Patent ID: 8828514

Claim:
A heat-shrinkable fluororesin tube that covers a rotary member for a fixing device of an image-forming apparatus to form an outermost layer of the rotary member, wherein one or more linear scratch is present on a surface of the fluororesin tube, wherein a maximum depth of the one or more linear scratch on the surface of the fluororesin tube is 0.8 μm or less, and, in the case of a plurality of linear scratches being present on the surface of the fluororesin tube the depths of each of the plurality of linear scratches is suppressed to 0.8 μm or less so that no linear scratch has a depth of more than 0.8 μm; the fluororesin is a tetrafluoroethylene/perfluoroalkylvinylether copolymer (PFA); a maximum length of the linear scratch is 1 mm or less; the fluororesin tube has a thickness of 100 μm or less; the linear scratch extends in a direction tilted by an angle of 20° at the maximum with respect to the axial direction of the fluororesin tube; and the fluororesin tube is obtained by the method in which a tube inflated by sending air inside the tube is pinched with two pairs of pinch rollers, thereby filling the tube with air, and the distance between the pairs of pinch rollers is decreased to increase the internal pressure of the tube, thereby inflating the tube, and a surface of the inflated fluororesin tube is not rubbed with a fixing member.