阅读说明：本技术 玻璃卷筒、玻璃卷筒的制造方法及品质评价方法 (Glass roll, method for producing glass roll, and method for evaluating quality ) 是由 森弘树 森浩一 于 2019-01-29 设计创作，主要内容包括：本发明的技术课题为提供在利用卷对卷方式的情况下能够防止带状玻璃膜发生斜行、单侧松弛的玻璃卷筒。本发明是形成有褶皱(5)的带状玻璃膜(2)卷成卷状而成的玻璃卷筒(1),带状玻璃膜(2)具备有效区间(6),该有效区间(6)是宽度方向的一侧端缘(2g)与另一侧端缘(2h)平行地延伸的区间,且其前端部(6a)及末端部(6b)分别与带状玻璃膜(2)的宽度方向平行地延伸,在分别沿着带状玻璃膜(2)的沿着一侧端缘(2g)的第一位置(P1)及沿着另一侧端缘(2h)的第二位置(P2)测定有效区间(6)的沿着表面(2f)的从前端部(6a)到末端部(6b)的长度的情况下,所测定的第一测定长度(L1)及第二测定长度(L2)的两个测定长度(L1、L2)之差为两个测定长度(L1、L2)中的较长测定长度的400ppm以下。(The present invention provides a glass roll (1) in which a ribbon-shaped glass film (2) having wrinkles (5) formed thereon is rolled, the ribbon-shaped glass film (2) having an effective section (6) in which one end edge (2g) in the width direction extends parallel to the other end edge (2h), and the tip end (6a) and the tip end (6b) extend parallel to the width direction of the ribbon-shaped glass film (2), wherein the difference between lengths (2, 2 ppm, 2.)

1. A glass roll in which a wrinkled band-shaped glass film is wound in a roll shape,

the glass roll is characterized in that it is,

the belt-shaped glass film includes an effective section extending in parallel with one end edge and the other end edge in the width direction, and a leading end portion and a trailing end portion of the effective section extend in parallel with the width direction of the belt-shaped glass film,

when the lengths of the effective sections along the surface from the tip end portion to the end portion are measured along a first position along the one side edge and a second position along the other side edge of the ribbon-shaped glass film, respectively, the difference between the two measurement lengths of a first measurement length and a second measurement length measured along the first position and the second position is 400ppm or less of the longer measurement length of the two measurement lengths.

2. The glass spool according to claim 1,

the difference between the two measurement lengths is 200ppm or less of the longer of the two measurement lengths.

3. The glass spool according to claim 2,

the difference between the two measurement lengths is 100ppm or less of the longer of the two measurement lengths.

4. The glass spool as claimed in any one of claims 1 to 3,

when the length of the effective section from the distal end portion to the distal end portion along the surface is measured as a third measurement length along the width direction center line without the wrinkle in the ribbon-shaped glass film in addition to the first measurement length and the second measurement length, a larger difference between a difference between the first measurement length and the third measurement length and a difference between the second measurement length and the third measurement length is 500ppm or less of the longest measurement length among the first measurement length to the third measurement length.

5. The glass spool according to claim 4,

the large difference is 300ppm or less of the longest measurement length among the first measurement length to the third measurement length.

6. The glass spool according to claim 5,

the large difference is 200ppm or less of the longest measurement length among the first measurement length to the third measurement length.

7. A method of manufacturing a glass web, comprising: a forming step of forming a ribbon-shaped glass film having wrinkles formed thereon by cooling and solidifying a glass ribbon obtained by forming molten glass into a ribbon shape by a forming body while stretching the glass ribbon in a longitudinal direction; a dividing step of dividing two unnecessary portions located at both ends of the ribbon-shaped glass film in the width direction and an effective portion located between the two unnecessary portions; and a winding step of winding the divided ribbon-like glass film formed of the effective portion into a roll shape to form a glass roll,

the method for manufacturing a glass roll is characterized in that,

further comprising a measuring step of measuring a length of a section to be measured from a tip end portion to a tip end portion of the section along a surface of the effective portion, the section to be measured being a section along a longitudinal direction of the effective portion and the tip end portion extending in parallel to a width direction of the ribbon-shaped glass film, respectively, with respect to one side end portion and the other side end portion of the section to be measured along the width direction of the effective portion,

in the method for manufacturing a glass roll, a first adjustment step is performed in which, when a difference between two measurement lengths, namely a first measurement length and a second measurement length, measured along the one side end portion and the other side end portion, respectively, exceeds 400ppm of the longer measurement length of the two measurement lengths, the adjustment is performed so that the difference between the two measurement lengths is reduced.

8. The method of manufacturing a glass roll as claimed in claim 7,

the first adjusting step is a step of adjusting the difference in cooling and solidifying speed between one end portion and the other end portion in the width direction of the glass ribbon, which are connected to the one end portion and the other end portion of the effective portion, respectively, to be small.

9. The method of manufacturing a glass roll as claimed in claim 8,

when the difference between the two measurement lengths exceeds 400ppm of the longer measurement length, the two steps of the measurement step and the first adjustment step are alternately performed so that the measurement target interval is changed to a new interval each time the measurement step is performed, until the difference between the two measurement lengths is 400ppm or less of the longer measurement length.

10. The method of manufacturing a glass roll according to claim 8 or 9,

in the measuring step, a length of the measurement section along the surface from the tip end portion to the tip end portion is measured as a third measurement length along a center portion without the wrinkle between the one side end portion and the other side end portion of the effective portion in addition to the first measurement length and the second measurement length,

in the method for manufacturing a glass roll, a second adjustment step is performed in which, when at least one of a difference between the first measurement length and the third measurement length and a difference between the second measurement length and the third measurement length exceeds 500ppm of the longest measurement length from among the first measurement length to the third measurement length, the adjustment is performed so that the difference of 500ppm exceeding the longest measurement length from among the two differences is reduced.

11. The method for manufacturing a glass roll as claimed in claim 10,

the second adjusting step is a step of adjusting the difference in cooling and solidifying speed between the one-side end portion and the other-side end portion of the glass ribbon and a central portion between the two end portions to be smaller.

12. The method of manufacturing a glass roll as claimed in claim 10 or 11,

when at least one of the two differences exceeds 500ppm of the longest measurement length, the two steps of the measurement step and the second adjustment step are alternately performed so that the measurement target section is changed to a new section each time the measurement step is performed, until both of the two differences are 500ppm or less of the longest measurement length.

13. The method of manufacturing a glass roll as claimed in any one of claims 8 to 12,

a measuring mechanism is used in each measurement of the measurement length,

the measuring mechanism includes a rotating body that rotates by friction with a surface of the section to be measured in a state of being in contact with the surface, and is capable of moving in a thickness direction of the section to be measured following irregularities on the surface of the section to be measured formed by the wrinkles, and measuring each measurement length based on a distance by which the rotating body rolls on the surface of the section to be measured.

14. The method of manufacturing a glass roll as claimed in claim 13,

the section to be measured is divided from the effective portion and discarded.

15. The method of manufacturing a glass roll as claimed in any one of claims 8 to 14,

the speed of cooling and solidification of each portion is adjusted using three heating mechanisms capable of heating each of the one-side end portion, the other-side end portion, and a central portion between the two end portions of the glass ribbon.

16. A method for evaluating the quality of a glass roll, comprising:

an extraction step of extracting sample glass rolls from a plurality of glass rolls produced under the same conditions;

a measurement step of measuring a length from a leading end portion to a trailing end portion of an effective section along a surface of the belt-shaped glass film, while roll-to-roll measuring the effective section, the effective section being a section in which a widthwise one-side end edge and a widthwise other-side end edge of the belt-shaped glass film, which forms the wrinkle of the sample glass roll, extend in parallel, and the leading end portion and the trailing end portion extend in parallel to the widthwise direction of the belt-shaped glass film, respectively; and

and a determination step of determining quality of the plurality of glass rolls other than the sample glass roll based on a difference between two measurement lengths of one side measurement length and the other side measurement length measured along the one side end portion and the other side end portion, respectively.

17. The method of evaluating the quality of a glass roll according to claim 16,

in the determination step, when the difference between the two measurement lengths is 400ppm or less of the longer measurement length of the two measurement lengths, the quality of the plurality of glass rolls other than the sample glass roll is determined to be acceptable.

18. The method of evaluating the quality of a glass roll according to claim 17,

in the measuring step, in addition to the one-side measured length and the other-side measured length, a length from the tip end portion to the tip end portion along the surface of the effective section along a center portion of the ribbon-shaped glass film between the one-side end portion and the other-side end portion, the center measured length being measured along a center portion of the ribbon-shaped glass film without the wrinkle,

in the determination step, when the difference between the two measurement lengths is 400ppm or less of the longer measurement length of the two measurement lengths, and the larger difference between the one-side measurement length and the central measurement length and the difference between the other-side measurement length and the central measurement length is 500ppm or less of the longest measurement length of the one-side measurement length, the other-side measurement length, and the central measurement length, the quality of the plurality of glass reels other than the sample glass reel is determined to be good.

