KR20090066271A - Process for producing glass sheet - Google Patents

Abstract

Foreign substances which have adhered to a glass ribbon, such as tin and tin oxide, are removed during glass sheet production. In producing a glass sheet by the float method, a removing member comprising a heat-resistant fibrous sheet is brought into contact with a surface of a glass ribbon which has been drawn from a molten tin bath and has a temperature in a range in which the tin is in a molten state, and foreign substances, e.g., molten tin, adherent to the glass ribbon surface are wiped off. The foreign-substance removal is conducted with a removing device comprising: a removing member (made of a heat-resistant fibrous sheet) which comes into contact with the glass ribbon surface to wipe the foreign substances, e.g., molten tin, from the glass ribbon surface; and a fixing member which supports the removing member, the removing device being disposed so as to extend in the glass-ribbon width direction.

Description

Manufacturing method of glass sheet {PROCESS FOR PRODUCING GLASS SHEET}

The present invention relates to a method for producing a glass sheet by a float method, and more particularly, to remove foreign substances such as molten tin adhered to a glass ribbon to produce a glass sheet, and to remove foreign substances such as molten tin. A method and an apparatus for removing foreign substances such as molten tin thereof.

In glass sheets, such as architectural plate glass, automobile plate glass, and display plate glass, further high quality and low cost are calculated | required. There are several factors that hinder high quality and low cost. Tin, tin oxide or the like caused by the molten tin in a molten tin bath (float bath) attached to a glass sheet is not a problem.

In manufacture of the glass sheet by a float method, a molten glass is shape | molded in the form of a continuous sheet on the molten tin surface of a molten tin bath, it becomes a continuous glass sheet of a predetermined width (henceforth a glass ribbon), and a molten tin surface It is taken out from and cut into a predetermined size to obtain a glass sheet. In this case, taking out a glass ribbon is performed by lifting a glass ribbon by the roll normally called a lift out roll. The area where this lift out roll exists is called lift out station. The glass ribbon taken out is then cooled in a slow cooling process called a layer. This area to be cooled is referred to as a layer region below, and a roll supporting and conveying a glass ribbon in the layer region is referred to as a layer roll below. Since molten tin in a float bath is easy to oxidize, the atmosphere in a float bath is maintained in a reducing atmosphere. The lift out station is also usually maintained in a reducing atmosphere.

In the manufacturing process of the said glass sheet, molten tin adheres easily to the lower surface of the glass ribbon taken out from the molten tin surface. The lift-out roll is not intended to remove molten tin or the like attached to the lower surface of the glass ribbon, but the molten tin attached to the lower surface of the glass ribbon moves to the roll surface when the roll surface contacts the lower surface of the glass ribbon. It has the effect | action which removes the molten tin adhering to (refer patent document 1). However, removal of molten tin by a lift out roll is inadequate, and molten tin is likely to remain on the lower surface of the glass ribbon. Moreover, the material of a lift out roll is iron and ceramic, and does not necessarily contact the whole surface of a glass ribbon. In addition, although molten tin adhered to a lift-out roll is removed from the roll surface, it does not remain on the roll surface in many cases, and the remaining molten tin may reattach to the glass ribbon lower surface. Molten tin remaining in the glass ribbon may also contaminate the layer roll.

The molten tin remaining on the glass ribbon surface tends to be oxidized, and the resulting tin oxide has a very high melting point. Therefore, when tin oxide adheres to the glass ribbon surface, it is difficult to remove it. In addition to tin oxide, tin compounds such as sulfides may be generated due to impurities in the atmosphere in the float bath, impurities in molten tin, glass, and the like. The mixture of molten tin or tin compound removed at the lift out station is called dross. If these foreign matters are cooled while attached to the glass ribbon, it is difficult to remove the foreign matters from the glass sheet.

Thus, foreign matters, such as tin and tin oxide which adhered to the lower surface of a glass ribbon, become a fault and become a cause of the quality fall of a glass sheet and the fall of a production yield. In some cases, since the foreign matter needs to be removed from the glass ribbon and the glass sheet after cooling, a process of removing the foreign matter may be newly formed, further increasing the cost. In addition, tin and tin oxide remaining on the glass ribbon surface or the roll surface may damage the glass ribbon surface, and the scratch may be a cause of cracking in the slow cooling and subsequent processes, and further, a decrease in production yield. .

