A paper-quality monitor using a quartz-crystal tuning-fork tactile sensor

Sample sheets of five kinds of papers (fine paper, newspaper paper, copy paper, semi-fine paper, and straw paper in `hanshi´ size) were each fixed on copper plates with acrylic resin paste or placed on copper plates or silicone rubber. In the case of both the fixed papers and the papers placed on silicone rubber under application of a certain load onto the sensor, the quartz-crystal tuning-fork impedance change decreased in the order listed above when the sensor´s base was brought into contact with the papers. These results have been found to correspond with the ratio of pulp to recycled paper ingredient. This sensor functions as a paper-quality sensor capable of sensing the mixing ratio of pulp to recycled paper ingredient