Round bar glass, methods for manufacturing round bar glass, and apparatus for manufacturing round bar glass.

Abstract

The present invention aims to provide a method for manufacturing cylindrical glass with extremely small diameters without grinding and abrasion of the sides, and the cylindrical glass obtained by this method. A method for manufacturing cylindrical glass from a glass block includes: arranging three or more calendering rolls with cylindrical or conical tops such that their rotation axes intersect; rotating all the calendering rolls in the same direction; pressing the softened glass block into a gap formed at a position surrounded by the rotation axes by the rotation of the tops; and elongating and shaping the glass block into a cylindrical glass by being pressed. The cylindrical glass obtained by this manufacturing method is also described.

Description

TECHNICAL FIELD

[0001] The present application relates to a round rod glass having a very small diameter, a manufacturing method of the round rod glass, and a manufacturing apparatus of the round rod glass. BACKGROUND

[0002] As a band-shaped material or an elongated plate-shaped material called an E-bar, an optical glass can be generally obtained, and it is shaped into a glass product having a prescribed shape. Specifically, first, a small glass piece having a relatively simple shape is produced with the same glass volume as an object, and then the small glass piece is precisely shaped. From the viewpoint of industrial convenience, for an optical glass, it is desired to be able to mass-produce products of the same shape, and therefore even when such a small glass piece is manufactured, it is desired to be able to mass-produce small glass pieces of the same shape.

[0003] As an example of a method of manufacturing such a small glass piece, a method in which an elongated cuboid glass having one side sufficiently longer than the other sides is prepared, the cuboid glass is shaped into a cylindrical round rod glass, and then it is cut in a vertical direction with respect to the cylindrical height, thereby obtaining a flat plate-shaped (here, a disc-shaped or cylindrical) small glass piece can be given. The flat plate-shaped small glass piece is preferably used as a material for an optical lens due to the similarity of the shape.

[0004] As a method of manufacturing a flat plate-shaped small glass piece as described above, for example, the method of Patent Literature 1 can be given. Patent Literature 1 discloses "a method of manufacturing a lens, characterized by: charging a glass block heated to a temperature above a softening temperature and less than a flow temperature into three or more rollers rotating in the same direction in parallel with each other, shaping into a glass round rod having a prescribed diameter that can be pinched based on the interval of the rotating rollers, and then cutting, shaping, and polishing the glass round rod to form a lens having a prescribed radius of curvature".

[0005] In addition, Patent Literature 2 discloses "a method of manufacturing a glass round rod, characterized by: moving a glass material heated to a temperature of 10 10 a viscosity of 100 poise or less onto a guide slope (chute) provided in parallel with the rotation axis of the rollers, and shaping the glass material into a round rod shape having a circular cross section by rotating the glass material in a direction opposite to the rotation direction of the rollers, the movement of the glass material on the guide slope (chute) being performed by rolling the glass material along the guide slope (chute)".

[0006] Patent Document 3 discloses "A method for manufacturing small glass materials for lenses, characterized by: in manufacturing a plurality of small glass materials for lenses using a glass round bar, inserting the glass round bar between two rollers rotating in the same direction, reducing the interval of the two rollers, and extruding the glass round bar heated to a temperature above the softening temperature from both sides, simultaneously forming a plurality of circumferential groove portions in the glass round bar by providing a plurality of flange-like blades at equal intervals in the axial direction on at least one of the two rollers, and thereafter cutting each of the groove portions of the glass round bar to form small glass materials of equal weight suitable for lenses."

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Patent Laid-Open No. 54-117514;

[0010] Patent Document 2: Japanese Patent Laid-Open No. 2000-16822;

[0011] Patent Document 3: Japanese Patent Laid-Open No. 2002-114532.

[0012] Problems to be Solved by the Invention

[0013] As shown in Patent Documents 1 to 3, research and development of a manufacturing method of a round bar glass (hereinafter also referred to as a round bar glass) as a material of a flat plate-shaped small glass sheet is in progress. However, as a glass product, there is a large demand for a small-sized glass product, and even in the field of optical lenses, miniaturization of lenses is required. If the cross-sectional diameter of the round bar glass as an optical lens material can be made close to the diameter of the optical lens as a final product, the time and the amount of cutting of the glass on the side surface of the round bar glass can be reduced, and thus the cost of glass manufacturing can be suppressed, and the amount of waste glass (chips) discharged along with the cutting of the glass can be suppressed, which is also beneficial to the environment.