Patent Document 1: Japanese Patent Application Laid-Open No. 11-335127

Problems to be Solved by the Invention

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and the removal of foreign matter adhering to the surface of the glass ribbon directly from the surface of the glass ribbon in the high temperature state (that is, in the state of melting the tin which is the main foreign matter) from the surface thereof. The purpose. In addition, since the glass ribbon surface is relatively soft at this stage, the member which contacts the glass ribbon surface and wipes off a foreign material should have heat resistance and be able to contact the glass ribbon surface flexibly without gap.

Means to solve the problem

The present invention provides a method for producing a glass sheet by the float method, wherein the foreign matter such as molten tin adhered to the glass ribbon surface is directly removed from the glass ribbon surface by a removal member that abuts on the glass ribbon surface. The present invention relates to a method for removing the foreign matter from the apparatus, and a device for removing the foreign matter suitable for these methods.

(1) In the method for producing a glass sheet by the float method, the removal member made of a heat-resistant fiber sheet is brought into contact with the surface of the glass ribbon taken out from the molten tin bath and in the melting temperature range of the tin, and the glass A method for producing a glass sheet, which comprises wiping off and removing foreign substances such as molten tin adhered to a ribbon surface.

(2) The manufacturing method of said (1) whose said removal member is in a non-oxidizing atmosphere.

(3) The method for producing (1) or (2) above, wherein the heat resistant fiber sheet is a felt-like sheet or a woven or nonwoven fabric-like sheet composed of at least one selected from carbon fibers and silica fibers.

(4) The manufacturing method of said (1), (2) or (3) which elastically supports the said removal member to the glass ribbon surface by elastic force or gas pressure.

(5) The manufacturing method of the glass sheet in any one of said (1)-(4) which makes the said removal member abut on the lower surface of a glass ribbon.

(6) In the process of manufacturing a glass sheet by the float method, the method removes foreign substances, such as molten tin, which were taken out from the molten tin bath and adhered to the surface from the surface of the glass ribbon in the melting temperature range of the tin. As

A foreign material such as molten tin is removed by contacting a surface of the glass ribbon with a removing member made of a heat-resistant fiber sheet to wipe off foreign matter such as molten tin from the surface of the glass ribbon.

(7) The removal method according to the above (6), wherein the removal member is in a non-oxidizing atmosphere.

(8) In the process of manufacturing a glass sheet by the float method, removal removes foreign substances, such as molten tin, which were taken out from the molten tin bath and adhered to the surface from the surface of the glass ribbon in the melting temperature range of the tin. As a device,

The removal device includes a removal member that abuts on the surface of the glass ribbon and wipes off foreign substances such as molten tin from the surface of the glass ribbon, and a fixing member that supports the removal member, and extends in the width direction of the glass ribbon. A removal device comprising a sieve, and the removal member made of a heat resistant fiber sheet.

(9) The removal device according to (8), wherein the fixing member has an elastic body elastically supporting the removal member on the surface of the glass ribbon.

(10) The removal device according to (8), wherein the fixing member has a gas passage for elastically supporting the removal member by the gas pressure on the surface of the glass ribbon.

(11) The removal device according to the above (8), (9) or (10), wherein the removal member forms a mountain shape in a state supported by the fixing member, and the top of the mountain shape contacts the surface of the glass ribbon. .

The removal apparatus in any one of said (8)-(11) whose said heat resistant fiber sheet is a felt-like sheet which consists of at least 1 sort (s) chosen from carbon fiber and a silica fiber, or a woven or nonwoven fabric sheet.

Effects of the Invention

According to the manufacturing method of the glass sheet of this invention, a foreign material, such as molten tin, which adhered to the glass ribbon surface can be removed directly from a glass ribbon surface with a removal member. As a result, since the foreign matter adhering to the roll which touches a glass ribbon downstream from a removal member can also be reduced, it can also prevent that a foreign material from these rolls reattaches to the glass ribbon surface. In addition, not only the foreign matter adhering to the lower surface of the glass ribbon, but also the foreign matter adhering to the upper surface of the glass ribbon (such as brick debris or other foreign matter dropped from the top of the float bath) can be removed by forming the removal member on the upper surface of the glass ribbon. .

By the above effect, the defect of the glass sheet resulting from the foreign material, such as tin and tin oxide which adhered to the glass ribbon surface, is reduced, and the flaw of the glass ribbon surface resulting from the foreign material adhered to a roll also becomes small, Higher quality and lower manufacturing costs can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the cross section of the removal apparatus of embodiment.

