KR20120102939A - Forming roller, method and apparatus for manufacturing glass utilizing the same - Google Patents

Abstract

PURPOSE: A forming roller for glass plate manufacturing and manufacturing method and device using the same are provided to remove oxygen inflowed into a float bath due to the defects of side sealing. CONSTITUTION: A forming roller for glass plate manufacturing(40) comprises a forming portion(42) and a rod(46). The glass plate for glass plate manufacture includes a gas supplying portion(44) prepared in the rod. The gas supply part comprises a gas supply path and one or more fumaroles. The gas supply path is formed in the rod. The fumaroles are formed on the surface of the rod in order to be connected with the gas supply path. A glass plate device(100) includes a gas supply unit which is installed in the forming roller and provides hydrogen gas around the forming roller. A glass plate manufacturing method comprises the following steps: providing mixing gas of nitrogen and hydrogen from the ceiling of a chamber; and additionally providing hydrogen gas around the forming roller installed at the side sealing(30) of the chamber.

Description

Forming roller for manufacturing glass plate, apparatus and method for manufacturing glass plate using same {Forming roller, method and apparatus for manufacturing glass utilizing the same}

The present invention relates to a forming roller for producing a glass plate, a glass plate manufacturing apparatus and method using the same, and more particularly, to a forming roller for producing a glass plate used for producing float glass by the float method, and a glass plate manufacturing apparatus and method using the same.

For example, nearly 95% of the full range of flat glass used in the industry, such as windshields, windscreens of vehicles, mirrors, etc., is produced using the well-known float method. In addition, thin glass panes or glass films for TFT displays and the like are also glass by the float method, that is, 'float glass'.

Background Art Known float glass manufacturing apparatus have a float bath in which molten metal, such as molten tin or molten tin alloy, is stored and flowed, for example. The molten glass, which has a lower viscosity than the molten metal and is about 2/3 lighter than the molten metal, is fed into the float bath continuously through the inlet of the float chamber and floats and spreads onto the molten metal downstream to the float bath. In this process, the molten glass is shaped to a somewhat solidified glass strip or ribbon form, which glass ribbon is drawn out of the float bath by rollers disposed adjacent to the outlet of the float bath. Further, in order for the molten glass introduced through the inlet of the float bath to be molded into the float glass in the forming region and discharged through the outlet, the molten glass is respectively a relatively high temperature region on the upstream side and a middle temperature region on the upstream side in the longitudinal direction of the float bath. , And the relatively low temperature region on the downstream side. In addition, the molten metal supporting the molten glass (or glass ribbon) inside the float bath, and the temperature of the atmosphere inside the float bath is generally lower than the temperature of the molten glass (or glass ribbon) and thus the heat of the molten glass inside the float bath Is naturally taken away, the temperature of the glass ribbon on the downstream side of the float bath is significantly cooled.

Moreover, in operation of the conventional glass plate manufacturing apparatus by a float method, oxygen flows into the float bath by various factors. This oxygen is vaporized in the molten tin to generate bubbles or to react with the molten metal to generate tin oxide. Bubbles can cause defects, such as 'OBB', which can be generated by being attached to the lower surface of the glass ribbon, and tin oxide is vaporized upward in the float chamber and then liquefied in the low temperature region inside the float chamber to It can create defects like so-called 'top specs' that fall onto and stick to the top.

Therefore, in the conventional glass plate manufacturing apparatus by a float method, in order to reduce the defective rate of the float glass by oxygen, nitrogen and hydrogen mix injecting mixed atmosphere gas into a float chamber, and create a protective atmosphere. This protective atmosphere gas converts oxygen that can be generated inside the float chamber into water.

However, oxygen that causes defects in the glass ribbon is mostly introduced into the float chamber through a gap around the side seal installed between the floor and the ceiling constituting the float chamber, while the atmosphere gas mixed with nitrogen and hydrogen is floated. Since it flows into the float chamber through the ceiling of the chamber, hydrogen is not used to react with oxygen when the flow of atmospheric gas is not suitable inside the float chamber or, in particular, when a vortex of atmospheric gas occurs near the siding seal. By being discharged out of the float chamber, the reducing action by the reducing gas may be insufficient.

