JP2002047019A - Rollout molding method and apparatus for sheet glass product - Google Patents

Abstract

(57) [Summary] To provide a glass ribbon with an appropriate conveying force in steam generation roll-out molding. A roll (18, 20) is formed of a roll base material made of a material or a structure capable of containing water therein, and a non-steam generating region (A) in which steam is not generated is partially formed on the surface of the roll (18, 20). Provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for roll-out forming a sheet glass product using a roll to form a sheet glass.

[0002]

2. Description of the Related Art As a method of forming a sheet glass, a pulling method, a downdraw method, a rollout method, a fusion method, a tin float method and the like are known.

[0003] Among these sheet glass forming methods, the roll-out method has a great advantage that the sheet glass can be formed at low cost because of the simple structure of the apparatus, but the high-temperature molten glass comes into contact with the roll and is rapidly cooled. By doing so, it is unavoidable that contact marks with rolls, wrinkles and irregularities remain on the surface of the formed glass sheet, and the quality of the product is deteriorated. Further, the roll-out molding method has a drawback that the molten glass is greatly affected by the temperature of the roll, so that the molded glass ribbon tends to have a temperature distribution, and is likely to be warped or cracked.

[0004] Therefore, the applicant of the present application has previously reported that a glass ribbon having a temperature equal to or higher than the glass transition point is formed by rotating a roll made of a roll base made of a material or a structure capable of containing a liquid therein. We proposed a roll forming method for sheet glass that conveys while forming through a thin layer of vapor film in which a vapor film forming agent is vaporized.

[0005]

However, the roll-out molding method for sheet glass in which a vapor film forming agent is conveyed while being molded through a thin layer of vaporized vapor film is a method in which the vapor is formed between a glass ribbon and a roll. Since the film is interposed, there is a disadvantage that the rotating roll easily slips on the glass ribbon. For this reason, there is a problem that it is difficult to apply an appropriate conveying force to the glass ribbon.

The present invention has been made in view of such circumstances, and in a roll-out molding of a sheet glass, a vapor film forming agent is conveyed while forming through a thin layer of a vapor film vaporized. An object of the present invention is to provide a method and an apparatus for roll-out sheet glass, which can impart an appropriate conveying force to a glass ribbon when forming.

[0007]

According to the present invention, there is provided a method of forming a sheet glass by passing glass supplied in a molten state through a pair of rolls. A step of introducing a vapor film forming agent that is not a gas at around normal temperature but a gas at least at a glass transition point of glass in a liquid state, into a roll substrate made of a material or a structure capable of containing a liquid therein, While rotating the pair of rolls, while passing the molten glass between the rolls,
A step of forming and transporting a glass ribbon through a thin layer of a vapor film in which the vapor film-forming agent is vaporized, the method comprising the steps of: It is characterized by using a roll having a surface that does not.

In order to achieve the above object, the present invention is an apparatus for forming a sheet glass by passing glass supplied in a molten state through a pair of rolls. Means for introducing, in a liquid state, a vapor film forming agent that is not a gas at around normal temperature but is a gas at least at the glass transition point of glass, in a roll substrate made of a material or structure that can be included, and the pair of rolls. Means for passing glass in a molten state between rolls while rotating, and for conveying the glass ribbon while forming a glass ribbon through a thin layer of a vapor film in which the vapor film forming agent is vaporized. In the forming apparatus, a surface that does not generate steam is partially formed on a surface of the roll.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a side view schematically showing an apparatus 10 for rolling out a sheet glass product of the present invention.

The forming apparatus 10 mainly includes a roll apparatus 12 provided with a plurality of pairs of rolls each of which includes a roll substrate capable of containing a vapor film forming agent therein, and supplies the vapor film forming agent to the roll base material of each roll. A liquid supply device (not shown) for liquid supply. Further, a glass melting furnace 16 is disposed at a front stage side of the roll forming apparatus 10, and the molten glass G melted from the glass material is supplied to an exit slit 16 </ b> A of the glass melting furnace 16.
Is supplied to the roll device 12.