It is a figure which shows the manufacturing equipment cross section of the glass sheet containing the removal apparatus of embodiment.

3 is a view showing a cross section of the removal apparatus according to another embodiment.

4 is a view showing a cross section of the removal apparatus according to another embodiment.

5 is a view showing a cross section of the removal apparatus according to another embodiment.

6 is a cross-sectional explanatory diagram showing an example in the case of horizontally moving the removal device in the embodiment.

Explanation of the sign

One… Molten tin bath, 2... Molten tin, 3... Glass ribbon, 4... Removal member, 5... Fixed member, 6.. Platelet, 7... Removal device, 8... Lift out roll, 9.. Lift out roll, 10.. Lift out roll, 11... Roll of layers, 12... Layer, 13... Drive belt, 14... Drive motor, 15... Drive unit, A... Space across the width direction of the glass ribbon between the removal member and the fixing member, B... Through hole, C... Advancing direction of ribbon glass, D... Space, E… Floor.

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described according to drawings (FIGS. 1-6). 1: shows the cross section of the removal apparatus which is embodiment. FIG. 2: shows the cross section of the manufacturing equipment of the glass sheet containing the removal apparatus in embodiment. 3-5 show the cross section of the removal apparatus which concerns on another embodiment. 6 shows an example in the case where the removal apparatus is horizontally moved. In addition, in the following description, downstream means the direction side opposite to a molten tin bath with respect to the moving direction of a glass ribbon (direction side of the arrow shown by C in FIG. 1), and the opposite direction side is an upstream. do.

The removal apparatus 7 which shows the cross section in FIG. 1 is an apparatus which removes the foreign material adhering to the lower surface of the glass ribbon 3. The glass ribbon 3 shape | molded on the molten tin bath is taken out from the molten tin bath, and is moving in the direction shown by C. FIG. The removal apparatus 7 consists of the removal member 4 which abuts on the lower surface of the glass ribbon 3, and the fixing member 5 which supports the removal member, and both the removal member 4 and the fixing member 5 are glass ribbons. It is a long body extended in the width direction (perpendicular to the surface) of (3). The removal member 4 consists of a heat resistant fiber sheet, and the both ends of the removal member 4 in the width direction (direction orthogonal to the longitudinal direction of the elongate body) are attached to the fixing member 5, and the both ends are mountain-shaped (convex-shaped). ), And its top portion abuts against the lower surface of the glass ribbon 3. The fixing member 5 is a long pipe-shaped long body, and the internal space A of the hollow portion D and the bulging portion of the removal member 4 communicates with the through-hole (or slit) B. It is. By introducing a pressurized gas into the hollow portion D of the fixing member 5, the removal member 4 is swollen into an acid form, and the expansion pressure causes the contact pressure or the contact with the glass ribbon 3 of the removal member 4 to swell. The area can be adjusted. For this reason, it is preferable that the edge part of the removal member 4 and the fixing member 5 is closed. The fixing of the removal member 4 to the fixing member 5 can be performed by screwing, adhering, inserting with a backing plate, or the like. Foreign substances such as molten tin attached to the lower surface of the glass ribbon 3 are removed from the lower surface of the glass ribbon 3 by the removal member 4, and the removed foreign matter is usually upstream of the removal member 4 (glass Drop in the ribbon direction (opposite side).

FIG. 2: shows the manufacturing equipment cross section of the glass sheet which provided the above removal apparatus 7 in the lift out area. In the manufacturing method of the glass sheet by the float method, the process of melt | dissolving a raw material in a melting kiln not shown and making molten glass mainly, and shape | molds a molten glass into a flat plate on the molten tin 2 of the molten tin bath 1 Step of taking out the glass ribbon 3 from the molten tin bath 1 by the lift-out rolls 8, 9 and 10, and moving the glass ribbon to the layer roll 11 in the layer region 12 while moving the glass ribbon ( 3) it is annealed so as not to leave strain in it. These processes should just be operation by a normal installation, and there is no influence by installation of the removal apparatus 7. As shown in FIG. In FIG. 2, the removal apparatus 7 is formed in the downstream of the lift out roll 10 of the lowest downstream of a lift out area.

