Method of processing roll

Abstract

Method for correcting deflection of a plastic roll under conditions of use. A drilled roll for processing thermoplastic material such as vinyl or the like is deflected during the use due to a thermal distortion to cause a thickness fluctuation in the rolled products. To extinguish this deflection, the roll is corrected by a process having the steps of heating the roll up to the operating temperature, measuring the amount and direction of the deflection of the heated roll, cooling the roll to the room temperature, mechanically imparting to the roll a deflection of the same amount and direction as those observed in the heated roll, and processing the roll by grinding the roll in the mechanically deflected state. After the processing, the roll exhibits an apparent deflection of the same amount in the opposite direction to those exhibited in the heated state, as it is relieved from the mechanical deflecting force. Then, as the roll is heated to the operating temperature before the rolling work, the roll is thermally deflected to negate the apparent deflection so that the rolling is effected by the roll surface having no apparent deflection.