WO2016100417A1

WO2016100417A1 - Apparatus for manufacturing a glass ribbon

Info

Publication number: WO2016100417A1
Application number: PCT/US2015/065929
Authority: WO
Inventors: Satoshi IKEZAWA; Makoto KAWAHATA; Seiji Sakamoto; Makoto TANIYAMA
Original assignee: Corning Incorporated
Priority date: 2014-12-19
Filing date: 2015-12-16
Publication date: 2016-06-23
Also published as: JP6632625B2; TWI672277B; CN107108308A; TW201627235A; KR20170099936A; JP2018505119A; CN107108308B

Abstract

A glass manufacturing apparatus comprising a forming body from which molten glass is drawn to produce a glass ribbon, a roll configured to engage a first edge portion of the glass ribbon at a predetermined distance from a bottom edge of the forming body, the roll comprising a body portion coupled to a shaft. A diverter is positioned to extend over the shaft and the body portion of the roll in a direction perpendicular to a draw direction of the glass ribbon, the diverter comprising a central portion angled downward in a direction away from the glass ribbon and configured to direct molten glass in contact with an upper surface of the central portion away from the glass ribbon.

Description

APPARATUS FOR MANUFACTURING A GLASS RIBBON

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S.

Provisional Application Serial Number 62/094313 filed on December 19, 2014 the content of which is relied upon and incorporated herein by reference in its entirety.

BACKGROUND

Field

[0002] The present disclosure relates generally to an apparatus for drawing a glass ribbon from a molten material, and in particular to a shield configured to prevent errant molten material from fouling rolls contacting the glass ribbon during the drawing.

Technical Background

[0003] Downdraw glass making processes for forming glass sheets typically draw a molten material, hereinafter "molten glass", from a forming body in the shape of a ribbon using rollers ("rolls"). Such rolls may include driven pulling rolls, designed to apply a downward pulling force to the glass ribbon, or other rolls that are undriven and may serve, among other things, to apply an outward tension to the ribbon. In either case, the rolls are arranged as counter-rotating pairs that engage edge portions of the glass ribbon.

[0004] Occasionally, molten glass may fall from above onto the rolls. Such errant molten glass may become wrapped around the roll, disrupting the draw process.

SUMMARY

[0005] Many glass manufacturing apparatus utilize rolls, often arranged in pairs, to engage with and draw or shape the molten glass, for example in the manufacture of glass sheet from a glass ribbon. Molten glass dropping from regions of a glass manufacturing apparatus onto these rolls can cause disruptions in the manufacturing process, including down-time during which no glass ribbon can be produced, or even necessitating equipment replacement. To avoid such difficulty, diverters are positioned above the rolls to divert the falling molten glass from a path to the rolls. [0006] Accordingly, in one embodiment, an apparatus for drawing a glass ribbon is disclosed comprising a forming body from which molten glass is drawn to produce a glass ribbon, a roll configured to engage a first edge portion of the glass ribbon at a predetermined distance from a bottom edge of the forming body, the roll comprising a body portion coupled to a shaft, and a diverter extending over the shaft and the body portion of the roll in a direction perpendicular to a draw direction of the glass ribbon, the diverter comprising a central portion angled downward in a direction away from the glass ribbon and configured to direct molten glass in contact with an upper surface of the central portion away from the glass ribbon. An angle a between the central portion and a horizontal plane may be in a range 0 < a < 20 degrees.

[0007] The central portion may comprise a first edge extending along a length of the central portion and an upper lip portion extending upward from the first edge. The central portion may also comprise a second edge extending along a length of the central portion and a lower lip portion extending downward from the second edge.

[0008] In some embodiments the apparatus may comprise a plurality of rolls and a plurality of diverters.

[0009] In some embodiments the forming body may comprise a trough positioned in an upper surface thereof and configured to receive a flow of molten glass. The forming body may also comprise converging forming surfaces configured to receive a flow of molten glass from the trough.

[0010] Additional features and advantages of these and other embodiments will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

[0011] It is to be understood that both the foregoing general description and the following detailed description present embodiments of the present disclosure, and are intended to provide an overview or framework for understanding the nature and character of the embodiments as claimed. The accompanying drawings are included to provide a further understanding of these and other embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of these and other embodiments, and together with the description serve to explain the principles and operations thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is an elevational view of an example glass manufacturing apparatus;

[0013] FIG. 2 is a side view of an example roll for engaging with an edge portion of a glass ribbon drawn from the manufacturing apparatus of FIG. 1

[0014] FIG. 3 is a perspective view of a diverter according to the present disclosure and illustrating optional upper and lower lip portions;

[0015] FIG. 4 is an edge view of the diverter of FIG. 3 seen from and end, and including the upper and lower lip portions;

[0016] FIG. 5 is a perspective view of a portion of the glass manufacturing apparatus of FIG. 1 showing a pair of rolls protected by a pair of diverter positioned above the rolls; and

[0017] FIG. 6 is a side view of the rolls and diverters of FIG. 5, as seen from an end of the rolls.