The removal apparatus 7 can be formed in any position of the lift out area of the said process, or upstream in the layer area 2. Here, the upstream portion in the layer region 12 refers to a region (melting temperature region of tin) at a temperature higher than the melting point of tin in the layer region 12. The lift out zone is typically at the melting temperature range of tin. Therefore, as long as it is this temperature range, the removal device 7, for example, upstream of the lift out roll 8, between the lift out roll 8 and the lift out roll 9, the lift out roll 9 and the lift It may be formed between the out rolls 10, the upstream side of the layer roll 11 on the most upstream side in the layer region 12, between the layer roll 11 and the next layer roll 11, and the like. Moreover, the removal apparatus 7 can also be provided in two or more points of these positions.

FIG. 3 is an enlarged cross-sectional view of the removal device 7 in FIG. 2, and is a removal device having the same configuration as that shown in FIG. 1 except for having the plate-shaped body 6. The plate 6 is mounted on the upstream side of the upper part of the fixing member 5, and is present in the internal space A which has swelled in the shape of the removal member 4, and supports the removing member 4 from the back side. have. The plate-like member 6 elastically supports the removal member 4 so that the pressure at the contact of the removal member 4 with the lower surface of the glass ribbon 3 can be adjusted. If it can support | support, what is elongate continuously in the width direction of a glass ribbon may be formed, and may be formed intermittently. The contact pressure can be adjusted by changing the thickness of the plate-shaped body 6. In the plate-like body 6 in FIG. 3, the portion having the curvature of the bottom portion of the substantially J-shape is substantially J-shaped and abuts on the rear side of the ridge of the removal member 4.

The plate-shaped body 6 can make the removal member 4 swell in an acid form, and can adjust the shape and adjust the contact area of the removal member 4 with respect to the glass ribbon 3. Moreover, the contact pressure with respect to the glass ribbon 3 of the removal member 4 can be adjusted using the elasticity of the thickness direction of the removal member 4 by adjusting the position of the thickness direction of the removal member 4. Moreover, the plate-shaped body 6 can be comprised by an elastic body, and the contact area and contact pressure can be adjusted using the plate-shaped body 6 using elasticity. 3 shows an example in which the plate-like member 6 having elasticity is used. The plate-like body 6 may not have elasticity. The cross-sectional shape of the plate-shaped body 6 is not limited to the shape of FIG. 3, It may have a rectangle or another shape. 4 is an example using a plate-shaped body 6 having a substantially rectangular cross section. Moreover, the plate-shaped body 6 can also be mounted in the downstream of the upper part of the fixing member 5, and FIG. 5 attaches the plate-shaped body 6 to both the upstream side and the downstream side of the upper part of the fixing member 5 ,. One example. In the removal apparatus 7 provided with these plate-shaped bodies 6, it is not necessary to make the removal member 4 swell to an acid form by gas pressure. However, also in the removal apparatus 7 provided with these plate-shaped bodies 6, it is preferable to make the removal member 4 protrude in an acid form by gas pressure. This is because the gas pressure makes it easier to adjust the contact area and the contact pressure.

Since the removal member 4 is easy to bounce molten tin etc., and the glass ribbon surface is also easy to bounce molten tin etc. relatively, the removal member 4 wipes and removes the foreign material on the glass ribbon surface by having a relative speed with a glass ribbon ( Scrape). In order to effectively remove the foreign matter, it is preferable that the removal member and the glass ribbon abut at a relative speed. Since the glass ribbon is moving in the advancing direction shown by C of FIG. 2 at a predetermined advancing speed (hereinafter, referred to as Gv), even if the removal member 4 is fixed, both of them are brought into contact with the relative velocity Gv. You can change this relative speed as desired. In order to make the relative speed slower than Gv, it is preferable to move the removal member 4 in the same direction as the glass ribbon moving direction at a speed later than Gv. In order to make the relative speed faster than Gv, it is preferable to move the removal member 4 in the direction opposite to the moving direction of the glass ribbon. Moreover, the removal member 4 can also be reciprocated in the direction opposite to the moving direction of a glass ribbon. 6 shows an example in the case where the removal device is horizontally moved. The removal device 7 of FIG. 6 is mounted on the drive belt 13 of the drive device 15, and at a speed different from the traveling speed of the glass ribbon by the drive motor 14 fixed on the floor E, It reciprocates in parallel with the advancing direction of the ribbon 3.

