WO2018100981A1

WO2018100981A1 - Method for producing glass plate

Info

Publication number: WO2018100981A1
Application number: PCT/JP2017/040105
Authority: WO
Inventors: 世志彦端
Original assignee: 日本電気硝子株式会社
Priority date: 2016-12-02
Filing date: 2017-11-07
Publication date: 2018-06-07
Also published as: KR102435172B1; CN109923079B; JP6757496B2; JP2018090446A; KR20190090783A; CN109923079A

Abstract

This method includes a scribing step for forming scribe lines 3 on a glass ribbon 2 that is conveyed downward in a vertical orientation, and a splitting step in which the glass ribbon 2 is split and a part to be cut out 2x is cut out as a glass plate by bending a scribe-line-forming part 2s while supporting the part to be cut out 2x by a splitting arm 8. A plurality of pairs of claws 10a are provided along the vertical direction on the splitting arm 8. In the splitting step, the glass ribbon 2 is supported by the uppermost claw 10ax after being split in a state in which the support by the uppermost claw 10ax has been released.

Description

Manufacturing method of glass plate

The present invention relates to a glass including a step of forming a scribe line along a width direction with respect to a glass ribbon conveyed downward in a vertical posture, and a step of breaking the glass ribbon along the scribe line and cutting out a glass plate. The present invention relates to a method for manufacturing a plate.

As is well known, as a method for manufacturing a glass plate, there is a method in which a glass plate is cut out from a long glass ribbon formed by a downdraw method. A specific form of such a method is disclosed in Patent Document 1.

As shown in FIG. 9, in the form disclosed in the same document, first, along the glass ribbon 100 conveyed downward in a vertical posture after forming, first, along the width direction (in FIG. 9, a direction perpendicular to the paper surface). A scribe line 101 is formed. Next, the portion to be cut 100x existing below the scribe line 101 is supported by a plurality of support portions 102a provided in the support means 102, and the forming portion of the scribe line 101 is bent in accordance with the operation of the support means 102. . Thereby, the glass ribbon 100 is broken along the scribe line 101. As a result, the cut-out portion 100x is cut out from the glass ribbon 100 as a glass plate.

JP 2002-137930 A

By the way, in recent years, there is an increasing demand for thinning the glass plate, and accordingly, the glass ribbon that is the base of the glass plate may be formed into a film-like thickness (for example, a thickness of 300 μm or less). However, when the glass plate is cut out from the film-like glass ribbon under the above-described form, as shown in FIG. 9, the scribe line 101 and the support portion 102 a that supports the portion nearest to the scribe line 101 are provided. Based on the length of the mutual distance L, the following two problems have occurred.

As a first problem, when the mutual distance L is short, when the glass ribbon 100 is broken, the portion where the scribe line 101 is formed is excessively curved along with the operation of the support means 102. Thereby, an excessive bending stress is generated in the formation part of the scribe line 101, and the cut part formed by the splitting is formed away from the scribe line 101, and the glass ribbon 100 is bent along the scribe line 101. It becomes difficult. As a second problem, when the mutual distance L is long, the upper end portion 100xa of the film-like glass plate cut out by folding (the cut-out portion 100x) bends downward due to its own weight, resulting from this bend. As a result, the glass plate (the cut-out portion 100x) may be damaged.

The first and second problems are both problems that have been sought to be solved, but the situation in which the second problem occurs remarkably when the distance L between them is long in order to solve the first problem. Will be invited. On the contrary, if the mutual distance L is shortened in order to solve the second problem, a situation in which the first problem frequently occurs is caused. Under such circumstances, establishment of a technique capable of avoiding both problems has been expected.

The present invention made in view of the above circumstances, even when the glass ribbon is thin in a film shape, can be reliably broken along the scribe line, and also about the bending of the upper end portion of the glass plate cut out by folding. The purpose is to provide technology that can prevent this.

The present invention, which was created to achieve the above object, includes a scribing process for forming a scribe line along the width direction of the glass ribbon, and a lower side than the scribe line, with respect to the glass ribbon conveyed downward in a vertical posture. The glass ribbon is broken along the scribe line by bending the forming part of the scribe line along with the operation of the support means while supporting the cut-out part existing in the support means, and the cut-out part is made of the glass plate And a folding step of cutting out as a glass plate manufacturing method, wherein the support means has a plurality of support portions along the vertical direction, and in the splitting step, the uppermost support among the plurality of support portions After the glass ribbon is broken in a state in which the support by the part is released, the support by the uppermost support part is performed.