19. The method of evaluating the quality of a glass roll according to any one of claims 16 to 18,

the measuring means is used for measuring each measurement length,

the measurement mechanism includes a rotating body that rotates by friction with a surface of the effective section in a state of being in contact with the surface, and is capable of moving in a thickness direction of the effective section following irregularities on the surface of the effective section formed by the wrinkles, and measures each measurement length based on a distance by which the rotating body rolls on the surface of the effective section.

Technical Field

The invention relates to a glass roll, a method for manufacturing the glass roll, and a method for evaluating quality of the glass roll.

Background

As is well known, mobile devices such as smartphones and tablet PCs, which have been rapidly spreading in recent years, are required to be lightweight, and therefore, thinning of glass substrates used for the devices is currently in progress. As a result, development and production of a glass film in which a glass substrate is thinned to a film shape (for example, a thickness of 300 μm or less) have been advanced.

The glass film has flexibility to the extent that it can be easily bent manually because it is very thin. Thus, for example, a glass roll can be produced by winding a continuously formed ribbon-shaped glass film around a core in a roll shape by an overflow down-draw method. In addition, the glass roll may be subjected to various treatments (e.g., division of unnecessary portions) on a tape-like glass film by a roll-to-roll method (see patent document 1).

The roll-to-roll method is a method in which a band-shaped glass film wound around a first core in the form of a glass roll is processed while being unwound from the first core and conveyed, and then the processed band-shaped glass film is wound around a second core different from the first core to form a glass roll again.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-077995

Disclosure of Invention

Problems to be solved by the invention

However, the following problems are to be solved in the case of using the roll-to-roll system.

That is, in the roll-to-roll method, as shown in fig. 10a, a strip-shaped guide section 200 for guiding the strip-shaped glass film 100 to a second winding core (not shown) by pulling may be coupled to the strip-shaped glass film 100 by a tape 300. In this case, in order to appropriately perform the processing on the strip-shaped glass film 100, it is desirable that the subsequent strip-shaped glass film 100 passes through the pass line through which the leading guide 200 passes without being displaced. However, as shown in fig. 10b, there is a problem that the passing line of the belt-shaped glass film 100 is shifted in the width direction due to improper skew of the belt-shaped glass film 100 (indicated by an open arrow in the figure) and does not coincide with the passing line of the guide 200 (indicated by a two-dot chain line in the figure), and as a result, the process cannot be executed properly.

Further, as shown in fig. 11a, when a pinch roller 600 composed of a pair of rollers that pinch the belt-like glass film 100 in the thickness direction is disposed on the conveyance path of the belt-like glass film 100 from the first winding core 400 to the second winding core 500, a problem due to the slack of the belt-like glass film 100 also occurs. Specifically, as shown in fig. 11b, there is a case where slack (hereinafter, referred to as one-side slack) is generated only in one of both end portions of the ribbon-shaped glass film 100 in the width direction on the immediately upstream side of the nip roller 600 in the conveyance path, and the one-side slack gradually deteriorates to cause breakage of the ribbon-shaped glass film 100.

In view of the above circumstances, an object of the present invention is to provide a glass roll that can prevent a ribbon-like glass film from being skewed and one-side-slack when a roll-to-roll system is used.

Means for solving the problems

The inventors of the present invention have intensively studied and found that, in the case of using the roll-to-roll system, wrinkles formed in the ribbon-shaped glass film are a factor of the occurrence of skew and one-side slack in the ribbon-shaped glass film. Further, when the balance of the number and size of wrinkles existing between one end portion and the other end portion in the width direction of the ribbon-shaped glass film is poor, skew and one-side slack are likely to occur. The wrinkles are present not only in the tape-shaped glass film but also in, for example, a tape-shaped resin film having the same shape, but oblique running and one-side sagging are not likely to occur even in the roll-to-roll method for the tape-shaped resin film. This is because the resin is rich in stretchability, and when the tape-shaped resin film is subjected to tension in the roll-to-roll method, wrinkles are stretched, and the effect thereof is small even if the above-described balance is poor. On the other hand, the wrinkles formed on the ribbon-shaped glass film are not substantially spread even by the tension when the roll-to-roll system is used. Therefore, when the balance is poor, the influence of wrinkles cannot be eliminated, and skew and one-side slack are likely to occur.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a glass roll in which a wrinkled, band-shaped glass film is wound in a roll shape, wherein the band-shaped glass film includes an effective section extending in parallel with one side edge and the other side edge in a width direction, and a tip end portion of the effective section extend in parallel with the width direction of the band-shaped glass film, and when a length from the tip end portion to the tip end portion along a surface of the effective section is measured along a first position of the band-shaped glass film along the one side edge and a second position of the band-shaped glass film along the other side edge, a difference between two measurement lengths of a first measurement length and a second measurement length measured along the first position and the second position is 400ppm or less of a longer measurement length of the two measurement lengths.

In the glass roll, both the first measurement length and the second measurement length are obtained by measuring the length from the leading end to the trailing end of the effective section along the surface of the effective section of the belt-like glass film. By performing the measurement along the surface in this manner, the influence of the surface irregularities formed by the wrinkles is reflected in the measurement results of the two measurement lengths, and the number of wrinkles and the size of the wrinkles existing between the distal end portion and the distal end portion of the effective section are reflected in the length of the measurement length at the first position and the second position. Here, the first position and the second position are a position along one end edge and a position along the other end edge of the belt-shaped glass film in the width direction, respectively. Thus, by calculating the difference between the two measurement lengths, it is determined whether the balance between the number and the size of wrinkles between the one end portion and the other end portion of the ribbon-shaped glass film in the width direction is good or not based on the magnitude of the difference. Further, the smaller the difference between the two measurement lengths, the better the balance. The present inventors have intensively studied and found that, when a roll-to-roll system is used for a glass web having a difference between two measurement lengths of 400ppm or less in the longer measurement length of the two measurement lengths, the ribbon-shaped glass film can be prevented from being skewed and one-side slackened. As described above, according to the glass roll, when the roll-to-roll system is used, the ribbon-shaped glass film can be prevented from being skewed and one-side slackened.

In the glass roll, two measurement lengths, namely, a first measurement length and a second measurement length, are measured with respect to an effective section, which is a section in which one end edge and the other end edge in the width direction of the ribbon-shaped glass film extend in parallel, and a tip end portion of which extend in parallel to the width direction of the ribbon-shaped glass film, respectively. In this way, it is possible to avoid the problem that not only is the balance between the number and size of wrinkles good between the one side end portion and the other side end portion in the width direction of the ribbon-shaped glass film, but also the difference in the length of the end portion itself between the one side end portion and the other side end portion (the length of the ribbon-shaped glass film in the longitudinal direction) is reflected as the difference between the two measured lengths. For example, when the length from the leading end portion to the trailing end portion of the belt-shaped glass film along the surface of the belt-shaped glass film is measured along the first position and the second position, respectively, unlike the case where the effective zone is not measured with respect to the glass roll, there may be the following problems. That is, when the length of the end portion itself is different between the one side end portion and the other side end portion in the width direction of the ribbon-shaped glass film, even if the balance of the number and the size of wrinkles is good between the one side end portion and the other side end portion, the difference between the two measurement lengths is significantly increased in accordance with the difference in the length between the one side end portion and the other side end portion. Therefore, it may not be possible to accurately determine whether the balance is good or not based on the difference between the two measurement lengths. To eliminate this possibility, two measurement lengths are measured for the valid interval in the above manner.

Preferably, in the glass roll, a difference between the two measurement lengths is 200ppm or less of a longer measurement length of the two measurement lengths.

In this manner, the balance between the number and size of wrinkles between the one side end portion and the other side end portion in the width direction of the ribbon-shaped glass film is more improved. Therefore, it is more advantageous to prevent the ribbon-shaped glass film from being skewed and one-side slackened when the roll-to-roll system is used.

Preferably, in the glass roll, a difference between the two measurement lengths is 100ppm or less of a longer measurement length of the two measurement lengths.

In this manner, the balance between the number and size of wrinkles between the one side end portion and the other side end portion in the width direction of the ribbon-shaped glass film is more improved. Therefore, it is more advantageous to prevent the ribbon-shaped glass film from being skewed and one-side slackened when the roll-to-roll system is used.

