• Title/Summary/Keyword: roll speed

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Establishment of Manufacturing Conditions for Magnesium Alloy Thin Plate using Melt Drag Method (용융드래그방법을 이용한 마그네슘 합금 박판의 제조조건 확립)

  • Han, Chang-Suk;Kwon, Yong-Jun
    • Korean Journal of Materials Research
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    • v.31 no.9
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    • pp.511-518
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    • 2021
  • An investigation is performed to clarify the manufacturing conditions of pure magnesium and AZ31 magnesium alloy thin plate using the melt drag method. By the melt drag method, suitable for magnesium molten metal, pure magnesium can be produced as a continuous thin plate with a thickness of 1.4 mm to 2.4 mm in the range of 5 m/min to 20 m/min of roll speed, and the width of the thin plate to the nozzle outlet width. AZ31 magnesium alloy is able to produce a continuous sheet of thickness in the range of 5 m/min to 30 m/min in roll circumferential speed, with a thickness of 0.6 mm to 1.6 mm and a width of the sheet matching the nozzle outlet width. In the magnesium melt drag method, the faster the circumferential speed of the roll, the shorter the contact time between the molten metal and the roll, and it is found that the thickness of the produced thin plate becomes thinner. The effect of the circumferential roll speed on the thickness of the thin plate is evident in the low roll circumferential region, where the circumferential speed is 30 m/min or less. The AZ31 thin plate manufactured by the melt drag method has a finer grain size as the thickness of the thin plate decreases, but it is currently judged that this is not the effect of cooling by the roll.

A Study on Rudder-Roll Stabilization System Design for Ship with Varying Ship Speed (선박 주행속도 변화를 고려한 Rudder-Roll Stabilization System 설계에 관한 연구)

  • Kim, Young-Bok;Chea, Gyu-Hoon
    • Journal of Institute of Control, Robotics and Systems
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    • v.8 no.5
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    • pp.363-372
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    • 2002
  • In ship operation, the roll motions can seriously degrade the performance of mechanical and personnel effectiveness. So many studies for the roll stabilization system design have been performed and good results have been achieved. In many studies, the stabilizing fins are used. Recently rudders, which have been extensively modified, have been used exclusively to stabilize the roll. But, in the roll stabilization control system, the control performance is very sensitive to the ship speed. So, we can see that it is important to consider the ship speed in the rudder roll control system design. The gain-scheduling control technique is very useful in the control problem incorporating time varying parameters which can be measured in real time. Based on this fact, in this paper we examine the;$H_{\infty}$-Gain Scheduling control design technique. Therefore, we assume that a parameter, the ship speed which can be estimated in real time, is varying and apply the gain-scheduling control technique to design the course keeping and anti-rolling control system far a ship. In this control system, the controller dynamics is adjusted in real-time according to time-varying plant parameters. The simulation result shows that the proposed control strategy is shown to be useful for cases when the ship speed is varying and robust to disturbances like wind and wave.

Study on Spring-Back Effect according to Roll Gap and Forming Velocity of Roll Forming Process (롤 포밍 공정의 롤 갭과 성형속도에 따른 스프링 백 영향 연구)

  • Kim, Dong Hong;Yoon, Dae-Hwan;Seol, Sang-Seok;Jung, Dong Won
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.6
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    • pp.477-483
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    • 2016
  • The spring-back and bow phenomenon in the roll forming process are important factors regarding the accuracy of evaluation of production goods. The purpose of this study was to determine the influence of spring-back and bow phenomenon according to the main variables (forming velocity and roll gap). The material of the forming sheet was high tension steel (SPFH 590), which has been used commonly in recent years. In order to accurately measure the spring-back and bow phenomenon, the forming sheet was formed into a V-shape. The study was applied to OFAT (One Factor at a Time) experimentation, with respect to the experimental variables (the forming speed and the roll gap). In the experimental results, the forming speed had a small influence on the spring-back and bow phenomenon. However, the roll gap had a greater influence on the springback and the bow phenomenon, as opposed to the forming speed.