In the present invention, the removal device is not limited to the one shown. For example, the roll-shaped removal apparatus and the continuous belt-shaped removal apparatus which rotate in the axis parallel to the width direction of a glass ribbon similarly to a lift out roll can be used. As a roll-shaped removal apparatus, the roll-shaped removal apparatus which has a round pipe-shaped fixing member and the heat resistant fiber sheet layer (removing member) formed in the surface can be used, for example. Through holes and slits may be formed in the round pipe-like fixing member, and gas may be supplied from the fixing member to apply a gas pressure to the heat resistant fiber sheet layer. As a continuous belt-shaped removal apparatus, for example, the surface of the belt 13 driven by the drive device 15 shown in FIG. 6 is comprised by the heat resistant fiber sheet, and this belt is made to contact the glass ribbon surface as a removal member. One removal device can be used. It is preferable to drive a roll or a belt in these removal apparatuses to have a relative speed with a glass ribbon, and to remove the foreign material on the glass ribbon surface.

It is preferable that the removal member is in continuous contact with the glass ribbon over almost the entire length of the width direction. However, the present invention is not limited to this, and when there is a place where foreign matter easily adheres to the glass ribbon, it may be used in contact with only that portion. For example, when a foreign material is easy to adhere to the width direction both ends of a glass ribbon, the removal member which abuts only in that part can be used. Moreover, it is preferable that the removal member is in contact with a glass ribbon in the direction orthogonal to the advancing direction of a glass ribbon over the substantially full length of the width direction. However, it is not limited to this, It can also make an angle other than a right angle with respect to the advancing direction of a glass ribbon, and can make it contact.

The removal member may be brought into contact with the upper surface of the glass ribbon to remove foreign substances adhering to the upper surface of the glass ribbon. For example, the removal member may be removed from the glass ribbon by driving the removal member in the width direction of the glass ribbon and moving the foreign matter to the width direction end of the glass ribbon. In addition, when foreign matter adheres to the removal member, the foreign matter on the upper surface of the glass ribbon can be removed by replacing the removal member at appropriate intervals.

In the present invention, the removal member is made of a heat resistant fiber sheet. As heat resistant fiber, the fiber which is a material which can endure the temperature in 750 degreeC (approximately temperature of a molten glass), especially about 1000 degreeC is preferable. Specifically, they are inorganic fibers, such as carbon fiber, a silica fiber, an alumina fiber, a silicon carbide fiber, a metal fiber, for example, Among these, carbon fiber and a silica fiber are preferable, Especially, since it is low in hardness, it is hard to scratch a glass ribbon well. Moreover, the carbon fiber which repels molten tin is preferable. As the fiber sheet, a sheet of felt or a sheet of woven or nonwoven fabric is preferable. Specifically, for example, a felt sheet (carbon felt) of carbon fiber, a woven fabric of carbon fiber (carbon cross), or the like can be used. The heat resistant fiber sheet may be a fiber sheet made of two or more kinds of inorganic fibers of different materials. In addition, even if carbon fiber remains on the lower surface of a glass ribbon, it is preferable also in the point which does not become a defect, such as a contamination, since it burns and disappears in comparatively high temperature oxidizing atmosphere, for example in the latter half part of a layer area | region.

Although the thickness of a removal member is not specifically limited, In order to provide flexibility, it is preferable that it is 5 mm or more. Although there is no upper limit in particular in thickness, in the case of gas supply mentioned later, 30 mm, especially 15 mm is preferable from a viewpoint of the pressure loss with respect to gas. In the formation of the removal member, only the felt-like sheet or a plurality of woven or nonwoven fabrics may be stacked, or the felt-like sheet and the woven or nonwoven fabric may be combined.

The removal member is brought into contact with the surface of the glass ribbon after being taken out of the molten tin bath and in the melting temperature range of tin. The melting temperature of tin is about 230 ° C. The melting temperature range of tin is typically in the range of 230 ° C to 230 + 10 ° C. Therefore, the position where the removal member abuts on the glass ribbon is a temperature range higher than the melting point of this tin. In this temperature range, since tin, which is the main foreign matter, is in the liquidus temperature range, the foreign matter can be easily wiped off by the removal member. High-melting-point foreign substances such as tin oxide are usually supported on molten tin and can be easily wiped off with molten tin. Even the high-melting point foreign matter not supported on the molten tin does not adhere firmly to the surface of the glass ribbon due to the high temperature of the glass ribbon, and thus can be wiped off. As above, the lift-out zone is usually at a temperature range above the melting temperature of tin, and the upstream of the layer zone is also typically at a temperature range above the melting temperature of tin. Therefore, it is preferable that the removal member is in contact with the surface of the glass ribbon in the lift out area or the upstream area of the layer area, and in particular in contact with the surface of the glass ribbon in the lift out area.