The glass melting furnace 16 melts a predetermined raw material to be a sheet glass and controls a melting temperature to prepare a molten glass G having a viscosity range and a temperature range suitable for forming. Since the viscosity of the molten glass G is governed by the temperature, the viscosity is simultaneously controlled by controlling the temperature. When molding sheet glass, the melting depends on the glass composition, but usually 10
In a temperature range of about 00 to 1600 ° C., a glass foam defect,
This is carried out for a sufficient time so that variation in composition and other disadvantages are eliminated.

The molten glass G whose temperature and viscosity have been adjusted by the glass melting furnace 16 is converted into a ribbon-like flow from an exit slit 16A of the glass melting furnace 16 to form a roll 12.
The molten glass G is supplied to the roll device 12 as a glass ribbon 14 and then formed as a sheet glass 15.

The roll device 12 includes a roll 18 and a roll 2
A pair of rolls of 0 is provided in one or more stages, and for example, as shown in FIG. 1, the rolls are constituted by three stages of a first-stage roll 22, a second-stage roll 24, and a third-stage roll 26. The first to third rolls 22, 24, 26 are sequentially arranged along the transport path of the glass ribbon 14, and are rotated in the direction of the arrow by a rotation drive source (not shown). In addition, the clearance between the rolls 18 and 20 in each of the first to third rolls 22, 24, and 26 is usually set to be narrower toward the downstream side of the glass ribbon 14. As a result, the glass ribbon 14 is gradually thinned by being conveyed while being formed stepwise by the rolls 22, 24, 26 of the first to third stages. In this case, it is desirable that the clearance between the rolls 18 and the roll 20 and the number of rotations can be changed so as to be able to cope with a desired thickness of the sheet glass to be formed.

In the rolls 18 and 20, the peripheral surface of the roll body is formed of a roll base material capable of containing a vapor film forming agent therein, and the vapor film forming agent introduced into the roll base material is vaporized from the roll peripheral surface. It is configured to Thereby, a thin layer of a vapor film is stably formed between the glass ribbon 14 and the rolls 18 and 20. As a method of supplying the vapor film forming agent to the roll base material, the vapor film forming agent may be supplied to the center of the rolls 18 and 20 so as to penetrate the entire roll base material,
Alternatively, a wetting roll (not shown) is arranged in contact with the rolls 18 and 20 not facing the glass ribbon 14 so that the vapor film forming agent supplied to the wetting rolls is transferred to the rolls 18 and 20. Is also good. Further, a spray method or a dip method may be used. In short, any method can be used as long as it can be supplied so that the vapor film forming agent is necessary and sufficiently contained in the roll substrate.

The roll substrate has a material or structure capable of containing a liquid therein, and for example, a porous or fibrous material can be suitably used. In the case of a porous body,
It is preferably a communication hole. The surface of the porous body has fine pores having a pore diameter of preferably 5 mm or less, more preferably 1 mm or less, and still more preferably 100 μm or less. Further, it is preferable that the material has high affinity with the vapor film forming agent.

As a basic material of the roll base material, porous hydrophilic carbon having a communicating hole is preferable, and other materials such as cellulose, paper, wood, bamboo and other natural materials derived from natural materials, Carbon-based materials can also be used. Also iron,
Uses metal materials such as stainless steel, nickel, aluminum, titanium-based metals, and platinum; metal oxides such as aluminum oxide, zirconium oxide, silicon carbide, and silicon nitride; and ceramic materials mainly containing metal carbides and metal nitrides. it can. The molding surface of the roll base material desirably has flatness except for fine holes and fibrous irregularities, but may have certain irregularities depending on the sheet glass product.

