Systems and methods for glass tube separation and sealing using laser

Abstract

A system for finishing an end of a glass tube or glass rod includes a conveyor operable to translate and rotate the glass tube or glass rod, and a split laser system including a laser source operable to generate a split laser beam and a beam delivery system operable to deliver the split laser beam to the conveyor. The beam delivery system is operable to modify the shape, power density, or power density distribution of the split laser beam and direct the split laser beam to the glass tube or glass rod. A method of cutting and finishing the ends of the glass tubes or rods with the system comprises: rotating each glass tube or rod about a central axis of the glass tube or rod; heating a target area of the glass tube or rod by exposing the target area to a split laser beam while rotating the glass tube or rod; and applying a pulling force to the end of the glass tube or rod.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority benefit under 35 U.S.C. §119 to U.S. Provisional Application No. 63 / 441,305, filed on January 26, 2023, the contents of which are relied upon and incorporated herein by reference in their entirety. Technical Field

[0003] The present specification relates generally to methods, apparatus, and systems for continuously producing glass tubing and glass rods, and more particularly, to methods, apparatus, and systems for finishing the ends of lengths of glass rods and glass tubes produced from continuous hollow glass tubes. Background Art

[0004] In history, glass has been used to produce various goods. Specifically, due to the airtightness, optical transparency and excellent chemical durability of glass relative to other materials, it has been the preferred material for pharmaceutical applications, including but not limited to bottle, syringe, ampoule, cartridge, jar and other glassware. Producing these goods by glass begins with providing glass tubing, which can be formed and separated into multiple glassware subsequently. Specifically, the glass used for pharmaceutical packaging must have enough mechanical and chemical durability, so as not to affect the stability of the pharmaceutical preparation contained therein. Glass with suitable chemical durability comprises those glass compositions in ASTM standard ' IA type ' and ' IB type ' glass compositions, and said glass composition has a proven chemical durability history.

[0005] Glass tubes used as starting material for producing glass products are produced by a continuous process for producing continuous hollow glass cylinders, such as the Danner process or the Vello process. The continuous hollow glass cylinder is annealed and cut into multiple sections of approximately equal length using a high-speed continuous cutter. After the initial separation of the continuous hollow glass cylinder into multiple glass tubes, each glass tube is further processed to fine-tune the ends of the glass tube, for example by cutting to length and polishing the ends to reduce breakage during transportation and handling. Glass rods can also be produced by a similar process as continuous solid glass cylinders and then cut to rough lengths. The ends of the glass rods are further processed to fine-tune the ends of the rods to cut to the final length and reduce breakage during transportation and handling. Summary of the Invention

[0006] Therefore, there is a need for methods, apparatus, and systems for continuously producing glass tubes or glass rods, and in particular, for continuously finishing the ends of lengths of glass tubes and glass rods.

[0007] According to one or more aspects of the present disclosure, a method for producing glass tubes may include: producing a continuous hollow glass cylinder; cutting the continuous hollow glass cylinder into glass tubes having an initial length; and finishing at least one end of the plurality of glass tubes. Finishing the at least one end of the plurality of glass tubes may include: rotating each glass tube about a central axis of the glass tube; heating a target region of the glass tube by exposing the target region to a separating laser beam while rotating the glass tube; and applying a tensile force to the at least one end of the glass tube while exposing the target region to the separating laser beam. Applying the tensile force while exposing the target region to the separating laser beam can separate a section of the glass tube from the at least one end of the glass tube, and can finish the new end of the glass tube.

[0008] A second aspect may include the first aspect, wherein finishing the at least one end of the glass tube can reduce the length of the glass tube to a final length and the new end of the glass tube can be polished in a single manufacturing step. A third aspect may include any of the preceding aspects, wherein finishing the at least one end of the glass tube can produce the new end, which is an open end of the glass tube, such as having an opening therethrough. A fourth aspect may include the first or second aspect, wherein finishing the at least one end of the glass tube can seal the new end of the glass tube to produce a sealed end of the glass tube. A fifth aspect may include any of the preceding aspects, wherein the new end of the glass tube can be substantially free of surface defects. A sixth aspect may include any of the preceding aspects, wherein the new end of the glass tube can be substantially free of molten glass particles, hydrocarbon combustion products, or both.

[0009] A seventh aspect may include any one of the preceding aspects, wherein applying the pulling force to the at least one end of the glass tube can convey the segment of the glass tube away from the glass tube in an axial direction relative to the central axis of the glass tube, which separates the segment from the glass tube.

[0010] An eighth aspect may include any of the preceding aspects, further comprising preheating the target area of ​​each of the plurality of glass tubes, wherein preheating the target area of ​​each of the plurality of glass tubes may include rotating each of the glass tubes and exposing each of the glass tubes to a preheating laser beam positioned upstream of the separation laser beam. A ninth aspect may include the eighth aspect, wherein the preheating laser beam may be separated from the separation laser beam.

[0011] A tenth aspect may include any of the preceding aspects, further comprising finishing the first end of each of the plurality of glass tubes with a first split laser beam and finishing the second end of each of the plurality of glass tubes with a second split laser beam. An eleventh aspect may include the tenth aspect, further comprising finishing the first and second ends of each of the plurality of glass tubes in parallel. A twelfth aspect may include the tenth aspect, further comprising finishing the second end with the second split laser beam downstream of finishing the first end with the first split laser beam.