DETAILED DESCRIPTION

[0018] Reference will now be made to embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.

[0019] FIG. 1 illustrates an example fusion-type glass manufacturing apparatus 10 comprising a first enclosure 12, a forming body 14 positioned within the first enclosure and a second enclosure 16 positioned below the first enclosure. Also shown are a plurality of rolls 18 positioned below the forming body. Rolls 18 may be positioned, for example, within the second enclosure. Rolls 18 are typically arranged as counter-rotating pairs configured to engage with edge portions of the glass ribbon. There can be one or more pairs of counter- rotating rolls configured to engage with the edge portions of the glass ribbon.

[0020] Forming body 14 may comprise a trough 20 formed in an upper surface of the forming body, and converging forming surfaces 22 located on an exterior of the forming body that join at a lower edge 24, of forming body 14. Molten glass 26 is supplied to and overflows the walls of trough 20. The overflowing molten glass flows over converging forming surfaces 22 as separate streams that join at lower edge 24 to form glass ribbon 28. Glass ribbon 28 is engaged by rolls 18 along edge portions of the glass ribbon and drawn downward in a draw direction 29 to a predetermined thickness. Pairs of rolls may be positioned at different distances from the lower edge. Cooling members 30 may be positioned adjacent the converging forming surfaces and near the lower edge of the forming body to aid in thickness control. On the glass ribbon has reached the predetermined thickness and cooled sufficiently to become an elastic solid, individual glass sheets are subsequently separated from the glass ribbon and provided to downstream processing apparatus that further process the sheets.

[0021] FIG. 2 illustrates an example roll 18 that includes a body portion 32 coupled to a shaft 34. Shaft 34 may be further coupled to a drive mechanism (not shown) such as an electric motor if the roll is a driven roll, or the shaft may be coupled to a bearing mechanism that positions the roll and allows the roll, e.g. shaft 34, to freely rotate.

[0022] In some instances molten glass may seep from joints between delivery apparatus (e.g. pipes that convey the molten glass to the forming body) and forming body 14. In some instances this seepage, or errant molten glass 36, may fall from regions of the manufacturing apparatus 10 located above rolls 18 and contact the rolls. If contact with the rolls occurs, the errant molten glass 36 may stick to and become wrapped about the roll. This can be a particular problem if the location where the errant molten glass adheres coincides with the surface of the roll body portion that engages with the glass ribbon. In extreme cases, a complete disruption of the drawing process can occur where the glass ribbon is no longer guided by the rolls and flows freely from the forming body.

[0023] Accordingly, glass manufacturing apparatus 10 further comprises a diverter 38 positioned above roll 18. As shown in FIG. 3, diverter 38 comprises a central portion 40 that extends along a length of roll 18 in a direction perpendicular to the draw direction 29, thereby protecting both body portion 32 and shaft 34 from errant molten glass 36. Central portion 40 may be configured, for example, as a rectangular plate having a length L and a width W, wherein the length is oriented parallel to longitudinal axis 42 of roll 18. Diverter may comprise a high temperature material capable of withstanding temperatures that can reach 1 100°C or greater in the vicinity of the forming body. For example, the diverter may comprise one or more high temperature metal alloys such as Haynes® Alloy No. 214 or Haynes® Alloy No. 230. Central portion 40 is positioned so that upper surface 44 of central portion 40 is angled downward, in a direction away from a vertical plane 46 parallel to and intersecting with lower edge 24. In different terms, and referring to FIG. 4, a vector 48 normal to upper surface 44 of central portion 40 has an upward vertical vector component 48v and a non-zero horizontal component 48h in a direction away from vertical plane 46. Thus, errant molten glass 36 that falls from above roll 18 will be intercepted by central portion 40 and guided away from roll 18 by upper surface 44. Errant molten glass 36 can then flow downward and laterally over upper surface 44 and drop safely to a location below. For example, in some embodiments, a container (not shown) may be positioned below the diverter to collect errant molten glass that has dripped from the diverter.

