• The Journal of Natural Sciences
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• v.8 no.1
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• pp.145-151
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• 1995

The stretching of synthetic fibers by hot dry process is very difficult, because these fibers have high glass transition temperature at above $150^{\circ}C$. But, we used a swell-wet stretching precess; the fibers are stretched in a swelling agent such as organic solvents at lower temperature. In this study, 100% acryl fibers were uniaxially stretched with free width at $70^{\circ}C$ by swell-wet process in organic solvents. The stretchability was estimated by stretching work. This work is concerned with stretching stress and strain, and initial modulus. We found that it is a good parameter for the estimatation of high strength to the acrylic fiber. The effects of stretching conditions on the molecular orientation for high strength and mechanical properties of PAN fibers were measured.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.3
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• pp.49-59
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• 2009

The bast fibers of paper mulberry were dyed by using sappan wood, gardenia, and gallnut extracted under various extraction conditions. The surface absorption rates, color, and sunlight fastness of the dyed fibers were compared to those of the dyed cotton and silk. The K/S values of silk showed the highest values, followed by gallnut, gardenia, and sappan wood. The optimum extraction conditions of the dye materials were 20 g/L (input amount of dye materials per liter), $90^{\circ}C$ (extraction temperature), and 30 minutes (extraction time). The values of saturation were observed to increase with the increase of the amount of dye materials, extraction time, and extration temperature. However, no effect were found on the values of hue and lightness. In all samples, the developed colors dyed by sappan wood and gardenia were the series of YR, and Y, respectively. The colors of dyed cotton and bast fibers of paper mulberry by gallnut were the series of Y and the dyed silk showed the series of YR. The values of saturation of the bast fibers of paper mulberry by sappan wood and gardenia showed the highest values of saturation, followed by cotton, and silk. In the case of gallnut, cotton showed the highest values of saturation, followed by the bast fibers of paper mulberry, and silk. The sunlight fastness were not improved in all dyeing conditions.

• Weed & Turfgrass Science
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• v.3 no.3
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• pp.196-205
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• 2014

In this study, to obtain basic data for searching potential resources as new natural fibers, we investigated morphological and classificatory characteristics of 21 weed seed fibers. According to classification keys in this study, the collected weed seed fibers could be classified into total 13 types, showing their diversity. Seven species among them belonged to BOT3 type. Two species belonged to B2N0 and DOS3 type, respectively. Many of weed seed fibers had not branched. However, three species had various branched fibers at one main fibers on the seed. Three species had various branched fibers at several main fibers on the seed. Eight species had a smooth fiber surface but 13 species had a weakly or significantly developed-corniculum on the fiber surface. In the fiber cell shape, fiber cells of eight weed species were composed of one long cell without septum. But others had a fiber cell shape composed of a bunch of several long cells. Based on the easiness of harvesting, productivity of fibers, and morphological characteristics of seed fiber, it seemed that five seed fibers (TYPLA, METJA, HEMLY, IMPCK, and EREHI) should be additionally investigated if they are practically applicable as renewable resources for new natural fibers.

• Fashion & Textile Research Journal
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• v.11 no.5
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• pp.818-826
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• 2009

Dyeability of microbial violacein produced from Chromobacterum violaceum CV107 on to multifiber fabrics has been studied. The bluish-purple colourants were produced by cultivation of Chromobacterum violaceum using LB liquid medium for 2 days. The colourant was extracted with 80% acetone and identified as violacein by LC/MS analysis. The violacein could be dyed on not only natural fibers such as Cotton, Silk and Wool but also synthetic fibers such as Diacetate, Triacetate, Creslan 61 and Nylon 66. Maximum K/S values were shown at 540-580 nm according to different fiber with color appearance of purple or blue. An optimum pH and temperature under dyeing condition were 10 and $70^{\circ}C$, respectively. Any mordants were not improved colour density and quality on various fabrics. From this studies, pigments produced microbe have a high potentials for natural dyeing on fabrics. Finally, development of new colourants from microbe has made a possible change for new dyeing field in respects of eco-friend and repeatability of natural dyeing for apparels.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.4
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• pp.431-441
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• 2011

Microbial colorants produced from Zooshikella sp. were developed as a reddish dye for fabrics. The reddish colorants were extracted from cell mass of Zooshikella sp. using 100% ethanol and were identified as prodiginine by 1H-NMR and FT-IR analysis. Microbial prodiginine had a maximum spectrophotomatric absorbance at 530nm and were chemically stable and 30 to $60^{\circ}C$. The microbial prodiginine could dye natural fibers such as cotton, silk, and wool as well as synthetic fibers such as nylon. The maximum K/S values of the dyed fiber were shown at 540 run with a color appearance of RP (reddish purple). Silk and nylon had an excellent dyeability among the experimental fibers. The optimum pH for the dyeing of experimental fibers was at pH 3.0 and dyeability was improved as the temperature increased. The cover change of dyed multifiber fabrics with the microbial prodiginine were measured after washing with detergents and a dry cleaning solvent for the selection of a proper fabric against microbial prodiginine. Among the experimental fibers, silk and nylon did not show significant color change after washing. Therefore, under the criteria of dyeability, silk and nylon were excellent fabrics for being dyed by microbial prodiginine.