[0012] A thirteenth aspect may include any of the preceding aspects, wherein the separating laser beam may be an elongated beam, and the method may include simultaneously exposing the target areas of a subset of the plurality of glass tubes to the separating laser beam. A fourteenth aspect may include any of the preceding aspects, wherein at the point along the beam path where the separating laser beam impinges on the outer surface of the subset of glass tubes, the ratio of the total length of the separating laser beam to the beam width may be from about 5 to about 2000. A fifteenth aspect may include any of the thirteenth or fourteenth aspects, wherein exposing the target areas of the plurality of glass tubes to the separating laser beam may include sequentially passing each of the plurality of glass tubes through the elongated beam of the separating laser beam, from a leading edge to a trailing edge of the separating laser beam. Passing each of the plurality of glass tubes through the total length of the long axis of the separating laser beam may gradually heat the glass at the target area and separate the segment from the at least one end of each of the plurality of glass tubes; and the total length of the separating laser beam may be sufficient to simultaneously contact each of the subset of glass tubes. A sixteenth aspect may include the fifteenth aspect, wherein conveying each of the plurality of glass tubes sequentially through the elongated light beam may include arranging the plurality of glass tubes side by side on a conveyor, the conveyor including a plurality of rollers and at least one conveyor belt, wherein each glass tube may be positioned between two adjacent rollers of the conveyor, the plurality of rollers of the conveyor may rotate each of the plurality of glass tubes, and the at least one conveyor belt may move the rollers and the plurality of glass tubes horizontally through the elongated light beam.

[0013] The seventeenth aspect may include any one of the foregoing aspects, wherein the separation laser beam may include an infrared laser. The eighteenth aspect may include any one of the foregoing aspects, wherein the separation laser beam may be a continuous laser beam or an alternating laser beam. The nineteenth aspect may include any one of the foregoing aspects, wherein the separation laser beam may include a laser power of 200W to 2000W. The twentieth aspect may include any one of the foregoing aspects, wherein the separation laser beam may be an elliptical beam. The twenty-first aspect may include any one of the foregoing aspects, wherein the separation laser beam may be an elliptical laser beam having a ratio of a major axis to a minor axis of about 5 to about 2000 at a point on the beam path where the separation laser beam is incident on the outer surface of the plurality of glass tubes. The twenty-second aspect may include any one of the foregoing aspects, wherein the separation laser beam may have a Gaussian power density distribution along the major axis of the separation laser beam. The twenty-third aspect may include any one of the foregoing aspects, wherein the separation laser beam may have a flat-top power density distribution along the major axis of the separation laser beam.

[0014] A twenty-fourth aspect may include any of the foregoing aspects, wherein the length of the splitting laser beam may be from about 100 mm to about 1000 mm, wherein the length of the splitting laser beam may be the distance from the leading edge to the trailing edge of the splitting laser beam at the point on the beam path where the splitting laser beam impinges on the outer surfaces of the plurality of glass tubes. A twenty-fifth aspect may include any of the foregoing aspects, wherein the beam width of the splitting laser beam may be from about 0.5 mm to about 20 mm at the point on the beam path where the splitting laser beam impinges on the outer surfaces of the plurality of glass tubes. A twenty-sixth aspect may include any of the foregoing aspects, wherein the beam width of the splitting laser beam may be from 0.5 mm to 5 mm at the point on the beam path where the splitting laser beam impinges on the outer surfaces of the plurality of glass tubes, and exposing each of the plurality of glass tubes to the splitting laser beam may remove the segment of the at least one end of each glass tube to produce the new end including the opening. A twenty-seventh aspect may include any one of the first to twenty-fifth aspects, wherein a beam width of the splitting laser beam may be approximately 3 mm to 20 mm at a point on the beam path where the splitting laser beam is incident on the outer surfaces of the plurality of glass tubes, and exposing each of the plurality of glass tubes to the splitting laser beam may remove the segment of the at least one end of each glass tube to produce the new end, and seal the new end to produce a sealed end of the glass tube.

[0015] A twenty-eighth aspect may include any of the preceding aspects, further comprising: determining whether to finish the at least one end of the plurality of glass tubes to produce an open or sealed new end; and changing one or more of the beam shape, power, power density distribution, or a combination thereof of the splitting laser beam, wherein: changing the beam shape, power, power density distribution, or a combination thereof of the splitting laser beam may change the volume of glass heated in the target region of the plurality of glass tubes; reducing the volume of glass heated in the target region may produce a new end having an opening; and increasing the volume of glass heated in the target region may produce a glass meniscus that seals the new end when the segment is removed from the at least one end of the plurality of glass tubes. A twenty-ninth aspect may include the twenty-eighth aspect, comprising transitioning from forming the new end as open to forming the new end as sealed, wherein the transition may include one or more of: increasing the beam width of the splitting laser beam; increasing the power density of the splitting laser beam; changing the power density distribution from a Gaussian distribution to a flat-top distribution; or a combination thereof. The thirtieth aspect may include the twenty-ninth aspect, wherein the transition from forming the new end as open to forming the new end as sealed may include heating a volume of glass sufficient to form a glass meniscus above the new end of the plurality of glass tubes when the segment is removed from at least one end of the plurality of glass tubes.

[0016] A thirty-first aspect may include any one of the twenty-ninth or thirtieth aspects, comprising changing the beam shape of the separation laser beam by changing the beam width to a range of 3 mm to 20 mm. A thirty-second aspect may include the thirty-first aspect, wherein changing the beam shape may include adjusting a spacing between lenses of a beam delivery system. A thirty-third aspect may include any one of the thirty-first or thirty-second aspects, wherein changing the beam shape may include passing the separation laser beam through a variable beam expander. A thirty-fourth aspect may include any one of the thirty-first to thirty-third aspects, wherein changing the beam shape may include adjusting a distance between a beam delivery system and the plurality of glass tubes, which may change the point at which the separation laser beam contacts the outer surfaces of the plurality of glass tubes within the beam path relative to the beam waist of the separation laser beam.

