• Title/Summary/Keyword: roll speed

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Development of Technology for Setting Rolling Speed of Finishing Rolling Process in Hot Strip Mill (열연 마무리 압연공정 압연롤 회전속도 설정 기술 개발)

  • Hong, Seong-Cheol;Lee, Haiyoung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.11
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    • pp.47-56
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    • 2013
  • Rolling speed, roll gap, and cooling pattern in hot strip finishing mill process should be determined before inserting strip into roll. Such parameters are initially calculated by a mathematical set-up model. The technique to find adequate roll speed via a mathematical model has inherently limit because required working conditions are various and rolling process is nonlinear. To improve the accuracy of initial rolling speed for a finishing mill, this paper suggests a correction technology for initial rolling speed. The proposed method was implemented in hot strip mill process. As the results, the magnitude of width error in strip head-end part caused by excessive strip tension was decreased remarkably.

Estimation of thickness variation due to skid mark Using Speedometer (속도계를 이용한 스키드 마크로 인한 두께 변동량 추정)

  • 이영교;조성은;김상우;홍성철
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.40-40
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    • 2000
  • Generally a RF AGC controls the roll gap using the variation of rolling force caused by the roll eccentricity and the entry thickness of material, but these can not be classified. The Feed- forward AGC method, which controls the next stand roll 9ap by estimation the skid mark of the previous stand output thickness is needed to supplement the shortage of RF AGC. In this paper, an improved filtering method of skid mark which take account of the kinds of materials, the final objective thickness and the roll speed is proposed, In addition, an improved estimation method of control point using the speedometer and looper angle is suggested, Via simulation, the performance improvement of the suggested FF AGC method is verified.

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Stability Analysis of the Tension Control System of a High-speed Roll-to-Roll Printing Machine (고속 롤투롤 인쇄기의 장력제어시스템 안정도 해석)

  • Kang, Chul-Goo;Lee, Bong-Ju
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.873-878
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    • 2007
  • Stability of high-speed roll-to-roll printing machines is one of the most important factors that are required for the printing machines to operate properly and to obtain reasonable printing performance. This paper proposes a new model for the web-tension system of a high-speed gravure printing machine considering span-length variations due to dancer rollers, and analyzes the stability of plant dynamics of the printing machine using the proposed model. Span-length variations due to dancer motions are considered for the modeling of plant dynamics in two ways; one is to include the effect of span-length variations without considering dancer inertias and viscous frictions, and the other is to include the effect of span-length variations with considering dancer inertias and viscous frictions. The stability of the plant model is analyzed for various web-speeds using the eigenvalues of the linearized model about operating points.

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Development of Deformation Texture in Aluminum Sheets during Asymmetrical Rolling with a Roll Speed Ratio of 1.5/l.0 (롤속도 비 1.5/l.0 비대칭 압연 시 알루미늄 판재에서 변형집합조직의 형성)

  • 지영규;정효태;허무영
    • Transactions of Materials Processing
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    • v.12 no.3
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    • pp.244-250
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    • 2003
  • Sheets of aluminum alloy 1100 were asymmetrically cold rolled in a rolling mill with different roll speeds. In order to promote the shear deformation during asymmetrical rolling, cold rolling without lubrication was performed with a roll speed ratio of 1.5/l.0. The evolution of texture components during asymmetrical rolling was investigated by the calculation of the orientation distribution function (ODF) using the monoclinic sample symmetry. The strain state during asymmetrical rolling was tackled by means of FEM calculations. Asymmetrical rolling gave rise to the development of pronounced strain gradients throughout the thickness layers which resulted in the formation of strong texture gradients in the aluminum sheet.

Analysis of tension properties at roll changing process of a high speed printing machine (고속인쇄기 롤 교체과정의 장력특성 해석)

  • Lee B.J.;Kim S.H.;Kang C.G.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.281-282
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    • 2006
  • Tension control performance is very important in high-speed printing machine. One of the major factors that effect to tension control performance is the process of roll changing. Even if the turret arm moves during roll changing process and the span length of the unwinding system varies, it is customary to neglect it in motion and tension control and to consider it as a disturbance. In this paper, its effect is modeled nonlinearly and compared with linear model, and an effect of an infeeder dancer is analyzed under the condition with no unwinder dancer. We verify the performance of the proposed method via simulation in the high-speed printing machine.

