PURPOSE: To facilitate disengagement of a pressing member from a shaft and to prevent degradation of the pressing member due to heat of a heater roll by including the pressing member which is provided with a groove corresponding to the shaft and shaped in a sector in the cross section and mounting members formed at both ends of the pressing member.

CONSTITUTION: In a pressure roll 184, a pressing member 198 can be disengaged from a shaft 204 by disengaging a bolt 210 from a female screw part 206 of a mounting part 200. In this instance, as a groove 202 corresponding to the shaft 204 is formed in a semicircular column, the pressing member 198 can be disengaged easily from the shaft 204 without displacing the member 198 in a longitudinal direction of the shaft 204 for disengagement. In addition, as the pressing member 198 shaped in a semicircular column is always kept out of a contact with a heater roll 182, the member 198 is protected from degradation due to heat of the heater roll 182.