Preferably, in the above glass roll, when a length from the distal end portion to the distal end portion of the surface of the effective section is measured along the width-direction center line without wrinkles in the ribbon-shaped glass film as a third measurement length in addition to the first measurement length and the second measurement length, a larger difference between a difference between the first measurement length and the third measurement length and a difference between the second measurement length and the third measurement length is 500ppm or less of a longest measurement length of the first measurement length to the third measurement length.

When the treatment is performed on the ribbon-shaped glass film by the roll-to-roll method, it is preferable to perform the treatment appropriately and to suppress the number and size of wrinkles formed in the ribbon-shaped glass film as much as possible. As described above, in the measurement results of the first measurement length and the second measurement length, the number of wrinkles and the size of the wrinkles existing between the distal end portion and the distal end portion of the effective section are reflected in the length of the measurement length. In contrast, the third measurement length is obtained by measuring the length from the distal end portion to the distal end portion of the effective section along the flat width-direction center line without wrinkles. That is, in the measurement result of the third measurement length, the influence of the surface unevenness formed by the wrinkles is not exerted. Thus, when the difference between the first measurement length and the third measurement length and the difference between the second measurement length and the third measurement length are calculated, the smaller these differences are, the more the number and size of wrinkles existing in the one end portion and the other end portion in the width direction of the ribbon-shaped glass film are suppressed. Further, the inventors of the present invention have intensively studied and found that, with respect to a glass roll having a larger difference of the two differences of 500ppm or less of the longest measurement length of the first to third measurement lengths, the treatment can be appropriately performed on a ribbon-shaped glass film by the roll-to-roll method. As described above, according to this glass roll, it is advantageous to appropriately perform processing for a ribbon-like glass film by a roll-to-roll method.

Preferably, in the glass roll, the large difference is 300ppm or less of the longest measurement length among the first measurement length to the third measurement length.

In the above aspect, the number and size of wrinkles existing in the one end portion and the other end portion in the width direction of the ribbon-shaped glass film are further suppressed. Therefore, it is more advantageous to appropriately perform processing for the ribbon-shaped glass film by the roll-to-roll method.

Preferably, in the glass roll, the large difference is 200ppm or less of the longest measurement length among the first measurement length to the third measurement length.

In the above aspect, the number and size of wrinkles existing in the one end portion and the other end portion in the width direction of the ribbon-shaped glass film are further suppressed. Therefore, it is more advantageous to appropriately perform processing for the ribbon-shaped glass film by the roll-to-roll method.

Further, the present invention proposed to solve the above problems is a method for manufacturing a glass roll, including: a forming step of forming a ribbon-shaped glass film having wrinkles formed thereon by cooling and solidifying a glass ribbon formed by forming molten glass into a ribbon shape by a forming body while stretching the glass ribbon in a longitudinal direction; a dividing step of dividing two unnecessary portions located at both ends in the width direction of the belt-shaped glass film and an effective portion located between the two unnecessary portions; and a winding step of winding the divided ribbon-shaped glass film composed of the effective portion into a roll shape to form a glass roll, the glass roll manufacturing method being characterized by further comprising a measuring step of measuring lengths from a leading end portion to a trailing end portion along a surface of a measured section, which is a region along a longitudinal direction of the effective portion and extends in parallel to a width direction of the ribbon-shaped glass film, with respect to one side end portion and the other side end portion of the measured section along the width direction of the effective portion, respectively, in which a first adjusting step is performed in which, when a difference between two measurement lengths of a first measurement length and a second measurement length measured along the one side end portion and the other side end portion, respectively, exceeds 400ppm of a longer measurement length of the two measurement lengths, the adjustment is made in such a way that the difference between the two measuring lengths becomes small.

According to this method, by performing the measurement step, it is calculated whether the balance of the number and size of wrinkles between the one end portion and the other end portion in the width direction of the effective portion wound as the divided strip-shaped glass film is good or not as the difference between the two measurement lengths of the first measurement length and the second measurement length. The first adjustment step is performed when the difference between the two measurement lengths exceeds 400ppm of the longer of the two measurement lengths, i.e., when the balance is poor. This improves the equalization by adjusting the difference between the two measurement lengths to be smaller. As a result, the divided ribbon-shaped glass film composed of the effective portions having a good balance can be wound to produce a glass roll, and the divided ribbon-shaped glass film can be appropriately prevented from being skewed and loosened on one side when the roll-to-roll method is applied to the glass roll.

Preferably, in the above method, the first adjusting step is a step of adjusting so as to reduce a difference in cooling and solidifying speed between one end portion and the other end portion in the width direction of the glass ribbon connected to the one end portion and the other end portion of the effective portion, respectively.

The inventors of the present invention have intensively studied and found that a factor of deterioration in the balance between the number and size of wrinkles between one end portion and the other end portion in the width direction of the effective portion is a difference in the cooling and solidification rates of both the one end portion and the other end portion in the width direction of the glass ribbon connected to the one end portion and the other end portion of the effective portion, respectively. Thus, if the first adjustment process is performed in a case where the difference between the two measurement lengths exceeds 400ppm of the longer measurement length of the two measurement lengths, and the difference between the cooling and solidifying speeds of the one end portion and the other end portion of the glass ribbon is adjusted to be small, the above-described balance can be effectively improved.

Preferably, in the above method, when the difference between the two measurement lengths exceeds 400ppm of the longer measurement length, the two steps of the measurement step and the first adjustment step are alternately performed so that the measurement target interval is changed to a new interval each time the measurement step is performed until the difference between the two measurement lengths becomes 400ppm or less of the longer measurement length.

In this way, the effective portion having a good balance between the number and the size of the wrinkles can be reliably formed between the one side end portion and the other side end portion in the width direction. Therefore, the glass roll in which the divided ribbon-shaped glass film composed of the effective portions having a good balance is wound can be reliably manufactured.

Preferably, in the above method, in the measuring step, a length along the surface of the measurement section from the front end portion to the rear end portion along the center portion without wrinkles, which is located between the one side end portion and the other side end portion of the effective portion, is measured as a third measurement length along the first measurement length and the second measurement length, and in the manufacturing method of the glass roll, a second adjusting step is performed in which, when at least one of two differences, which is a difference between the first measurement length and the third measurement length and a difference between the second measurement length and the third measurement length, exceeds 500ppm of a longest measurement length among the first measurement length to the third measurement length, the difference exceeding 500ppm of the longest measurement length among the two differences is adjusted to be smaller.

In this manner, the difference between the first measurement length and the third measurement length and the difference between the second measurement length and the third measurement length can be calculated as the measurement step is performed, and whether or not the number and size of wrinkles are suppressed at each of the one end portion and the other end portion in the width direction of the effective portion (the divided strip-shaped glass film) can be determined based on the two differences. Then, the second adjustment step is performed when at least one of the two differences exceeds 500ppm of the longest measurement length of the first to third measurement lengths, that is, when the number and size of wrinkles are not sufficiently suppressed. Thus, the number and size of wrinkles are suppressed by adjusting the difference of more than 500ppm of the longest measurement length out of the two differences to be small. As a result, the effective portion in which the number and size of wrinkles existing at the one end portion and the other end portion are sufficiently suppressed can be formed, and the glass roll in which the divided ribbon-shaped glass film composed of the effective portion is wound can be manufactured. In addition, when the roll-to-roll method is used for the glass roll, the process for the divided strip-shaped glass film can be appropriately performed.

Preferably, in the above method, the second adjusting step is a step of adjusting so as to reduce a difference in cooling and solidifying speed between one end portion and the other end portion of the glass ribbon and a central portion between the two end portions.

The inventors of the present invention have conducted extensive studies and found that the number and size of wrinkles cannot be sufficiently suppressed at one end portion and the other end portion of the effective portion because there is a difference in cooling and solidifying rates between the one end portion and the other end portion of the glass ribbon and a central portion between the two end portions. Therefore, when at least one of the two differences exceeds 500ppm of the longest measurement length of the first to third measurement lengths, the number and size of wrinkles can be effectively suppressed by performing the second adjustment step so that the difference between the cooling solidification rates of the one and other end portions and the central portion of the glass ribbon is reduced.

Preferably, in the above method, when at least one of the two differences exceeds 500ppm of the longest measurement length, the two steps of the measurement step and the second adjustment step are alternately performed so that the measured area is changed to a new area each time the measurement step is performed, until both the two differences are 500ppm or less of the longest measurement length.

In this way, it is possible to reliably form the effective portion in which the balance between the number and the size of the wrinkles is good between the one end portion and the other end portion in the width direction, and the number and the size of the wrinkles existing at both end portions are sufficiently suppressed. Therefore, a high-quality glass roll made of the divided ribbon-shaped glass film formed by the effective portion can be reliably manufactured.