[0017] Aspect thirty-fifth may include any one of aspects twenty-eighth to thirty-fourth, further comprising changing the power density of the separation laser beam at a point on the beam path where the separation laser beam contacts the outer surfaces of the plurality of glass tubes, wherein changing the power density of the separation laser beam may include adjusting the power of a laser source used to generate the separation laser beam, changing the vertical distance between a beam delivery system and the plurality of glass tubes, or both.

[0018] A thirty-sixth aspect may include any one of the preceding aspects, further comprising changing the heating rate of the separating laser beam, wherein changing the heating rate of the separating laser beam may include changing the power density of the separating laser beam, changing the power density distribution of the separating laser beam, changing the speed at which a conveyor translates the plurality of glass tubes through the separating laser beam, or a combination thereof. A thirty-seventh aspect may include the thirty-sixth aspect, comprising changing the power density of the separating laser beam, wherein changing the power density of the separating laser beam may include adjusting the power of a laser source used to generate the separating laser beam, changing the vertical distance between a beam delivery system and the plurality of glass tubes, or both. A thirty-eighth aspect may include any one of the thirty-sixth or thirty-seventh aspects, comprising changing the power density distribution of the separating laser beam, wherein changing the power density distribution may include passing the separating laser beam through a cylindrical lens to generate a Gaussian power density distribution with a lower heating rate, or passing the separating laser beam through an aspherical cylindrical lens to generate a flat-top power density distribution with a higher heating rate.

[0019] A thirty-ninth aspect may include any of the preceding aspects, further comprising: changing the type of glass tubes from a first type to a second type by changing the glass composition, nominal diameter, thickness, or a combination thereof of the plurality of glass tubes; and changing the heating rate of the separation laser beam in response to the change in the type of the glass tubes. A fortieth aspect may include the thirty-ninth aspect, wherein changing the heating rate may include changing the power density of the separation laser beam, changing the power density distribution of the separation laser beam, changing the speed at which a conveyor translates the plurality of glass tubes through the separation laser beam, or a combination thereof. A forty-first aspect may include any of the thirty-ninth or fortieth aspects, wherein changing the heating rate does not require changing a lens of a beam delivery system.

[0020] A forty-second aspect may include any of the preceding aspects, further comprising increasing the rate of production of the glass tubes, wherein increasing the rate of production of the glass tubes may include changing the speed of a conveyor translating the plurality of glass tubes through the beam path of the separating laser beam and increasing the power density of the separating laser beam, changing the power density profile from a Gaussian power density profile to a flat-top power density profile, or both. A forty-third aspect may include the forty-second aspect, wherein increasing the rate of production of the glass tubes may further include preheating the target area of ​​the plurality of glass tubes using a preheat laser system.

[0021] A forty-fourth aspect may include any of the preceding aspects, wherein the target area of ​​each glass tube may be located within at least 100 mm from the at least one end of the glass tube. A forty-fifth aspect may include any of the preceding aspects, wherein the length of the segment removed from the at least one end of the plurality of glass tubes may be less than 100 mm. A forty-sixth aspect may include any of the preceding aspects, further comprising horizontally conveying the plurality of glass tubes while rotating the plurality of glass tubes, and finishing the at least one end of each of the plurality of glass tubes. A forty-seventh aspect may include any of the preceding aspects, wherein exposing each of the plurality of glass tubes to the separate laser beam may include: generating a laser beam using a laser source; passing the laser beam through an optical device that shapes the laser beam to generate the separate laser beam and directs the separate laser beam toward the plurality of glass tubes; and passing each of the plurality of glass tubes through a beam path of the separate laser beam.

[0022] A forty-eighth aspect may include any of the preceding aspects, wherein producing the continuous hollow glass cylinder may further include pulling the continuous hollow glass cylinder from a tube forming apparatus. A forty-ninth aspect may include any of the preceding aspects, wherein producing the continuous hollow glass cylinder may include: forming the continuous hollow glass cylinder from molten glass in a tube forming apparatus; pulling the continuous hollow glass cylinder from the tube forming apparatus through an annealing process; annealing the continuous hollow glass cylinder; cutting the continuous hollow glass cylinder to produce the plurality of glass tubes having an initial length; and transferring the plurality of glass tubes to a horizontal conveyor upstream of finishing the at least one end of the plurality of glass tubes.

[0023] A fiftieth aspect disclosed herein may include a system for finishing the ends of a plurality of glass tubes or glass rods, the system comprising: a conveyor operable to horizontally translate the plurality of glass tubes or glass rods while also rotating each of the plurality of glass tubes or glass rods about a central axis of the glass tube or glass rod; and a separation laser system comprising: a laser source operable to generate a laser beam; and a beam delivery system operable to modify the shape, power density, power density distribution, or a combination thereof of the laser beam to generate a separation laser beam and direct the separation laser beam to the plurality of glass tubes or glass rods being translated and rotated by the conveyor. The system may also include: one or more axial separation conveyors separable from the conveyor and operable to apply a tensile force to the end of each of the plurality of glass tubes or glass rods in at least an axial direction relative to the central axis.

