抄録
Most of multicolor web rotary presses have been equipped with automatic control devices of paper tension for keeping correct registration of prihting with the uniform tension. It seems to be, however, the devices are not proving adequately in their abilities, for the improvement we measured both quantities of paper tension and misregistration during printing, and could clarify scientifically a part of relations between them.
In measuring as to the paper tension a strain gauge was utilized, being applied on guide roller arm and carried out a benting variation of the arm on electromagnetic oscillographs, and as to the misregistration actual printed matters, identified with the above measuring, are sampled for the measuring. The results are following.
1. The stronger tension makes the misregistration at the front in printing but at the back as the tension turns to weaken.
2. An average range of the paper tension in printing is 13-40kg/m and the maximum fluctuation rate is about 100%.
3. The misregistration depends on the absolute quantity of the tension and also on its fluctuating periodicity.
4. A time constant of the tension fluctuation, spreading throughout printing units, can be explained approximately as the following formula: T=Li/v Where T: time of constant Li: distance between printing units V: speed of printing paper
