• Title/Summary/Keyword: In-process dressing

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(Electrolytic in-Process Dressing)-Grinding of Ceramics (세라믹스의 ELID연삭가공)

  • Ohmori, Hitoshi;Katahira, Kazutoshi
    • Ceramist
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    • v.9 no.6
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    • pp.37-41
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    • 2006
  • A novel grinding technology, known as ELID (Electrolytic In-Process Dressing), which incorporates 'inprocess dressing' of metal- bonded diamond grinding wheels, provides continuous protruding abrasives effectively applied to ceramic grinding. This article describes the ELID-grinding method and introduces its application examples on ceramics

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Effectiveness of double tie-over dressing compared with bolster dressing

  • Lee, Seo Hyung;Kim, Yu Jin
    • Archives of Plastic Surgery
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    • v.45 no.3
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    • pp.266-270
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    • 2018
  • Background Skin grafting is a commonly performed operation in plastic and reconstructive surgery. The tie-over dressing is an effective technique to secure the grafted skin by delivering persistent downward pressure. However, if an additional dressing is required due to incomplete graft healing, the process of re-implementing the tie-over dressing may be frustrating for both patients and surgeons. Therefore, we introduce the double tie-over dressing, which readily allows for an additional tie-over dressing after the first dressing, and we present a comparison of its effectiveness with that of the simpler bolster dressing. Methods Of 128 patients with a skin defect, 69 received a double tie-over dressing and 59 patients received a simple bolster dressing. Using the independent t-test, the mean healing time, which was defined as the mean time it took for the wound to heal completely so that no additional dressing was required and it was washable with tap water, was compared between the 2 groups in both the head and neck region and in other areas. Results The mean healing time for the head and neck region in the double tie-over dressing group was $9.19{\pm}1.78days$, while it was $11.05{\pm}3.85days$ in the bolster dressing group. The comparison of the 2 groups by the independent t-test revealed a P-value of 0.003 for the mean healing time. Conclusions In the head and neck area, the double tie-over dressing required less time to heal than the simple bolster dressing.

A Study on the Internal Grinding with High Quality Using Interval Type Electrolytic Dressing Method (전해 드레싱을 이용한 고품의 내면 연삭 가공에 관한연구)

  • 강재훈
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.2
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    • pp.138-143
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    • 2000
  • The establishment of a practical ultra-precision grinding technique using Diamond and CBN wheels is one of the major key technolo-gies to improve production techniques for machine-to-difficult materials without finishing process such as lapping and polishing. But the special efficient dressing technique for ultra-fine grit type grinding wheels to stabilize the grinding ability was not developed. Recently electrolytic in-process dressing technique is proposed to ultra-fine grit type metal bonded diamond wheels to protrude abra-sives continuously from the tool surface. This technology can be widely used to surface grinding and cylindrical grinding but cannot be used efficiently to internal grinding because of the electrode attachment trouble. This paper describes the effect of interval type electrolytic dressing as proposed newly to cast iron bonded diamond wheel for efficient internal grinding with mirror type high quality ground surface.

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Selecting Optimal Dressing Parameters of Ultra-precision Centerless Grinding Based on the Taguchi Methodology (다구찌 방법론에 근거한 초정밀 센터리스 연삭의 최적 드레싱 가공 조건 선정)

  • Chun Y.J;Lee J.H.;Lee E.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.108-113
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    • 2005
  • In this study, rotary type diamond dressing system for ultra-precision centerless grinding for ferrule was developed at the first time and experiments were conducted with AE sensor and hall sensor system to verify the optimum dressing condition for ultra-precision centerless grinding for ferrule. The correlations with the condition of dressing are evaluated by AE signal analysis with root mean square (RMS) and frequency analysis. And current signals from hall sensor are also studied as a factor of dressing optimum condition selection. Dressing process was conducted to investigate the effects of depth of cut, rotating speed, and the number of overlap to select the optimum condition of rotary dressing system of ultra-precision centerless grinding machine for ferrule fabrication. In order to verify the optimum condition of dressing, AE and current signals were compared with the surface quality of dressing wheel and grinding wheel for ultra-precision ferrule grinding. All of these experiments were completed by Taguchi Methodology to reduce experimental time. Hence, the optimum condition of rotary dressing system for ultra-precision centerless grinding for ferrule fabrication can be selected following to the experiment result from signals of AE and hall sensor.

