M. Nagai, S. Shigemura, Tocalo Co., Ltd., Akashi-City, Hyogo, Japan; A. Yoshiya, Mitsubishi Plastics, Inc., Chuo-ku, Tokyo, Japan
Carbon rollers composed mainly of carbon fiber reinforced plastics (CFRP) have great advantages over metal rollers, such as light weight, low inertia, less deflection, and high natural frequency. Thermal spraying is a key technique to give carbon roller surface excellent abrasion resistance. But there are some technology hurdles. When carbon rollers are used in dryer part of paper machine, the highest hurdle is wide temperature changes (150°C - room temperature) at almost 100% water vapor environment. At the temperature changes, the water vapor is also changed to water and the water fall down on roller surface. High repeated thermal shock resistance is required to the surface material. The thermal sprayed carbon roller we’ve developed has not only the thermal shock resistance but also excellent abrasion resistance. The rollers are rotating in the dryer part and inhibiting the fluttering of running paper. As a result, the machine speed has been increased up to 10%.
