Seung-Jin Kim

The Synthesis of One-step Type Hydrophilic Non-porous Polyurethane Resin and the Physical Property of its Coated Fabric for the Garment

This study surveyed on the synthesis of one-step type hydrophilic non-porous PU resin and the physical property of the coated fabric for the garment. Three kinds of chain extender such as MEG, 1,4-BD and NPG were used for the preparation of one-step type hydrophilic non-porous PU resin in order to examine the effect of chain extender on the physical properties of PU-coated fabric. And the effects of isocyanate on the physical properties of PU coated fabric were surveyed by mixing with various TDI and MDI ratios. In addition, the physical properties of the coated fabric treated with one-step type hydrophilic non-porous PU resin were examined according to the pre-treatment conditions such as cire finishing. Finally, the washing durability of the coated fabrics was assessed. The coated fabrics treated with PU resin synthesized with PEG1000, MEG and TDI/MDI (6/4) showed the best physical properties. Considering the pre-treatment conditions, best performance of hydraulic pressure, water vapor permeability, and water repellency were obtained with top roller rotation ratio of 150% under 50 ton pressure at .

Modification of Carbon Nanotube for the Improvement of Dispersion and the Dispersion Characteristics of Carbon Nanotube in Polyurethane

The thermal treatment for carbon nanotube was applied to remove the water, metal catalyst and other impurities in carbon nanotube. The surface of carbon nanotube was changed into open structure with acid treatment by mixed solution of and . The dispersion property of the functionalized and modified carbon nanotube was assessed with naked eyes by dispersing it in DMF. Carbon nanotube mixd polyurethane film was made to estimate the dispersion property by reflectance of the film with UV-Vis spectrometer. Also the internal structure of carbon nanotube was observed with SEM and TEM and thermal pyrolysis property of the carbon nanotube was measured by TGA and DSC. The surface modification of carbon nanotube by thermal and acid treatments improved the dispersion property of carbon nanotube/polyurethane mixed materials.

Effects of loom characteristics on the physical properties of PET fabrics for emotional clothing

The fabric defects complained by garment manufacturers are stop marks, streaky phenomena on the warp direction, thickness variation and color differences between edges on the right and left sides of the fabrics, which are partly due to the tension variation of warp and weft directions. It is well known that these defects are related to the difference of fabric mechanical property according to the loom characteristics and fabric position such as center and both edges parts of the fabric, which affect garment formability and wearing performance of garment. This research is focusing about which factor is dominant for the difference of fabric mechanical properties which affects garment formability and wearing performance between loom characteristic factor and fabric position factor such as center and both edges of the fabric, which is affected by warp and weft tensions. For this purpose, two kinds of looms were selected, and warp and weft tensions during weaving were measured and the mechanical properties of the fabrics woven by two kinds of looms such as tensile, bending, shear, compression and surface properties were also measured according to the positions such as center and both edge parts of the fabric. These fabric mechanical properties were examined with warp and weft tensions according to the looms and were also analyzed according to the positions of the fabric woven by two kinds of looms. The warp tension on the vicinity of center parts of the looms was much higher than those on the vicinity of both edges of looms. It revealed that the warp tension difference makes differences of fabric mechanical properties such as tensile, bending, shear and surface properties except compressional property. And the differences of these mechanical properties according to the fabric positions and looms seem to make homogeneity of the fabric hand and tailorability of garment deteriorating.