[0014] The diameter of the round bar glass after the round bar is formed is not described in Patent Document 1. In addition, although a round bar glass having a diameter of 6 mm is disclosed in Patent Document 2 in paragraph

[0061] , a round bar glass smaller than this diameter is not disclosed. Furthermore, although a round bar glass having a diameter of 7 mm is disclosed in Patent Document 3 in paragraph

[0029] , a round bar glass smaller than this diameter (for example, a round bar glass having a diameter of 3.5 mm or less) is not disclosed.

[0015] The technology described in Patent Documents 1 to 3 and the like is inherently difficult to manufacture a round bar glass having a diameter of 3.5 mm or less.

[0016] In the technique of cutting by sandwiching a round bar glass with three rollers and rotating it as in Patent Literature 1, the diameter of the glass bar to be manufactured can be reduced as the diameter of the rollers is reduced. Theoretically, when the diameter of the three rollers is 40 mm, a round bar glass with a minimum diameter of 6.5 mm can be obtained, when the diameter of the rollers is 30 mm, a round bar glass with a minimum diameter of 5.0 mm can be obtained, and when the diameter of the rollers is 20 mm, a round bar glass with a minimum diameter of 3.5 mm can be obtained. Thus, it is theoretically possible to manufacture a round bar glass with a small diameter by reducing the diameter of the rollers. However, a roller with a diameter of 20 mm is deformed when subjected to high pressure. In order to prevent such deformation, it is necessary to shorten the length of the roller, but it is difficult to manufacture a long glass bar using a short roller, and in fact, it is not possible to manufacture a round bar glass that is cost-effective. It is presumed that the minimum diameters of 6 mm and 7 mm of the round bar glasses disclosed in Patent Literatures 2 and 3 are the limit of the existing round bar glass manufacturing technique. SUMMARY

[0017] SOLUTION TO THE PROBLEM

[0018] The present inventors have focused on the above problem and developed a method of obtaining a round bar glass with a small diameter from a round bar forming device without polishing or grinding the side surface by employing a special manufacturing method.

[0019] That is, the present application includes the following steps.

[0020] [1] A manufacturing method of manufacturing a round bar glass from a glass block, comprising:

[0021] a step of arranging three or more calender rollers whose top end portions are in a cylindrical or conical shape so that the rotation axes of the calender rollers cross each other;

[0022] a step of rotating all of the calender rollers in the same direction;

[0023] a step of pressing the softened glass block into a gap formed at a position surrounded by the rotation axes by the rotation of the top end portions; and

[0024] a step of elongating and forming the glass block into a round bar glass by being pressed.

[0025] [2] A manufacturing device for manufacturing a round bar glass from a glass block, having:

[0026] three or more calender rollers whose top end portions are in a cylindrical or conical shape;

[0027] a rotation unit for rotating the calender rollers; and

[0028] a heating unit for heating a glass block as a material,

[0029] the rotation axes of the calender rolls are respectively crossed,

[0030] The softened glass block is pressed into a gap formed at a position surrounded by the rotation axes by rotation of the calender rolls, thereby manufacturing the round rod glass.

[0031] [3] A round rod glass composed of a side surface which is not polished,

[0032] The side surface is not formed by grinding,

[0033] The surface of the side surface has a spiral pattern.

[0034] [4] The round rod glass according to [3], wherein the cross-sectional diameter is 3.5 mm or less, and the aspect ratio (major axis / cross-sectional radius) is 35 or more.

[0035] [5] The round rod glass according to [3] or [4], wherein the side surface has a component from a release agent.