Preferably, in the above method, the measuring mechanism is used for measuring each of the measurement lengths, and the measuring mechanism includes a rotating body that rotates by friction with a surface of the measurement target section in a state of being in contact with the surface of the measurement target section and is movable in a thickness direction of the measurement target section following irregularities on the surface of the measurement target section formed by wrinkles, and each of the measurement lengths is measured based on a distance by which the rotating body rotates on the surface of the measurement target section.

In this way, since the rotating body provided in the measuring mechanism can move in the thickness direction of the measurement target section in conformity with the surface irregularities of the measurement target section, it is possible to reliably eliminate the possibility that the wrinkles are pressed and crushed by the force applied to the wrinkles when measuring each measurement length. Thus, the influence of the surface irregularities formed by the wrinkles can be accurately reflected in the measurement result of each measurement length, and the measurement accuracy of each measurement length can be improved.

Preferably, in the above method, the section to be measured is divided from the effective portion and discarded.

In this manner, the measurement target section having a contaminated surface due to contact with the rotating body provided in the measurement mechanism may be discarded and not become a part of the divided ribbon-shaped glass film (effective portion) constituting the glass roll. Therefore, a glass roll made of only the divided strip-like glass film having a clean surface can be manufactured.

Preferably, in the above method, the speed of cooling and solidifying each portion is adjusted by using three heating mechanisms capable of heating each of one end portion, the other end portion, and a central portion between the two end portions of the glass ribbon.

In this way, the cooling and solidification rates of the one end portion, the other end portion, and the central portion of the glass ribbon can be easily adjusted individually. Therefore, it is advantageous to manufacture a glass roll of higher quality.

Further, the method for evaluating the quality of a glass roll according to the present invention includes: an extraction step of extracting sample glass rolls from a plurality of glass rolls manufactured under the same conditions; a measurement step of measuring, by a roll-to-roll method, lengths from a front end portion to a rear end portion of an effective section along a surface of a belt-shaped glass film along one side end portion and the other side end portion in a width direction of the belt-shaped glass film, the effective section being a section in which one side end edge and the other side end edge in the width direction of the belt-shaped glass film constituting a sample glass roll, the one side end edge and the other side end edge in the width direction of the belt-shaped glass film being formed with wrinkles, and the front end portion and the rear end portion being extended in parallel to the width direction; and a determination step of determining quality of the plurality of glass rolls other than the sample glass roll based on a difference between two measurement lengths of the one-side measurement length and the other-side measurement length measured along the one-side end portion and the other-side end portion, respectively.

In the method, whether the balance of the number and the size of wrinkles between the one side end portion and the other side end portion in the width direction of the belt-like glass film constituting the sample glass roll is good or not is calculated as a difference between two measurement lengths of the one side measurement length and the other side measurement length by performing the measurement step. Further, the smaller the difference between the two measured lengths, the better the balance, and the oblique running and one-side sagging of the ribbon-shaped glass film are less likely to occur in the case of the roll-to-roll system. Here, the sample glass roll is drawn from the plurality of glass rolls by the drawing process, and the plurality of glass rolls are manufactured under the same condition. That is, the sample glass roll and the plurality of glass rolls other than the sample glass roll can be regarded as substantially the same glass rolls, respectively. Therefore, if the sample glass roll can prevent the skew and the one-side slack from occurring, it is considered that the skew and the one-side slack can be similarly prevented from occurring even in a plurality of glass rolls other than the sample glass roll. As described above, according to this method, the quality of the plurality of glass rolls can be appropriately evaluated along with the execution of the determination step based on the difference between the two measurement lengths.

Preferably, in the above method, in the determination step, when the difference between the two measurement lengths is 400ppm or less of the longer measurement length of the two measurement lengths, the quality of the plurality of glass reels other than the sample glass reel is determined to be acceptable.

In this manner, the number and size of wrinkles formed between one end portion and the other end portion in the width direction of the ribbon-shaped glass film constituting each of the plurality of glass rolls determined to be of acceptable quality in the determination step are sufficiently well balanced. Thus, the plurality of glass rolls can be evaluated as glass rolls capable of appropriately preventing the ribbon-like glass film from being skewed and one-side-slack when the roll-to-roll system is used.

Preferably, in the above method, in the measuring step, in addition to the one-side measured length and the other-side measured length, a length from a tip end portion to a tip end portion along a surface of the effective region along a center portion of the ribbon-shaped glass film between the one-side end portion and the other-side end portion is measured as a center measured length in a roll-to-roll manner, in the judging step, when the difference between the two measurement lengths is 400ppm or less of the longer measurement length of the two measurement lengths, and when the larger difference between the one-side measurement length and the center measurement length and the difference between the other-side measurement length and the center measurement length is 500ppm or less of the longest measurement length among the one-side measurement length, the other-side measurement length, and the center measurement length, the quality of the plurality of glass rolls other than the sample glass roll was judged to be excellent and acceptable.

In this manner, the number and size of wrinkles formed between the one end portion and the other end portion in the width direction of the ribbon-like glass film constituting each of the plurality of glass rolls determined to be of good quality in the determination step are sufficiently well balanced, and the number and size of wrinkles formed at the one end portion and the other end portion are sufficiently suppressed. Therefore, each of the plurality of glass rolls can be evaluated as a glass roll which can appropriately prevent the ribbon-shaped glass film from being skewed and one-side loosened and can appropriately perform processing on the ribbon-shaped glass film when the roll-to-roll system is used.

Preferably, in the above method, the measuring means is used for measuring each of the measurement lengths, and the measuring means includes a rotating body that rotates by friction with a surface of the effective section in a state of being in contact with the surface of the effective section and is movable in a thickness direction of the effective section in conformity with surface irregularities of the effective section formed by the wrinkles, and the measuring means measures each of the measurement lengths based on a distance over which the rotating body rolls on the surface of the effective section.

In this way, the influence of the surface irregularities formed by the wrinkles can be accurately reflected in the measurement result of each measurement length, and the measurement accuracy of each measurement length can be improved.

Effects of the invention

According to the present invention, it is possible to provide a glass roll which can prevent a ribbon-like glass film from being skewed and one-side loosened when a roll-to-roll system is used.

Drawings

Fig. 1 is a perspective view showing a glass roll according to an embodiment of the present invention.

Fig. 2a is a plan view of a tape-shaped glass film constituting a glass roll according to an embodiment of the present invention, in which the entire length of the tape-shaped glass film is supposed to be unwound from a winding core.

Fig. 2b is a plan view of a tape-shaped glass film constituting the glass roll according to the embodiment of the present invention, in which the entire length of the tape-shaped glass film is supposed to be unwound from the winding core.

Fig. 3 is a side view showing a mode of measuring the first to third measurement lengths of the glass roll according to the embodiment of the present invention.

Fig. 4 is a plan view of a glass roll according to an embodiment of the present invention, showing a mode of measuring the first to third measurement lengths.

Fig. 5a is a side view of the glass roll according to the embodiment of the present invention, in which the periphery of the roller encoder is enlarged to show the manner of measuring the first to third measurement lengths.

Fig. 5b is a side view of the glass roll according to the embodiment of the present invention, in which the periphery of the roller encoder is enlarged to show the manner of measuring the first to third measurement lengths.

Fig. 5c is a side view of the glass roll according to the embodiment of the present invention, in which the periphery of the roller encoder is enlarged to show the manner of measuring the first to third measurement lengths.

Fig. 6 is a side view showing a method of manufacturing a glass roll according to an embodiment of the present invention.

Fig. 7 is a plan view showing a method of manufacturing a glass roll according to an embodiment of the present invention.

Fig. 8 is a front view showing a method of manufacturing a glass roll according to an embodiment of the present invention.

Fig. 9 is a diagram illustrating a method for evaluating the quality of a glass roll according to an embodiment of the present invention.

Fig. 10a is a plan view for explaining a problem in the conventional glass roll.

Fig. 10b is a plan view for explaining a problem in the conventional glass roll.

FIG. 11a is a side view for explaining a problem in a conventional glass roll.

Fig. 11b is a perspective view for explaining a problem in the conventional glass roll.

Detailed Description

Hereinafter, a glass roll, a method for manufacturing a glass roll, and a method for evaluating quality according to embodiments of the present invention will be described with reference to the drawings.

< glass roll >

First, the glass roll is explained.

As shown in fig. 1, a glass roll 1 is formed by winding a flexible belt-shaped glass film 2 and a flexible belt-shaped protective sheet 3 for protecting the belt-shaped glass film 2 from damage or the like in a roll shape around a core 4 in a stacked state. The entire width of the belt-shaped glass film 2 is formed to have a substantially uniform thickness, and the thickness is 300 μm or less as an example. The entire length of the belt-like glass film 2 is 100m or more, for example.

