TOP ROLLER, FLOAT GLASS PRODUCTION DEVICE, AND FLOAT GLASS PRODUCTION METHOD

摘要

Disclosed is a top roller wherein it is difficult for a coolant water duct to become narrowed or obstructed, and which operates appropriately over the long term. The top roller is used for restraining the contraction of a molten glass ribbon within a float bath, contacts the aforementioned molten glass ribbon, has a rotatable end, said end having a hollow structure with an end space inside, and is characterized by coolant water having a hardness of no more than 100 (mg/liter) flowing through the aforementioned end space.