[0036] Effects of the Invention

[0037] The round rod glass of the present application can be shaped into a round rod glass having an extremely small diameter and a prescribed length or more without cutting or grinding the side surface. The round rod glass having an extremely small diameter is cut substantially perpendicularly in the length direction, whereby the cut glass can be directly used as a lens material, and a prescribed size of glass lens material can be manufactured while suppressing the cutting amount of the glass, i.e., the amount of glass waste. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 (a) of FIG. 1 is a schematic view of a shaped round rod glass, Figure 1 (b) of FIG. 1 is a view showing the positional relationship of a glass block introduction portion and calender rolls;

[0039] Figure 2 is a view showing a combined state of three calender rolls as viewed from above;

[0040] Figure 3 is a view showing a state in which a round rod glass is formed;

[0041] Figure 4 is a view of a shaped round rod glass when various calender rolls are used;

[0042] Figure 5 is a view showing adjustment of the combined state of three calender rolls;

[0043] Figure 6 is a view showing the pressing angle of three calender rolls;

[0044] Figure 7is a view showing a process of finalizing the shape of a glass rod discharged from the calender rolls while annealing by rotating two cylinders;

[0045] Figure 8 is a perspective view of a glass rod manufactured according to the manufacturing method of the glass rod of the present application;

[0046] Figure 9 is an enlarged view of the glass rod of the present application. DETAILED DESCRIPTION

[0047] In the present specification, unless otherwise specified, "~" used when designating a numerical range means that both the upper limit and the lower limit are included in the range.

[0048] [Manufacturing method of glass rod]

[0049] The manufacturing method of the glass rod of the present application is a method of manufacturing a glass rod from a glass block, comprising: a process of arranging three or more calender rolls having a top end portion in a cylindrical or conical shape so that the rotation axes of the calender rolls cross each other; a process of rotating all of the calender rolls in the same direction; a process of pressing the softened glass block into a gap formed at a position surrounded by the rotation axes by the rotation of the top end portion; and a process of elongating the glass block by the pressing to form a glass rod.

[0050] Hereinafter, a detailed description will be given using the drawings.

[0051] The manufacturing method of the glass rod is as shown in Figure 1 The glass block 31 before being put in is heated, and then put into the glass block introduction portion 4 in a state of being pressed and formed into a glass rod as soon as it falls to the calender rolls 1. The glass block 31 immediately passes through the glass block introduction portion 4 and falls to the calender rolls 1. In addition, the glass block introduction portion 4 can be heated by a prescribed heating unit (not shown).

[0052] The glass block 31 before being put in can be a glass of a prescribed size, and is not particularly limited in shape. As the shape of the glass block, for example, a cube, a cuboid, a pyramid, a cone, a sphere, a cylinder, a flat plate, and the like are mentioned. In addition, in the present specification, for the cube, the cuboid, the pyramid, the cylinder, the flat plate, and the like, each of the shapes also includes a shape with corners removed (a shape with rounded corners). In addition, if the corners are removed, it is less likely to be damaged at the time of being put in, and thus is preferable.

[0053] The glass block introduction portion 4 has a function of being put in such that the glass block 31 comes into contact with the side surface of the top end portion 11 of the three calender rolls 1. As long as this function can be achieved, there is no particular limitation on the shape, but as Figure 1As shown, if it is mortar-shaped (funnel-shaped), the inlet is wide, making it easy to operate. Additionally, if the glass block inlet 4 is mortar-shaped, then as... Figure 1 As shown in (b), the fine, mortar-shaped portion can be arranged so as not to interfere with the calender roll 1 even when it is located directly above the top end 11 of the calender roll 1. Furthermore, the bottom opening of the mortar shape allows glass blocks 31 to be inserted near the top end 11 of the calender roll 1.

[0054] Before being fed into the glass block inlet 4, the glass block 31 is softened by heating. At this time, the viscosity of the glass only needs to be sufficient to deform the glass; however, depending on the composition of the glass, if it is overheated, the viscosity becomes very low, sometimes making it difficult to form the glass. Therefore, the viscosity of the heated glass block 31 in the glass block inlet 4 is preferably 10. 3 ~10 6 Approximately Pa·s.

[0055] The temperature required to achieve this viscosity cannot be specified due to the influence of glass composition and various conditions, but it is preferable that the temperature of the glass block is at least above the softening point. For example, the viscosity can be set to a range above the softening point and below the softening point +300°C.

[0056] The softened glass block 31 falls from the glass block inlet 4 to the top end 11 of the rotating calendering roller 1 due to gravity.

[0057] By combining three or more calendering rolls 1 and rotating them individually, the calendering rolls 1 further press the softened glass block 31 downwards. The calendering rolls 1 can be rotated by any rotating unit.