Here, in the present embodiment, the width dimension of the belt-shaped protective sheet 3 is larger than the belt-shaped glass film 2, but is not limited thereto. As a modification of the present embodiment, the width dimensions of both the glass films 2 and 3 may be the same, or the width dimension of the belt-shaped glass film 2 may be larger than the belt-shaped protective sheet 3.

Fig. 2a shows an imaginary state in which the entire length of the belt-like glass film 2 constituting the glass roll 1 is unwound from the winding core 4. As shown in the figure, in the belt-like glass film 2, a front end portion 2a as one end portion and a rear end portion 2b as the other end portion in the longitudinal direction thereof are formed in parallel with the width direction of the belt-like glass film 2.

The ribbon-shaped glass film 2 is a glass formed by drawing a glass ribbon formed from a molten glass into a ribbon shape in a longitudinal direction, typically by an overflow down draw method, and cooling and solidifying the glass ribbon, wherein ears (portions having a larger thickness than other portions) formed at both ends in a width direction in accordance with the forming are divided and removed, and the ribbon-shaped glass film 2 has one end portion 2C in the width direction including a first position P1 described later, the other end portion 2d including a second position P2 described later, and a central portion 2e including a width direction center line C L and located between the both end portions 2C, 2d, and has wrinkles 5 formed at the one end portion 2C and the other end portion 2d and irregularities on a surface 2f, while the wrinkles 5 are not formed at the central portion 2e and the surface 2f is flat.

Here, in the present embodiment, the wrinkles 5 are formed in the one end portion 2c and the other end portion 2d of the three portions of the one end portion 2c, the other end portion 2d, and the central portion 2e of the ribbon-shaped glass film 2, but the present invention is not limited thereto. As a modification of the present embodiment, the wrinkle 5 may be formed only at one of the three positions. For example, the wrinkles 5 may be formed only at the one end portion 2c or only at the other end portion 2 d.

The above-described ribbon-shaped glass film 2 includes an effective section 6 that is an object of measurement of a first measurement length L1 to a third measurement length L3, which will be described later, the effective section 6 being a section in which one end edge 2g in the width direction of the ribbon-shaped glass film 2 extends parallel to the other end edge 2h and the tip end portion 6a and the tip end portion 6b of the ribbon-shaped glass film extend parallel to the width direction, that is, the effective section 6 is formed in a rectangular shape when the ribbon-shaped glass film 2 is viewed in plan view, and thus, in the ribbon-shaped glass film 2 shown in fig. 2a, if the effective section 6 is longest, the entire length of the ribbon-shaped glass film 2 becomes the effective section 6, and in this case, the tip end portion 2a of the ribbon-shaped glass film 2 coincides with the tip end portion 6a of the effective section 6 and the tip end portion 2b of the ribbon-shaped glass film 2 coincides with the tip.

Here, according to the definition of the effective section 6 described above, as a modification of the present embodiment, as shown in fig. 2b, when the leading end portion 2a and the terminal end portion 2b of the ribbon glass film 2 extend in directions inclined with respect to the width direction, even if the effective section 6 is longest, the section where the cross-hatched portion is shown is removed. In this case, the leading end 2a of the belt-shaped glass film 2 does not coincide with the leading end 6a of the effective section 6, and the terminal end 2b of the belt-shaped glass film 2 does not coincide with the terminal end 6b of the effective section 6.

As is clear from the above description, the length of the effective segment 6 (the length along the longitudinal direction of the ribbon-shaped glass film 2) can be any length, and the length of the effective segment 6 is preferably 20m or more.

The first measured length L1, the second measured length L2, and the third measured length L3 are lengths obtained by measuring the length of the effective section 6 from the distal end portion 6a to the distal end portion 6b along the surface 2f at the first position P1 along the one side end edge 2g of the belt-shaped glass film 2, the second position P2 along the other side end edge 2h, and the width direction center line C L, respectively, by measuring the respective measured lengths L1 to L3 along the surface 2f in this manner, the influence of the irregularities of the surface 2f formed by the wrinkles 5 is reflected in the measurement results of the first measured length L1 and the second measured length L2, and the magnitude and the number of the wrinkles 5 and the size of the dimension are reflected in the form of the length of the measured length, and on the measurement results of the third measured length L3, the influence of the irregularities of the surface 2f formed by the wrinkles 5 is not reflected.

In the present embodiment, the first measurement length L and the second measurement length L measured along the first position P1 and the second position P2 are both measured using the roller encoder 7 described later, and therefore, when there is an obstacle that is an obstacle for measurement using the roller encoder 7 at the position deviated by 50mm, the position deviated from the obstacle is instead set to the first position P1 and the second position P2, specifically, the position deviated by 10mm to the inside in the width direction from the obstacle is set to the first position P1 and the second position P2.

The difference between the two measurement lengths L1 and L2 (absolute values of L1-L2) of the first measurement length L1 and the second measurement length L2 is 400ppm or less of the longer measurement length of the two measurement lengths L1 and L2, and when this condition is satisfied, the balance between the number and size of wrinkles 5 between the one end 2c and the other end 2d of the ribbon-shaped glass film 2 is favorable in that the ribbon-shaped glass film 2 is not inclined or slacked on one side when the roll-to-roll system is used, and the difference between the two measurement lengths L1, L2 is preferably 200ppm or less of the longer measurement length, and more preferably 100ppm or less of the longer measurement length.

Further, the larger difference between the first measured length L1 and the third measured length L3 (absolute value of L1 to L3) and the difference between the second measured length L2 and the third measured length L3 (absolute value of L2 to L3) is 500ppm or less of the longest measured length among the first measured length L1 to the third measured length L3, and when this condition is satisfied, the number and size of wrinkles 5 respectively located at the one end portion 2c and the other end portion 2d of the ribbon-shaped glass film 2 are sufficiently suppressed in terms of the ribbon-shaped glass film 2 being appropriately processed in the roll-to-roll manner.

< measuring method of first to third measuring lengths >

Hereinafter, the measurement method of the first to third measurement lengths L1 to L3 will be described.

As shown in fig. 3, for example, the first measured length L1 to the third measured length L3 are measured in a roll-to-roll manner with respect to the glass roll 1 of the present embodiment, that is, the roll core 4 is set as the first roll core 8, the strip-shaped glass film 2 constituting the glass roll 1 is unwound from the first roll core 8 and conveyed, and the respective measured lengths L1 to L3 are measured at the measurement position MP on the conveyance path, and thereafter, the strip-shaped glass film 2 having passed the measurement position MP is wound around the second roll core 9 different from the first roll core 8 to form the glass roll 10 again.

The distal end portion 2a of the belt-shaped glass film 2 is coupled to a distal end portion of a belt-shaped guide portion (not shown) wound around the second winding core 9 prior to the belt-shaped glass film 2. That is, the belt-like glass film 2 is pulled by the guide portion and conveyed.

The belt-shaped protective sheet 3 overlapped with the belt-shaped glass film 2 in the glass roll 1 is unwound from the first winding core 8 together with the belt-shaped glass film 2, and then separated from the belt-shaped glass film 2 and recovered as a first sheet roll 11. The belt-shaped glass film 2 having passed the measurement position MP is wound around the second winding core 9 in a state of being overlapped with the belt-shaped protective sheet 13 supplied from the second sheet roll 12.

The belt-like glass film 2 being unwound from the first winding core 8 and conveyed toward the second winding core 9 is in a state of being wound around a plurality of rollers 14 arranged along the conveying path. Each of the plurality of rollers 14 is a roller having an axis extending in the width direction of the belt-like glass film 2. Each of the plurality of rollers 14 may be a drive roller connected to a drive source (e.g., a motor) or a free roller.

Of the plurality of rollers 14, the roller 15 disposed at the measurement position MP is disposed so as to sandwich the belt-like glass film 2 passing through the measurement position MP in a flat posture in the thickness direction together with the roller 7a of the roller encoder 7. Specifically, the roller 15 abuts against the belt-shaped glass film 2 from below, and the roller 7a abuts against the belt-shaped glass film 2 from above. Note that the diameter of the roller 15 is larger than that of the roller 7 a.

Here, as a modification of the present embodiment, the roller 15 may be in contact with the belt-shaped glass film 2 from above, and the roller 7a provided in the roller encoder 7 may be in contact with the belt-shaped glass film 2 from below.

