Method and apparatus for forming a glass ribbon

Abstract

A roll forming apparatus (201) includes at least one forming roll (207) spaced from a forming body (209) so as to define a gap (211). The forming roll (207) includes: a working area portion (215) having a working area surface (217) having a length extending along the rotational axis of the forming roll; and a thermal resistance boundary relative to the rotational axis ( 219) extending at an acute angle. In a further example, a method includes the step of feeding a stream of molten glass through the gap to form a glass ribbon including a shaped thickness. The thermally resistive boundary promotes substantially uniform radial expansion of the working area surface (217) relative to the axis of rotation across the length of the working area surface (217) in response to heating of the working area portion (215) by the molten glass (205). Embodiments include a frustoconical end surface of the working area portion (215), a plurality of apertures spaced radially around the axis of rotation (219) or frustoconical grooves (407, 407, 409).

Description

[0001] related applications [0002] This application claims priority under 35 U.S.C. §119 to U.S. Provisional Application Serial No. 61 / 858,295, filed July 25, 2013, the contents of which are the basis herein and are incorporated by reference in their entirety This article. technical field [0003] The present disclosure relates generally to methods and apparatus for forming glass ribbons, and more particularly, to methods and apparatus for forming glass ribbons with at least one forming roll and a forming body spaced apart to define a glass forming gap. Background technique [0004] Rolled glass sheets are typically formed using a pair of forming rolls. However, conventional glass roll forming machines employing forming rolls typically produce glass ribbons without highly precise dimensional uniformity (e.g., thickness uniformity within + / - 0.025mm) and cannot form thin glass less than 2mm to 3mm thick bring. One factor contributing to this lack of precise thickness co...

AI Technical Summary

Problems solved by technology

However, conventional glass roll forming machines employing forming rolls typically produce glass ribbons without highly precise dimensional uniformity (e.g., thickness uniformity within + / - 0.025mm) and cannot form thin glass less than 2mm to 3mm thick bring

One factor contributing to this lack of precise thickness control is the non-uniform radial thermal expansion of the forming rolls that heat the flow of molten glass that forms the glass ribbon.

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