[0058] The calendering roll 1 has a rod 10 and a top end 11 for pressing glass downwards. The top end 11 has sides that receive a softened glass block 31 and press it downwards through three or more calendering rolls 1. The softened glass block 31 is configured to face the top ends of the three or more calendering rolls 1 and to contact the top ends of the three or more calendering rolls 1 simultaneously. In addition to adjusting the downward pressing force, in order to manufacture round bar glass with a small diameter, the softened glass block 31 is positioned at the intersection of the extension lines of the rotation axes 2 of the rod 10 and the top end 11 (see reference). Figure 2 As described above, by rotating the calendering rollers 1 individually, the softened glass block 31 is formed into a cylindrical glass rod.

[0059] use Figure 3 The forming process of the round bar glass 32 is explained.

[0060] In actual manufacturing, three or more calendering rolls are used, but in Figure 3In the image, only two calendering rolls are shown to indicate the state of the glass.

[0061] First, the softened glass block 31 falls onto the side of the top end 11 of the calendering roll 1. Figure 3 (a) and (b)). As the calendering rollers 1 rotate, the glass block 31 is elongated. The smaller the distance between the calendering rollers 1, the stronger the pressing pressure. Figure 3 In the middle, the closer to the bottom glass, the longer it extends while rotating ( Figure 3 (c) and (d) are spiraled downwards, eventually yielding a round glass rod 32 with a specified diameter. Figure 3 (e) and (f)).

[0062] The rotational speed of the calendering roll 1 is not particularly limited. Increasing the rotational speed of the calendering roll increases the manufacturing speed of the cylindrical glass 32, but the resulting cylindrical glass 32 exhibits larger waviness, making it difficult to produce uniform cylindrical glass 32. Furthermore, during manufacturing, the softened cylindrical glass 32 may wobble, sometimes preventing the production of uniform cylindrical glass 32. Therefore, the rotational speed should be appropriately determined based on the viscosity characteristics of the glass used. For example, it can be freely set from 50 rpm to 10000 rpm. Regarding the rotational speed, the speed of three or more calendering rolls can be adjusted individually, but usually all are set to the same rotational speed. With the same rotational speed, since the same pressing force is formed, cylindrical glass with less waviness and a uniform shape can be produced.

[0063] exist Figure 1 The manufacturing method of round bar glass uses three calendering rolls 1, but round bar glass can also be manufactured using more than three calendering rolls 1. For example, by making the calendering rolls 1 smaller, round bar glass can also be manufactured using four or more calendering rolls. However, considering the simplicity of configuration and cost, it is preferable to use three calendering rolls.

[0064] exist Figure 4 The image shows a calendering roll 1 with various shaped tip portions. Here, the tip portion of the calendering roll refers to the part that contacts the softened glass block 31, which presses the glass block 31 downward by rotating.

[0065] exist Figure 4 In (a), the calender roll 1 has a conical top portion 11 (mushroom-shaped). It has the same... Figures 1 to 3The softened glass block 31 is in contact with the side surface of the conical top end portion 11 (contact portion C) using the same shape of the calender roll 1, and the glass is pressed downward when the softened glass is in contact with the side surface of three top end portions 11 (two top end portions 11 in the figure) at the same time. For the round bar glass 32, the round bar glass 32 is shaped while a spiral pattern is formed on the surface of the glass by the top end portion 11. Further, when the top end portion 11 is conical, it is preferable that the shape of the apex portion is cut off (the top end is not pointed).

[0066] Further, the diameter size of the round bar glass 32 is affected by the size of the smallest gap among the gaps formed by the three calender rolls 1.

[0067] Figure 4 (b) uses the same top end portion 11 as (a) of Figure 4 but is configured in a state where the apex of the cone is upward and the bottom surface of the cone is downward. In Figure 4 (b) of (b), the softened glass also comes in contact with the side surface of the cone, and is discharged downward from the gap formed by the three calender rolls 1.

[0068] Further, as shown in (c), (d) of Figure 4 the conical top end portion 12 having a portion that is tapered in the middle in the side surface, as shown in (e) of Figure 4 the cylindrical top end portion 13, as shown in (f) of Figure 4 the cylindrical reduced diameter top end portion 14 having a reduced diameter portion at the top end of the cylinder, and the like can also shape the round bar glass. Further, in the present specification, the shape shown in (a), (b) of Figure 4 is included in the conical shape, and the shape shown in (c), (d) of Figure 4 is included in the cylindrical shape.

