• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.653-659
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• 2018

High-rise buildings and complex facilities are a representative urban system for the masses, and it requires an increasing role of commodity and safety. Smoke and toxic gasses can cause accidents due to fire in these systems. The purpose of this study is to develop a fiber screen material for emergency evacuation passages that can be avoided quickly and safely in cases of disasters. The fiber screen material is applicable to folding devices for emergency evacuation passages. The material is different from general steel material in that it is lightweight with less burden during storage for a long time in a roll form in a folding device. It also has an excellent secondary function in that it is less affected by radiant heat. Three kinds of fiber screen materials were selected that have good flame retardancy and post-processing characteristics. A performance evaluation was performed by a heat shrinkage test, contact heat test, combustibility test, flame retardancy test, tensile strength test, and tear strength test. As a result, the lightweight fabric shows excellent performance through post-processing, and silicone resin coating can secure safety of the pizza by the fiber screen material performance and radiant heat. The optimum post-treatment conditions were evaluated by performing a burning test after coating two kinds of glass fibers and four types of flame-retardant silicone resins with different weight and thickness.

• Journal of Conservation Science
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• v.30 no.4
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• pp.353-364
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• 2014

Formaldehyde(HCHO) may have a damage effect on Korean traditional textiles, because concentration is high and occurrence frequency is frequent at the exhibition room and storage area. Total 20 specimens were prepared using 4 different materials (silk, cotton, ramie, hemp) after dyeing with 5 colors (undyed, red, yellow, blue, black). The specimens were exposed to HCHO gas in the test chamber. The gas acceleration test was conducted to identify the deterioration of Korean traditional textiles according to HCHO concentration(0.5, 1, 10, 100, 500ppm), to temperature-humidity condition at HCHO 500ppm, and deterioration conditions at HCHO 500ppm. Optical, chemical, and physical evaluation was carried out after the exposure. The results, color difference, grey scale rating, formate($HCO_2{^-}$) of some textiles increased at 500ppm, while pH decreased at 500ppm. Also, color difference, grey scale rating, formate($HCO_2{^-}$) of some textiles increased double damage at high temperatures & humidity, high humidity condition. But, damages of accelerated degradation textiles were slight, because of degradation degree and degradation products. The results suggest that determined the damage to the korean traditional textile, damage level, damage-weighted condition, damage to accelerated degradation textiles. In addition, formaldehyde damaged to yellowing of red textiles, bleaching of accelerated degradation textiles, formic acid damaged to bleaching of total 20 specimens.

• Textile Coloration and Finishing
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• v.18 no.1
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• pp.33-43
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• 2006

The purpose of this study was to eximine the effect of different yam twisting methods on mechanical properties and 3D CAD images of plain knitted fabrics made of composite yarns. Six yams were used in this study: four different composite yams of the six consist of acetate and functional polyester (Poly-m) with the ratio of 70:30, and the rest two are the original acetate $100\%$ yam and the poly-m $100\%$ yarn. The four kinds of composite yarns were processed in combinations of twisting processes such as interlacing, false twisting, two for one twisting, combined twisting and single covering, and the two original yams were knitted without any twisting process. Sixteen mechanical properties of all the six knitted fabrics, knitted under the same knitting conditions, were measured by KES-FB system with the outer knit condition. The results were as follows; 1) When the sample applied with the false twisting process at the temperature as high as $220^{\circ}C$, ENT, B, HB, G and RC values of samples increased which leads to increasing dimensional stability. 2) To gain the high bending and shear properties in the single covering process, selecting the core yarn with such properties is the most important factor. 3) Interlacing process effected to increase RC value. 4) False twisting process after interlacing process gave bulkiness and un-interlaced part in yam was increased SMD value. The SMD value of the kilted fabric of the composite yarn, which was put through the combined twist process, was higher than those of which simple process such as the two for one twist or the single covering process applied. In order to achieve the silk-like surface feel of knitted fabric, the sin91e covering process is recommended. 5) Examining the simulation images of the knifed fabrics of composite yarn, which were generated by the 3D CAD system based on the mechanical properties of the fabric, led that appearance could be changed as different twisting methods were applied.