As the vapor film forming agent to be used, various organic and inorganic substances which are liquid at ordinary temperature and are gas at least at the glass transition point of glass or higher can be used. From the viewpoint of the operability of supply to the roll base material, those having a melting point of 40 ° C. or less and a boiling point at atmospheric pressure of 50 to 500 ° C., more preferably 300 ° C. or less are good. Further, it is preferable that the vaporized vapor of the vapor film forming agent does not chemically react to the extent that it adversely affects the glass and the roll substrate, has low toxicity, and is nonflammable at the temperature used. Can be used as water. As described above, as the vapor film forming agent, it is necessary to appropriately select a liquid capable of instantaneously vaporizing due to the high heat of the glass ribbon 14 and forming a stable vapor film. Since the thermal conductivity of the thin layer of the vapor film formed by instantaneous vaporization with high heat is significantly smaller than the thermal conductivity of a liquid or a solid, it forms an adiabatic environment for the glass ribbon 14. be able to.

The glass ribbon 14 and the roll 1
In the forming apparatus 10 for forming a vapor film between the glass ribbons 8 and 20, the rolls 18 and 20 rotate in the direction of the arrow in FIG.
It is necessary to draw in the clearance between 8, 20 and transport it while forming it into a thin glass ribbon 14. That is,
It is necessary to apply an appropriate conveyance force to the glass ribbon 14 so that the rotating rolls 18 and 20 do not slip with respect to the glass ribbon 14. Therefore, in the forming apparatus 10, a surface region where the vapor of the vapor film forming agent vaporized from the surfaces of the rolls 18 and 20 is not partially generated on the roll surface is provided in a dispersed manner. Here, a surface region where steam is not partially generated on the roll surface is referred to as a “non-steam generating region A”, and a region other than the “non-steam generating region A” on the roll surface is referred to as a “steam generating region B”. I do. The “non-steam generating region A” referred to here is a region that does not generate steam at all or generates a very small amount of steam, and is considered substantially not generating steam.

FIG. 2 shows an example in which a large number of “non-steam generating regions A” are arranged on the surfaces of the rolls 18 and 20 in the form of minute circles.

The "non-steam generating region A" is formed of a non-water-containing base material having a property of not containing a steam film forming agent, for example, water, on the surfaces of the rolls 18 and 20 formed of the above-described roll base material. It is formed by dispersing minute surfaces in a constant distribution state. When the “non-vapor generation region A” is a dispersed phase (discontinuous phase), the size of one location is desirably 5 mm ² or more and 1 cm ² or less. Further, when a continuous phase is formed, the roll 1
0.5 mm or more and 5 mm with respect to the circumferential direction of 8, 20
It is desirable to have the following length. If it is less than 0.5 mm, the effect of the “non-steam generating region A” is small, and if it is more than 5 mm, the adhesion of the glass may be too large or the surface may be scratched.

When porous carbon is used as the roll substrate, the “non-steam generating area A”
It is formed by constituting a predetermined portion of the surface of the surface 0 with a non-hydrous base material such as a platinum plate. In this case, it is preferable that the surfaces of the “non-steam generation region A” and the “steam generation region B” be flush.

As described above, the rolls 18, 2 in which the "non-steam generating region A" is partially formed on the surfaces of the rolls 18, 20 are provided.
0, the glass ribbon 14 at the forming temperature taken out of the glass melting furnace 16 is formed and conveyed through a thin layer of the vapor film in which the vapor film forming agent is vaporized. The portion of the glass ribbon 14 corresponding to the instantaneously exerts adhesiveness. Due to this tackiness, the roll 1
When 8 and 20 are rotated, the affinity (wettability) between the glass ribbon 14 and the rolls 18 and 20 can be increased. Therefore, when the rolls 18 and 20 rotate,
Slip with respect to the glass ribbon 14 is reduced, and the rotational force of the rolls 18 and 20 can be efficiently transmitted to the glass ribbon 14. Thereby, an appropriate conveyance force can be given to the glass ribbon 14.

