• Title/Summary/Keyword: Polishing time

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The evaluation of surface roughness and polishing time between polishing systems (연마시스템에 따른 복합레진의 표면거칠기와 연마시간에 대한 평가)

  • Kim, Ye-Mi;Shin, Su-Jung;Song, Min-Ju;Park, Jeong-Won
    • Restorative Dentistry and Endodontics
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    • v.36 no.2
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    • pp.119-124
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    • 2011
  • Objectives: The purpose of this experiment was to evaluate four different polishing systems of their polishability and polishing time. Materials and Methods: 4 mm diameter and 2 mm thickness Teflon mold was made. Z-250 (3M ESPE) hybrid composite resin was slightly overfilled and pressed with slide glass and cured with Optilux 501 for 40 sec each side. Then the surface roughness (glass pressed: control group) was measured with profilometer. One surface of the specimen was roughened by #320 grit sand paper and polished with one of the following polishing systems; Sof-Lex (3M ESPE), Jiffy (Ultradent), Enhance (Dentsply/Caulk), or Pogo (Dentsply/Caulk). The surface roughness and the total polishing time were measured. The results were analyzed with one-way ANOVA and Duncan's multiple range test. Results: The surface roughness was lowest in Pogo, and highest in Sof-Lex. Polishing times were shortest with Pogo, and followed by the Sof-Lex, Enhance and Jiffy. Conclusions: One-step polishing system (Pogo) is very effective to get the smooth surface in a short time, therefore it can be recommended for final polishing system of the restoration.

Effect of Recycling Time on Stability of Colloidal Silica Slurry and Removal Rate in Silicon Wafer Polishing (연마 Recycling 시간에 따른 콜로이드 실리카 슬러리의 안정성 및 연마속도)

  • Choi, Eun-Suck;Bae, So-Ik
    • Journal of the Korean Ceramic Society
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    • v.44 no.2 s.297
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    • pp.98-102
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    • 2007
  • The stability of slurry and removal rate during recycling of colloidal silica slurry was evaluated in silicon wafer polishing. The particle size distribution, pH, and zeta potential were measured to investigate the stability of colloidal silica. Large particles appeared as recycling time increased while average size of slurry did not change. Large particles were identified by EDS(energy dispersive spectrometer) as foreign substances from pad or abraded silicon flakes during polishing. As the recycling time increased, pH of slurry decreased and removal rate of silicon reduced but zeta potential decreased inversely. Hence, it could be mentioned that decrease of removal rate is related to consumption of $OH^-$ ions during recycling. Attention should be given to the control of pH of slurry during polishing.

Development of Automatic System for Die Polishing (금형의 자동연마 시스템 개발)

  • 안중환;정해도;이민철;전차수;이만형;조규갑
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.4
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    • pp.69-80
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    • 2000
  • Generally, die polishing is a lime consuming process, resulting in 30∼50% of the whole die manufacturing time. However, die polishing has not been automated yet, since it needs a great deal of experience and skill. This paper describes a new development of automated system for die polishing and focuses on the successful achievements of the element techniques to realize from hand skill to automation, as followings: (1) The 5 axes polishing system by the aid of robot with 2 degrees of freedom, is developed for the application of curved surface die. (2) The CAM system realizes a 5 axes tool path control for polishing and measuring. (3) The conductive elastic tool is able to meet curved surfaces of die and gives a high efficient and quality polishing characteristics. (4) The surface roughness measurement device with noncontact laser is developed and has a high reliability without surface damage.

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A Study on Internal Surface Finishing of Tube Using Magnetic Assisted Polishing (원통내면의 자기연마에 관한 연구)

  • 이용철;박상길;송치성;이종렬;이득우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.792-795
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    • 2000
  • The magnetic assisted finishing thought to be one of the potential methods for the automatic polishing process. In this study, magnetic assisted finishing process was experimentally attempted to polish the intrnal surface of the cylindrical tube. The newly developed magnetic tool was used, and its polishing performance exmined. From the experimental results, it is found that i ) the newly developed tool is suitable for intrnal surface finishing of the tube. ii ) the surface roughness of 0.9~1${\mu}{\textrm}{m}$Rmax before polishing is improved to the value of 0.2 ${\mu}{\textrm}{m}$Rmax in the finishing experiment of stainless steel STS3602L tube in 6 minutes finishing time.