[0024] The fifty-first aspect may include the fiftieth aspect, wherein the beam delivery system may include one or more beam expansion optics, shaping optics, and steering mirrors. The fifty-second aspect may include any one of the fiftieth or fifty-first aspects, wherein the beam delivery system may further include one or more of a variable beam expander, a cylindrical lens, an aspheric cylindrical lens, a polygonal mirror, or a combination thereof to control the beam size, beam shape, beam power density distribution, or a combination thereof. The fifty-third aspect may include any one of the fiftieth to fifty-second aspects, wherein the beam delivery system may include at least one cylindrical lens, the at least one cylindrical lens being operable to produce a separated laser beam having a Gaussian power density distribution. The fifty-fourth aspect may include any one of the fiftieth to fifty-third aspects, wherein the beam delivery system may include an aspheric cylindrical lens, the aspheric cylindrical lens being operable to produce a beam having a flat-top power density distribution. The fifty-fifth aspect may include any one of the fiftieth to fifty-fourth aspects, wherein the beam delivery system includes a variable beam expander.

[0025] A fifty-sixth aspect may include any one of the fiftieth to fifty-fifth aspects, further comprising a preheating laser system positioned upstream of the separation laser delivery system, wherein the preheating laser system may include a preheating laser source and a preheating beam delivery system, and is operable to direct a preheating laser beam to target areas of the plurality of glass tubes or glass rods to preheat the glass in the target area upstream of the separation laser beam.

[0026] A fifty-seventh aspect may include any one of aspects 50 to 56, wherein the split laser system may include: a first split laser system operable to direct a first split laser beam to a target area near a first end of the plurality of glass tubes or glass rods; and a second split laser system operable to direct a second split laser beam to a target area near a second end of the plurality of glass tubes or glass rods. A fifty-eighth aspect may include aspect 57, wherein the first split laser system may include a first laser source and a first beam delivery system, and the second split laser system may include a second laser source and a second beam delivery system.

[0027] A fifty-ninth aspect may include any one of the fifty-seventh or fifty-eighth aspects, further comprising: a first preheating laser system positioned upstream of the first separation laser system; and a second preheating laser system positioned upstream of the second separation laser system, wherein each of the first preheating laser system and the second preheating laser system comprises a preheating laser source and a preheating beam delivery system.

[0028] A sixtieth aspect may include any one of the fiftieth to fifty-ninth aspects, further comprising a positioning system operatively coupled to the separation laser system, wherein the positioning system is operable to change the distance between the separation laser system and the plurality of glass tubes or glass rods.

[0029] A sixty-first aspect may include any one of the fiftieth to sixtieth aspects, wherein the laser source may be an infrared laser. A sixty-second aspect may include any one of the fiftieth to sixty-first aspects, wherein the laser source may be a CO laser or a CO2 laser. A sixty-third aspect may include any one of the fiftieth to sixty-second aspects, wherein the system does not include a gas burner and does not include a mechanical tool for scoring the surfaces of the plurality of glass tubes or glass rods.

[0030] A sixty-fourth aspect may include any one of the fiftieth to sixty-third aspects, wherein the conveyor may include a variable speed drive operatively coupled to one or more of the plurality of conveyor belts and operable to vary the speed at which the conveyor translates the plurality of glass tubes or glass rods through the beam path of the separating laser beam. A sixty-fifth aspect may include any one of the fiftieth to sixty-fourth aspects, wherein the conveyor may include a plurality of rollers and a plurality of conveyor belts.

[0031] A sixty-sixth aspect may be directed to a method for producing glass rods, wherein the method may include: producing a continuous solid glass cylinder; cutting the continuous solid glass cylinder into glass rods having an initial length; and finishing at least one end of a plurality of glass rods. Finishing the at least one end of the plurality of glass rods may include: rotating each glass rod about a central axis of the glass rod; heating a target region of the glass rod by exposing the target region to a separating laser beam while rotating the glass rod; and applying a tensile force to the at least one end of the glass rod while exposing the target region to the separating laser beam, wherein applying the tensile force while exposing the target region to the separating laser beam can separate a section of the glass rod from the at least one end of the glass rod and can finish the new end of the glass rod.

[0032] Additional features and advantages of the systems and methods disclosed herein will be set forth in the detailed description that follows, and some of these features and advantages will be readily apparent to those skilled in the art from the described description, or will be recognized by practicing the embodiments described herein, including the detailed description that follows, the claims, and the accompanying drawings.

[0033] It should be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 schematically depicts a side view of a system for finishing at least one end of a plurality of glass tubes or glass rods according to one or more embodiments shown and described herein;

[0035] Figure 2 schematically depicts a side perspective view of a glass tube according to one or more embodiments shown and described herein;

[0036] Figure 3 schematically depicts a top view of a process for continuously producing glass tubing according to one or more embodiments shown and described herein;

[0037] Figure 4 Schematically depicts a method for continuously producing glass tubing according to one or more embodiments shown and described herein. Figure 3 Lateral elevational view of the process;

[0038] Figure 5 Schematically depicts a method for finishing the ends of a plurality of glass tubes or glass rods according to one or more embodiments shown and described herein. Figure 1 A top view of the system;

[0039] Figure 6 graphically depicting relative beam intensity (y-axis) as a function of beam position (x-axis) for an elongated beam having Gaussian and flat-top power density profiles according to one or more embodiments shown and described herein;

[0040] Figure 7 Schematically depicts a system with a positioning system according to one or more embodiments shown and described herein. Figure 1 Another side elevation view of the system;

[0041] Figure 8 Schematically depicts a device according to one or more embodiments shown and described herein. Figure 1 a side perspective view of the system during operation of the system;

[0042] Figure 9schematically depicts an elevational view of a system for finishing both ends of a glass tube or rod according to one or more embodiments shown and described herein;

[0043] Figure 10 schematically depicts a side view of another system for finishing the end of a glass tube or rod, the system having a separation laser system and a preheat laser system according to one or more embodiments shown and described herein;