The present invention has been conceived to solve the above problems, by adding a flow path for supplying a mixed gas of hydrogen and nitrogen to the forming roller (for example, top roll) installed in the side sealing to widen the molten glass The present invention provides a forming roller for manufacturing a glass plate, and a glass plate manufacturing apparatus and method using the same, the structure of which is improved to efficiently convert oxygen derived from defects of the side sealing into water by directly supplying hydrogen gas to the vicinity of the side sealing. It is a task.

In order to solve the above problems, the forming roller for manufacturing a glass plate according to an exemplary embodiment of the present invention, the disk-shaped molded part that can be in contact with the edge of the glass ribbon, and is connected to the molding part to be rotated In the shaping roller for glass plate manufacture provided with the rod which can be provided, the gas supply part provided in the said rod is provided.

Preferably, the gas supply unit: a gas supply flow path formed in the rod; And at least one or more gas ejection holes formed in the surface of the rod so as to communicate with the gas supply passage.

Preferably, the rod further comprises a cooling passage for cooling the molded part; The gas supply unit further includes a heat insulating member provided between the gas supply passage and the cooling passage.

In order to solve the above problems, the glass plate manufacturing apparatus according to an exemplary embodiment of the present invention, the glass plate manufacturing having a forming roller installed in the side sealing of the float bath to be in contact with the glass ribbon moved on the molten metal An apparatus is provided with a gas supply portion provided in the forming roller to supply hydrogen gas to the vicinity of the forming roller in order to remove oxygen introduced into the float bath due to a defect in the side sealing.

Preferably, the gas supply unit: a gas supply flow path provided in the rod portion of the forming roller; And at least one or more gas ejection holes formed in the surface of the rod portion so as to communicate with the gas supply passage.

Preferably, the gas supply flow path includes a common supply flow path formed in a ring shape along the longitudinal direction of the rod portion or at least two separate supply flow paths formed radially with respect to the center of the rod portion.

Preferably, the gas supplied through the gas supply unit may supply a gas in which nitrogen gas is mixed with the hydrogen gas.

Preferably, the temperature of the gas supplied through the gas supply is 500 ° C to 1000 ° C.

Preferably, the flow rate of the gas supplied through the gas supply is 0.2 to 5.0 m ³ / hr.

Preferably, the forming roller may include: a disk-shaped hollow molding unit which may be in contact with the edge of the glass ribbon, and a cooling passage provided in the rod portion of the molding roller to be in parallel with the gas supply unit so as to communicate with the molding unit. It is further provided.

Preferably, the cooling passage includes: a first pipe provided at the center of the rod portion to supply a cooling medium to the molding portion; And a second pipe coaxially spaced apart from the outer surface of the first pipe so as to discharge the cooling medium supplied to the molding part.

Preferably, the gas supply unit: a third pipe spaced apart from the outer surface of the second pipe by a predetermined interval; A sealing part capable of sealing an end adjacent to the molding part; And at least one or more gas blowing holes penetrating the third pipe.

Preferably, further comprising a heat insulating member interposed between the second pipe and the third pipe.

Preferably, the heat insulating member includes heat insulating fibers that can be wound around the outer circumferential surface of the second pipe.

Glass plate manufacturing method according to an exemplary embodiment of the present invention for solving the above problems, by injecting the molten glass over the molten metal stored in a closed chamber to form a glass ribbon while moving the molten glass on the molten metal A glass plate manufacturing method comprising: (a) supplying a mixed gas of hydrogen and nitrogen from a ceiling of the chamber; And (b) additionally supplying hydrogen gas near a forming roller installed in the side sealing of the chamber.

Preferably, the step (b) is to supply the hydrogen gas through a gas supply unit formed integrally with the forming roller.

The present invention claims a glass plate produced by the method described above.

The glass plate manufacturing apparatus and method which concern on this invention have the following effects.

Additional additional gas other than the reducing atmosphere gas supplied from the ceiling of the float chamber to the inside of the float chamber by adding a flow path for supplying a reducing atmosphere gas mixed with hydrogen and nitrogen to each forming roller installed in the side sealing of the float chamber. Can be supplied directly around the side sealing, so that defects in the glass ribbon caused by oxygen generated from defects in the side sealing can be reduced.