The roller encoder 7 functions as a measuring means for measuring the respective measured lengths L1 to L3, the roller 7a serving as a rotating body provided in the roller encoder 7 can rotate without slipping due to friction with the surface 2f of the effective section 6 in a state of always abutting against the surface 2f, and the roller 7a measures the respective measured lengths L1 to L3 based on the distance of rolling on the surface 2f, it is noted that the material of the rotating peripheral portion of the roller 7a abutting against the surface 2f is not particularly limited, but it is necessary to exclude the possibility that the respective measured lengths L1 to L3 are measured inaccurately due to slippage between the surface 2f and the rotating peripheral portion, and therefore, in the present embodiment, silicone rubber suitable for preventing slippage is used as the material of the rotating peripheral portion.

As shown in fig. 4, three roller encoders 7 are disposed so as to measure a first measured length L1, a second measured length L2, and a third measured length L3 measured along the first position P1, the second position P2, and the width-direction center line C L, respectively, and three rollers 7a provided in the three roller encoders 7 are aligned along the width direction of the belt-shaped glass film 2 and are located at the same point on the conveyance path of the belt-shaped glass film 2.

As shown in fig. 5a to 5c, the roller 7a of each roller encoder 7 can move in the thickness direction of the effective section 6 in accordance with the irregularities on the surface 2f of the effective section 6 formed by the corrugations 5. Therefore, as shown in the figure, when the roller 7a passes over the wrinkle 5 reaching the measurement position MP along with the conveyance of the belt-like glass film 2, the roller 7a moves upward from the initial position shown by the two-dot chain line in fig. 5b to the position shown by the solid line. The "initial position" is a position where the roller 7a rolls on a flat portion of the effective section 6 where there is no wrinkle 5. The roller 7a is configured to always apply a fixed load (a load acting in the thickness direction of the ribbon-shaped glass film 2) to the effective section 6. The magnitude of the load is such that the wrinkles 5 are not crushed and flattened while the roller 7a is always in contact with the surface 2 f.

In addition, as a modification of the present embodiment, the magnitude of the load applied to the effective section 6 by the roller 7a may be set to a magnitude to which the wrinkles 5 are flattened by the roller 7a being crushed, and in this case, the first measurement length L1, the second measurement length L2, and the third measurement length L3 may be measured without any problem.

When the roller 7a of each roller encoder 7 rolls along the surface 2f of the effective section 6 from the leading end portion 2a to the trailing end portion 2b at the first position P1, the second position P2, and the width-direction center line C L, the measured lengths L1 to L3 are measured, and as a result, the difference between the two measured lengths L1 and L2, the difference between the first measured length L1 and the third measured length L3, and the difference between the second measured length L2 and the third measured length L3 are determined.

< method for producing glass roll >

A method for manufacturing the glass roll 1 will be described below.

As shown in fig. 6 to 8, the manufacturing method includes: a forming step of cooling and solidifying a glass ribbon 18, which is formed by forming a molten glass 17 into a ribbon shape by a forming body 16, while stretching the ribbon in a longitudinal direction, thereby obtaining a ribbon-shaped glass film 19 having wrinkles 5 formed thereon; a dividing step of dividing the two unnecessary portions 19a, 19a located at both ends in the width direction of the ribbon-shaped glass film 19 and the effective portion 19b located between the two unnecessary portions 19a, 19 a; a winding step of winding the divided strip-shaped glass film 2 composed of the effective portion 19b into a roll shape to form a glass roll 1; and a measuring step of measuring a length from the front end portion Sa to the end portion Sb along the front surface 2f for a measured section S (a section indicated by oblique lines in fig. 7) provided in the effective portion 19b, the length being measured along one end portion 2c and the other end portion 2d in the width direction of the effective portion 19b and along the central portion 2e between the two end portions 2c and 2 d.

In addition, in this manufacturing method, the first adjustment step is performed based on the result of the measurement step, and the difference between the cooling and solidification speeds of both end portions 18a, 18b of the one side end portion 18a and the other side end portion 18b in the width direction of the glass ribbon 18 connected to the one side end portion 2c and the other side end portion 2d of the effective portion 19b is adjusted to be small. Further, a second adjusting step is performed based on the result of the measuring step, and the difference between the cooling and solidifying speed of the both end portions 18a, 18b of the glass ribbon 18 and the cooling and solidifying speed of the central portion 18c between the both end portions 18a, 18b is adjusted to be small.

Here, the phrase "the difference in the cooling solidification speed is reduced between the portions of the glass ribbon 18" means that the distance along the path (in the present embodiment, the distance in the vertical direction) between the point where one portion is cooled and solidified and the point where the other portion is cooled and solidified is reduced on the path through which the glass ribbon 18 passes. Therefore, if the difference in the cooling solidification speed between the two portions is zero, the two portions are cooled and solidified at the same point on the path through which the glass ribbon 18 passes.

The forming process is carried out mainly using the following members: a wedge-shaped molded body 16 for overflow downdraw method; a roller group 20 composed of roller pairs arranged in a plurality of stages in the vertical direction and capable of sandwiching the glass ribbon 18 flowing down from the forming body 16 from the front and back sides and drawing downward; and a heater group 21 including three heaters 21a, 21b, and 21c, the three heaters 21a, 21b, and 21c serving as heating means capable of heating both end portions 18a and 18b and a central portion 18c of the glass ribbon 18 in the process of flowing down. Since the structure and operation of the molded body 16 and the roll group 20 among the three bodies 16, 20, 21 used in the molding step are known, the detailed description thereof will be omitted, and only the heater group 21 will be described in detail.

The heater group 21 is disposed in a slow cooling furnace (not shown) for slowly cooling the glass ribbon 18 to a temperature equal to or lower than the strain point, and the heaters 21a, 21b, and 21c constituting the heater group 21 are disposed at the same point on the path along which the glass ribbon 18 flows down. That is, the heaters 21a, 21b, 21c are located at the same height position as each other. The heaters 21a, 21b, and 21c can independently change the magnitude of the thermal energy applied to the glass ribbon 18. Thus, the cooling and solidification speeds of the one end portion 18a, the other end portion 18b, and the central portion 18c of the glass ribbon 18 can be individually adjusted.

In the present embodiment, only one heater group 21 is disposed on the path along which the glass ribbon 18 flows, but the present invention is not limited thereto. As a modification of the present embodiment, the plurality of heater groups 21 may be arranged in a plurality of stages in the vertical direction along the path along which the glass ribbon 18 flows downward. Further, if the difference in the cooling solidification rate between the portions of the glass ribbon 18 can be changed, it is not necessary to dispose three heaters 21a, 21b, and 21 c. For example, as a modification of the present embodiment, only the three heaters 21c may be arranged.

The one-side end portion 18a of the glass ribbon 18 includes a portion that becomes the unnecessary portion 19a of the ribbon-shaped glass film 19 after cooling and solidification, and a portion that becomes the one-side end portion 2c of the effective portion 19b of the ribbon-shaped glass film 19. Similarly, the other end portion 18b includes a portion that becomes the unnecessary portion 19a of the ribbon-shaped glass film 19 after cooling and solidification, and a portion that becomes the other end portion 2d in the effective portion 19b of the ribbon-shaped glass film 19. The central portion 18c of the glass ribbon 18 becomes the central portion 2e of the effective portion 19b after cooling and solidification.

The thickness of the ribbon-shaped glass film 19 obtained in the molding step is, for example, 300 μm or less. The unnecessary portion 19a of the ribbon-shaped glass film 19 includes an ear portion having a larger thickness than other portions. The mode of forming the wrinkles 5 in the ribbon-shaped glass film 19 is not limited to the description in the present embodiment, but here, the case where the wrinkles 5 are formed in the one end portion 2c and the other end portion 2d of the two unnecessary portions 19a and the effective portion 19b of the ribbon-shaped glass film 19, and the wrinkles 5 are not formed in the central portion 2e of the effective portion 19b is exemplified.

Here, in the present embodiment, the ribbon-shaped glass film 19 is formed by the overflow downdraw method, but as a modification of the present embodiment, the ribbon-shaped glass film 19 may be formed by a slit downdraw method, a redraw method, or the like.

The belt-like glass film 19 conveyed vertically after molding is converted from a vertical downward direction to a horizontal direction by a roller group 22 composed of a plurality of rollers arranged along a curved conveying track. The belt-shaped glass film 19 is conveyed in the horizontal direction by the conveyor 23, the plate-shaped body 24, and the conveyor 25, and the belt-shaped glass film 19 is passed through the measurement position X and the division position Y in the conveyance path in this order.

Here, in the present embodiment, the measurement position X is disposed in a section where the belt-shaped glass film 19 is conveyed in the horizontal direction in the conveyance path of the belt-shaped glass film 19, but the present invention is not limited thereto. As a modification of the present embodiment, the measurement position X may be disposed in a zone in which the ribbon-shaped glass film 19 is conveyed in the vertical downward direction.