[0044] Figure 11 For use according to one or more embodiments shown and described herein Figure 1 a photograph of the ends of the glass tubes separated by the system; and

[0045] Figure 12 For use according to one or more embodiments shown and described herein Figure 1 Photograph of the system separating and sealing the ends of the glass tubes. DETAILED DESCRIPTION

[0046] Reference will now be made in detail to embodiments of apparatus, systems, and methods for continuously producing composite glass tubes or rods, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or like components. Figure 1 The system 100 of the present disclosure for finishing one or both ends of a glass tube 102 or glass rod (not shown) may include a conveyor 110 operable to horizontally translate a plurality of glass tubes 102 or glass rods while also rotating each of the plurality of glass tubes 102 or glass rods about a central axis A of the glass tube 102 or glass rod. The system 100 further includes a separation laser system 120 comprising a laser source 130 operable to generate a separation laser beam 132 and a beam delivery system 140 operable to modify a shape and / or property of the separation laser beam 132 and to direct the separation laser beam 132 to the plurality of glass tubes 102 or glass rods as the plurality of glass tubes 102 or glass rods are translated and rotated by the conveyor 110. The system 100 may also include one or more axial separation conveyors 180 that are separate from the conveyor 110 and are operable to apply a pulling force to the end of each of the plurality of glass tubes 102 or glass rods in at least an axial direction relative to the central axis A of each of the plurality of glass tubes 102 or glass rods.

[0047] The system 100 disclosed herein can be used in a method for finishing the ends of glass tubes 102 or glass rods. The method for finishing the ends of glass tubes 102 or glass rods includes: rotating each glass tube 102 or glass rod about a central axis A; heating a target region of the glass tube 102 or glass rod by exposing the target region to a separating laser beam 132 while rotating the glass tube 102 or glass rod; and applying a tensile force to at least one end of the glass tube 102 or glass rod while exposing the target region to the separating laser beam 132, wherein applying the tensile force while exposing the target region to the separating laser beam can separate a section of the glass tube 102 or glass rod from at least one end of the glass tube 102 or glass rod and finish the new end of the glass tube 102 or glass rod. The method disclosed herein for producing a glass tube 102 may include producing a continuous hollow glass cylinder, cutting the continuous hollow glass cylinder into glass tubes 102 having an initial length, and then finishing at least one end of the glass tube 102 according to any of the methods disclosed herein for finishing the ends of the glass tube 102. The method disclosed herein for producing a glass rod may include producing a continuous solid glass cylinder, cutting the continuous solid glass cylinder into glass rods having an initial length, and then finishing at least one end of the glass rod according to any of the methods disclosed herein for finishing the ends of the glass tube 102 or glass rod.

[0048] Unless otherwise expressly stated, it is not intended that any method described herein be construed as requiring that its steps be performed in a specific order, nor that any apparatus require a specific orientation. Therefore, in the absence of a method claim that actually recites the order in which its steps must be followed, or any apparatus claim that actually recites the order or orientation of individual components, or in the absence of other specific statements in the claims or specification that the steps are limited to a specific order, or in the absence of a specific order or orientation of the components of an apparatus, no order or orientation is intended to be inferred in any respect. This applies to any possible non-express basis for interpretation, including: matters of logic regarding arrangement of steps, operational flow, order of components, or orientation of components; ordinary meaning derived from grammatical organization or punctuation; and the number or type of embodiments described in the specification.

[0049] Directional terms used herein—such as up, down, right, left, front, back, top, bottom—refer only to the drawn figures and the coordinate axes provided therewith, and are not intended to imply absolute orientations.

[0050] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a" component includes aspects having two or more such components unless the context clearly dictates otherwise.

[0051] As used herein, "axial direction" refers to a direction parallel to the central axis A of a glass tube or glass rod.

[0052] As used herein, the "beam waist" of a laser beam refers to the point along the beam path of the laser beam at which the power density of the laser beam is a maximum.

[0053] As used herein, the terms "upstream" and "downstream" refer to the location of features of a glass tube in a glass rod manufacturing process relative to the direction of travel of the glass tube during the manufacturing process. For example, if the glass tube encounters a first feature before encountering the second feature, the first feature is "upstream" of the second feature. Conversely, if the glass tube encounters the second feature before encountering the first feature, the first feature is "downstream" of the second feature.

[0054] As used herein, the terms "upstream" and "downstream" refer to the positioning of two or more features of a system relative to the direction of travel of a laser beam along a beam path through the system. If the laser beam encounters a first component before encountering a second component, the first component can be considered upstream of the second component. Conversely, when the laser beam encounters the second component before encountering the first component, the first component can be considered downstream of the second component.

[0055] Due to its airtightness, optical clarity, and excellent chemical durability relative to other materials, glass has become a preferred material for pharmaceutical applications, including but not limited to vials, syringes, ampoules, cartridges, jars, and other glass products. These pharmaceutical glass containers, as well as other types of glass products, can be produced by the following process: a length of glass tubing is converted into one or more of the glass products through multiple heating and forming operations. Figure 2, schematically depicts one embodiment of a glass tube 102 for use as a starting point for manufacturing a plurality of glass articles. Glass tube 102 comprises a hollow glass cylinder having an outer surface 104 and an inner surface 106. Inner surface 106 defines the interior of glass tube 102. Glass tube 102 has a first end 107 and a second end 108 opposite the first end. Glass tube 102 is characterized by a tube length L, an outer diameter OD, and a thickness t. Tube length L is the distance from first end 107 to second end 108, and thickness t refers to the average radial distance between outer surface 104 and inner surface 106 of glass tube 102. Glass tube 102 further includes a central axis A. Although described in the context of glass tube 102, the methods of separating and end finishing can be applied with equal success to multiple lengths of glass rod, which can also be used to produce a plurality of glass articles.