[0069] The method of manufacturing the round bar glass of the present application can control the size of the cross-sectional diameter of the round bar glass. For example, as shown in (a) of Figure 5 by separating the calender rolls 1 from each other from the state of being combined with the three calender rolls 1, the diameter of the obtained round bar glass 32 can be increased (refer to (b) of Figure 5 ). That is, by adjusting the distance between the top end portions of the calender rolls 1, the diameter of the round bar glass 32 can be adjusted.

[0070] Further, by adjusting the pressing-in angle of the calender roll 1 to a prescribed angle, the pressing-in speed can be adjusted. The pressing-in angle refers to the inclination angle of the calender roll with respect to the direction perpendicular to the ground (the angle with respect to the central axis of the pressing direction, refer to Figure 6 ), and in Figure 6 , the pressing-in angle is set to 10°.

[0071] The press-in angle is usually set to be greater than 0°, and is preferably set to a degree of, for example, 3 to 20°. If the press-in angle is small, the press-in speed becomes slow, and there is a tendency for the surface of the glass rod 32 to become fine, and, if the press-in angle is large, the press-in speed becomes fast, but the side surface of the glass rod 32 becomes rough, and the spiral pattern described later is clearly exhibited.

[0072] One glass block 31 is capable of manufacturing one glass rod 32. Therefore, in consideration of the diameter and length of the glass rod 32 to be manufactured, it is preferable to input a glass block 31 having a glass volume corresponding to the diameter and length.

[0073] With respect to the formed glass rod 32, as shown in Figure 7 , two cylinders 5 rotating in the same direction are placed adjacent to each other, and the vertically falling glass rod 32 is placed between the two cylinders 5 arranged obliquely, and the glass rod 32 is annealed while adjusting the final shape. However, the annealing method is not limited to the method of Figure 7 , and, for example, a method of receiving with a refractory material, a method of receiving with a mold having good sliding properties, and the like can be given.

[0074] Although not shown in Figure 7 , the cylinder 5 can also be heated to an appropriate temperature by a heating unit such as a torch. The cross-sectional diameter of the cylinder 5 is not particularly limited, but in the case where the diameter of the glass rod 32 is small, the glass rod 32 can be placed by reducing the gap between the cylinders 5. Further, the rotation speed of the cylinder 5 can be appropriately selected depending on the state of the glass rod.

[0075] (Release agent)

[0076] A release agent can be applied to the surface of the glass block 31 before the glass rod 32 is formed. By applying the release agent, the glass rod 32 can be easily removed from the rod forming device. In addition, the release agent can be applied not only to the glass block 31, but also to the calender roll 1.

[0077] Since the release agent adheres to the surface of the glass and is used to easily remove the glass rod from the calender roll 1 or the like, the release agent tends to be thinly distributed on the glass rod. Therefore, the surface of the glass rod of the present application contains a compound from the release agent.

[0078] Further, as the release agent, a release agent containing boron nitride (BN) is preferably used. Although molybdenum disulfide can also be used, since the heat resistance is low compared to boron nitride, boron nitride is preferably used.

[0079] (Glass rod)

[0080] The round bar glass 32 obtained by the manufacturing method of the round bar glass of the present application is cross-sectionally circular and is formed by calendering, and thus the side surface is not formed by polishing and is constituted by an unpolished side surface. The surface of the side surface of the round bar glass 32 has a spiral pattern 321 according to the configuration of the round bar glass manufacturing method.

[0081] In the present application, the round bar glass 32 is characterized by being unpolished. After the round bar glass of the present application is manufactured, if a polishing process is newly added and performed, the polishing process is performed, but the round bar glass of the present application is generally shipped in an unpolished state.

[0082] In addition, the round bar glass 32 of the present application is formed while rotating a glass block, and has a good linearity in the longitudinal direction, and thus can be shipped without cutting and polishing. In the case where cutting and polishing are not performed, the surface does not have a surface formed by a diamond cutter or the like (typically, the Ra of the polished surface is 2.0 to 4.0 μm, and the Rz is 12.00 to 20 μm).

