• 한국염색가공학회지
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• 제21권3호
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• pp.37-42
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• 2009

The low melting PET yarn has sheath/core structure: sheath portion consists of low melting point PET and core portion is regular PET. Dyeing properties of fabric made from low melting PET yarn were investigated at different dyeing temperatures. It was found that the exhaustion yield on the low melting PET fabric was higher than on regular PET fabric. The total K/S value of the dyed low melting PET fabric increased as heat setting temperature increased above $150^{\circ}C$ because the sheath portion of the low melting yarn melted. Although fastness to light of the low melting PET fabric was similar to regular PET fabric, fastness to washing was inferior to regular PET fabric by 1 grade.

• 한국의류산업학회지
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• 제14권6호
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• pp.1024-1031
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• 2012

The thermal bonding PET fabrics were produced through high temperature steaming (HTS) of low melting PET yarn as warp and composite fancy yarn containing low melting PET yarn as weft. The low melting PET yarn of sheath-core structure consisted of a regular PET in core portion and low melting PET in sheath portion. The composite fancy yarn consisted of regular PET yarn as inner part and effect part and low melting PET yarn as binding part. This study was carried out to investigate the melting behavior of thermal bonded PET fabric, the effect of HTS on the thermal bonding, mechanical properties, and dyeing properties. The melting peak of low melting PET yarn showed two melting peaks caused by sheath-core structure. Almost the entire thermal bonding of the fancy PET fabrics containing low melting PET yarn has formed at $200^{\circ}C{\times}3min$ of HTS. The tensile strength in warp and weft direction of the fancy PET fabrics slightly decreased as temperature of HTS increased. The total K/S value of the fancy PET fabrics decreased slightly to $180^{\circ}C{\times}3min$ of HTS, while increased slightly above $200^{\circ}C{\times}3min$ of HTS. The changes in the hue angle ($H^{\circ}$) of the thermal bonded fancy PET fabrics dyed with disperse dyes hardly ever happened.

• 한국주조공학회지
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• 제22권5호
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• pp.265-270
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• 2002

A novel jewelry master pattern manufacturing process which reduce manufacturing steps by employing a Duraform rapid prototyping mold and a low melting alloy has been suggested. The novel process follows the steps of 'jewelry 3D CAD design ${\rightarrow}$ Durafrom RP mold ${\rightarrow}$ low melting alloy master pattern' while the previous process follows more complicated steps of 'jewelry idea sketch ${\rightarrow}$ detailed drawing ${\rightarrow}$ wax carving ${\rightarrow}$ flask ${\rightarrow}$ silver master pattern.' An upper and a lower part of molds have been manufactured of Duraform powder, of which melting point is $190^{\circ}C$. A maser pattern was manufactured by pouring a low melting alloy of Pb-Sn-Bi-Cd, so called Woods Metal, of which melting point is $70^{\circ}C$, into the mold. The master pattern is a shape of a disk of 20mm diameter that contains various design factors. The variations of dimensions, surface roughness, surface pore ratio were measured by an optical microscope, a surface roughness profilometer, and a Rockwell hardness tester. The pattern made of were maeasured by an optical microscope, a surface roughness profilometer, and a Rockwell hardness tester. The pattern made of low melting alloy has sufficient surface hardness, and surface pore ratio to be used as the jewelry master pattern.

• 한국안전학회지
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• 제19권1호
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• pp.60-65
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• 2004

The PVC insulated flexible cords are used mainly as power supply cords of electric appliance. This electric wire is a stranded wire consisted of dozens of strands. In case stranded wires are disconnected by mechanical stress, it weakens electrically. Finally, the over current flows through stranded wires, and electrical fire occurs. In this study, we analyzed the melting properties of strands by over current, such as melting process, melting current and melting time. And we analyzed that quantity of heat for melting, a cross sectional structure, and surface structure by optical microscope and SEM. As analysis results, melting time decreased as melting current increased. And quantity of heat for melting was low, too. From the cross sectional structure of melted wire, when a melting current low and melting time long, it was found that the dendrite structure grew. However, the dendrite structure is hard to grow because growing time is not enough when a melting current high and melting time short.