The foregoing summary of the invention as well as the following detailed description of the preferred embodiments of the invention will be better understood when read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of illustrating a glass plate manufacturing apparatus and method according to a preferred exemplary embodiment of the present application, and a forming roller for manufacturing a glass plate used therein, drawings of preferred embodiments are shown. It should be understood, however, that the present application is not limited to the precise arrangements and instrumentalities shown in such drawings.
1 is an exploded perspective view schematically showing a glass plate manufacturing apparatus according to a preferred embodiment of the present invention.
2 is a cross-sectional view schematically showing a forming roller portion of the glass plate manufacturing apparatus according to an exemplary embodiment of the present invention.
3 is a cross-sectional view of the forming roller shown in FIG. 2.
4 is a cross-sectional view schematically showing a forming roller for producing a glass plate according to another preferred exemplary embodiment of the present invention.
5 is a cross-sectional view taken along the line VV of FIG. 4.
6 is a cross-sectional view taken along the line VI-VI 'of FIG. 4.
7 is a cross-sectional view of a rod portion of a forming roller according to another preferred exemplary embodiment of the present invention.

The specific terminology used in the detailed description that follows is for the purpose of convenience and not of limitation. The words "right", "left", "top" and "bottom" indicate directions in the figures to which reference is made. The words "inwardly" and "outwardly " refer to directions toward or away from the geometric center of a designated apparatus, system, and members thereof, respectively. "Forward", "backward", "upward", "downward" and their related words and phrases are indicative of the positions and orientations in the figures to which reference is made and are not limiting. These terms include the words listed above, derivatives thereof, and words of similar meaning.

Certain exemplary embodiments of the present invention will be described with reference to the drawings.

1 is an exploded perspective view schematically showing a glass plate manufacturing apparatus according to a preferred embodiment of the present invention.

Referring to FIG. 1, the glass plate manufacturing apparatus 100 according to the present exemplary embodiment includes a bottom 10 in which molten metal M is filled and flows, and a loop 20 positioned at an upper portion thereof to cover the bottom 10. And a side seal 30 interposed between the roof 20 and the bottom 10.

The bottom 10, the roof 20 and the side seal 30 constitute an enclosed float chamber 106 having an inlet 12 and an outlet 14 as a whole. The internal atmosphere of the float chamber 106 consists of a mixed gas of nitrogen and hydrogen. This mixed gas is supplied from a gas supply line 22 installed in the loop 20 and maintained at a pressure slightly higher than the outside atmosphere. The molten glass (M) flowing in the bottom 10 and the molten glass or glass ribbon (G) moving on the molten metal (M) inside the float chamber 106 is maintained at about 600-300 ° C. by the heater 21. do. The molten glass G is an alkali free glass or soda-lime glass. Principle and structure of the flow of molten metal M in the float chamber 106 and the introduction, ribboning, moving, and discharging of the molten glass G are known by the general float method. Omit the description. Reference numeral 40 denotes a number of forming rollers designated as 'top-rollers' for forming molten glass G, reference numeral 50 denotes a transformer for supplying and / or regulating the heater 21, reference numeral 60 denotes Bus bar for electrically connecting the transformer 50 and the heater 21, reference numeral 70 is a tin barrier to control the flow direction of the molten metal (M), reference numeral 80 is a float chamber ( 106) Venting system for discharging gas inside, reference numeral 90 denotes a cooling member for cooling the bottom 10, respectively.

The bottom 10 is composed of a plurality of bricks B arranged elongated in the longitudinal direction of the float chamber 106, for example, to store molten metal M such as molten tin, molten tin alloy, and the like. The bricks B are wrapped by a metal casing (not shown).

The side seal 30 is positioned on the upper surface of the bottom 10 and the lower surface of the roof 20 to substantially seal and seal the inside of the float chamber 106 from the outside. The side seal is arranged such that a plurality of structures having a substantially hexahedral shape are adjacent to each other in the longitudinal direction of the float chamber 106.