Technology of Stip Rolling of Shadow Mask Steel Plate By Reversing Cold Rolling Mill (가역식 냉간압연기의 Shadow Mask재 압연기술)

  • 김광수;박성권;이중웅;김종호
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.08a
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    • pp.403-411
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    • 1999
  • The steel plate for shadow mask is used in a Cathode-ray tube of TV monitor and is the strictest product in surface quality because hundreds thousand of holes are perforated in a plane of 25 ${\times}$25 inches. To mass-produce this product, a reversible cold rolling mill for silicon steel was used and the rolling technology and the activity for quality improvement are described in this work. Because the steel plate is a mild steel, which is very sensitive to strip-breakage even in a low tension, we reset the minimum tension values matching to the operating conditions. The roll mark due to the multi-segmented araangement of shape controlling roll was prevented by hardening the intermediate shape controlling roll and by changing the existing working-roll into a HSS (Hig Speed Steel) roll. The scratch caused by the speed difference between a idle roll and a strip was prevented by increasing the roll roughness. With these activities, the steel plate for shadow mask can be stable. The continuous improvement of quality is, however, required for the customer satisfaction both of domestic and overseas market.

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Register Control on Compensator Roll type Converting Machines (보상롤 타입 컨버팅 머신의 레지스터 제어)

  • Kang Hyun-Kyoo;Kim Jung-In;Shin Kee-Hyun
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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    • pp.323-324
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    • 2006
  • This paper presents dynamics of register error on a compensator roll type converting machine. Though a register control is an important aspect of a converting machine, it has not been taken into account as a main subject. Lately, demands for high speed converting machines over 500mpm(m/min) are raising but domestic converting industries can not come up with the high speed machines because capacities fur designing of the converting machine is restricted lower than 300mpm. Moreover register control is the key to product flexible displays through roll-to-roll systems. In this paper, a compensator roll type register controller is analyzed using mathematical model of register error. A case study for reducing transient register errors is discussed.

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Statistical Analysis on Process Variables in Linear Roll-CMP (선형 Roll-CMP에서 공정변수에 관한 통계적 분석)

  • Wang, Han;Lee, Hyunseop;Jeong, Haedo
    • Tribology and Lubricants
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    • v.30 no.3
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    • pp.139-145
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    • 2014
  • Nowadays, most micro-patterns are manufactured during flow line production. However, a conventional rotary chemical mechanical polishing (CMP) system has a limited throughput for the fabrication of large and flexible electronics. To overcome this problem, we propose a novel linear roll-CMP system for the planarization of large-area electronics. In this paper, we present a statistical analysis on the linear roll-CMP process of copper-clad laminate (CCL) to determine the impacts of process parameters on the material removal rate (MRR) and its non-uniformity (NU). In the linear roll-CMP process, process parameters such as the slurry flow rate, roll speed, table feed rate, and down force affect the MRR and NU. To determine the polishing characteristics of roll-CMP, we use Taguchi's orthogonal array L16 (44) for the experimental design and F-values obtained by the analysis of variance (ANOVA). We investigate the signal-to-noise (S/N) ratio to identify the prominent control parameters. The "higher is better" for the MRR and "lower is better" for the NU were selected for obtaining optimum CMP performance characteristics. The experimental and statistical results indicate that the down force and roll speed mainly affect the MRR and the down force and table feed rate determine the NU in the linear roll-CMP process. However, over 186.3 N of down force deteriorates the NU because of the bending of substrate. Roll speed has little relationship to the NU and the table feed rate does not impact on the MRR. This study provides information on the design parameter of roll-CMP machine and process optimization.

Focused-Infrared-Light Assisted Roll-to-Roll Hot Embossing (Focused Infrared Light를 이용한 롤투롤 핫엠보싱)

  • Jo, Jeongdai;Kim, Wooseop;Kim, Kwang-Young;Choi, Young-Man
    • Journal of the Korean Society for Precision Engineering
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    • v.34 no.3
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    • pp.199-203
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    • 2017
  • Hot embossing techniques are used to engrave patterns on plastic substrates. Roll based hot embossing uses a heated roll for a continuous process. A heated roll with relief patterns is impressed on a preheated plastic substrate. Then, the substrate is cooled down quickly to prevent thermal shrinkage. The roll speed is normally very slow to ensure substrate temperature increase up to the glass transition temperature. In this paper, we propose a noncontact preheating technique using focused infrared light. The infrared light is focused as a line beam on a plastic substrate using an elliptical mirror just before entering the hot embossing roll. The mid range infrared light efficiently raises the substrate temperature. For preliminary tests, substrate deformation and temperature changes were monitored according to substrate speed. The experiments show that the proposed technique is a good possibility for high speed hot embossing.

