• Journal of the Korean Ceramic Society
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• v.19 no.1
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• pp.44-50
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• 1982

Drawing optical fibers in a graphite furnace is one of the most convenient and economical means of producing optical fiber. Since the flaw formation on optical fiber is mainly due to dust contaminations during drawing and surface corrosion by water vapor penetration through coating layer, the tensile strength of optical fiber drawn in a graphite furnace is greatly inflenced by the drawing conditions. The important factors found in this investigation were preform treatment (fire polishing), furnace interior environment (dust contamination, inert gas flows), primary coating condition (resin curing temperature, coating materials, method, thickness) and fiber pulling condition (furnace temperature, drawing speed, pulling tension). The tensile strength at optimum drawing conditions turned out to be 5 ~ 6 GPa.

• Textile Coloration and Finishing
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• v.22 no.1
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• pp.51-60
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• 2010

This research works on the effects of drawing conditions on the physical properties of the drawn worsted yarns. The drawn worsted yarns were made by the yarn drawing system under various drawing conditions such as concentration of reducing agent, draw ratio, setting time of drawn yarn, and concentration of oxidizing agent. The drawn worsted yarns from 2/80Nm to 2/90Nm were obtained from 2/60Nm worsted yarns, the surface and cross-sectional shapes and tensile properties of these various specimens were measured and discussed with the various drawing conditions. The drawing of worsted yarn made constituent wool fiber scratched and made it changing to polygonal cross-sectional shape. The tenacity and modulus were increased with draw ratio and concentration of reducing agent. And tensile strain was increased with draw ratio, which decreased with concentration of reducing agent.

• Textile Coloration and Finishing
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• v.22 no.1
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• pp.61-70
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• 2010

This effects of drawing conditions on the physical properties of the drawn worsted yarns were investigated. The drawn worsted yarns were made on the yarn drawing system with various drawing conditions such as concentration of reducing agent, draw ratio, setting time of drawn yarn and concentration of oxidizing agent. The dry and wet shrinkage, irregularity(CV%), thin and thick part, hairiness and abrasion resistance of these various specimens were measured and discussed in terms of various drawing conditions.

• Transactions of Materials Processing
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• v.14 no.9 s.81
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• pp.779-784
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• 2005

MTS(Monobloc Tube Shaft) has been used for the reduction in weight of shaft and increase in supply of power in the auto industry nowadays. Cold drawing process having high productivity and reduction in the cost has been regarded as the effective technology that is able to substitute for swaging process as forming MTS with constant outer diameter or hollow shaft without surface defects. The objective of this study is not only to (md out the optimal process conditions understanding the effect of process parameters on carrying out cold drawing process of SIS(Steering Input Shaft) but also to control the defects resulted from inappropriate process conditions. Therefore, the proper drawing conditions are presented using FE-Analysis and experiment in the paper.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.431-434
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• 2005

MTS(Monobloc Tube Shaft) has been used for the reduction in weight of shaft and increase in supply of power in the auto industry nowadays. Cold drawing process having high productivity and reduction in the cost has been regarded as the effective technology that is able to substitute for swaging process as forming MTS with constant outer diameter or hollow shaft without surface defects. The objective of this study is not only to find out the optimal process conditions understanding the effect of process parameters on carrying out cold drawing process of SIS(Steering Input Shaft) but also to control the defects resulted from inappropriate process conditions. Therefore, the proper drawing conditions are presented using FE-Analysis and experiment in the paper.

• Textile Coloration and Finishing
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• v.28 no.4
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• pp.253-270
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• 2016

In the wool textile industry, the necessity for technology development has been steadily raised to create improved fineness and yarn count of existing wool yarns with thick fineness for ensuring higher quality grades of wool yarn. Recently, through controlling fineness of wool yarn for making finer wool in relation with environmentally-friendly and high-sensitivity trend, a differentiated continuous drawing process where the quality of wool can be artificially manipulated has been suggested in the latest textile industry. This study investigated the basic conditions during the continuous drawing process which enable to manufacture wool yarn with fine count by controlling reducing agent treatment, physical drawing and drying after reducing agent treatment, and oxidizing agent post-treatment conditions. Furthermore, this study reviewed the drawing effects by applying the basic conditions for reduction and oxidation reaction in the drawing processes of wool/cashmere, wool/silk, wool/polyester blended yarns as well as such wool yarns. Also, in order to review the practicability, this study examined the physical properties and dyeability of drawn wool yarn applied textile materials in comparison with normal wool yarn applied textile materials.

• Polymer(Korea)
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• v.25 no.5
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• pp.699-706
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• 2001

The effects of uniaxial drawing conditions on the molecular orientation of poly (ethylene 2,6-naphthalate) (PEN) are investigated. Birefringence measurements show that the orientation is significantly enhanced at high draw ratio, low drawing temperature, and fast drawing speed. The characteristics of orientation examined by FTIR- ATR dichroism method represent almost same results. Amorphous orientation function increases with drawing rate at $120^{\circ}C$, but it decreases with drawing rate at $141^{\circ}C$. These behaviors can be explained with the relation between crystallization and chain relaxation rates. It is observed that the orientation of PEN film is accompanied by significant alignment of the naphthalene rings of PEN parallel to the film surface.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.260-265
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• 2004

In order to analyze the shaped drawing process, it is necessary that the friction boundary condition between dies and blanks should be worked out the accurate numerical friction models. But, the existing numerical models of the drawing may be large different from the actual conditions. In this paper, accurate analysis of the drawing process should be subjected. It is to develop accuracy of the numerical friction models and potentialize to apply for the high speed forming work in the drawing process. Therefore, the results should improve the accuracy, cause the energy saving for the drawing process and finally expand the applying areas of the results.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.294-297
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• 2007

Due to their low densities and high specific strength and stiffness, magnesium alloy sheets are very attractive lightweight materials for automotive and electrical products. However, the magnesium alloy sheets are usually formed at elevated temperature because of their poor formability at room temperature. To use of the magnesium alloy sheets for an industrial, their mechanical properties at elevated temperature and appropriate forming process conditions have to be developed. In this study, non-isothermal simulations of a square cup drawing from magnesium alloy sheets have been conducted to evaluate a proper forming process conditions such as the tool temperature, the tool shoulder radius, friction between the blank and the tools. According to this study, appropriate forming process conditions of square cup drawing at elevated temperature from magnesium alloy sheets are suggested.

• Transactions of Materials Processing
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• v.16 no.5 s.95
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• pp.401-405
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• 2007

Due to the low densities and high specific strength and stiffness, magnesium alloy sheets are very attractive lightweight materials for automotive and electrical products. However, the magnesium alloy sheets should be usually formed at elevated temperature because of their poor formability at room temperature. For the use of the magnesium alloy sheets for an industrial, their mechanical properties at elevated temperature and appropriate forming process conditions have to be developed. In this study, non-isothermal simulation of a square cup drawing of magnesium alloy sheets have been conducted to evaluate a proper forming process conditions such as the tool temperature, the tool shoulder radius, friction between the blank and the tools. According to this study, appropriate forming process conditions of square cup drawing at elevated temperature from magnesium alloy sheets are suggested.