In this method, as the support means for supporting the cut-out portion, one provided with a plurality of support portions along the vertical direction is used. And in the splitting step, the support by the uppermost support part is released at the time of splitting, so the cut-out part at the time of splitting is made by a support part provided below the uppermost support part. The lower part than the upper end is placed in a supported state. Therefore, at the time of folding, the scribe line and the support part that supports the nearest part to the scribe line (here, lower than the uppermost support part) are released as much as the support by the uppermost support part is released. It is possible to increase the distance between the support portion and the support portion. Accordingly, it is possible to avoid the occurrence of a situation in which the scribe line forming portion is excessively bent in accordance with the operation of the support means, and an excessive bending stress is generated in the forming portion. As a result, even when the glass ribbon is thin like a film, it can be reliably broken along the scribe line. In addition, in this method, after the splitting, the cut-out portion (the glass plate cut out by the splitting) is supported by the uppermost support portion. Thereby, even when the glass ribbon is thin like a film, it is possible to prevent the upper end portion of the glass plate cut out by folding.

In the above method, when the cut-out part has an ineffective part that exists at both ends in the width direction and an effective part that exists between the two ineffective parts, the ineffective part is provided by a plurality of support parts. Is preferably supported.

In this way, the plurality of support portions come into contact with non-effective portions that are not products, rather than effective portions that are products. Therefore, it is possible to avoid the contamination of the effective portion and the generation of scratches due to the contact with the support portion, and it is possible to improve the quality of the finally obtained product glass plate.

In the above method, in the folding step, it is preferable to support the upper end portion by bringing an abutting member into contact with the upper end portion of the cut-out portion before performing support by the uppermost support portion.

¡When cutting the glass ribbon, the cut-out part is inclined with respect to the vertical line. For this reason, after the splitting, the upper end portion of the cut-out portion (the glass plate cut out by the splitting) tries to bend so as to hang down by its own weight. Therefore, if the contact member is brought into contact with and supported by the upper end portion after the folding, the upper end portion can be more reliably prevented from being bent. In addition, after the contact member is brought into contact with the upper end portion, support by the uppermost support portion is performed, and thus it becomes easier to stably support the upper end portion.

In the above method, the contact member preferably extends along the width direction.

In this way, when the contact member is brought into contact with the upper end of the portion to be cut out (the glass plate cut out by folding), this can be performed stably.

In the above method, the contact member is preferably a suction nozzle that sucks the glass powder generated when the glass ribbon is folded.

If it does in this way, it will generate | occur | produce with execution of a folding process not only to support the upper end part of a to-be-cut part (the glass plate cut out by splitting) because a contact member is a suction nozzle. It is also possible to suck glass powder. Therefore, it is possible to suitably avoid the deterioration of the quality of the glass plate due to the adhesion of glass powder or the like.

According to the method for producing a glass plate according to the present invention, even when the glass ribbon is thin like a film, the glass plate can be reliably broken along the scribe line, and the upper end of the glass plate cut out by folding is bent. Can also be prevented.

It is a side view which shows the manufacturing apparatus used for the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a front view which shows the manufacturing apparatus used for the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a side view which shows the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a side view which shows the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a side view which shows the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a side view which shows the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a side view which shows the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a side view which shows the manufacturing method of the glass plate which concerns on embodiment of this invention. It is a side view which shows the manufacturing method of the conventional glass plate.

Hereinafter, a method for producing a glass plate according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the embodiment described below, a case where a glass plate is cut out from a flexible glass ribbon (for example, a thickness of 300 μm or less) will be described as an example. However, the present invention is not limited to this, and the method for producing a glass plate according to the present invention can also be applied to a case where a glass plate is cut out from a glass ribbon having no flexibility.

First, the structure of the manufacturing apparatus used for the manufacturing method of a glass plate is demonstrated with reference to FIG. 1 and FIG.