Development of Feed-forward AGC using Adaptive Control Algorithm (적응기법을 이용한 Feed-forward AGC 기술 개발)

  • 홍성철;이영교
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.05a
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    • pp.168-171
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    • 2003
  • Generally RF AGC (Roll Force Automatic Gauge Control) controls the roll gap using the variation of rolling force caused by the roll eccentricity and the entry thickness of material, but RE AGC takes the bad effect of the roll eccentricity. The Feed-forward (FF) AGC method, which controls the next stand roll gap by the estimation of the thickness variation due to skid mark is needed to supplement the shortage of RF AGC. In this paper, an adaptive filtering method which takes account of the kind of material, the final objective thickness and the rolling speed is proposed to predict skid mark thickness variation. In addition, an improved estimation method of control point using a speedometer and looper angle is suggested. Via on line test, the performance improvement of the suggested FF AGC method is verified.

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Application of Machine Learning to Predict Web-warping in Flexible Roll Forming Process (머신러닝을 활용한 가변 롤포밍 공정 web-warping 예측모델 개발)

  • Woo, Y.Y.;Moon, Y.H.
    • Transactions of Materials Processing
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    • v.29 no.5
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    • pp.282-289
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    • 2020
  • Flexible roll forming is an advanced sheet-metal-forming process that allows the production of parts with various cross-sections. During the flexible process, material is subjected to three-dimensional deformation such as transverse bending, inhomogeneous elongations, or contraction. Because of the effects of process variables on the quality of the roll-formed products, the approaches used to investigate the roll-forming process have been largely dependent on experience and trial- and-error methods. Web-warping is one of the major shape defects encountered in flexible roll forming. In this study, an SVR model was developed to predict the web-warping during the flexible roll forming process. In the development of the SVR model, three process parameters, namely the forming-roll speed condition, leveling-roll height, and bend angle were considered as the model inputs, and the web-warping height was used as the response variable for three blank shapes; rectangular, concave, and convex shape. MATLAB software was used to train the SVR model and optimize three hyperparameters (λ, ε, and γ). To evaluate the SVR model performance, the statistical analysis was carried out based on the three indicators: the root-mean-square error, mean absolute error, and relative root-mean-square error.

Dynamics and Instability of a Polymeric Paint in Roll Coating Process for Automotive Pre-coating Application (자동차 선도장을 위한 롤코팅 공정에서 고분자 도료의 동적 거동 및 불안정성)

  • Kim, Jin-Ho;Lee, In-Jun;Noh, Seung-Man;Kang, Choong-Yeol;Nam, Joon-Hyun;Jung, Hyun-Wook;Park, Jong-Myung
    • Polymer(Korea)
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    • v.35 no.6
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    • pp.574-579
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    • 2011
  • 3-Roll coating process as a key application technology for manufacturing automotive pre-painted metal-sheets has been studied. The 3-Roll coating system for this study consists of pick-up roll for picking up and distributing coating liquid from the reservoir, metering roll to properly meter coating liquid in metering gap regime, and applicator roll for directly transferring liquid into metal-sheet surface. Flow dynamics and operable coating windows of a polymeric paint (primer) with shear-thinning rheological property have been correlated with processing parameters such as speed ratio and metering gap between pick-up and metering rolls. In the uniform coating regime, dry coating thickness increased with increasing metering gap or decreasing speed ratio. Ribbing and cascade instabilities were observed in low speed and high speed ratio conditions, respectively. It is revealed that lower speed ratio makes severity and wavelength of the ribbing increase, aggravating flow instability in coating systems.