[0056] The subject matter disclosed herein relates to systems and methods for separating and finishing the ends of glass tubes or glass rods during the production process of glass tubes and glass rods. During production, molten glass is first formed into a continuous hollow glass cylinder using a glass tube forming process. The process used to form the molten glass into the continuous hollow glass cylinder may include the Danner process, the Vero process, or other currently or future developed processes for producing the continuous hollow glass cylinder. The continuous hollow glass cylinder is then stretched through an annealing process and then cut into individual glass tubes of the original length.

[0057] Reference Figure 3 and Figure 4 , schematically depicts one embodiment of a system 200 for manufacturing a plurality of glass tubes 102. The system 200 may include a melting furnace 210, a glass tube forming apparatus 220 downstream of the melting furnace 210, a muffle furnace 230 downstream of the glass tube forming apparatus 220, an annealing section 240 downstream of the muffle furnace 230, a tube drawing machine 250 downstream of the annealing section 240, a coiled tube cutting machine 260 downstream of the tube drawing machine 250, and a horizontal conveyor 110 positioned downstream of the coiled tube cutting machine 260.

[0058] In operation of the system 200, glass 202 is introduced into a melting furnace 210, which is operable to melt the glass to form molten glass 212. The molten glass 212 is then transferred to a glass tube forming apparatus 220, which is operable to form the molten glass 212 into a continuous hollow glass cylinder 222. Figure 4As shown, in some embodiments, the glass tube forming apparatus 220 may be a tube forming apparatus used in the Danner process, wherein the molten glass 212 flows from a feeder to a rotatable inclined hollow cylinder and is pulled from the rotatable inclined hollow cylinder into a muffle furnace 230 by a tube puller 250 to produce a continuous hollow glass cylinder 222. While the continuous hollow glass cylinder 222 is being pulled away from the tube forming apparatus 220, compressed air or other gas supplied to the center of the continuous hollow glass cylinder 222 by the tube forming apparatus 220, together with a vacuum applied from the outside of the continuous hollow glass cylinder 222, helps control the tube diameter and prevents the continuous hollow glass cylinder 222 from collapsing before it cools sufficiently to retain its shape. Although in Figure 4 The Danner process is shown in FIG, but it should be understood that the continuous hollow glass cylinder 222 can be manufactured using the Vero process or any other current or future process for manufacturing continuous hollow glass cylinders.

[0059] Reference again Figure 3 and 4 After being formed, the continuous hollow glass cylinder 222 is then pulled through the muffle furnace 230 and the annealing section 240 by a tube drawing machine 250. The annealing section 240 is operable to anneal the continuous hollow glass cylinder 222 to produce an annealed continuous hollow glass cylinder 242. The tube drawing machine 250 may include one or more sets of driven rollers 252 operable to apply a tensile force to the annealed continuous hollow glass cylinder 242 sufficient to pull it through the muffle furnace 230 and the annealing section 240. After passing through the annealing section 240 and the tube drawing machine 250, the annealed continuous hollow glass cylinder 242 reaches a tube cutter 260 where the annealed continuous hollow glass cylinder 242 is roughly cut into glass tubes 102 having an initial length.

[0060] The process for making glass rods is similar to that for making glass tubes, except for the equipment and method used to pull the glass rods from the melting furnace 210. Once a continuous solid glass rod is formed from molten glass, it is pulled through a muffle furnace and an annealing section by a rod puller. The annealed continuous solid glass cylinder is then continuously cut into rough lengths by a cutting machine to produce glass rods of the initial length.

[0061] Since the first cut performed by the tube cutter 260 or rod cutter is a rough cut, further processing of the glass tube 102 or glass rod is performed to cut the glass tube 102 or glass rod to final length and to finish the ends of the glass tube 102 or glass rod. Figure 3After the tube cutter 260, the glass tube 102 is conveyed in a direction 116 perpendicular to the draw direction 242 for a second cut-to-length and edge finishing step. In conventional tube manufacturing processes, the glass tube 102 is cut to final length in a second cut using a combination of mechanical tools for crack (scratch) initiation, heating with a gas burner, and quenching the glass tube 102, thereby creating thermal shock conditions and causing cracks to propagate around the circumference of the glass tube 102, thereby completing the separation of the segments from the ends of the glass tube 102. After the second cuts at both ends, the edges of the ends of the glass tube are finished by fire polishing using a gas burner. A glass rod (not shown) can be processed in a similar manner to cut the rod to length and finish the ends. Conventional manufacturing processes for final cut-to-length and edge finishing are well-established but present many challenges and opportunities for improvement, particularly given the growing demand for pharmaceutical products and the increasing focus on high quality, manufacturing efficiency, and environmental sustainability.

[0062] One of the challenges of existing tube production or glass rod production processes is manufacturing throughput. As the drawing speed of continuous hollow glass cylinders or continuous solid glass cylinders continues to increase, especially for thin-walled products, the cutting and finishing steps must be able to achieve high edge quality (no glass defects, acceptable geometry, high strength) and accurate final length of the tube or rod to achieve low losses and high yields at high processing speeds. The existing cutting process relies on the creation of an initial scratch on the surface of the tube or rod by a cutting blade (or other mechanical tool) and the subsequent propagation of the crack. Starting from the initial mechanical defect and propagating it around the circumference of the glass tube by thermal stress is not very precise and requires several processing steps, which is not efficient. In addition, separation is followed by edge fire polishing, which is required to repair surface defects caused by the scoring and breaking method. Edge or end fire polishing represents an additional process step and requires additional time to complete, further reducing the efficiency of the manufacturing process.