The roof 20 is a steel roof casing 24 suspended from an upper structure (not shown) such as a beam of a building in which the float chamber 106 is installed, and a lining insulating brick disposed in a lower space of the roof casing 24. A side block 26 is made. The roof brick layer 28 is a modular structure constituted by a combination of a plurality of bricks, and one brick module is formed by various kinds of refractory materials. That is, the roof brick layer 28 is named PBA on a lattice frame formed by a plurality of silimite support tiles (not shown) and rail tiles arranged to be orthogonal thereto, and a substantially rectangular parallelepiped brick module is mounted thereon. Structure. The support tile is suspended by a hanger (not shown) from the ceiling portion of the roof casing 24 of the roof 20. That is, the roof brick layer 28 is held horizontally at a predetermined height above the molten metal M by a hanger. The side surface of the roof brick layer 28 is in contact with the upper side of the side block 26, and the top surface of the roof brick layer 28 is disposed at about the same height as the top surface of the side block 26. The heater 21 is penetrated to the roof brick layer 28.

2 is a cross-sectional view schematically showing a forming roller portion of the glass plate manufacturing apparatus according to an exemplary embodiment of the present invention, Figure 3 is a cross-sectional view of the forming roller shown in FIG.

Referring to FIGS. 2 and 3, the forming roller 40 may be rotated in connection with a disk-shaped molding part 42, which may be in contact with the edge of the glass ribbon G, and the molding part 42. The rod 46 provided with the gas supply part 44 is provided. The molding part 42 is positioned inside the float chamber 106, and the rod 46 penetrates the side sealing 30 and is rotatably installed at a predetermined speed (eg, 0.01 to 10 rpm) by a motor not shown. do. To this end, a plurality of gears (not shown) are installed between the rod 46 and the motor. Here, the rotation direction of the rod 46 is set similarly to the advancing direction of the glass ribbon G. As shown in FIG.

The gas supply part 44 mixes hydrogen gas or hydrogen and nitrogen near the forming roller 40 to remove oxygen introduced into the float chamber 106 due to a defect (eg, a gap) of the side seal 30. As for supplying gas, the gas supply part 44 has a gas supply passage 45 formed in the rod 46 and four gas ejection holes formed in the surface of the rod 46 so as to communicate with the gas supply passage 45. 47 is provided. In addition, the rod 46 includes a cooling flow passage 48 for cooling the forming portion 42, and the gas supply portion 44 has a heat insulating member 41 provided between the gas supply flow passage 45 and the cooling flow passage 48. ). Cooling flow path 48 is a cooling medium such as, for example, cooling water from the outside of the float chamber 106 to prevent the forming part 42 and the rod 46 from melting by the high temperature heat inside the float chamber 106. It is to supply.

The gas supply flow passage 45 is preferably a common supply flow passage formed in an annular shape along the longitudinal direction of the rod 46. The temperature of the gas supplied through the gas supply part 44 has a range of 500 ° C to 1000 ° C, and the flow rate thereof is preferably 0.2 to 5.0 m ³ / hr. The velocity and supply flow rate of the gas supplied through the gas supply part 44 are correlated with the velocity distribution of the gas flow field formed by the mixed gas supplied through the gas supply pipe 22 provided in the loop 20 of the float chamber 106. It can be calculated while maintaining. When the speed of the gas supplied through the gas supply part 44 provided in the shaping roller 40 is too low compared with the speed of the mixed gas supplied from the gas supply line 22 provided in the loop 20, the oxygen removal effect will fall remarkably. When the flow rate is too high compared to the speed of the mixed gas supplied from the gas supply pipe 22, there is a risk that the flow of molten metal is disturbed and the molding uniformity of the glass ribbon G is lowered.

As shown in FIG. 3, the shaping portion 42 of the shaping roller 40 has a head portion 42a that is sharpened to be in contact with the edge of the glass ribbon G, and the head portion 42a The interior of it forms a hollow space. The cooling passage 48 provided in the rod 46 of the forming roller 40 has a first pipe 43 and a forming portion 42 provided at the center of the rod 46 so as to supply a cooling medium to the forming portion 42. And a second pipe 57 arranged concentrically to be spaced apart from the outer surface of the first pipe 43 by a predetermined interval so as to discharge the cooling medium supplied thereto.

On the other hand, the gas supply unit 44 provided on the rod 46 is a third pipe 49, a third pipe 49 disposed adjacent to the molding portion 42 spaced apart from the outer surface of the second pipe (57). A sealing portion 49a capable of sealing the end of the pipe, and four gas blowing holes 47 passing through the third pipe 49. The heat insulating member 41 is interposed between the second pipe 57 and the third pipe 49. In addition, the heat insulating member 41 includes heat insulating fibers that can be wound around the outer circumferential surface of the second pipe 57. In addition, the forming part 42 includes a fastening part 42b provided with a female screw, and a male screw to which the fastening part 42b can be coupled is formed on the outer circumference of the end of the second pipe 57. In FIG. 3, the solid line shows the movement path of a cooling medium, and the dashed-dotted line shows the movement path of hydrogen or the mixed gas of hydrogen and nitrogen.

