• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.937-941
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• 1997

Utomatic finishing process requires the development of high efficient and precision abrasive machining method for die and molds. This study describes the evaluation of the finishing characteristics, such as sufrace roughness, topography and material removal depth, of the electrolytic chemical mixed abrasive machining method. Experimental setup is composed of 3 axis machining center, a newly developed finishing attachment with constant pressure, electrode and electrolytic bath. Finally, we achieved a successful result that surface roughness is 0.01 .mu. m Ra and material removal depth is 145 .mu. m after 100 times repeat-finishing using electrolytic (0.8A,30V) mixed abrasive (#400 CBN, #320 Sic) machining method.

• International Journal of Precision Engineering and Manufacturing
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• 제8권2호
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• pp.38-43
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• 2007

This paper describes ultrasonically assisted grinding used to obtain a glossy surface quickly and precisely. High-quality surfaces are required for plastic injection molding dies used in the production of plastic parts such as dials for cellular phones. Traditionally, in order to finish the dies, manual polishing by a skilled worker has been required after the machining processes, such as electro discharge machining (EDM), which leaves an affected layer, and milling, which leaves tooling marks. However, manual polishing causes detrimental geometrical deviations of the die and consumes several days to finish a die surface. Therefore, a machining process for finishing dies without manual polishing to improve the surface roughness and form accuracy would be extremely valuable. In this study, a 3D positioning machine equipped with an ultrasonic spindle was used to conduct grinding experiments. An electroplated diamond tool was used for these experiments. Generally, diamond tools cannot grind steel because of excessive wear as a result of carbon atoms diffusing into bulk steel and chips. However, ultrasonically assisted grinding can achieve a fine surface (roughness Rz of $0.4{\mu}m$) on die steel without severe tool wear. The final aim of this study is to realize mirror surface grinding for injection molding dies without manual polishing. To do this, it is necessary to fabricate an electroplated diamond tool with high form accuracy and low run-out. This paper describes a tool-making method for high precision grinding and the grinding performance of a self-electroplated tool. The ground surface textures, tool performance and tool life were investigated A ground surface roughness Rz of 0.14 um was achieved Our results show that the spindle speed, feed rate and cross feed affected the surface texture. One tool could finish $5000mm^2$ of die steel surface without any deterioration of the ground surface roughness.

• 산업기술연구
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• 제17권
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• pp.5-10
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• 1997

Fatigue tests were performed to investigate how much vary the fatigue limit under the different surface conditions on Carbon Steel(SM55C). Four types of specimen which have different surface roughness each other, Series A by turning, Series B by grinding, Series C by polishing and Series D by roller finishing showed the fatigue limit of 265, 320, 335 and 365MPa, respectively. Series D show 36% higher than Series A, which is caused by compressive residential stress on the surface. Therefore, roller finishing machining is helpful not only increase the fatigue limit but also improve the surface roughness. Moreover, to predict the fatigue limit under the conditions of knowing surface roughness and hardness of specimen, ${\sqrt{area}}$ area parameter method is very useful.

• 한국표면공학회지
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• 제8권2호
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• pp.7-13
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• 1975

• 한국표면공학회지
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• 제15권4호
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• pp.226-235
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• 1982

• 한국표면공학회지
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• 제9권1호
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• pp.27-29
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• 1976

• 한국표면공학회지
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• 제9권2호
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• pp.16-24
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• 1976

• 한국표면공학회지
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• 제12권2호
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• pp.115-122
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• 1979

금속이 함유된 폐기물의 처리는 점차 금속표면처리산업(Metal Finishing Industry)에서 큰 관심이 되어가고 있다. 위생침적지(Sanitary Landfills), 혹은 소각로에서 다른 도시 쓰레기들과 같이 처리되는 것은 환경상 불안전하며 이러한 행위는 중단되어야 한다. 다른 방법으로는 특수한 위생침적지의 운영, 안전한 침적지, 금속폐기물의 고정(Fixation), 혹은 포장(Capsule)에 넣어 버리는 방법등이 있으나 이러한 것들은 비실용적이며 예상되는 금속 폐기물의 양에 대하여 비용이 많이 들 것이다. 간단하고 경제적이며 보다 효과적인 분리침적지(Segregated Landfill)가 대신에 제안되고 있다.

• 한국표면공학회지
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• 제24권1호
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• pp.40-40
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• 1991

원문 이미지 참조

• 한국염색가공학회지
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• 제27권2호
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• pp.119-125
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• 2015

The effects of e-beam irradiation on water-repellency and washing durability of water-repellent finished chemically-recycled PET(CR-PET) fabrics were investigated. As results, more doses of e-beam irradiation damaged the fabric surface more severely. It was thought because the high densed energy was formed, where the more e-beam was converged. The contact angle measurement showed that as the dose of e-beam irradiation increased, water wettability of the CR-PET fabric increased slightly. It was thought to be due that the surface etching by e-beam irradiation let water droplet permeate into the fabric surface better. The concentration of the water-repellent finishing agent was more important factor than curing temperature as finishing parameter. It was considered because the water-repellent finishing agent used in this study got to cure sufficiently at low temperature. Consequently, e-beam irradiation improved the washing durability of water-repellent finishing on the CR-PET fabrics.