[0083] As can be understood from the above description of the manufacturing method, the round bar glass 32 of the present application is formed while elongating a glass while rotating. Since the object of the present application is glass, which has a high transmittance, it has the following characteristics, although it is formed while rotating, it is difficult to determine from the appearance that the glass is twisted.

[0084] As shown in Figs. 1 and 2, the round bar glass 32 of the present application is formed while rotating, and thus has a spiral pattern 321 (a texture) as a characteristic. Figure 8 and Figure 9 As shown in Figs. 1 and 2, the round bar glass 32 of the present application is formed while rotating, and thus has a spiral pattern 321 (a texture) as a characteristic. The depth of the spiral pattern 321 is generally less than 10 μm.

[0085] In addition, the round bar glass 32 has a visible spiral concave-convex at a predetermined interval in the longitudinal direction as a characteristic. Although it depends on the speed, angle of the calender roll 1, and viscosity of the glass, the spiral concave-convex is sometimes generated depending on the set conditions. In the case where the spiral concave-convex is generated, the spiral concave-convex is not a problem, and the round bar glass 32 can be shipped as it is. Figure 9 In the present application, the round bar glass 32 is characterized by being unpolished. After the round bar glass of the present application is manufactured, if a polishing process is newly added and performed, the polishing process is performed, but the round bar glass of the present application is generally shipped in an unpolished state.

[0086] As described above, as one of the characteristics of the present application, a block-shaped glass block is used as a material instead of a material having a shape in which one side is longer than the other sides, and thus a round bar glass having a very large aspect ratio can be obtained. Specifically, it can be discussed based on the following shape change rate.

[0087] (Shape change rate)

[0088] In the manufacturing method of the present application, the glass block 31 as a material is rotated while being greatly elongated to obtain the round rod glass 32, and thus the shape change rate is large. For example, the change rate C of the long axis of the glass block 31 as a material to the long axis of the round rod glass 32 is 5 or more, more preferably 10 or more, and further preferably 20 or more. L Although depending on the shape of the glass block 31 selected as a material, it is preferably 5 times or more, more preferably 10 times or more, and further preferably 20 times or more.

[0089] As a feature of the round rod glass 32 of the present application, for example, the aspect ratio (long axis / cross-sectional radius) can be 35 or more, but is not limited thereto, and for example, can be 70 or more, can be 100 or more, and can be 150 or more.

[0090] The glass that can be used in the manufacturing method of the round rod glass 32 of the present application is not particularly limited. In the field of optical glass, even a glass that is likely to devitrify can be used as long as it can be set to the temperature at which the glass is softened in the present application, and in addition, for example, a round rod glass having a diameter of 1 mm or more can be manufactured, and for example, a round rod glass having a diameter of 1 mm and a length of 1 m can be manufactured. Regarding the manufacturing time, in the case of manufacturing a round rod glass 32 having a diameter of 1 mm and a length of 1 m, it can be manufactured within 10 minutes, and the round rod glass can be manufactured before the glass crystallizes.

[0091] The glass that can be used in the manufacturing method of the round rod glass of the present application is not particularly limited, and borosilicate glass, soda-lime glass, various optical glasses (lanthanum borate-based glass, fluorophosphate-based glass, and the like) can be used, but in order to be able to exert an advantage when a lens is manufactured, it is preferable to use an optical glass as a target.

[0092] [Examples]

[0093] A round rod glass was manufactured using three calender rolls having a conical shape (mushroom shape) as shown in FIG. 1, which were arranged downward, using a substantially cubic glass as a material. Figure 1 The glass used was a glass block having a cube shape with a corner removed having the following prescribed size. Regarding this glass, first, a glass raw material (content ratio by mass %) was prepared, and was melted at 1300 to 1450°C according to the state of the glass, was cast into a mold, and was annealed at a temperature at which the Tg temperature of each glass was increased by 50 to 100°C, whereby a plate-shaped optical glass was obtained, and by cutting this, the above glass block was obtained.

[0094]

[0095] (Examples 1 and 2)

[0096] Glass 1: M-NBFD130 (manufactured by Gohar Co., Ltd., specific gravity: 4.56, Tg (glass transition temperature): 567°C, Ts (glass softening point): 604°C) was used; ​

[0097] Glass volume used: Approximately 206mm 3 Approximately 487mm 3 ;

[0098] Use glass block temperature: 600~800℃ (the set temperature of the electric furnace when heating the glass block before it is put in).