[0063] Products used for pharmaceutical packaging, such as vials, cartridges, syringes, ampoules, or other containers converted from glass tubes, require a high level of cleanliness. Current conventional tube finishing processes use mechanical means to induce cracks, which scratch the surface of the tube or rod. This produces glass particles that contaminate the outer and inner surfaces of the glass tube or the surface of the glass rod. These glass particles must then be removed from the glass tube or rod through a thorough cleaning process. The cleaning process becomes even more complicated if a large number of particles are generated during the manufacturing process, especially if glass particles adhere to the surface, such as when fused to the glass surface during fire polishing of the edge of the glass tube or rod.

[0064] Furthermore, conventional manufacturing processes for finishing the ends of glass tubes or rods expose the surface of the glass product to undesirable elements due to contact with the glass, chemical reactions with the glass, and interaction with combustion products from gas burners, further contaminating the final product. Specifically, interaction of the glass with combustion products from gas burners used in heat treatment and fire polishing can contaminate the surface of the glass final product (e.g., the finished tube or rod). The combustion of the fuel used in the gas burners also generates process exhaust gases containing combustion products, which can have negative environmental impacts.

[0065] Furthermore, certain glass tubing products require sealed tube ends. In conventional glass tubing manufacturing processes, sealing the ends of the glass tubes is currently performed at the end of the aforementioned conveyor line as an additional step using a gas burner after final cut-to-length cutting and edge polishing. Using a gas burner to seal the ends of the glass tubes adds an additional manufacturing step, which reduces the efficiency of the manufacturing process and further increases the generation of combustion products, which can contaminate the surface of the glass tubes and generate additional process waste gases. Therefore, there is a need to improve current glass cutting and finishing processes to increase manufacturing efficiency and quality, and to reduce pollution and waste gases during glass tube and glass rod manufacturing.

[0066] The present application relates to a novel laser-based system and method for separating and finishing the ends of glass tubes or glass rods during their manufacture using laser-based methods and apparatus. The disclosed system for finishing the ends of glass tubes or glass rods includes a conveyor operable to horizontally translate a plurality of glass tubes or glass rods while simultaneously rotating each of the plurality of glass tubes or glass rods about a central axis. The system further includes a separation laser system, a laser source operable to generate a separation laser beam, and a beam delivery system operable to shape and direct the separation laser beam toward the plurality of glass tubes or glass rods that are translated and rotated by the conveyor. The system may also include one or more axial separation conveyors, separate from the conveyor and operable to apply a tensile force to the end of each of the plurality of glass tubes or glass rods in at least an axial direction relative to the central axis of each of the plurality of glass tubes or glass rods.

[0067] The laser-based method disclosed herein for finishing the ends of glass tubes or glass rods includes: rotating each glass tube or glass rod about a central axis of the glass tube or glass rod; heating a target region of the glass tube or glass rod by exposing the target region to a splitting laser beam while rotating the glass tube or glass rod, the splitting laser beam being generated by a splitting laser system; and applying a tensile force to at least one end of the glass tube or glass rod while exposing the target region to the splitting laser beam. Applying the tensile force while exposing the target region to the splitting laser beam separates a section of the glass tube or glass rod from at least one end of the glass tube or glass rod, and finishing the new end of the glass tube or glass rod.

[0068] The systems and methods disclosed herein enable cutting of glass tubes and glass rods to produce finished new ends. Due to the clearly defined area affected by the separation laser beam and the stability of the laser power over an extended period of time, the method enables a more stable, precise and controllable way of transferring heat to the glass. Precise heating by the laser system can minimize dimensional changes in the final component, reduce the number of scrap and increase yield by strictly controlling the viscosity of the glass. For glass tubes, the systems and methods can complete the cutting of the glass tube to produce a new end as an open end, or produce a sealed new end in the tube cutting accompanied by sealing. The systems and methods disclosed herein combine cutting and edge finishing into a one-step process. The systems and methods disclosed herein allow for simultaneous separation of glass tubes and bottom forming. In addition, the systems and methods disclosed herein can enable beam characteristics (e.g., length, beam width, power density, etc.) to be switched between tube separation and finishing mode and tube separation and bottom forming mode without changing the lens of the beam delivery system.

[0069] Additionally, the design of the beam delivery system for the separation laser beam, the preheating laser beam, or both produces an elongated laser beam, which enables simultaneous and continuous processing of multiple tubes or rods, improving heating efficiency and reducing processing time. Heating of the tubes or rods by the elongated laser beam occurs continuously without interruption as the tubes or rods are translated horizontally by the conveyor, representing an advantage over separate heating by multiple gas burners and enabling faster conveyor speeds. The heating rate of the tubes or rods can be adjusted by varying the power density and / or power density distribution of the separation laser beam in the longitudinal direction, depending on the type and size of the tubes or rods. The systems and methods allow for adjustment of the beam characteristics (e.g., length, beam width, power density, etc.) of the separation laser beam to tailor the process for tubes or rods of varying glass types, diameters, and wall thicknesses. If desired, the systems and methods can also use an additional elongated laser beam (i.e., a preheating laser beam) to preheat a targeted area of ​​the tube or rod to accelerate separation and / or processing of tubes or rods with larger diameters or thicker sidewalls.