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A Study on the Monitoring of Grinding Stability Using AE Sensor in Electrolytic In-Process Dressing Grinding (전해 인프로세스 드레싱 연삭에서 AE를 이용한 가공안정성 감시에 관한 연구)

  • Kim, Tae-Wan;Lee, Jong-Ryul;Lee, Deug-Woo;Song, Ji-Bok;Choi, Dae-Bong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.6 s.165
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    • pp.1011-1017
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    • 1999
  • Electrolytic in-process dressing grinding technique which enables application of metal bond wheels with fine superabrasives in mirror surface grinding operations has developed. It is possible to make efficient precision machining of hard and brittle material such as ceramic and hard metal by the employment of this technique. However, in order to ensure the success of performances such as efficient machining, surface finish, and surface quality, it is important to sustain the insulating layer that has sharply exposed abrasives in wheel surface. Using AE(Acoustic Emission) sensor, this paper will show whether the insulating layer sustains stably or not in real grinding time. And by comparing AErms value and surface roughness their thresholds for stable electrolytic in-process dressing grinding will be determined.

Internal Cylindrical Grinding with Super Abrasive Wheel and Electrolytic In- process Dressing (ELID를 이용한 초미립 숫돌의 원통내면연삭)

  • Jun Qian;Gyung Nyun Kim;Hitoshi Ohmori;Hae Do Jeong
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.4
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    • pp.155-162
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    • 2000
  • 전해 인프로세스 드레싱(ELID)의 응용기술로써 간헐적 드레싱(ELID II) 및 무전극 드레싱(ELID III)이 원통내면 마무리 연삭에 이용되고 있다. 주철본드(CIB-D) 및 메탈레진본드 다이아몬드 숫돌(HRB-D)이 이 방식들에 사용되고 있다. 경면 가공에 있어서 이 두방식은 미립의 숫돌이용으로 일반연삭기에 정밀부속 장치의 보완없이 이용될 수 있다. ELID II 연삭에서 CIB-D숫돌은 파이프 형상의 전극에 의하여 간헐적으로 드레싱되고, 반면에 MRB-D 숫돌은 인프로세스 드레싱 되며 전극은 필요로 하지 않는다. 본 연구에서는 ELID II 및 ELID III 방식에 있어서, 연삭조건 및 연삭입자크기에 대한 연삭특성을 비교검토 하였다. 그 결과, ELID II, III방식 공히 대단히 작은 표면거칠기를 갖는 경면이 얻어짐을 확인하였다.

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Wheel Loading Diagnosis and De-noising by Wavelet Transform (Wavelet 변환에 의한 숫돌로딩 진단과 노이즈 제거)

  • Yang, J.Y.;Ha, M.K.;Kwak, J.S.;Park, H.M.;Lee, S.J.
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.1 no.1
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    • pp.29-37
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    • 2002
  • The wavelet transform is a popular tool for studying intermittent and localized phenomena in signals. In this study the wavelet transform of cutting force signals was conducted for the diagnosis of grinding conditions in grinding process. We used the Daubechies wavelet analyzing function to detect a sudden change in cutting signal level. STD11 workpiece was 85 times of machined pieces cut by the WA wheel and a tool dynamometer obtained cutting force signals. From the results of the wavelet transform, the obtained signals were divided into approximation terms and detailed terms. At dressing time, the approximation signals were slowly increased and 45 machined times noticed dressing time.

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Manufacture of Lapping Wheel for Electrolytic Dressing and Evaluation of Electrolytic Characteristics (연속 전해드레싱용 래핑지석의 제작 및 전해 특성 평가)

  • 최재영;이은상;송지복
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.914-917
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    • 2000
  • Application of ceramics, carbide, ferrite has grown considerably due to significant improvement in their mechanical properties such as light weight, chemical stability , super wear resistance and electronical. Despite these character, the me of advanced material has not increased because of poor machinability. The method of using of metal bond wheel was proposed. But it is difficult that metal bond wheel can be dressed. Recently, the technology of in-process electrolytic dressing is developed to solve this problem. This method need wheel for electrolytic dressing, power supply and electrolyte. But development of wheel for electrolytic dressing is the most need. The aim of this study is development of wheel for electrolytic and appraisement of CIB-diamond lapping wheel

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