[0099] Forming time (from the time the glass rod is inserted until the forming process is complete): 2~5 minutes;

[0100] Calendering roll speed: 180 rpm (206 mm) 3 (glass block)

[0101] 200rpm (487mm) 3 (glass block);

[0102] Calendering roll temperature: 640~670℃;

[0103] The pressing angle of the calendering roll is 10°.

[0104] Based on the above conditions, use approximately 206mm 3 The glass blocks were obtained with an average length of approximately 159 mm and a diameter (equivalent to) Figure 9 φA (hereinafter the same) is approximately 1.22 mm, and the outer diameter of the helix (equivalent to...) Figure 9 The φB (hereinafter the same) of the round glass rod is about 1.33 mm, and the round glass rod with an average length of 50 mm, a diameter of about 1.96 mm, and a spiral outer diameter of about 2.08 mm is obtained.

[0105] (Example 3)

[0106] Glass 2 used: M-FCD1 (manufactured by Hoya Corporation, specific gravity: 3.64, Tg (glass transition temperature): 384℃, Ts (glass softening point): 427℃).

[0107] Glass volume used: Approximately 164mm 3 ;

[0108] Use glass block temperature: 450~580℃ (the set temperature of the electric furnace when heating the glass block before it is put in).

[0109] Forming time (from the time the glass rod is inserted until the forming process is complete): 2~2.5 minutes;

[0110] Calendering roll speed: 220 rpm;

[0111] Calendering roll temperature: 460~480℃;

[0112] The pressing angle of the calendering roll is 10°.

[0113] Based on the above conditions, a round glass rod with an average length of approximately 163 mm, a diameter of approximately 1.21 mm, and a spiral outer diameter of approximately 1.29 mm was obtained.

[0114] Since the cylindrical glass obtained in Examples 1 and 3 was not ground or polished, the presence of spiral patterns was confirmed.

[0115] Explanation of reference numerals in the attached figures

[0116] 1: Calendering roll;

[0117] 11, 12, 13, 14: Top part;

[0118] 2: Rotation axis;

[0119] 3: Glass;

[0120] 31: Glass block (glass);

[0121] 32: Round bar glass;

[0122] 321: Spiral pattern (texture);

[0123] 4: Glass block inlet section;

[0124] 5: Cylinder.

Claims

1. A method for manufacturing cylindrical glass from glass blocks, comprising: The process of arranging three or more calendering rolls with cylindrical or conical tops in such a way that the rotation axes of the calendering rolls intersect. The process of rotating all the calendering rolls in the same direction; The process of inserting the glass block into the glass block inlet section; The process of passing the softened glass block through the glass block inlet and pressing the softened glass block into a gap formed at a position surrounded by the rotating shaft by rotating the top end; and The process of extending and shaping the glass block into a cylindrical glass rod by being pressed in.

2. The method for manufacturing round bar glass according to claim 1, wherein, The cylindrical glass bar is composed of unpolished sides. The side surface was not formed by grinding. The surface of the side has a spiral pattern.

3. The method for manufacturing round bar glass according to claim 1, wherein, The diameter of the cylindrical glass section is less than 3.5 mm, and the ratio of the major axis to the cross-sectional radius is more than 35.

4. The method for manufacturing cylindrical glass according to claim 1, wherein, The side surface of the cylindrical glass has components derived from the release agent.

5. The method for manufacturing cylindrical glass according to claim 1, wherein, The glass block inlet is shaped like a mortar and pestle.

6. An apparatus for manufacturing cylindrical glass from glass blocks, comprising: Three or more calendering rolls, the top of which is cylindrical or conical; A rotating unit for rotating the calendering roll; A heating unit for heating a block of glass as a material; and Glass block inlet section, The calendering rolls are configured such that their rotation axes intersect. The softened glass block is passed through the glass block inlet, and the softened glass block is pressed into the gap formed at the position surrounded by the rotating shaft by the rotation of the calendering roller, thereby producing the cylindrical glass.

7. The apparatus for manufacturing cylindrical glass according to claim 6, wherein, The glass block inlet is shaped like a mortar and pestle.

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