As shown in FIGS. 1 and 2, the manufacturing apparatus 1 travels along the width direction (in FIG. 1, a direction perpendicular to the paper surface) on the surface 2 a of the glass ribbon 2 that is conveyed downward in a vertical posture. A wheel cutter 4 that forms the scribe line 3, a support bar 5 that is long in the width direction for supporting the portion of the glass ribbon 2 where the wheel cutter 4 travels from the back surface 2b side, and a scribe line forming portion 2s (hereinafter referred to as scribe). The line forming portion 2s) is supported by the back surface 2b side, and is split through a fulcrum bar 6 that is long in the width direction and serves as a fulcrum for splitting, and an opening 7a facing the surface 2a of the glass ribbon 2. By supporting the suction nozzle 7 for sucking the generated glass powder and the portion to be cut 2x (the portion to be cut out as a glass plate), the scribe line forming portion 2s is curved in accordance with its own operation, thereby making glass A bend-breaking arm 8 Dividing folding Bonn 2 comprises as main components.

Among the constituent elements of the manufacturing apparatus 1, the wheel cutter 4 and the suction nozzle 7 are mounted on a first housing (not shown) disposed on the surface 2 a side of the glass ribbon 2, and the support bar 5 and the fulcrum bar 6. Is mounted on a second housing (not shown) arranged on the back surface 2b side of the glass ribbon 2. Each of the first casing and the second casing can be moved along the vertical direction. Thereby, the wheel cutter 4 and the suction nozzle 7 are configured to move up and down integrally with the first housing in a state in which the relative positional relationship in the vertical direction is maintained. On the other hand, the support bar 5 and the fulcrum bar 6 are configured to move up and down integrally with the second housing while maintaining a relative positional relationship along the vertical direction.

Each of the first housing and the second housing can descend following the glass ribbon 2 at the same speed as the conveying speed of the glass ribbon 2 when moving downward. As a result, each of the wheel cutter 4, the support bar 5, the fulcrum bar 6, and the suction nozzle 7 has the glass ribbon 2 as the first casing and the second casing follow and drop on the glass ribbon 2. It is configured to exhibit its own functions while moving downward at the same speed as the transport speed. Similarly, the folding arm 8 can exhibit its own function while moving downward at the same speed as the conveying speed of the glass ribbon 2. That is, each component of the manufacturing apparatus 1 is in a state in which the relative speed along the vertical direction with respect to the glass ribbon 2 is zero when performing its function.

Among the above components, the wheel cutter 4, the support bar 5, the fulcrum bar 6, and the suction nozzle 7 are as shown by arrows in FIG. It is possible to move along the thickness direction of the glass ribbon 2 between a retreat position for retreating away from 2. The movement of these components along the thickness direction is performed while moving downward at the same speed as the glass ribbon 2. In the wheel cutter 4 and the support bar 5, the position indicated by a two-dot chain line in FIG. 1 is an operating position, and the position indicated by a solid line in FIG. On the other hand, in the fulcrum bar 6 and the suction nozzle 7, the position indicated by the solid line in FIG. 1 is the operating position, and the position indicated by the two-dot chain line in FIG.

The wheel cutter 4 is formed in a disk shape having a blade (edge) on a peripheral portion that rotates during traveling.

The support bar 5 has an abutting surface that abuts on a portion where the wheel cutter 4 travels. The abutting surface may be formed on a flat surface, or if the glass ribbon 2 tends to be bent along the width direction due to the molding conditions of the glass ribbon 2, etc. It may be formed on a curved surface that follows the curvature of the ribbon 2. Note that a cylindrical support roller may be used instead of the support bar 5. In this case, in a state where the glass ribbon 2 is sandwiched from both the front and back sides by both the support roller and the wheel cutter 4, the wheel cutter 4 runs on the outer peripheral surface of the support roller so that both run synchronously in the width direction. Touch to the site.

The fulcrum bar 6 has a semicircular abutting section that abuts against the scribe line forming portion 2s. The contact portion may be formed to extend in a straight line along the width direction, or may be formed to be curved following the curve of the glass ribbon 2 in the same manner as the contact surface of the support bar 5. In some cases.