• 설비공학논문집
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• 제7권4호
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• pp.547-555
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• 1995

Melting process of ice in a rectangular cavity with different temperature walls has been studied experimentally. Front shape of ice and melting rate were affected by initial temperature of ice and variation of temperature distribution and density gradient. When the hot wall temperature was below $8^{\circ}C$, the melting rates were higher at the bottom than those of at the top due to the density inversion, but with increasing the hot wall temperature the melting rates at the top were affected by hot wall and were higher than those of at the bottom. When the initial temperature of ice was low, melting rates were low, but with increasing the time melting rates were almost the same with those of each initial temperature of ice.

• 한국염색가공학회지
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• 제24권2호
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• pp.113-120
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• 2012

Jacquard floor covering could be prepared from low-melting/regular sheath-core hybrid polyester, where the fiber is dyed in yarn state. With regard that the expected high shrinkage of the hybrid polyester in water makes problems in yarn dyeing, low-temperature dyeing properties of the hybrid polyester were studied. The rate of shrinkage of low-melting hybrid polyester exceeds 9% in hot water above $90^{\circ}C$, at such condition, cheese yarn dyeing is very difficult. Although disperse dyes exhaust in a relatively high speed on low-melting hybrid polyester, diffusion of these dyes to the core regular polyester was extremely slow under $90^{\circ}C$. Foron Blue E-BL 150, an anthraquinone E-type disperse dye, showed appreciable diffusion after 48hrs dyeing at $90^{\circ}C$. The fastness to rubbing and drycleaning were improved by one grade after reduction cleaning.

• 한국생활과학회지
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• 제12권4호
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• pp.529-537
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• 2003

This study was conducted to manufacture the soluble micro-fiber and to synthesize low melting polymer for the interior fabric not to use the polyurethane resin causing some problems. Low melting polyester for weft yarn was introduced by adding 30-40 mol% ratio of isophthalic acid to a main chain of polyethylene terephthalate to decrease the melting temperature up to heat setting temperature. Micro-fiber for warp yarn consisted of both soluble and insoluble components with multi-layered structure. When the soluble micro-fiber was treated by alkaline hydrolysis with 3-5% concentration of NaOH, it showed the turning point at 28% weight loss since soluble polyester was hydrolyzed approximate five times faster than regular polyester.

• 한국의류산업학회지
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• 제11권3호
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• pp.474-480
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• 2009

The purpose of this study is to prepare the hardness of polyester(PET) fabric by thermal bonding with low melting component of bicomponent fiber and to describe the change of physical properties of thermal bonded PET fabrics. The PET fabrics were prepared with regular PET fiber as warp and bicomponent fiber as weft. The bicomponent fiber of sheath-core type were composed with a regular PET core and low melting PET sheath. The thermal bonding of PET fabric was carried out in pin tenter from 120 to $195^{\circ}C$ temperature range for 60 seconds. In this study, we investigated the physical properties and melting behavior of PET fiber and the effect of the temperature of the pin tenter on the thermal bonding, mechanical properties. Melting peak of warp showed the thermal behavior of general PET fiber. However, melting peak of weft fiber(bicomponent fiber) showed the double melting peak. The thermal bonding of the PET fabric formed at about temperature of lower melting peak. The optimum thermal bonding conditions for PET fabrics was applied at $190{\sim}195^{\circ}C$ for 60seconds by pin tenter. On the other hand, the tensile strength of the PET fabric decreased with an increasing temperature of thermal bonding.

• Transactions on Electrical and Electronic Materials
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• 제3권2호
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• pp.24-27
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• 2002

The NdBaCuO superconductor samples were zone-melted in low oxygen partial pressure (1%O$_2$+99%Ar). The zone-melting temperature was decreased about 12$0^{\circ}C$ film 1,06$0^{\circ}C$, the zone-melting temperature in air. Thus the loss of liquid phase (BaCuO$_2$ and CuO) was reduced during: the zone-melting process. The content of non-superconducting phase Nd422 in zone-melted NdBaCuO samples was clearly decreased and, therefore, the substitution of Nd for Ba was occurred. The superconductivity of zone-melted Nd$_{1+x}$Ba$_{2-x}$Cu$_3$O$_{y}$ prepared under low oxygen partial pressure was distinctively improved.d.d.d.

• 한국공작기계학회논문집
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• 제17권1호
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• pp.126-131
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• 2008

In this investigation, various factors affecting manufacturing conductive inks are presented, examined and discussed. The discussion includes inherent difficulties in making conductive inks successful and at the same time offers ways in which these difficulties might be overcome. One of the solutions to overcome such difficulties is to use low melting metals and alloys. This aspect is also detailed.