4 is a cross-sectional view schematically illustrating a forming roller for manufacturing a glass plate according to another exemplary embodiment of the present invention, FIG. 5 is a cross-sectional view taken along the line VV of FIG. 4, and FIG. 6 is a line VI-VI ′ of FIG. 4. It is a cross section. The same components as those described in FIGS. 2 and 3 are the same members with the same functions.

4 to 6, the forming roller 140 according to the present embodiment includes a hollow molding part 142 and a rod part 144 communicating with the molding part 142.

The rod portion 144 may include a shaft 146 provided at the center, an intermediate pipe 148 spaced apart from the shaft 146 by a predetermined interval so that the coolant supply path 141 may be formed, and a coolant discharge path 143. And an outer pipe 145 spaced apart from the intermediate pipe 148 by a predetermined distance. Meanwhile, a gas supply path 147 is provided in the intermediate pipe 148, and the gas supply path 147 penetrates the cooling liquid discharge path 143 to extend to the outer circumferential surface of the outer pipe 145. ) Is formed. Here, the gas supply passage 147 is in the form of a common supply flow passage formed in an annular shape along the longitudinal direction of the rod portion 144.

7 is a cross-sectional view of a rod portion of a forming roller according to another preferred exemplary embodiment of the present invention. The same components as those described in FIGS. 4 to 6 are the same members with the same functions.

As shown in FIG. 7, the forming roller 240 according to the present embodiment has four gas supply passages 247 in a separated form, unlike the common supply passage of the above-described embodiment. The gas supply passage 247 is formed in the intermediate pipe 148 so as to be intermittently disposed only in the portion where the gas discharge hole 149 is formed.

The process of manufacturing the glass plate using the forming rollers 40, 140 and 240 as described above is as follows.

In the process of forming the glass ribbon G while injecting the molten glass G over the molten metal M stored in the closed float chamber 106 to move the molten glass G over the molten metal M, the float chamber In addition to the main gas supply process for supplying a mixed gas of hydrogen and nitrogen from the loop 20 of 106, the sub gas additionally supplies hydrogen gas to each forming roller 40 provided in the side seal 30. Go through the supply process. The sub gas supply process may supply hydrogen gas around the supply molding part 42 through the gas supply part 44 formed integrally with the molding roller 40. Therefore, the loop of the float chamber 106 is added to each forming roller 40 installed in the side seal 30 of the float chamber 106 by adding a flow path capable of supplying a reducing atmosphere gas mixed with hydrogen and nitrogen separately. Since the additional additional gas other than the reducing atmosphere gas supplied from the 20 into the float chamber 106 can be supplied directly around the side sealing 30, the glass ribbon G caused by oxygen generated from the defect of the side sealing 30 can be supplied. ) Defects can be reduced.

While the foregoing detailed description and drawings illustrate preferred embodiments of the invention, it is evident that various additions, modifications, combinations and / or alternatives are possible without departing from the spirit and scope of the invention as defined in the appended claims. It should be understood that it can be made. In particular, it will be understood by those skilled in the art that the present invention may be embodied in other specific forms, structures, arrangements, ratios, using other elements, materials, components, without departing from the spirit essential features of the present invention. It will be appreciated by those skilled in the art that the present invention may be used with many modifications of the structure, arrangement, proportions, materials, and components so as to be particularly suited to the specific environments and operating conditions without departing from the principles of the invention. Furthermore, the features described herein may be used alone or in combination with other features. For example, features described in connection with one embodiment may be used interchangeably and / or interchangeably with features described in other embodiments. Accordingly, the presently disclosed embodiments are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and not limited to the foregoing detailed description.

Those skilled in the art will appreciate that various modifications and variations of the present invention are possible without departing from the broad scope of the appended claims. Some of these have been discussed above and others will be apparent to those skilled in the art.

