• Composites Research
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• v.31 no.4
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• pp.122-127
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• 2018

Sandwich composites of carbon fiber reinforced plastic(CFRP) and polymer foam will be used to automobile and aerospace industry according to increasing importance of light weight. In this study, mechanical and heat resistance properties of sandwich composites were compared with type of polymer foam (polyethylene terephthalate(PET), polyvinylchloride(PVC), epoxy and polyurethane). All types of polymer foams were degraded to 30, 60, 120, 180 minutes in $180^{\circ}C$. After heat degradation, the polymer foams were observed using optical microscope and compressive test was performed using universal testing machine(UTM). Epoxy foam had the highest compressive property to 2.6 MPa and after thermal degradation, the mechanical property and structure of foam were less changed than others. Epoxy foam had better mechanical properties than other polymer foams under high temperature. Because the epoxy foam was post cured under high temperature. As the results, Epoxy foam was optimal materials to apply to structures that thermal energy was loaded constantly.

• Textile Coloration and Finishing
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• v.5 no.4
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• pp.29-41
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• 1993

In order to surface Hydrophobilization of Poly(ethylene terephthalate) (PET) fiber samples were treated in the atmosphere of CF$_{4}$ or $C_{2}$F$_{6}$glow discharge. The sample used in this study was PET film which is 75$\mu$m thick made by Teijin, O-Type(Japan). The cleaned samples were placed in plasma reactor made of pyrex glass cylinder, and plasma processing was carried out by glow discharge of CF$_{4}$ or $C_{2}$F$_{6}$ gas, being continuously fed by gas flow and continuously pumped out by a vacuum system. Electric power source for generate plasma state was sustained alternating current(60Hz) and voltage was sustained 600 volt. The duration of plasma treatment varied from 15 to 120 seconds except special case, the monomer gase pressure varied from 0.02 to 0.3 Torr and power range was 10 to 90 watts. The hydrophobic features of changed PET surface were evaluated by contact angle measurement and surface chemical characteristics were analyzed by ESCA. Results can be summerized as follows. 1. The most favorable setting position of substrate was the center area between the two electrodes. 2. $C_{2}$F$_{6}$ discharge current was lower than that of CF$_{4}$ when same voltage was sustained. Treated efficiency between CF$_{4}$ and $C_{2}$F$_{6}$ did not revealed significant differences under same electric power(wattage). 3. When monomer pressure is very low below 0.02 torr, as though substrate is exposed to CF$_{4}$ or $C_{2}$F$_{6}$ plasma, it tend to be hydrophilic through a little of fluorine bond and a great deal of oxidizing reaction. 4. There brought good hydrophobilization when monomer pressure was more 0.1 torr and duration of glow discharge treatment was over 45 seconds. When monomer pressure was too high, discharge current became low. Although prolong the duration, there was no more high hydrophobilization. 5. According to ESCA analysis, there were a little CF bond and a prevailing CF$_{2}$ bond in CF$_{4}$-treated substrate. There were CF$_{3}$, a little CF and a prevailing CF$_{2}$ bond in $C_{2}$F$_{6}$-treated substrate.d substrate.

• Textile Coloration and Finishing
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• v.12 no.1
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• pp.52-60
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• 2000

In the prior studies, we reported that the dye uptakes of C. I. Disperse Violet 1 on polyester fiber in hexane and cyclohexane were higher than those in the other solvents, as the number of carbon atoms of alkanes decreased, the dye uptake increased, and the logarithmic plot of the dye uptakes vs. the solubilities of the dye showed that the dye uptakes are inversely proportional to the solubilities. In this study, for Interpretation of dyeing behavior of C. I. Disperse Violet 1 on polyester in alkanes, the thremodynamic parameters of dyeing, such as standard affnity, heat of dyeing(enthalpy change), entropy change, diffusion coefficient, and activation energy of diffusion, were obtained from isotherms and dyeing rates at different temperature. As the number of carbon atoms of alkanes increased, the standard affinity decreased, but the heat of dyeing(enthalpy change) and the entropy change showed larger negative values. These results mean that as the number of carbon atoms of alkanes increases, the dye uptake decreases, but both the fraction of the dye molecules dyed at relatively highly aligned or compact region of polyester fiber and the regularity of dye aggregates in the fiber become increased. As the number of carbon atoms of alkanes increased, the diffusion coefficient decreased, but the activation energy of diffusion increased. In the alkane of larger number of carbon atoms, because the solubility of the dye is higher, the desorption rate of the dye is faster and the diffusion coefficient is smaller than those in the smaller alkanes. But the energy required to separate the dye molecules from the alkane molecules is much higher because the interaction between the alkane molecule and the dye molecule become strong with the number of carbon atoms.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.48-64
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• 2019

With evolution in the production environment of the textile industry, the need for non-water-based dyeing technologies and eco-friendly process facilities in the dyeing and processing stages has increased. In recent years, supercritical fluid dyes have been developed and commercialized in Europe, centering on this demand. However, so far, such dyes have been mainly applied in the processing of PET fibers. Basic research has mainly involved investigation of dyeing by supercritical carbon dioxide or solubility of such dyes, and more in-depth research should be continuously carried out. In this review, we describe the types and characteristics of supercritical fluids that exhibit specific properties at pressures and temperatures over the critical point. In addition, the state of the art in the dyeing and processing technology using supercritical fluids and associated, processing problems, environmental regulation, and wastewater treatment issues are described in detail. We hope this review can contribute to the supercritical fluid technology being further developed as an environment friendly dyeing processing method. Furthermore, we expect that the technique can be used as a means of ensuring different, high-quality dyed products.

