Abstract: A method of manufacturing a vitreous silica crucible includes: a taking-out process of taking out the vitreous silica crucible from the mold, a honing process of removing the unfused silica powder layer on the outer surface of the vitreous silica crucible, and further comprising, after the taking-out process and before the honing process, a marking process of marking an identifier comprised of one or more groove line on the outer surface of the vitreous silica crucible, wherein the groove line after the honing process has a cross-sectional shape of an inverse trapezoid and a depth of 0.2 to 0.5 mm, and a width of 0.8 mm or more at the opening of the groove line. The groove line is formed by repeating shifting a focal point of a laser.

Abstract: A method of manufacturing a vitreous silica crucible includes: a taking-out process of taking out the vitreous silica crucible from the mold, a honing process of removing the unfused silica powder layer on the outer surface of the vitreous silica crucible, and further comprising, after the taking-out process and before the honing process, a marking process of marking an identifier comprised of one or more groove line on the outer surface of the vitreous silica crucible, wherein the groove line after the honing process has a cross-sectional shape of an inverse trapezoid and a depth of 0.2 to 0.5 mm, and a width of 0.8 mm or more at the opening of the groove line. The groove line is formed by repeating shifting a focal point of a laser.

Abstract: The present invention provides a method of manufacturing a vitreous silica crucible including: a taking-out process of taking out the vitreous silica crucible from the mold, a honing process of removing the unfused silica powder layer on the outer surface of the vitreous silica crucible, and further comprising, after the taking-out process and before the honing process, a marking process of marking an identifier comprised of one or more groove line on the outer surface of the vitreous silica crucible, wherein the groove line after the honing process has a depth of 0.2 to 0.5 mm, and a width of 0.8 mm or more at the opening of the groove line.

Abstract: An object of the present invention is to provide a crucible handling device that can firmly sandwich and reliably move a quartz glass crucible under a clean environment and a method of handling a quartz glass crucible using the crucible handling device.

Abstract: The present invention provides a method of manufacturing a vitreous silica crucible including: a taking-out process of taking out the vitreous silica crucible from the mold, a honing process of removing the unfused silica powder layer on the outer surface of the vitreous silica crucible, and further comprising, after the taking-out process and before the honing process, a marking process of marking an identifier comprised of one or more groove line on the outer surface of the vitreous silica crucible, wherein the groove line after the honing process has a depth of 0.2 to 0.5 mm, and a width of 0.8 mm or more at the opening of the groove line.

Abstract: An object of the present invention is to provide a crane device suitable for handling a wrapped crucible, which crane device is capable of realizing mechanical handling of the wrapped crucible by way of a machine without manual work. In view of this, the present invention provides a crane device adapted to be capable of making reciprocal movements along a path between a position above a lifting-up point where a wrapped quartz glass crucible is placed and another position above a putting-down point where a packing container is placed and ascending to/descending from the path at each of the lifting-up point and the putting-down point, the crane device having: four arms extending in the ascend-descend direction and disposed at apexes of a quadrangle such that two arms paired on a diagonal line of the quadrangle are movable to advance to/separate from each other; and a claw provided at a rear end of each arm to extend in the advancing direction of the arm.

Abstract: An object of the present invention is to provide a crucible handling device that can firmly sandwich and reliably move a quartz glass crucible under a clean environment and a method of handling a quartz glass crucible using the crucible handling device.