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Monitoring of Break-in time in Si wafer polishing (실리콘 웨이퍼 연마에서의 Break-in 모니터링)

  • Jeong, Suk-Hoon;Park, Boum-Young;Park, Sung-Min;Lee, Sang-Jik;Lee, Hyun-Seop;Jeong, Hae-Do;Bae, So-Ik;Choi, Eun-Suck;Baeck, Kyoung-Lock
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.360-361
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    • 2005
  • Rapid progress in IC fabrication technology has strong demand in polishing of silicon wafer to meet the tight specification of nanotopography and surface roughness. One of the important issues in Si CMP is the stabilization of polishing pad. If a polishing pad is not stabilized before main Si wafer polishing process, good polishing result can not be expected. Therefore, new pad must be subjected into break-in process using dummy wafers for a certain period of time to enhance its performance. After the break-in process, the main Si wafer polishing process must be performed. In this study, the characteristics of break-in process were investigated in Si wafer polishing. Viscoelastic behavior, temperature variation of pad and friction were measured to evaluate the break-in phenomenon. Also, it is found that the characteristic of the break-in seems to be related to viscoelastic behavior of pad.

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Effect of electropolishing process time on electrochemical characteristics in seawater for austenitic stainless steel (오스테나이트 스테인리스강의 해수에서 전기화학적 특성에 미치는 전해연마시간의 영향)

  • Hwang, Hyun-Kyu;Shin, Dong-Ho;Heo, Ho-Seong;Kim, Seong-Jong
    • Journal of the Korean institute of surface engineering
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    • v.55 no.4
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    • pp.236-246
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    • 2022
  • Electropolishing is a surface finishing treatment that compensates for the disadvantages of the mechanical polishing process. It not only has a smooth surface, but also improves corrosion resistance. Therefore, the purpose of this investigation is to examine the corrosion resistance and electrochemical characteristics in seawater of UNS S31603 with electropolishing process time. The roughness improvement rate after electropolishing was improved by about 78% compared to before polishing, indicating that the electropolishing is effective. As a result of potential measuring of mechanical polishing and electropolishing, the potential of electropolishing was nobler than the mechanical polishing condition. As a result of calculating the corrosion current density after potentiodynamic polarization experiment with electropolishing conditions, the corrosion current density of mechanical polishing was about 6.4 times higher than that of electropolishing. After potentiodynamic polarization experiment with electropolishing conditions, the maximum damage depth of mechanical polishing was about 2.2 times higher than that of electropolishing(7 minutes). In addition, the charge transfer resistance of the specimen electropolished for 7 minutes was the highest, indicating improved corrosion resistance.

Identifying Factors Affecting Surface Roughness with Electropolishing Condition Using Full Factorial Design for UNS S31603 (UNS S31603에 대하여 완전요인설계를 이용한 전해연마조건에 따른 표면 거칠기의 유효인자 산출)

  • Hwang, Hyun-Kyu;Kim, Seong-Jong
    • Corrosion Science and Technology
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    • v.21 no.4
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    • pp.314-324
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    • 2022
  • The objective of this investigation was to indentify major factors affecting surface roughness among various parameters of electropolishing process using the design of an experiment method (full factorial design) for UNS S31603. Factors selected included electrolyte composition ratio, applied current density, and electrolytic polishing time. They were compared through analysis of variance (ANOVA). Results of ANOVA revealed that all parameters could affect surface roughness, with the influence of electrolyte composition ratio being the highest. As a result of surface analysis after electropolishing, the specimen with the deepest surface damage was about 35 times greater than the condition with the smallest surface damage. The largest value of surface roughness after electropolishing was higher than that of mechanical polishing due to excessive processing. On the other hand, the smallest value of surface roughness after electropolishing was 0.159 ㎛, which was improved by more than 80% compared to the previous mechanical polishing. Taken all results together, it is the most appropriate to perform electrolytic polishing with a sulfuric acid and phosphoric acid ratio of 3:7, an applied current density of 300 mA/cm2, and anelectrolytic polishing time of 5 minutes.