In the measurement step performed using the measurement position X, the first measurement length (hereinafter, referred to as a first measurement length LL 1), the second measurement length (hereinafter, referred to as a second measurement length LL 2), and the third measurement length (hereinafter, referred to as a third measurement length LL 3) measured at each of the one end portion 2c, the other end portion 2d, and the central portion 2e of the effective portion 19b are measured using three roller encoders 26 each functioning as a measurement means, and it is noted that the "central portion 2 e" of the effective portion 19b indicates a portion having a width of 200mm located at the center in the width direction of the effective portion 19b, the "one end portion 2 c" and the "other end portion 2 d" of the effective portion 19b indicate portions located outside the central portion 2e in the width direction, and the measurement lengths LL 1 to LL 3 are measured at arbitrary positions within the widths of the one end portion 2c, the other end portion 2d, and the central portion 2 e.

The measurement target section S to be measured for each of the measurement lengths LL 1 to LL 3 is a section along the longitudinal direction of the effective portion 19b of the strip-shaped glass film 19, and the distal end portion Sa and the distal end portion Sb extend parallel to the width direction, that is, the measurement target section S is formed in a rectangular shape when the strip-shaped glass film 19 is viewed in plan view, and the length of the measurement target section S (the length along the longitudinal direction of the strip-shaped glass film 19) may be any length, and preferably the length of the measurement target section S is 20m or more.

Since the measurement lengths LL 1 to LL 3 are measured along the surface 2f of the measurement target section S, the influence of the irregularities of the surface 2f formed by the wrinkles 5 is reflected in the measurement results of the first measurement length LL 1 and the second measurement length LL 2, and the number of the wrinkles 5 and the size of the measurement are reflected in the length of the measurement length, whereas the influence of the irregularities of the surface 2f formed by the wrinkles 5 is not reflected in the measurement results of the third measurement length LL 3.

The roller encoders 26 used for performing the measurement process have the same configuration as the roller encoder 7 described in the section of < the measurement mode of the first to third measurement lengths > and can perform the same operation, and therefore description thereof is omitted here, and the measurement of the measurement lengths LL 1 to LL 3 is completed when the rollers 26a as rotating bodies provided in the roller encoders 26 are respectively finished rolling from the leading end portion Sa to the trailing end portion Sb along the one end portion 2c, the other end portion 2d, and the central portion 2e of the effective portion 19b along the surface 2f of the measurement target section S.

As a result of the measurement process, the first adjustment process is performed when the difference between the two measurement lengths LL 1, LL 2 (absolute values of LL 1-LL 2) of the first measurement length LL 1 and the second measurement length LL 2 exceeds 400ppm of the longer measurement length of the two measurement lengths LL 1, LL 2.

In the present embodiment, a case will be described as an example where the first measurement length LL 1 is longer than the second measurement length LL 2 and the difference between the two measurement lengths LL 1 and LL 2 exceeds 400ppm of the first measurement length LL 1, in this case, the number of pleats 5 is not sufficiently large in one end portion 2c of the effective portion 19b as compared with the other end portion 2d, and the balance between the number and size of the pleats 5 between the both end portions 2c and 2d is deteriorated.

The inventors of the present invention have intensively studied and found that the deterioration of the balance between the number and the size of the wrinkles 5 between the one side end portion 2c and the other side end portion 2d of the effective portion 19b is mainly caused by the difference in the cooling and solidifying speed between the central portion 18c and the one side end portion 18a of the glass ribbon 18 and the difference in the cooling and solidifying speed between the central portion 18c and the other side end portion 18 b. The cooling and solidification speed of the central portion 18c is usually higher than that of either of the both end portions 18a, 18 b. In the present embodiment, the difference in the cooling and solidification rates between the central portion 18c and the one end portion 18a is undesirably large relative to the difference in the cooling and solidification rates between the central portion 18c and the other end portion 18 b.

To correct such a state, the heaters 21a, 21b, and 21c are used to adjust so that the difference between the cooling and solidifying speeds of the both ends 18a and 18b of the glass ribbon 18 is reduced. As a result, the balance between the difference in the cooling/solidification rate between the central portion 18c and the one end portion 18a of the glass ribbon 18 and the difference in the cooling/solidification rate between the central portion 18c and the other end portion 18b is improved. It is preferable that the difference between the cooling and solidifying speeds of the both end portions 18a, 18b is zero, and the both end portions 18a, 18b are cooled and solidified at the same point on the path along which the glass ribbon 18 flows down.

Specifically, the operation of any one of the following (a) and (B) is performed. (A) In a state where the cooling and solidification speed of one end portion of the one end portion 18a and the other end portion 18b is fixed, the cooling and solidification speed of the other end portion is made to be close to the cooling and solidification speed of the one end portion. Specifically, the cooling and solidification speed of the one end portion 18a is increased in a state where the cooling and solidification speed of the other end portion 18b is fixed. (B) The cooling and solidification speeds of both the one end portion 18a and the other end portion 18b are changed so as to approach each other. Specifically, the cooling and solidification speeds of both the one end portion 18a and the other end portion 18b are increased, and the cooling and solidification speeds are made to be close to each other.

After the first adjustment step is performed, a section different from the measured section S is set as a new measured section S, and the measurement step is performed again. The "new section S to be measured" is a section along the longitudinal direction of the effective portion 19b formed after the execution of the first adjustment step.

As a result of the measurement process performed again, if the difference between the two measurement lengths LL 1, LL 2 is 400ppm or less of the first measurement length LL 1, it is considered that the balance is improved, and the operation state of the heaters 21a, 21b, 21c is maintained after the first adjustment process.

On the other hand, if the result of the measurement process performed again is that the difference between the two measurement lengths LL 1, LL 2 does not exceed 400ppm of the first measurement length LL 1, the two processes of the measurement process and the first adjustment process are alternately performed so that the measured section S is changed to a new section each time the measurement process is performed until the difference between the two measurement lengths LL 1, LL 2 becomes 400ppm or less of the first measurement length LL 1.

As a result of the measurement process, when at least one of the difference between the first measurement length LL 1 and the third measurement length LL 3 (absolute value of LL 1-LL 3) and the difference between the second measurement length LL 2 and the third measurement length LL 3 (absolute value of LL 2-LL 3) exceeds 500ppm of the longest measurement length among the first measurement length LL 1 to the third measurement length LL 3, the second adjustment process is performed.

In the present embodiment, a case where both of the difference between the first measurement length LL 1 and the third measurement length LL 3 and the difference between the second measurement length LL 2 and the third measurement length LL 3 exceed 500ppm of the longest first measurement length LL 1 of the first measurement length LL 1 to the third measurement length LL 3 will be described as an example, and in this case, the number and size of the wrinkles 5 cannot be sufficiently suppressed at both the one side end 2c and the other side end 2d of the effective portion 19 b.

The inventors of the present invention have made extensive studies and found that the difference in the cooling/solidification rates between the central portion 18c and the one-side end portion 18a and between the central portion 18c and the other-side end portion 18b of the glass ribbon 18 is large, which is a factor that the number and size of the wrinkles 5 cannot be sufficiently suppressed at the one-side end portion 2c and the other-side end portion 2d of the effective portion 19 b. In the present embodiment, the cooling and solidification speed of the one end portion 18a and the other end portion 18b is undesirably slow relative to the central portion 18 c.

To correct such a state, the difference between the cooling and solidifying speeds of the both end portions 18a, 18b and the central portion 18c of the glass ribbon 18 is adjusted to be small by using the heaters 21a, 21b, 21 c. It is preferable that the difference between the cooling and solidifying speed of the both end portions 18a, 18b and the cooling and solidifying speed of the central portion 18c is zero, and the both end portions 18a, 18b and the central portion 18c are cooled and solidified at the same point on the path along which the glass ribbon 18 flows down.

Specifically, the following operations (C) and (D) are performed. (C) In a state where one of the cooling and solidifying speeds of the both end portions 18a, 18b and the central portion 18c is fixed, the other cooling and solidifying speed is made to approach the one cooling and solidifying speed. Specifically, the cooling and solidification speeds of the both end portions 18a, 18b are increased in a state where the cooling and solidification speed of the central portion 18c is fixed. In another specific example, the cooling and solidification speed of the central portion 18c is reduced while the cooling and solidification speeds of the both end portions 18a and 18b are fixed. (D) Both the cooling and solidification speeds of the both end portions 18a, 18b and the cooling and solidification speed of the central portion 18c are changed so as to approach each other. Specifically, the cooling and solidification speeds of the both end portions 18a, 18b are increased, and the cooling and solidification speeds of the central portion 18c are decreased so that the speeds of both end portions are close to each other.

After the second adjustment step is performed, a section different from the measured section S is set as a new measured section S, and the measurement step is performed again. The "new section S to be measured" is a section along the longitudinal direction of the effective portion 19b formed after the second adjustment step is performed.