• Fashion & Textile Research Journal
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• v.2 no.4
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• pp.339-345
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• 2000

The effects of protease and/or lipase on the removal of protein soil and oily soil were investigated in this study. Cotton, rayon, nylon, and PET fabrics were soiled by padding of fresh bovine blood and spotting of mixed artificial sebum evenly. The soiled fabrics were aged at $130^{\circ}C$ for 30 minutes. The fabrics were washed by using Terg-O-Tometer at various conditions. Protease and/or lipase were added in the alcohol ethoxylate (AE) detergent solution. The removal efficiency was evaluated by analysis of protein and/or oil on the fabrics before and after washing, respectively. The detergency of protein and/or oil on the fabrics was discussed with enzyme concentration, washing time, washing temperature, pH of washing solution and fiber characteristics. The hydrolysis of protease improved effectively the removal of oil as well as protein by increasing removal of protein-oil mixed soil at the same time. The effect of lipase added detergent solution was slightly shown on the removal of oil and/or protein. The removal of mixed soils from cotton fabrics was very low because of large amount of residual soils caused by the physical characteristics of cotton fiber.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.11 s.158
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• pp.1572-1582
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• 2006

In this study, in order to compare a Tencel/cotton and a Tencel/Cotton/PET as Tencel blended fabrics with a Tencel fabric, the fabric samples were treated with chitosan after NaOH pretreatment and enzyme treatment thereof, And then its adherent efficiency was enhanced by using a crosslinking agent. After that, it was treated with a softener. In chitosan treatment, the functions of moisture regain, tensile strength, air permeability and crease resistance were more improved in the Tencel blended fabrics than in the Tencel fabric. Thus, it may be thought that the physical properties of the Tencel blended fabrics were more effectively modified than those of the Tencel fabric. And the friction charged voltage was very much reduced in all samples, so that chitosan treatment was effective for prevention of electrostatic charge. Further, chitosan finishing treatment improved remarkably the antibacterial activity in all samples regardless of the type of strains.

• Macromolecular Research
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• v.17 no.3
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• pp.149-155
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• 2009

The thermal decomposition behavior and degradation characteristics off our different thermotropic liquid crystalline polymers (TLCPs) were studied. The thermal decomposition behavior was determined by means of thermogravimetric analysis (TGA) at different heating rates in nitrogen and air. The order of the thermal stability was as follows: multi-aromatic polyester > hydroxybenzoic acid (HBA)/hydroxynaphthoic acid (HNA) copolyester > HNA/hydroxyl acetaniline (HAA)/terephthalic acid (TA) copolyester > HBA/Poly(ethylene terephthalate) (PET) copolyester. The activation energies of the thermal degradation were calculated by four multiple heating rate methods: Flynn-Wall, Friedman, Kissinger, and Kim-Park. The Flynn-Wall and Kim-Park methods were the most suitable methods to calculate the activation energy. Samples were exposed to an accelerated degradation test (ADT), under fixed conditions of heat ($63{\pm}3^{\circ}C$), humidity ($30{\pm}4%$) and Xenon arc radiation ($1.10\;W/m^2$), and the changes in surface morphology and color difference with time were determined. The TLCPs decomposed, discolored and cracked upon exposure to ultraviolet radiation.

• Korean Journal of Veterinary Research
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• v.37 no.2
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• pp.439-443
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• 1997

While the contents of protein, fat, fiber, sodium, vitamin A, and vitamin D in dry dog food were 22.0%, 7.8%. 5.4%, 0.36%, 2035 IU/100g and 201 IU/100g, respectevely, those in dry cat food were 29.8%, 6.5%, 4.5%, 0.38%, 1543 IU/100g and 163 IU/100g, respectively. Concerning the lipid contents of pet food, the concentration of unsturated fatty acid was slightly higher of dry dog food(59.2%) than that of dry cat food(55.9%), but the differences was statistically not significant. The lipid peroxide concentration in dry dog food after storage in a refrigerator at $4^{\circ}C$ or dark place of room temperture at $20{\pm}2^{\circ}C$ for 30 days(8.0 nmol/g and 7.8 nmol/g) was not different from the value at the beginning of storage. However, upon storage in direct sunlight at $20{\pm}2^{\circ}C$ of room temperture, the concentration increased 4.9-fold(35.5 nmol/g) after 5 days and 10.2-fold(73.6 nmol/g) after 30 days. These results suggest that pet food may be refrigerated or stored in a dark place after unsealing.

• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.210-214
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• 2008

This experiment was carried out investigation of optimum concentration of supply nutrient solution in hydroponics of sweet pepper using coir substrates (coconut dust fiber=70% : 30%, v/v). During the growing period, it was found out that the electric conductivity (EC) would increase in proportion to the supply nutrient concentration but it was in inverse proportion to the moisture content. The pH of drainage was stable, while EC was high showing EC $7.3\;dS{\cdot}m^{-1}$ in EC $4.0\;dS{\cdot}m^{-1}$ of supply nutrient concentration. Also, standard deviation and coefficient of variation were high. Plant length was no difference by the supply nutrient concentration. Photosynthesis rate was generally high in supply nutrient concentration EC$4.0\;dS{\cdot}m^{-1}$. Fruit weight was heavy in supply nutrient concentration EC $4.0\;dS{\cdot}m^{-1}$, fruit shape was close to a regular square in supply nutrient concentration EC $3.5dS{\cdot}m^{-1}$.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.46-48
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• 2008

Fabrics shrinkage are affected by weaving conditions and are very difficult to be estimated when the amount of fiber consumption and production are calculated. Therefore, we need to standardize fabric shrinkage according to various weaving conditions. To develop the new textile products, we collected and analysed data of fabric shrinkage with the weaving conditions including fabric density and woven structure, tension, and machinery used.