The suction nozzle 7 is formed to extend in the width direction. The dimension along the width direction of the suction nozzle 7 is approximately the same as the width of the glass ribbon 2 or wider than the width of the glass ribbon 2. Further, the suction nozzle 7 includes a plurality of openings 7a along the width direction. Each of the plurality of openings 7a is connected to a negative pressure generator (not shown) (for example, a vacuum pump), and sucks glass powder using the negative pressure generated when the negative pressure generator is operated. I do.

In the suction nozzle 7, an elastic member 7 b (for example, rubber or the like) rich in elasticity is attached to a tip portion facing the surface 2 a of the glass ribbon 2. The elastic member 7b is attached so as to extend in the width direction at each of the upper end and the lower end of the tip portion. The suction nozzle 7 has a function as an abutting member that abuts from the surface 2a side against the upper end portion 2xa of the cut-out portion 2x (glass plate) cut out by folding. In the present embodiment, as will be described later, an elastic member 7b provided at the lower end of the distal end portion is brought into contact with the upper end portion 2xa of the cut-out cut-out portion 2x. The suction nozzle 7 is positioned so that a gap is formed between the suction nozzle 7 and the upper end 2xa of the cutout portion 2x immediately before the cutout portion 2x is cut out.

The folding arm 8 functions as a support means for supporting the cut-out portion 2x in the glass ribbon 2. The folding arm 8 includes a group of chucks including an arm main body 9 extending along the longitudinal direction of the glass ribbon 2 and a plurality (five in the present embodiment) of chucks 10 attached to the arm main body 9 with a space therebetween. 11. It should be noted that each of the plurality of chucks 10 can be adjusted in the mounting position in the longitudinal direction of the arm body 9. The interval between the chucks 10 is appropriately set according to the outer dimensions and flexibility of the glass plate. The intervals between the chucks 10 may be equal intervals, or may not be equal intervals in order to avoid interference or the like.

The arm body 9 and the chuck group 11 are disposed on one side and the other side in the width direction of the glass ribbon 2. The plurality of chucks 10 belonging to the one chuck group 11 and the plurality of chucks 10 belonging to the other chuck group 11 are arranged symmetrically with respect to the center line 2c in the width direction of the glass ribbon 2. Yes.

Each of the plurality of chucks 10 holds a pair of claws 10a as support portions that directly support the cut-out portion 2x by gripping the cut-out portion 2x existing below the scribe line 3 in the thickness direction. Have. The pair of claws 10a can be freely opened and closed, and the pair of claws 10a are closed to support the cut-out portion 2x, and the open portion is released from support of the cut-out portion 2x. Note that the pair of claws 10a in the open state is in a state of being retracted to a position not in contact with the cut-out portion 2x even when the cut-out portion 2x is displaced along the thickness direction.

The pair of claws 10a is configured to support the ineffective portions 2d existing at both ends in the width direction of the cut-out portion 2x. Both ineffective portions 2d are portions that are discarded without being a product, unlike the effective portion 2e that is a product existing between them. Here, the thickness of the ineffective portion 2d varies along the width direction. Specifically, the thickness in the vicinity of the end surface of the ineffective portion 2d increases more than the effective portion 2e, and the thickness between the vicinity of the end surface and the effective portion 2e gradually decreases as the distance from the end surface increases. It is more preferable that the pair of claws 10a support a portion of the ineffective portion 2d where the thickness gradually decreases.

Here, with respect to the pair of claws 10 a provided in any of the plurality of chucks 10, the cut-out portion 2 x is supported and the support is released independently of the pair of claws 10 a provided in the other chucks 10. It is possible. 1 and 2, a pair of claws 10a (hereinafter referred to as the uppermost claw 10ax) provided in the uppermost chuck 10 (hereinafter referred to as the uppermost chuck 10x) among the plurality of chucks 10 are in an open state. And the support is released.

The folding arm 8 can change its posture from the basic posture shown by a two-dot chain line in FIG. 1 to the inclined posture shown by a solid line in the state where the cut portion 2x is supported. The change in the posture of the split arm 8 is made by the rotation of the split arm 8 around the fulcrum bar 6. Further, the posture of the folding arm 8 is changed while moving downward at the same speed as the glass ribbon 2. The folding arm 8 is configured to bend the glass ribbon 2 along the scribe line 3 by bending the scribe line forming portion 2 s so that the surface 2 a side is convex as the posture changes. Yes. As will be described later, after the cutout portion 2x is cut out, the folding arm 8 is configured to move downward at a higher speed than the conveying speed of the glass ribbon 2.