• Applied Chemistry for Engineering
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• v.10 no.2
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• pp.293-298
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• 1999

Reaction mechanism was elucidated and reaction condition were optimized for the catalytic reaction synthesizing 2-methyl-4-methoxy-diphenylamine (MMDPA) which is an intermediate of Fluoran heat-sensitive dyestuff. Reactants consisted of 2-methyl-4-methoxyaniline (MMA), 3-methyl-4-nitroanisole (MNA), and cyclohexanone, and 5 wt % Pd/C was used as a catalyst. Experiments were run in an open slurry reactor equipped with reflux condenser, and products were analyzed by means of GC/MS and NMR. MMDPA yield of 90 mole % could be obtained after reaction time of 8~10 hours under the optimal reaction conditions comprising the reaction mass composition of MMA : MNA : cyclohexanone = 1 : 2 : 150 based on MMA input of 0.01 gmoles in xylene solvent, reaction temperature of $160^{\circ}C$, and catalyst amount of 0.5 g. It was found that the rate-determining step of overall reaction was dehydrogenation of the intermediate product obtained from condensation of MMA and cyclohexanone. Overall reaction rate and MMDPA yield were enhanced owing to hydrogen transfer reaction by introducing MNA together with MMA in the reaction mass. Excess cyclohexanone in the reaction mass played an important role of promoting the condensation of MMA and cyclohexanone.

• Polymer(Korea)
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• v.29 no.5
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• pp.433-439
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• 2005

The copolymers were prepared by the emulsion copolymerization of fluoroalky lacrylate-stearylacrylate-m-isopropenyl-${\alpha},\;{\alpha}'$-dimethylbenzyl isocyanate (TMI) in order to obtain water repellent polymers. The respective copolymerization rates of the three monomers considerably depended upon the use of the nonionic emulsifier and the nonionic-cationic mixed emusifier, and the optimum conditions were obtained. The particle sizes of the copolymers were in the range of 105 to 222nm. The particle sizes of the copolymers prepared by the use of the mixed emulsifiers were smaller than those of the copolymers prepared by the use of the nonionic emulsifier. The reactions of both TMI-N-methyl acetamide and TMI-cellobiose did not take place. However, the reaction of TMI-n-butylamine occurred. The water contact angles before and after washing three times for nylon and poly(ethylene terephthalate) (PET) fabrics coated with the copolymer prepared by the use of mixed emulsifier were about $139^{\circ}\;and\;133^{\circ}$ Therefore, the copolymer showed good durable repellency for nylon and PET.

• Journal of the Korean Wood Science and Technology
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• v.49 no.5
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• pp.514-534
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• 2021

To estimate the territorial size of Reticulitermes speratus, a species of subterranean termites that damages wooden structures in Korea, appropriate dye markers were selected and the diffusion tendency was analyzed. According to the results of the sensitivity assessment using sawdust diet, increase in dye concentration reduced the amount of feed consumption but the dyeing becomes more intense. Except for the Neutral Red 0.5% group, all other concentration groups, including the control group, showed a survival rate of > 85% until week 4. For both, Nile Blue A and Neutral Red dye markers, all concentration conditions > 0.2%, except for the 0.1% concentration, were maintained for 11 weeks, and no sign of transfer effect was found except when the termites were fed with the dye markers. Therefore, it appears that 0.2% of Nile Blue A and Neutral Red is the optimal concentration for monitoring the R. speratus colonies. Additionally, we prepared an indoor 40 m long foraging arena consisting of a colony of 25,000 termites and released individuals stained with 0.2% of Nile Blue A and Neutral Red at both ends to assess the diffusion trends over time. The results showed that it took approximately 7 days for each dyed individual to gradually cover the 40 m distance and mix with each other. These findings reveal that when mark-release-recapture monitoring is conducted on the R. speratus colonies damaging wooden structures, the extent of the colony's activity area could be measured and different colonies could be distinguished from each other.