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Development of High Precision Forward Slip Model By Using Roll Torque in Hot Strip Finishing Mill (압연롤 토크를 이용한 열연박판 마무리압연 선진율 예측 정밀도 개선연구)

  • 문영훈;김영환
    • Transactions of Materials Processing
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    • v.8 no.6
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    • pp.583-590
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    • 1999
  • New forward slip model has been developed for the precise prediction of rolling speed in the hot strip finishing mill. Besides those influential factors such as neutral point, work roll diameter, friction coefficient, bite angle and the thickness at each side of entry and delivery of the rolls, roll torque was specifically taken into account in this study. To consider the effect of width change on forward slip, calibration factors obtained from rolling torque has been added to new prediction model and refining method has also been developed to reduce the speed unbalance between adjacent stands. The application of the new model showed a good agreement in rolling speeds between the predictions and the actual measurements, and the standard deviation of prediction error has also been significantly reduced.

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Parameter Analysis for the Lateral Thickness of the Coated Layer to Improve Product Quality in Large Area Roll-to-Roll Slot-Die Coating Process (대면적 롤투롤 슬롯-다이 코팅의 횡 방향 두께 품질 개선을 위한 공정 파라미터 분석)

  • Park, Janghoon;Lee, Changwoo
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.2
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    • pp.159-166
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    • 2015
  • Slot-die coating is well known technique to guarantee a uniformly coated layer and is compatible with roll-to-roll process. In actual roll-to-roll slot-die coating process, the lateral difference of coated layer thickness is observed. An experimental study was performed to improve the coating quality. Coating speed and coating gap were selected as the experimental factors. A full factorial, statistical method was conducted to optimize the process conditions. Based on the results of repeated experiment, the lowest deviation of lateral thickness (700 nm, <10%) was achieved at 10 m/min coating speed and $300{\mu}m$ coating gap. This result has significance because such optimized process guideline can be utilized with all process improvement in various coating applications.

Load Sharing Control by Following Average Torque Current in Continuous Casting (연속 주조 공정에서 평균 토크전류 추종에 의한 인발력 분배 제어)

  • Chun, Chang-Keun;Kim, Cheul-U
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.3
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    • pp.74-80
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    • 2004
  • If the withdrawal force of strand driven roll which is controlled with predetermined speed isn't distributed regularly in continuous casting process, mold level is changed cyclically and slab quality is not good. In this paper, both casting speed control and load sharing control algorithm of strand driven roll according to ratio which is set up by operator at same time is proposed. The proposed algorithm is to share the withdrawal force by following torque current of each driven roll as average torque current by changing speed reference of each driven roll motor. The load sharing control with anti-wind up for improvement transient state is adopted and the proposed algorithm is implemented in POSCO pilot caster.

Investigation of Nanopore Shape Formed on an Aluminum Roll Mold with Various Anodizing Conditions (다양한 양극산화 공정조건에 따른 롤 금형 표면에 형성되는 나노포어 형상에 대한 연구)

  • Ryu, In Gon;Han, Eui Don;Kim, Byeong Hee;Seo, Young Ho
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.2
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    • pp.166-171
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    • 2017
  • This study analyzes the effect of anodizing conditions on nanopore formation on a cylindrical aluminum roll. In general, a nanopore is formed at the center of a concave base-pattern. Occasionally, multiple nanopores are formed on a single base-pattern. However, to control the diameter and interpore distance precisely, single nanopores are required. In this study, the ratio of the number of single nanopores to the total number of nanopores was investigated by varying anodizing conditions such as electrode area, electrolyte concentration, and rotation speed of the roll mold. The areal ratio of the counter-electrode to the working electrode (aluminum), electrolyte concentration, and the roll-mold rotation speed were varied from 0.4% to 42%, 0.07 M to 0.3 M, and 5 rpm to 75 rpm, respectively. The experimental results showed that the single-nanopore ratio increased with increasing counter-electrode area and electrolyte concentration. However, the rotation speed had no significant effect on nanopore shape.