• Journal of Mechanical Science and Technology
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• v.15 no.9
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• pp.1207-1216
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• 2001

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.48-50
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• 2005

This paper presents the design and development of web control algorithm of continuous process control system using vector inverter. The Diameter of web is calculated, tension is controlled by PID control and the speed reference of motor is calculated at current diameter. The performance of web control in this paper is verified by experiment.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.6
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• pp.81-89
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• 2009

Dancer systems are typical equipment for attenuation of tension disturbances. Lately, demands for high speed roll-to-roll machines are rising but it is prior to attenuate the tension variation on the web entering into the printing zone to achieve the speed increment. Maintaining a constant tension before the first printing cylinder is the key of high speed, high quality printing. Dancer has been researched in two ways, whether it is controlled or not. The first one is active dancer and the other one is passive dancer. In the active dancer, a position of idle roll of dancer is measured and the roll is moved by external hydraulic cylinder to control tension disturbances. While the passive one composed with spring, damper and idle roll has no external actuator to position the idle roll. The tension disturbance causes movement of dancer roll and the displacement of the roll regulates the tension variation. On the other hand a composite type of dancer is applied for roll-to-roll printing machines. It has same apparatus as passive dancer. The displacement of roll is measured and front(or rear) driven roller is controlled to position the roll. In this paper, it is presented an analysis of pendulum dancer including position feedback PI control and logic for PI gain tuning in roll-to-roll machines. Pole-zero map and root locus with varying system parameters gives a design method for control of the dancer.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.5
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• pp.9-15
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• 2013

Roll-to-roll printing technology has lately become a subject of special interests in the field of printed electronics. Since this technology has the advantage that continuous and mass production is possible. And for high precision register control is required in multi-layer printing to produce the electronic devices, this is one of the most important technologies in roll-to-roll printing technology. Register error could be generated by various reasons like eccentricity of roll and thermal deformation due to temperature variation in drying section. In this study, the effect of tension variation on the register was analyzed. The results of these analyses show that it is essential to consider the tension disturbance which is generated by the change of temperature in drying section, and conventional register model has limitation to estimate the register error. In order to overcome the limitation of the register model, advanced register model based on the SI process was developed. Also, the performance of the developed model was verified experimentally.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.3
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• pp.217-223
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• 2016

In this research, a continuous roll-to-roll screen printing system was developed using a flat screen. It has a newly devised sliding mechanism of screen printing module, which can be controlled accurately in sync with a moving web, driven by a roll-to-roll tension control and web-guiding system. In addition, the real-time precision alignment module that consists of a vision camera and an $X-Y-{\theta}$ alignment stage was implemented. With this developed system, the feasibility of continuous printing with minimum pattern width below $60{\mu}m$ was verified, and an overlay of ${\pm}60{\mu}m$ between the laser-patterned reference mark and the printed mark on a 300-mm-wide film was achieved.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.1 s.113
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• pp.21-26
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• 2006

A simple method of on-line stiffness measurement using the wrinkling behavior of paper web between rollers was developed. The theory and calculating equation were presented, and the theoretical maximum error associated with the equation was also presented. We called the stiffness measured by Taber tester as 'Taber stiffness', and by wrinkling behavior as 'wrinkle stiffness', respectively, for comparison. By using this method, on-line complete control of paper stiffness will be possible in near future. Special care about shear wrinkle and paper dimensional effects were addressed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.321-322
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• 2006

In many manufacturing processes such as web formation, manufacturing of paper and nonwoven, fabric weaving, etc., planar sheets are transported and at the same time appropriate tension is imposed. The input material rolled up on beams is fed by unwinding the beam and the processed is then taken up on beams by winding it. While processed, the planar sheets are thrown under the processing load of impulse form, which causes irregular thickness of the processed sheet. To improve the quality of the product, a dynamic model is needed and the dynamic characteristics is to be analyzed by simulation. This study shows that density variation dynamics of the in-process-sheet in the machine direction can be described at each moment of disturbing impacts in forms of difference equations, while the impacts and tension, the time-dependency of the material properties were taken into account. Simulation showed the most serious variation of the density occurred in the process starting phase. The starting velocity curve with step form showed the least variation of the density. As the time order of the function of the starting velocity cure becomes higher, the density variation gets greater.