Even when the contacting position of the removal member is in the melting temperature range of tin, when there are more foreign matters (especially tin oxide) having a high melting point, it may be difficult to wipe off the foreign substances sufficiently. Since molten tin is easy to oxidize, it is not preferable that oxidation of molten tin which is a foreign material advances before a removal member contacts. Therefore, it is preferable that at least the contact position of the removal member and the upstream atmosphere in which the glass ribbon exists are in a reducing gas atmosphere or an inert gas atmosphere (these two atmospheres are also referred to as non-oxidizing atmospheres). The lift out station is normally maintained in the same reducing gas atmosphere as the float bath. In addition, the part into which the gas of the lift out area of the layer area upstream part flows in is normally in a reducing gas atmosphere or an inert gas atmosphere. Therefore, as long as the abutting position of the removal member is in these regions, it is considered that oxidation of the molten tin will not proceed easily. In particular, there is a possibility that the oxidizing atmosphere is temporarily temporarily upstream of the layer region, so that the atmosphere can be maintained in a non-oxidizing atmosphere by supplying a reducing gas to the contact position of the removal member and the upstream thereof where the glass ribbon is present. have.

On the other hand, as shown in the figure, as a removal apparatus, the removal apparatus of the structure which inflated the removal member by acid type by gas pressure is preferable. In this case, pressurized gas introduced into the inner side A of the removal member from the fixing member 5 is used. This pressurized gas may come in contact with molten tin which is a foreign matter, and therefore, it is preferable that the pressurized gas is made of a non-oxidizing gas (that is, a reducing gas or an inert gas). In addition, when a removal member consists of materials which are easy to oxidize, such as carbon fiber, it is not preferable that the removal member exists in an oxidizing atmosphere. Also from this point of view, it is almost essential that the pressurized gas consists of a non-oxidizing gas. Moreover, even if a removal member is in a reducing atmosphere, since the oxygen concentration may rise temporarily, it is preferable to prevent shortening of the lifetime of a removal member using a reducing gas as a pressurized gas. The supply pressure of these gases is preferably set in consideration of the pressure loss. If the gas pressure is too low, the contact pressure with respect to the glass ribbon surface of the removal member is low, there is a fear that the effect of removing foreign matters. On the contrary, if it is too high, there exists a possibility that the foreign material adhering to the removal member may reattach to the glass ribbon surface. The amount of gas supplied may vary depending on the structure of the removal device and the like, but in general, 10 to 100 liters / minute per 1 m in the width direction is suitable. Moreover, supplying the gas of this supply amount also has the effect of cooling a removal member or a fixing member.

The oxygen concentration in the non-oxidizing gas or non-oxidizing atmosphere is preferably 1% or less, particularly 1000 ppm or less. As the reducing gas, hydrogen, acetylene, or an inert gas having these is preferable. As an inert gas, nitrogen gas or argon gas is preferable. The reducing atmosphere is preferably the same hydrogen-containing nitrogen gas atmosphere as that of the float bath.

The material of the fixing member in the removal apparatus is not limited as long as it has heat resistance. Usually, it consists of materials, such as a metal, carbon, and a ceramic. Preferably, metal, such as stainless steel, is preferable. The material of the plate-shaped body mounted on the fixing member is similarly made of a heat resistant material, and metal, carbon, ceramic, and the like are preferable. The plate-like body having elasticity is preferably metal such as stainless steel. Carbon etc. can also be used as a plate-shaped object which does not have elasticity.

A removal device was manufactured to confirm the effectiveness of the present invention. Moreover, this removal apparatus was arrange | positioned in the manufacturing apparatus of the glass sheet by the float method, and the experiment which confirmed the effect of tin and tin oxide removal was performed. The removal apparatus used for an experiment was installed in the layer side of the lift out roll of the most downstream of a plurality of lift out rolls. The removal member was in contact with 20 cm (length in the width direction of the glass ribbon) of one end of the lower surface of the glass ribbon for 20 days during the production period of the glass sheet. In that period, the surface of the glass ribbon which passed through the removal member was visually inspected once every 2 hours (240 times of total inspection times) under the high brightness light source used by normal quality inspection.