Next, a method for manufacturing a glass plate using the manufacturing apparatus 1 will be described with reference to FIGS.

In the glass plate manufacturing method according to the present embodiment, the glass ribbon 2 to be folded is glass formed by, for example, a downdraw method (such as an overflow downdraw method). The glass ribbon 2 is formed to have a thickness of, for example, 300 μm or less, and has such flexibility that it can be easily bent by the action of an external force.

In the method for manufacturing a glass plate according to the present embodiment, a scribing process for forming the scribe line 3 on the glass ribbon 2, a splitting process for splitting the glass ribbon 2 along the scribe line 3 formed in the scribing process, and cutting out the glass plate. And execute the process.

In the scribing step, as shown in FIG. 3, first, a plurality of chucks 10 (excluding the uppermost chuck 10x) provided in the folding arm 8 support the cut-out portion 2x by a pair of claws 10a, respectively. The wheel cutter 4 and the support bar 5 are moved from the retracted position to the operating position. Next, the wheel cutter 4 that has moved to the operating position is caused to travel along the width direction on the surface 2 a of the glass ribbon 2 to form the scribe line 3. Thus, the scribe process is completed.

Here, in the present embodiment, the scribing process is executed in a state in which the uppermost chuck 10x out of the plurality of chucks 10 releases the support of the cut-out portion 2x by the uppermost claw 10ax. Absent. As a modification of the present embodiment, the scribing process may be executed in a state where the cut-out portion 2x is supported by the uppermost claw 10ax.

After the scribing process is completed, the wheel cutter 4 and the support bar 5 are moved from the operating position to the retracted position. The support of the cut-out portion 2x by the plurality of chucks 10 is continued even after the scribing process is completed. Here, when the scribe process is completed, the wheel cutter 4 and the support bar 5 are in the same height position as the scribe line 3. In preparation for executing the splitting process from this state, both the first casing and the second casing (both not shown) move upward relative to the glass ribbon 2. As a result, as shown in FIG. 4, the fulcrum bar 6 and the suction nozzle 7 are shifted to the same height position as the scribe line 3 instead of the wheel cutter 4 and the support bar 5.

In the folding process, as shown in FIG. 5, first, the fulcrum bar 6 and the suction nozzle 7 are moved from the retracted position to the operating position. Next, as shown in FIG. 6, the posture of the split arm 8 is changed from the basic posture to the inclined posture in a state where the support of the cut-out portion 2 x by the uppermost claw 10 ax is released. Thereby, the glass ribbon 2 is broken along the scribe line 3, and the cut-out portion 2x is cut out from the glass ribbon 2 as a glass plate. The glass powder generated with the splitting is sucked by the suction nozzle 7.

Since the support of the cut-out portion 2x by the uppermost claw 10ax is released at the time of splitting, between the scribe line 3 and the pair of claws 10a that support the nearest part to the scribe line 3 The distance is L2 shown in FIG. Here, if the uppermost claw 10ax supports the cut-out portion 2x, the distance between the above is L1 shown in FIG. In other words, in the present method, by releasing the support by the uppermost claw 10ax, the mutual distance is extended and lengthened by the difference between L1 and L2.

Here, the preferable value as the distance L2 is different depending on the thickness of the glass ribbon 2, but when the thickness of the glass ribbon 2 is 300 μm or less, the value of the distance L2 is set to 400 mm. It is preferably within the range of -900 mm, more preferably within the range of 500 mm-800 mm, and most preferably within the range of 600 mm-700 mm.

As shown in FIG. 7, the cut-out cut-out portion 2x (glass plate) has its upper end portion 2xa inclined toward the suction nozzle 7 by its own weight. The upper end 2xa is supported by being brought into contact with the elastic member 7b provided in the suction nozzle 7, thereby stopping the inclination of the upper end 2xa.