The Characteristic of PU/MWNT Foaming Film

This study surveys the characteristics of the PU/MWNT foaming film according to foaming conditions. For this purpose, firstly, 16 kinds of PU/MWNT forming films were prepared with 4 kinds of dispersion solutions (IPA/MWNT, DMF/MWNT, MEK/MWNT, and Toluene/MWNT) and 4 kinds of blowing agents (organic I, organic II, capsule, and inorganic). The electrical resistivity of these PU/MWNT foaming films according to the dispersion solutions and blowing agents were analysed and discussed with surface profile and cell morphology of measured by SEM. And secondly, 24 kinds of PU/MWNT foaming films were also prepared with 2 kinds of IPA dispersion solution contents and 3 kinds of blowing agents with variation of the blowing temperatures and film thickness. The physical properties of the PU/MWNT foaming films such as electrical resistivity (surface and volume) and triboelectricity with cell morphology were measured and discused through the quantities of IPA, blowing agent added and also physical conditions(temperature, thickness so on) for establishing optimum foaming conditions with good electrostatic dissipation.

Study on Manufacturing Technology of Coating Yarns for Awning Fabrics

This paper investigated optimum process conditions of coating yarn for awning fabric. For this purpose, the simulation for processability and yarn quality using SPSS statistics package was carried out, and PP/TPO and PET/PVC coating yarns specimens were made with variation of extruder temperature and feed speed of core yarn on the yarn coating machine for examining simulation result. It was revealed that optimum coating conditions of PP/TPO 1000d coating yarn were extruder temperature , and core yarn feed speed 400~500m/min. Mechanical property and thermal shrinkage of PP/TPO coating yarn made at this conditions were best and core evenness rates of these coating yarns by yarn compression tester were also superior, which was certified by SEM photograph. In addition, these experimental results were coincided with simulation results. It was found that, in PET/PVC coating yarn, yarn physical properties between 1500d and 1200d coated yarns were not shown any difference, and core evenness rates of these coating yarns were superior. It revealed and concluded that these simulated coating conditions are applicable to production field.

Manufacturing and characteristics analysis of PU/MWNT film for electrosatic dissipation

This study surveys the characteristics of the nanocomposite film for PU/MWNT. For this purpose, several kinds of PU/MWNT nanocomposite films were prepared with four kinds of MWNT, MWNT contents and two kinds of dispersion times and ESD (Electrostatic Dissipation) films composed with polyurethane (PU) block copolymer and selected multi-walled carbon nanotube (MWNT) were also prepared by disperse processing with various MWNT contents and dispersion times, and their mechanical and chemical properties were investigated with electrical conductivity. The tensile properties and chemical properties of PU/MWNT nanocomposite films were measured using UV-visible spectrometer and discussed with the manufacturing conditions of nanocomposite film. Furthermore, the PU/MWNT films were made by dispersing with five kinds of CNT content and six kinds of dispersion time under the DMF (dimethylformamide) solution, and the mechanical properties of the PU/MWNT films were analyzed by Instron and discussed with various dispersion...

Measurement of Characteristics of PU/MWNT Films Made of Modified MWNT by Dry Heat Treatment

This study examines the electrical conductivity of multi-walled carbon nanotube (MWNT) /polyurethane (PU) nanocomposites film according to the dispersion conditions. For this purpose, various kinds of polyurethane block copolymer (PU)/multi-wall carbon nanotube (MWNT) with different MWNT contents were mixed and dispersed, and their characteristics related to the dispersion were investigated. Multi-walled carbon nanotubes (MWNT) are of interest in many areas of nanotechnology and used in a number of novel applications. However effective dispersion remains a problem and one solution is to functionalize the nanotubes. In this work, MWNTs are functionalized using an oxidative technique, including dry thermal treatment. The dispersion variation of the PU/MWNT nanocomposite films with MWNT content ranging from 0.1~5.0 wt% was examined. The various characteristics of the dispersed PU/MWNT nanocomposite film were characterized using thermo gravimetric analyser (TGA), scanning electron microscope (SEM) and measuring instrument of electrical conductivity. The degree of dispersion of PU/MWNT nanocomposite films according to the dispersion conditions was shown in various situations. The bad dispersion of PU/MWNT film was revealed during the phase separation between PU matrix and MWNT. Also PU/MWNT nanocomposite film shows good electro-conductivity on its surface because MWNT was collected on the surface of composite film due to its low density.