[0024] As also shown by FIG. 3 and FIG. 4, central portion 40 comprises an upper, or first longitudinal edge 50 and a lower, or second longitudinal edge 52, wherein both the first and second longitudinal edges 50, 52 extend along the length L of the central portion. The first and second edges may be parallel to each other, and may further be parallel to longitudinal axis 42. In some embodiments, diverter 38 may further comprise an optional upper, or first lip portion 54 extending along first longitudinal edge 50 and/or an optional lower, or second lip portion 56 extending along second longitudinal edge 52. As depicted in FIGS. 4 - 6, both first and second lip portions 54, 56 may be angled relative to respective surfaces of central portion 40. For example, first lip portion 54 may positioned such that an angle β between a surface of first lip portion 54 and upper surface 44 of central portion 40 is in a range from 90 < P < 180. Second lip portion 56 may be positioned such that an angle φ between a surface of second lip portion 56 and lower surface 58 of central portion 40 is in a range from 90 < φ < 180. Angle β and angle φ may, for example, be equal (β = φ). First lip portion 54 can prevent a buildup of errant glass from overflowing first longitudinal edge 50 of central portion 40 and contacting roll 18, thereby defeating the purpose of diverter 38, and second lip portion 56 can prevent errant molten glass reaching second longitudinal edge 52 from backflowing along lower surface 58 toward roll 18.

[0025] It should be apparent from the preceding that a diverter 38 may be positioned over any or all rolls used in the drawing of molten glass, and is not limited to a fusion down-draw process as depicted and described herein. For example, a diverter 38 may be used in slot draw processes, where molten glass is drawn from a slot formed in the lower surface of a forming body and drawn downward therefrom, or in an up-draw process, where molten glass is drawn upward from a pool of molten glass. In addition, diverter 38 may be used to protect a roll 18 from other potential contaminants, such as condensates that collect on interior surfaces of the enclosures and may drip or otherwise fall downward into potential contact with the roll.

[0026] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present disclosure without departing from the spirit and scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of these and other embodiments provided they come within the scope of the appended claims and their equivalents.

Claims

What is claimed is:

1. An apparatus for manufacturing a glass ribbon comprising:

a forming body from which molten glass is drawn to produce a glass ribbon;

a roll configured to engage a first edge portion of the glass ribbon at a predetermined distance from a bottom edge of the forming body, the roll comprising a body portion coupled to a shaft; and

a diverter extending over the shaft and the body portion of the roll in a direction

perpendicular to a draw direction of the glass ribbon, the diverter comprising a central portion angled downward in a direction away from the glass ribbon and configured to direct molten glass in contact with an upper surface of the central portion away from the glass ribbon.

2. The apparatus according to claim 1, wherein the central portion comprises a first edge extending along a length of the central portion and an upper lip portion extending upward from the first edge.

3. The apparatus according to claim 2, wherein the central portion comprises a second edge extending along a length of the central portion and a lower lip portion extending downward from the second edge.

4. The apparatus according to claim 1, wherein an angle a between the central portion and a horizontal plane is in a range 0 < a < 20 degrees.

5. The apparatus according to claim 1 , wherein the apparatus comprises a plurality of rolls and a plurality of diverters.

6. The apparatus according to claim 1 , wherein the forming body comprises a trough configured to receive a flow of molten glass.

7. The apparatus according to claim 6, wherein the forming body comprises converging forming surfaces configured to receive a flow of molten glass from the trough.

8. An apparatus for drawing a glass ribbon comprising:

a forming body from which molten glass is drawn to produce a glass ribbon, the

forming body comprising a trough in an upper surface thereof configured to receive a flow of molten glass, the forming body further comprising converging forming surfaces that meet at a bottom edge of the forming body; a plurality of roll configured to engage edge portions of the glass ribbon at a

predetermined distance from the bottom edge of the forming body, each roll of the plurality of rolls comprising a body portion coupled to a shaft; and a diverter extending over the shaft and the body portion of each roll of the plurality of rolls in a direction perpendicular to a draw direction of the glass ribbon, the diverter comprising a central portion angled downward in a direction away from the glass ribbon and configured to direct molten glass in contact with an upper surface of the central portion away from the glass ribbon.

9. The apparatus according to claim 8, wherein the plurality of rolls are arranged as a counter-rotating pair.

10. The apparatus according to claim 8, wherein the central portion comprises a first edge extending along a length of the central portion and an upper lip portion extending upward from the first edge.

1 1. The apparatus according to claim 10, wherein the central portion comprises a second edge extending along a length of the central portion and a lower lip portion extending downward from the second edge.