By arranging a large number of small “non-steam generating areas A” on the surfaces of the rolls 18 and 20 as shown in FIG. 2, the glass ribbon 14 to be formed and conveyed is partially observed. The non-adhesion in the "steam-generating region B" and the adhesion in the "non-steam-generating region A" are formed and conveyed while being repeated in time and place. As a result, a part of the glass ribbon 14 does not come into contact with the “non-steam generating region A” for a long time, so that contact marks of the rolls 18 and 20, wrinkles and unevenness remain on the surface of the formed sheet glass. Less is. In this case, it is preferable to rotate the roll at a linear speed (of the roll surface) of 5 cm / sec or more. This is because the glass ribbon 14 repeats instantaneous non-adhesion in the “steam-generating region B” and instantaneous adhesion in the “non-steam-generating region A” by rotating the roll at a certain speed or higher. Therefore, an intermediate adhesive force between non-adhesive and adhesive can be evenly applied to the surface of the glass ribbon 14. Accordingly, since an excessive force is not applied to a part of the glass ribbon 14, the glass ribbon 14 can be smoothly transported while preventing the glass surface from being damaged.

Various forms other than FIG. 2 are conceivable for partially forming the "non-steam generating area A" on the surfaces of the rolls 18 and 20, and the "non-steam generating area A" is formed linearly. Alternatively, a polygonal “non-steam generating region A” may be scattered over the entire surface of the rolls 18 and 20. In short, it is important that the rotation of the rolls 18 and 20 does not cause the glass ribbon 14 to always contact the “non-steam generating area A”. In some cases, it is desirable that the relationship between the “non-steam generating region A” and the “steam generating region B” on the roll surface be formed with irregular randomness rather than regular. It is desirable that the particles are distributed in a statistically uniform dispersion state. Either the “non-steam generation region A” or the “steam generation region B” may form a continuous phase.

The ratio of the area of the "non-steam generating region A" to the total surface area of each of the paired rolls 18 and 20 is preferably in the range of 5 to 80%.
This is because if it is less than 5%, sufficient affinity cannot be imparted to the entire glass ribbon, and if it exceeds 80%, the ratio of the glass ribbon in direct contact with the roll surface increases,
This is because there is a risk that the glass surface may be adversely affected such as generation of scratches.

The diameter of the rolls 18 and 20 depends on the amount and thickness of the glass.
It is preferably in the range of 00 mm. If it is less than 10 mm, there is a risk that the balance between the supply and retention of water and the amount of glass treatment may be deteriorated. If it exceeds 3000 mm, the contact area and contact time with the glass may become too large.

The method for roll-out forming a sheet glass product of the present invention using the forming apparatus 10 constructed as described above will be described. Note that an example of water will be described as a vapor film forming material.

The glass ribbon 14 supplied from the glass melting furnace 16 to the roll device 12 is conveyed while being sequentially formed by the first-stage roll 22, the second-stage roll 24, and the third-stage roll 26 while being at the glass forming temperature. Is done. Thus, the glass ribbon 14 is gradually formed into a thin plate glass by receiving the roll pressure from the rolls 18 and 20. In this case, the formability and the transportability are both rolls 18,
Since these factors are affected by the clearance between the rolls 20, the number of roll rotations, the temperature and viscosity of the glass ribbon 14, and the like, it is preferable to appropriately set these factors according to the type and thickness of the sheet glass to be formed.

Then, the glass ribbon 14 is placed in the first to third stages.
When sandwiched between the rolls 18 and the rolls 20 of the rolls 22, 24 and 26 of the stage, water contained in the roll base material is removed from the surfaces of the rolls 18 and 20 by the glass ribbon 14.
Evaporates instantaneously due to high heat. As a result, water vapor is continuously generated at the interface between the glass ribbon 14 and the two rolls 18 and 20, and a heat insulating layer of a thin vapor film is formed between the glass ribbon 14 and the two rolls 18 and 20. This heat insulating layer can prevent the glass ribbon 14 from being rapidly cooled.