Color Stability of Self-Cured Temporary Crown Resin according to Different Surface Treatments (자가중합 임시치관용 레진의 표면 처리에 따른 색 안정성)

  • Park, Ji-Won;Bae, Sung-Suk
    • Journal of dental hygiene science
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    • v.16 no.2
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    • pp.150-156
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    • 2016
  • In this study, the surface treatment of a self-cured temporary crown was polished using a denture bur, silicone bur, or pumice. The color stability of the temporary crown resin specimen was evaluated by immersing it in coffee, and cola, wine, beer, red pepper paste, or soybean paste. Two-hundred eighty-five identical resin specimens with six types of staining solution and three types of surface treatment were placed in a shaking incubator at $37^{\circ}C$. The degree of discoloration was observed using a time-lapse recording of days 1, 5, and 7. $L^*$, $a^*$, and $b^*$ were measured using a spectrophotometer, which shows the quantitative value of discoloration, and statistically processed after calculating ${\Delta}E^*$. The results show that as time passed, all the specimens showed a color change (p<0.001). The amount of color change was the greatest in in crowns with denture bur polishing on the day 1, 5, and 7. As the precipitation time increased, the ${\Delta}E^*$ value was also increased. Of the specimens immersed on day 1, the greatest color change in crowns polished with denture bur was observed in those immersed in red pepper paste, while the smallest color change was observed in those immersed in cola. On days 5 and 7, the greatest color change in crowns polished with denture bur was observed in those immersed in red wine. Crowns polished with silicone bur and immersed in soybean paste exhibited the smallest color change. Based on the results, compared to pumice polishing, silicone bur polishing results in better color stability, saves time and money, and is recommended for patients with temporary crowns.

Development of polishing tool system for robot (로보트용 금형 연마 공구 시스템의 개발)

  • 박종오;이대엽
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.190-193
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    • 1990
  • Die finishing (polishing and lapping) after NC machining is characterized as one bottleneck process for reducing lead time. For automation of this typical manual work, a flexible polishing tool system using industrial robot has been developed. This tool system has three principal functions in order to achieve reduction of waviness, 3 D.O.F. compliance and constant pressure structure. This polishing tool shows that adaptability to free form surface is increased and programmability to various areas of die surface is also acquired.

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Optimization of Polishing Conditions for Anodized Inner Surfaces in Large Hydraulic Devices (아노다이징 처리된 대형 유압장치의 내면에 대한 연마 조건의 최적화)

  • Choi, Su-Hyun;Cho, Young-Tae
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.7
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    • pp.14-21
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    • 2019
  • Large-diameter hydraulic devices such as the hydraulic reservoir in aircraft that serves to balance the hydraulic pressure in the various hydraulic devices in the cabin and to store hydraulic oil are operated by the internal piston systems. However, since this operates in an environment with high temperature and humidity, it may cause the inner surface to flake during its operation. Therefore, an anodizing surface treatment is applied to improve the corrosion resistance, abrasion resistance, and smooth operation. However, anodizing increases the surface roughness. Accordingly, the polishing process that improves the surface roughness after anodizing is important. However, the existing polishing process is performed manually, which results in an inefficient process. Therefore, in this study, we selected the optimum polishing conditions for effective polishing using the experimental design to improve the polishing process for the $Al_2O_3$ film that forms after anodization. Through experiments, we confirmed that the surface uniformity after polishing was superior as the feed rate was slower when the same polishing time had been applied.