As a result of the measurement process performed again, if both the difference between the first measurement length LL 1 and the third measurement length LL 3 and the difference between the second measurement length LL 2 and the third measurement length LL 3 are equal to or less than 500ppm of the longest first measurement length LL 1, it is considered that the number and size of wrinkles 5 can be sufficiently suppressed at both the one end 2c and the other end 2d, and the operation state of the heaters 21a, 21b, and 21c is maintained after the second adjustment process.

On the other hand, if the result of the measurement process being executed again is that at least one of the two differences does not exceed 500ppm of the longest first measurement length LL 1, the two processes of the measurement process and the second adjustment process are alternately executed so that the measured section S is changed to a new section each time the measurement process is executed until both of the two differences reach 500ppm or less of the longest first measurement length LL 1.

In the measurement process performed once or a plurality of times, the section of the effective portion 19b that is to be the section S to be measured may be contaminated due to the contact with the roller 26a provided in the roller encoder 26, and therefore, the section of the effective portion 19b that is to be the winding target is divided and discarded, and the section formed until the difference between the two measurement lengths LL 1 and LL 2 in the effective portion 19b is 400ppm or less of the longer measurement length (here, the first measurement length LL 1) is also divided from the section of the effective portion 19b that is to be the winding target and discarded as a defective item.

After passing through the measurement position X, the dividing process is performed on the belt-shaped glass film 19 that has reached the dividing position Y, and cutting using the laser 27 is performed along the boundary lines B1, B2 between the effective portion 19B and the two unnecessary portions 19a, respectively. This divides the effective portion 19b into two unnecessary portions 19a and 19 a. The cutting using the laser 27 can be performed by a known laser dicing method or the like, for example. The two divided unnecessary portions 19a and 19a are dropped downward from the conveyor 25 and discarded.

The effective portion 19b (the divided ribbon-shaped glass film 2) which is divided from the two unnecessary portions 19a and passes through the dividing position Y reaches the winding core 4 at the loosening conveyance position Z at which the effective portion 19b is conveyed in a state of being loosened downward. The effective portion 19b that reaches the core 4 through the slack conveyance position Z is not the section that becomes the measurement target section S and the section that becomes a defective product. The section that becomes the defective product and the section that becomes the measurement section S do not reach the core 4, are divided from the section to be wound, fall downward at the slack conveyance position Z, and are discarded.

When the effective portion 19b other than the section to be discarded is wound around the winding core 4 in the above manner and the winding of a desired length is completed, the glass roll 1 is completed. When the effective portion 19b is wound around the winding core 4, the effective portion is wound in a state of being overlapped with the belt-like protection sheet 3 supplied from the third sheet roll 28.

Here, in the present embodiment, as the first adjustment step, the difference between the cooling and solidification speeds of the both ends 18a, 18b of the one side end portion 18a and the other side end portion 18b of the glass ribbon 18 is adjusted to be small, but the present invention is not limited thereto, and the first adjustment step may be performed in a manner different from the present embodiment as long as the difference between the two measured lengths LL 1, LL 2 is made small.

In addition, in the present embodiment, as the second adjustment step, the difference between the speed at which the both end portions 18a, 18b of the glass ribbon 18 are cooled and solidified and the speed at which the central portion 18c between the both end portions 18a, 18b is cooled and solidified is adjusted to be small, but the present invention is not limited thereto, and the second adjustment step may be performed in a manner different from the present embodiment as long as the difference of 500ppm exceeding the longest measurement length of LL 1 to LL 3, out of the two differences (absolute value of LL 1 to LL 3) and (absolute value of LL 2 to LL 3) becomes small.

< method for evaluating quality of glass roll >

A method for evaluating the quality of the glass roll 1 will be described below. In the description of the present evaluation method, the same elements as those described in the above-mentioned parts of < glass roll >, < measurement method of first to third measurement lengths >, and < method of manufacturing a glass roll > are denoted by the same reference numerals as those denoted in the description of the two parts, and redundant description thereof will be omitted.

The flow of the evaluation method is shown in fig. 9. In the present evaluation method, first, an extraction step of extracting a sample glass roll 1a from a plurality of glass rolls 1 produced under the same conditions is performed. The plurality of glass rolls 1 are manufactured under the same forming conditions (the operating states of the heaters 21a, 21b, and 21c are also the same), the same dividing conditions, and the same winding conditions, for example, by the above-described < method for manufacturing glass rolls >.

Here, in the present embodiment, only one glass roll 1 is taken out as the sample glass roll 1a, but the present invention is not limited thereto. As a modification of the present embodiment, two or more glass reels 1 may be extracted. In this way, the accuracy of determination in the determination step described later can be improved in response to an increase in the number of samples. In addition, as an example, as the extraction frequency in the case of extracting only one sample glass roll 1a, it is preferable to extract one every three days on the glass roll manufacturing day, more preferably one every two days, and still more preferably one every day.

Specifically, the length of the effective section 6 from the distal end portion 2a to the distal end portion 2b along the surface 2f is measured in a roll-to-roll manner with respect to the strip-shaped glass film 2 having the wrinkles 5 formed thereon constituting the sample glass roll 1a, and the length is measured at the one end portion 2c and the other end portion 2d along the width direction of the effective section 6 and at the central portion 2e between the both end portions 2c and 2d, and the measurement results are respectively set as a one-side measurement length (hereinafter referred to as one-side measurement length M L1), a other-side measurement length (hereinafter referred to as the other-side measurement length M L2), and a central measurement length (hereinafter referred to as the central measurement length M L3).

Here, the "central portion 2 e" of the effective section 6 indicates a portion having a width of 200mm located at the center in the width direction of the effective section 6. The "one end 2 c" and the "other end 2 d" of the effective section 6 each indicate a portion located on the outer side in the width direction of the central portion 2 e.

The specific manner of measuring one-side measured length M L1, other-side measured length M L2, and center measured length M L3 is substantially the same as the manner of measuring first measured length L1, second measured length L2, and third measured length L3 described above (fig. 3 to 5c), and therefore only the differences from the measurement manners of first measured length L1 to third measured length L3 will be described.

The first measured length L1, the second measured length L2, and the third measured length L3 are lengths measured along the first position P1, the second position P2, and the width-direction center line C L, respectively, whereas the first measured length M L1, the second measured length M L2, and the center measured length M L3 are lengths measured along any position within the width of the first end portion 2C, any position within the width of the second end portion 2d, and any position within the width of the center portion 2e, that is, these three arbitrary positions may coincide with the first position P1, the second position P2, and the width-direction center line C L, respectively, or may be different.

When the measurement step is completed, a determination step of determining the quality of the plurality of glass rolls 1 other than the sample glass roll 1a based on the difference between the two measurement lengths M L1, M L2 of the one-side measurement length M L1 and the other-side measurement length M L2 is performed next.

Here, the sample glass roll 1a and the plurality of glass rolls 1 other than the sample glass roll 1a are manufactured under the same conditions, and can be regarded as substantially identical glass rolls 1. Therefore, the sample glass roll 1a is considered to obtain the same effect for each of the plurality of glass rolls 1 as long as the ribbon-shaped glass film 2 can be prevented from being skewed and slacked on one side in the roll-to-roll system. In addition, the sample glass roll 1a is also regarded as obtaining the same effect for each of the plurality of glass rolls 1 as long as the processing can be appropriately performed for the ribbon-like glass film in the case of using the roll-to-roll system.

In the determination step, when the difference between the two measurement lengths M L1 and M L2 (the absolute value of M L1 to M L2) is not more than 400ppm (preferably not more than 200ppm, and more preferably not more than 100 ppm) of the longer measurement length of the two measurement lengths M L1 and M L2, the quality of the plurality of glass rolls 1 other than the sample glass roll 1a is determined as being acceptable, that is, the glass roll 1 in which the ribbon-shaped glass film 2 is prevented from running obliquely and one-side sagging in the roll-to-roll system is determined.

In addition, when the larger difference between the one-side measured length M L1 and the center measured length M L3 (absolute value of M L01-M L3) and the difference between the other-side measured length M L2 and the center measured length M L3 (absolute value of M L2-M L3) is 500ppm or less (preferably 300ppm or less, more preferably 200ppm or less) of the longest measured length among the three measured lengths M L1, M L2, and M L3, the quality of the plurality of glass rolls 1 other than the sample glass roll 1a is determined as good pass, that is, the glass roll 1 is determined to be a glass roll 1 capable of preventing the ribbon-shaped glass film 2 from skewing and one-side sagging and appropriately performing the processing on the ribbon-shaped glass film 2 in the roll-to-roll system.