As the removal member used in this experiment, as a fibrous carbon, the thing of the felt shape of thickness 10mm of F-210G (manufactured by Kureha Co., Ltd.) of the brand name KRECA G FELT, and a bulk density of 0.10 g / cm <3> was used. It processed and used so that the length of the part which contacts this to a glass ribbon might be 200 mm, and width might be 100 mm. As the fixing member, a stainless steel square pipe having a width of 20 mm and a thickness of 1.2 mm was used. The plate-shaped body has a rectangular cross-sectional shape of 50 mm in height, 0.3 mm in thickness, and 200 mm in length crossing the width direction of the glass ribbon toward the molten tin bath side of the fixing member as shown in FIG. 4. It was formed by. In the abutting portion of the glass ribbon and the removal member, N ₂ was supplied at 5 liters / minute using the space inside the square pipe as an inert gas. The through holes of the fixing member for supplying the inert gas were 3 mm in diameter and formed at regular intervals of 10 mm in the width direction of the glass ribbon. The removal member was fixed to the fixing member by placing a stainless steel plate on the left and right ends of the removal member.

As a result of the experiment, defects and scratches of tin and tin oxide on the lower surface of the glass ribbon were not confirmed. Tin and tin oxide defects in the region when no removal device was used were found to be about 0.1 pieces / m 2. From this, the high effect by the removal of tin and tin oxide on the lower surface of the glass ribbon of the removal apparatus which concerns on this invention was demonstrated. Moreover, there was no abrasion and damage of the removal member, and there was no problem regarding durability.

Since this invention can manufacture a high quality glass sheet by removing foreign substances, such as molten tin, adhered to a glass ribbon, it can be used for manufacture of the glass sheet by a float method.

In addition, all the content of the JP Patent application 2006-331918, a claim, drawing, and the abstract for which it applied on December 8, 2006 is referred here, and it introduces as an indication of the specification of this invention.

Claims (12)

In the method of manufacturing a glass sheet by the float method, the removal member made of a heat-resistant fiber sheet is brought into contact with the surface of the glass ribbon taken out from the molten tin bath and in the melting temperature range of the tin, A method for producing a glass sheet characterized by wiping off and removing foreign substances such as molten tin attached. The method for producing a glass sheet according to claim 1, wherein the removal member is in a non-oxidizing atmosphere. The method for producing a glass sheet according to claim 1 or 2, wherein the heat resistant fiber sheet is a felt-like sheet or a woven or nonwoven sheet formed of at least one selected from carbon fibers and silica fibers. The manufacturing method of the glass sheet of any one of Claims 1-3 which elastically supports the said removal member to the glass ribbon surface by elastic force or gas pressure. The manufacturing method of the glass sheet of any one of Claims 1-4 which makes the said removal member abut on the lower surface of a glass ribbon. In the process of manufacturing a glass sheet by the float method, it removes from the molten tin bath and removes foreign substances, such as molten tin, which adhered to the surface from the surface of the glass ribbon in the melting temperature range of the tin, A foreign material such as molten tin is removed by contacting a surface of the glass ribbon with a removing member made of a heat-resistant fiber sheet to wipe off foreign matter such as molten tin from the surface of the glass ribbon. The method for removing foreign matters such as molten tin according to claim 6, wherein the removal member is in a non-oxidizing atmosphere. A removal apparatus for removing foreign substances such as molten tin from the surface of a glass ribbon which is taken out of the molten tin bath in the process of producing a glass sheet by a float method and adhered to the surface from the surface of the glass ribbon in the melting temperature range of the tin, The removal device includes a removal member that abuts on the surface of the glass ribbon and wipes off foreign substances such as molten tin from the surface of the glass ribbon, and a fixing member that supports the removal member, and extends in the width direction of the glass ribbon. A removal device comprising a sieve, and the removal member made of a heat resistant fiber sheet. The removal apparatus according to claim 8, wherein the fixing member has an elastic body elastically supporting the removal member on the surface of the glass ribbon. 9. The removal apparatus according to claim 8, wherein the fixing member has a gas passage for elastically supporting the removal member by the gas pressure on the surface of the glass ribbon. The removal apparatus according to any one of claims 8 to 10, wherein the removal member forms a hill shape in a state of being supported by the fixing member, and the top of the hill contact the surface of the glass ribbon. The removal apparatus according to any one of claims 8 to 11, wherein the heat resistant fiber sheet is a felt-like sheet or a woven or nonwoven sheet formed of at least one selected from carbon fibers and silica fibers.

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