In the vaporization of water from the surfaces of the rolls 18 and 20, in the present invention, a "non-steam generating region A" is partially formed on the surfaces of the rolls 18 and 20. Thereby, the glass ribbon 14 corresponding to the “non-steam generation region A”
Part instantaneously exhibits tackiness, so roll 18,
When the 20 is rotated in the direction of the arrow in FIGS. 1 and 2, the affinity (wettability) generated with the glass ribbon 14 can be increased. As a result, the rotating roll 18,
20 does not slip with respect to the glass ribbon 14, and the rotational force of the rolls 18, 20 is applied to the glass ribbon 14.
Is efficiently transmitted to Thereby, the glass ribbon 14
Can be smoothly drawn into the clearance between the rolls 18 and 20 and transported while being formed into a thin plate shape. In this case, the rolls 18 and 2 having the “non-steam generation region A”
0 indicates each of the rolls 22, 24, 26 of the first to third stages.
Or if the first stage completes the formation of the desired sheet glass, the second and third stages may be rolls having no "non-steam generating region A".

As the vapor film forming agent, various ones can be used as described above, but usually, water can be suitably used in terms of operability, availability, safety and the like. Further, as the roll substrate, various materials can be used as described above, but a material which easily contains a vapor film forming agent is preferable, and a hydrophilic porous or fibrous material is usually preferable. Can be used.

In the present embodiment, an example has been described in which the roll device 12 is formed with three roll stages of a first roll 22, a second roll 24, and a third roll 26. It is not limited, and it is preferable to set the number of roll stages according to the thickness of the sheet glass to be formed.

As described above, according to the present invention, the molding factors such as the clearance between the two rolls 18 and 20, the number of rotations of the rolls, the temperature and viscosity of the glass ribbon 14, and the like are organically related to each other, and high quality The method is for producing a sheet glass, and it is desirable to control these forming factors by computer control.

[0035]

As described above, according to the present invention,
In a roll-out molding of a sheet glass, when a sheet glass is formed by being conveyed while being formed through a thin layer of a vapor film in which a vapor film forming agent is vaporized, an appropriate conveying force can be applied to the glass ribbon.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing an apparatus for rolling out a flat glass product of the present invention.

FIG. 2 is a perspective view showing an example of a mode of a non-steam generating region formed on a roll surface.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Forming apparatus, 12 ... Roll apparatus, 14 ... Glass ribbon, 16 ... Glass melting furnace, 18 ... Roll, 20 ... Roll, 22 ... 1st roll, 24 ... 2nd roll, 26 ...
Third stage roll, A: non-steam generating area on roll surface, B:
Steam generation area on roll surface

Claims (5)

[Claims] 1. A method of forming glass into a sheet glass by passing glass supplied in a molten state between a pair of rolls, wherein the roll substrate is made of a material or a structure capable of containing a liquid therein. During the step of introducing a vapor film forming agent which is not a gas at around room temperature but a gas at least at the glass transition point of the glass in a liquid state, and rotating the pair of rolls, the molten glass between the rolls is rotated. Let it pass,
A step of forming and transporting a glass ribbon through a thin layer of a vapor film in which the vapor film forming agent has been vaporized, comprising: A roll-out molding method for a sheet-like glass product, comprising using a roll having a surface not to be rolled. 2. The method according to claim 1, wherein the glass ribbon is formed and conveyed while sandwiching the glass ribbon using a pair of the rolls. 3. The roll according to claim 1, wherein the ratio of the area of the surface of the roll where no steam is generated partially to the area of the entire roll surface is 5% to 80%.
Roll-out molding method for sheet glass products. 4. An apparatus for forming a sheet glass by passing glass supplied in a molten state through a pair of rolls, wherein the roll substrate is made of a material or a structure capable of containing a liquid therein. Means for introducing a vapor film forming agent, which is not a gas at around room temperature but a gas at least at the glass transition point of glass in a liquid state, and melting the glass between the rolls while rotating the pair of rolls. Let it pass,
Means for forming and transporting a glass ribbon through a thin layer of a vapor film in which the vapor film forming agent has been vaporized, and a roll-out molding apparatus for a sheet glass product, comprising: A roll-out molding apparatus for a sheet-like glass product, wherein a surface not to be formed is partially formed. 5. The flat glass product according to claim 4, wherein the surface that does not generate the vapor is dispersed in a constant minute distribution state on the roll surface formed of the roll base material. Roll-out molding equipment.