10 ... floor 12 ... entrance
14 ... exit 20 ... loop
21 Heater 22 Gas supply line
24 ... loop casing 26 ... side block
28.Loop brick floor 30.Side sealing
40,140 ... Forming roller 41 ... Insulation member
42,142 Molding part 43 ... First pipe
44 Gas supply section 45 Gas supply passage
46 ... 45 47 ... Gas spout hole
48.Cooling flow path 49 ... 3rd pipe
50 ... Transformers 57 ... Second Pipe
60 ... booth bar 70 ... tin barrier
80 Venting system 90 Cooling element
100... Glass Plate Manufacturing Unit ... Float Chamber
141.Coolant Supply Furnace 143 ... Coolant Discharge Furnace
144 Rods 145 Outer pipe
146 ... shaft 148 ... middle pipe

Claims (17)

In the shaping roller for manufacturing a glass plate having a disk-shaped molded part that can be in contact with the edge of the glass ribbon, and a rod that can be rotated in connection with the molded part,
And a gas supply part provided in said rod.
The method according to claim 1,
The gas supply unit:
A gas supply flow path formed in the rod; And
And at least one or more gas ejection holes formed in the surface of the rod so as to communicate with the gas supply passage.
The method according to claim 2,
The rod further comprises a cooling passage for cooling the molded part;
The gas supply part further comprises a heat insulating member provided between the gas supply flow path and the cooling flow path.
A glass plate manufacturing apparatus having a forming roller provided in a side seal of a float bath so as to be in contact with a glass ribbon moved over molten metal.
And a gas supply part provided in the forming roller so as to supply hydrogen gas to the vicinity of the forming roller in order to remove oxygen introduced into the float bath by the defect of the side sealing.
The method of claim 4,
The gas supply unit:
A gas supply passage provided in a rod portion of the forming roller; And
And at least one or more gas ejection holes formed in a surface of the rod portion so as to communicate with the gas supply passage.
The method according to claim 5,
The gas supply flow path is a glass plate manufacturing apparatus, characterized in that it comprises a common supply flow path formed in a ring shape along the longitudinal direction of the rod portion or at least two separate supply flow paths formed radially with respect to the center of the rod portion.
The method of claim 4,
Gas supplied through the gas supply unit is a glass plate manufacturing apparatus, characterized in that for supplying a gas mixed with nitrogen gas to the hydrogen gas.
The method of claim 4,
The temperature of the gas supplied through the gas supply unit is a glass plate manufacturing apparatus, characterized in that 500 ℃ to 1000 ℃.
The method of claim 4,
Flow rate of the gas supplied through the gas supply is a glass plate manufacturing apparatus, characterized in that 0.2 to 5.0 m ³ / hr.
The method of claim 4,
The forming roller is:
And a disk-shaped hollow molded part which may be in contact with the edge of the glass ribbon, and a cooling flow path provided in the rod portion of the forming roller to be in parallel with the gas supply part so as to communicate with the molded part. Glass plate manufacturing apparatus.
The method of claim 10,
The cooling passage is:
A first pipe provided at the center of the rod portion to supply a cooling medium to the molding portion; And
And a second pipe arranged coaxially to be spaced apart from the outer surface of the first pipe by a predetermined interval so as to discharge the cooling medium supplied to the molding part.
The method according to claim 13,
The gas supply unit:
A third pipe disposed to be spaced apart from the outer surface of the second pipe by a predetermined distance;
A sealing part capable of sealing an end adjacent to the molding part; And
And at least one or more gas blowing holes penetrating the third pipe.
The method of claim 12,
And a heat insulating member interposed between the second pipe and the third pipe.
The method according to claim 13,
The heat insulating member is a glass plate manufacturing apparatus, characterized in that it comprises a heat insulating fiber that can be wound on the outer peripheral surface of the second pipe.
In the glass plate manufacturing method of molding a glass ribbon while injecting a molten glass over the molten metal stored in the sealed chamber and moving the molten glass on the said molten metal,
(a) supplying a mixed gas of hydrogen and nitrogen from the ceiling of the chamber; And
(b) additionally supplying hydrogen gas to the vicinity of the forming roller installed in the side sealing of the chamber.
The method according to claim 15,
Step (b) is a glass plate manufacturing method characterized in that for supplying the hydrogen gas through a gas supply unit formed integrally with the forming roller.
The glass plate manufactured by Claim 15 or 16.

Images