• Journal of Fashion Business
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• v.9 no.1
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• pp.57-66
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• 2005

In natural dyeing, a number of supplementary methods have been practiced since deep shades of the dyed fabrics are not developed satisfactorily. The methods include using the mordants effectively or subjecting the fabrics to reiterated dyeing processes. In this study, we obtained deep shades in the dyeing of fabrics using Rhusjara ica as the dyestuff and applied chitosan to the fabric specimens in order to diversify the colors. Silk fibers and PET(polyethylene terephthalate) fibers were pretreated using chitosan, and subsequently dyed using different types of mordants. As the mordanting agents, Al, Sn, and Fe were employed. Various shades have been resulted in since the interactions of the mordants are different toward the silk fibers and PET fibers. In this study, we investigated the effect of the chitosan treatment along with the change of the mordanting agents on the color change for the silk and PET fibers.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.4
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• pp.370-379
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• 1989

In previous paper, the optical behavior of coloring matter of Cromwell under several conditions were investigated. In this paper, the fading behavior of color solution extracted from Growell by methanol, dyeing properties of this color on the silk fibers in water and methanol, the three property of color of dyed silk fabrics, and fading behavior of dyed silk fabrics with Cromwell color under light and washing were discussed.

• Carbon letters
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• v.12 no.3
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• pp.131-137
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• 2011

Kenaf fibers, cellulose-based natural fibers, were used as precursor for preparing kenafbased carbon fibers. The effects of carbonization temperature ($700^{\circ}C$ to $1100^{\circ}C$) and chemical pre-treatment (NaOH and $NH_4Cl$) at various concentrations on the thermal change, chemical composition and fiber morphology of kenaf-based carbon fibers were investigated. Remarkable weight loss and longitudinal shrinkage were found to occur during the thermal conversion from kenaf precursor to kenaf-based carbon fiber, depending on the carbonization temperature. It was noted that the alkali pre-treatment of kenaf with NaOH played a role in reducing the weight loss and the longitudinal shrinkage and also in increasing the carbon content of kenaf-based carbon fibers. The number and size of the cells and the fiber diameter were reduced with increasing carbonization temperature. Morphological observations implied that the micrometer-sized cells were combined or fused and then re-organized with the neighboring cells during the carbonization process. By the pre-treatment of kenaf with 10 and 15 wt% NaOH solutions and the subsequent carbonization process, the inner cells completely disappeared through the transverse direction of the kenaf fiber, resulting in the fiber densification. It was noticeable that the alkali pre-treatment of the kenaf fibers prior to carbonization contributed to the forming of kenaf-based carbon fibers.

• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.61-70
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• 2022

Natural and synthetic forms of calcium phosphate cement (CPC) have been widely used in bone repair and augmentation. The major challenge of injectable CPC is to deliver the cells without cell death in order to regenerate new bone. The study objective was to investigate for the potential of stem cell-laden gelatin fibers containing injectable, nanocrystalline CPC to function as a delivery system. Gelatin noddle fiber method was developed to delivered cells into nCPC. Experimental groups were prepared by mixing cells with nCPC, mixing cell-laden gelatin fibers with nCPC and mixing cell-laden gelatin fibers containing BMP-2 with nCPC. Media diffusion test was conducted after dissolving the gelatin fibers. SEM examined the generated channels and delivered cell morphology. Fibers mixed with nCPC showed physical setting and hardening within 20 min after injection and showed good shape maintenances. The gelatin fibers mixed nCPC group had several vacant channels generated from the dissolved gelatin. Particularly, proliferation and attachment of the cells were observed inside of the channels. While live cells were not observed in the cell mixed nCPC group, cells delivered with the gelatin fibers into the nCPC showed good viability and increased DNA content with culture. Cell-laden gelatin fiber was a novel method for cell delivery into nCPC without cell damages. Results also indicated the osteogenic differentiation of gelatin fiber delivered cells. We suggest that the cell-laden gelatin fibers mixed with nCPC can be used as an injectable cell delivery vehicle and the addition of BMP-2 to enhances osteogenesis.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.04a
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• pp.116-120
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• 2005

In this study, composites with polypropylene(PP) and Jute fiber were prepared by compression molding technique. Generally, hydrophilic jute fibers do not adhere well to PP, which is hydrophobic. Maleic anhydride grafted polypropylene(MAPP) had been widely used as a coupling agent to improve the bonding between ligno-cellulosic fibers and PP. The coupling agent improved the tensile and flexural properties when the mechanical properties were tested by using a UTM. The mechanical properties of natural fiber composites(NFCs) by modified thermoplastics were higher than those of NFCs by unmodified thermoplastics. Fracture surfaces of the composites and the fiber orientations were investigated by scanning electron microscopy. The mechanical performance of NFCs by modified thermoplastics appeared to be improved by the enhanced interface adhesion between the fiber and the matrix.