영향을 조사하였다. 안정화공정 동안 레이온직물에서 발생하는 중량감소와 열수축을 줄이고 안정화반응을 촉진시키기 위하여 안정화공정 전에 레이온직물을 먼저 초음파 세척하고 <TEX>$NH_4Cl$</TEX>, <TEX>$Na_3PO_4$</TEX>, <TEX>$H_3PO_4$</TEX> 및 <TEX>$ZnCl_2$</TEX>로 화학전처리 공정을 수행하였다. 결과는 초음파세척 및 화학전처리가 안정화된 레이온직물의 중량감소, 열수축, 미세구조 변화, 탄소함량, 열안정성, 및 직물 형상에 영향을 주었으며, 사용한 안정화시간과 화학전처리제의 종류에 의존하였다. In the present study, stabilized rayon fabrics were prepared from fast isothermal stabilization processes, which were carried out within four minutes at <TEX>$350^{\circ}C$</TEX>. The effects of ultrasonic cleaning and chemical pre-treatment on the chemical composition, physical characteristics, X-ray diffraction pattern, thermal stability and shape of the stabilized rayon fabrics were investigated extensively. In order to reduce the weight loss and thermal shrinkage of rayon fabrics occurring during the stabilization process, ultrasonic cleaning was first conducted and then chemical pre-treatments using <TEX>$NH_4Cl$</TEX>, <TEX>$Na_3PO_4$</TEX>, <TEX>$H_3PO_4$</TEX>, and <TEX>$ZnCl_2$</TEX> were performed, respectively. The results indicated that both ultrasonic cleaning and chemical pre-treatment influenced the weight loss, thermal shrinkage, microstructure, carbon content, thermal stability and fabric shape of stabilized rayon fabrics. Also the results depended on the fast-stabilization time and the type of chemical pre-treatment agents used.

Properties of Sorghum Red Pigment and its Application to Rayon Fabric Dyeing

Natural dye sorghum red pigment is a kind of natural product from sorghum shell. In this paper, the sorghum red pigment was extracted from a black sorghum shell produced. The spectrum property of and photostability were analysized. The results showed that the maximum absorption wavelength of the sorghum red pigment changed with pH values. The light stability changed with pH values under light and no light conditions. Then rayon fabrics were dyed with direct dyeing method by orthogonal experiments. The result indicated that the sorghum red pigment has good property for rayon fabric dyeing, the rubbing and washing color fastness of rayon fabric samples are reach to the requirement of textile dyeing.

Functional Modification of Bamboo Rayon (Cellulose) Fabric to Render it Antibacterial and UV Protective

In the current study, bamboo rayon fabrics grafted with mixture of acrylic acid and acrylamide was utilized as a backbone to immobilize ZnO nanoprticles. The swollen grafted fabric was treated with ZnCl2 followed by conversion of Zn2+ ions into ZnO nanoparticles. The modified product was characterized using FTIR, TGA and SEM and then evaluated for antibacterial activity against gram positive and gram negative bacteria as well as durability of their antibacterial activity after washing. The product showed antibacterial activity against both types of bacterias which was found to be durable till 40 washes. The modified material also showed improved UV protection because of presence of ZnO nanopartcles. The product can be claimed as suitable sustainable candidate for textile products in health and well being of the users.

Comparison between antibacterial activity of some natural dyes and silver nanoparticles

Curcuma longa rhizome (turmeric), walnut, and henna are medicinal plants which are traditionally used for fiber colorations. In this study, the viscose rayon fabrics were dyed with different mordant at a variety of conditions. The dyed fabric and treated fabric with Ag nanoparticles were evaluated for antibacterial activity against pathogenic strain of Gram-negative (Escherichia coli) bacteria. Durability of antibacterial activity to laundering was also investigated. The results indicated that treated fabrics with these natural dyes had excellent antibacterial activity as well as Ag nanoparticles before and after wash.

레이온직물의 특성에 미치는 등온 안정화공정 및 초음파세척의 영향

Cellulose-based rayon fibers or fabrics can be thermally decomposed very fast within a narrow temperature window during stabilization process. Therefore the stabilization stage is critically important for producing rayon-based carbon fibers. Consequently, in the present study the effects of isothermal stabilization and ultrasonic cleaning on the weight loss, chemical composition, microstructure, and fabric texture of cellulose-based rayon fabrics were explored. The temperature of the isothermal stabilization process performed in the range of influenced the processing time, carbon and oxygen contents, cellulose structural change, and fabric texture. The ultrasonic cleaning, which was conducted prior to the stabilization process, played a role in shortening the stabilization time, increasing the carbon contents, decreasing the oxygen contents, and changing the XRD pattern. Also, it was considered that the ultrasonic cleaning contributed to retarding the weight loss, to reducing the thermal shrinkage, and further to reducing the fast physical change of rayon fabrics.

Nanosilver containing grafted bamboo rayon as antibacterial material

Antibacterial textiles are gaining attention due to awareness of health and hygiene and also the requirement of protection from pathogenic bacterias. Silver nanoparticles can be best utilized for imparting such properties. As silver nanoparticles impart characteristic brown colour to substrates, material is more suitable for coloured antibacterial products. In the current study the bamboo rayon fabric was grafted with acrylamide using potassium persulfate (KPS) as an initiator and further treated with silver nitrate followed by borohydride reduction. The modified product was characterized using FTIR, TGA and SEM. The characteristic brownish tinge developed after reduction was measured spectrophotometrically. The grafted bamboo rayon with nanosilver was then evaluated for antibacterial activity against both gram positive and gram negative bacteria and durability of their antibacterial activity after washing. The product showed antibacterial activity against both types of bacterias which was found to be durable till 50 washes.