Thereafter, as shown in FIG. 8, the uppermost claw 10ax of the uppermost chuck 10x is closed, and the cut-out portion 2x is supported. The fulcrum bar 6 and the suction nozzle 7 are moved from the operating position to the retracted position after the support of the cut-out portion 2x by the uppermost claw 10ax is completed. Furthermore, after the support by the uppermost claw 10ax is completed, in order to avoid contact between the upper end portion 2xa of the cut-out cut-out portion 2x and the lower end portion 2f of the glass ribbon 2 cut out of the cut-out portion 2x, The folding arm 8 is moved downward at a higher speed than the conveying speed of the glass ribbon 2. Thereafter, the cut-out cut portion 2x is transported in a vertically placed posture by the folding arm 8 and transferred to the downstream process.

Here, in this embodiment, the upper end 2xa of the cut-out cut-out portion 2x is brought into contact with the elastic member 7b provided in the suction nozzle 7, but this is not restrictive. As a modification of the present embodiment, a member that comes into contact with the upper end 2xa from the surface 2a side may be arranged separately from the suction nozzle 7. Further, the upper end portion 2xa may be supported by the uppermost claw 10ax before the upper end portion 2xa of the cut out cut portion 2x comes into contact with the elastic member 7b.

Next, the main actions and effects of the above glass plate manufacturing method will be described.

According to the glass plate manufacturing method described above, the scribe line 3 and the portion closest to the scribe line 3 are removed by the amount that the support of the cut-out portion 2x by the uppermost claw 10ax is released at the time of folding. It is possible to increase the distance between the pair of claws 10a to be supported (the above L2). As a result, it is possible to avoid a situation in which the scribe line forming portion 2s is excessively bent and an excessive bending stress is generated. As a result, even when the glass ribbon 2 is thin like a film, it can be reliably broken along the scribe line 3. Further, after the split, the cut-out portion 2x is supported by the uppermost claw 10ax. Thereby, even when the glass ribbon 2 is thin like a film, it is possible to prevent the upper end portion 2xa of the cut-out portion 2x (glass plate) cut out by folding.

Here, the manufacturing method of the glass substrate which concerns on this invention is not limited to the aspect demonstrated by said embodiment. For example, in the above-described embodiment, each of the plurality of chucks has a pair of claws, and the pair of claws supports the cut-out portion of the glass ribbon. It is good also as an aspect which replaces with a pair of nail | claw and supports a to-be-cut part using the suction pad which adsorb | sucks the surface of a to-be-cut part, or a back surface.

Further, in the above-described embodiment, among the plurality of chucks, folding is performed in a state in which only the support of the cut-out portion by the uppermost claw of the uppermost chuck is released. Is not to be done. For example, as a mode in which folding is performed in a state where the support of the cut portion by the pair of claws of the chuck arranged adjacent to the lower side of the uppermost chuck is also released in addition to the uppermost claw of the uppermost chuck Also good.

2 glass ribbon 2a surface 2d ineffective portion 2e effective portion 2s scribe line forming portion 2x cut-out portion (glass plate)
2xa Upper end 3 Scribe wire 7 Suction nozzle 7a Opening 8 Folding arm 10a Claw 10ax Uppermost claw

Claims

A scribing process for forming a scribe line along the width direction of the glass ribbon, and a cut-out portion existing below the scribe line is supported by a supporting means for the glass ribbon conveyed downward in a vertical posture. A step of bending the glass ribbon along the scribe line by bending the scribe line forming portion in accordance with the operation of the support means, and cutting the cut-out portion as a glass plate. A method of manufacturing a glass plate,
The support means has a plurality of support portions along the vertical direction,
In the folding step, after the glass ribbon is broken in a state in which the support by the uppermost support portion is released among the plurality of support portions, the support by the uppermost support portion is performed. Manufacturing method of glass plate.
The cut-out portion has an ineffective portion that exists at both ends in the width direction, and an effective portion that exists between both ineffective portions,
The method for manufacturing a glass sheet according to claim 1, wherein the ineffective portion is supported by the plurality of support portions.
The upper end portion is supported in the folding step by bringing an abutting member into contact with the upper end portion of the cut-out portion before performing the support by the uppermost support portion. The manufacturing method of the glass plate of 1 or 2.
The method for manufacturing a glass plate according to claim 3, wherein the contact member extends along the width direction.
The method for producing a glass plate according to claim 3 or 4, wherein the contact member is a suction nozzle for sucking glass powder generated when the glass ribbon is folded.