[0070] Furthermore, the systems and methods disclosed herein do not require mechanical initiation and quenching to generate the thermal shock for crack propagation. Consequently, the systems and methods disclosed herein can reduce contamination of the surface of a glass tube or glass rod by molten glass particles. The systems and methods disclosed herein also do not use gases and do not produce combustion products, which reduces glass contamination from gases and / or combustion products and improves the environmental footprint of the glass tube and glass rod forming and finishing processes.

[0071] Reference again Figure 1 The system 100 for cutting and finishing the ends of a plurality of glass tubes 102 or glass rods includes a conveyor 110, a separation laser system 120, and one or more axial separation conveyors 180 (e.g., Figure 5 ). Separating laser system 120 includes a laser source 130 operable to generate a laser beam 131 and a beam delivery system 140 operable to shape laser beam 131 to generate a separating laser beam 132, and to direct separating laser beam 132 toward a plurality of glass tubes 102 or glass rods that are translated and rotated by conveyor 110. For ease of explanation, embodiments of the present disclosure will be described in the context of glass tubes. However, the systems and methods of the present disclosure can also be successfully applied to cutting and finishing the ends of glass rods.

[0072] In an embodiment, the conveyor 110 may include a plurality of rollers 112 and a plurality of conveyor belts 114. The conveyor 110 may be operable to convey horizontally (i.e., along Figure 1The plurality of rollers 112 can be moved along the +X direction of the coordinate axis in the glass tube 102, while also rotating each glass tube 102 around the central axis A of the glass tube 102. Figure 1 In an embodiment, the rollers 112 may extend axially in the + / -Y direction, which may be parallel to the central axis A of the glass tube 102. The rollers 112 may rotate in the same rotational direction. Figure 3 ) After being cut into initial lengths, each glass tube 102 can be positioned in a converging gap between two adjacent rollers 112 and supported by contact with the adjacent rollers 112. As the rollers 112 rotate, the contact of the outer surface 104 of the glass tube 102 with the surface of the rollers 112 can cause the glass tube 102 to rotate about the central axis A of the glass tube 102.

[0073] The plurality of conveyor belts 114 can be operatively coupled to a drive motor (not shown) that can move the conveyor belts 114 along a conveyor belt path. The conveyor belts 114 can contact a portion of the rollers 112 such that as the conveyor belts 114 move along the conveyor belt path, contact between the conveyor belts 114 and the rollers 112 can cause the rollers 112 and the glass tubes 102 positioned between each roller 112 to translate horizontally (i.e., along the conveyor belt path). Figure 1 The conveyor belts 114 and the rollers 112 may be in the +X direction of the coordinate axis of the glass tubes 102. The contact of the one or more conveyor belts 114 with the rollers 112 may also cause the rollers 112 to rotate, thereby facilitating the rotation of the glass tubes 102. In an embodiment, the drive motor operatively coupled to the conveyor belts 114 may be a variable speed drive operable to vary the speed at which the conveyor 110 horizontally translates the plurality of glass tubes 102 through the beam path of the separating laser beam 132. Although described as having a plurality of rollers 112 and conveyor belts 114, it should be understood that the conveyor 110 may have other configurations, so long as the conveyor is operable to horizontally translate the glass tubes 102 while simultaneously rotating the glass tubes 102 about the central axis A of each glass tube.

[0074] The system 100 includes one or more devices operable to apply a tensile force to the distal end of each of the plurality of glass tubes in at least an axial direction relative to a central axis A of each of the plurality of glass tubes. Figure 5 In an embodiment, the system 100 may include one or more axial separation conveyors 180. The axial separation conveyors 180 may be arranged in a longitudinal direction (ie, a transverse machine direction or Figure 5The axial separation conveyor 180 may be configured to gradually deviate from the conveyor 110 in the +Y or -Y direction of the coordinate axis in the axial separation conveyor 180. In an embodiment, the axial separation conveyor 180 may include a plurality of rollers, and the end of each glass tube 102 may be placed in a gap between adjacent rollers and supported by the adjacent rollers. The axial separation conveyor 180 may also have a plurality of conveyor belts (not shown) and a drive motor (not shown) for driving the axial separation conveyor 180. The axial separation conveyor 180 is operable to apply a pulling force to the end of each of the glass tubes 102 along at least an axial direction relative to the central axis A of each of the plurality of glass tubes 102. The system 100 may include a first axial separation conveyor 180 on one side of the conveyor 110 and a second axial separation conveyor 180' on the other side of the conveyor 110. The first axial separation conveyor 180 may apply a pulling force F to the first end 107 of the glass tube 102, which may help separate the first section 192 from the first end 107 of the glass tube during finishing of the glass tube 102. The second axial separation conveyor 180′ can apply a tensile force F to the second end 108 of the glass tube 102, which can help separate the second segment 194 from the second end 108 of the glass tube 102 during finishing of the glass tube 102. Methods or apparatus other than the axial separation conveyor 180 can be used instead of or in addition to the axial separation conveyor 180 to generate the tensile force F on the end of the glass tube.

[0075] Reference again Figure 1The separation laser system 120 may include a laser source 130 and a beam delivery system 140 positioned downstream of the laser source 130. The beam delivery system 140 refers to a collection of optical components (e.g., lenses, mirrors, filters, etc.) that modify one or more characteristics (e.g., shape, power density, power density distribution, etc.) of the laser beam 131 to generate a separation laser beam 132 and direct the separation laser beam 132 to the glass tube 102. The laser source 130 is operable to generate the laser beam 131. The wavelengths of the laser beam 131 and the separation laser beam 132 generated therefrom may be within a wavelength range that allows the separation laser beam 132 to be absorbed by the glass of the glass tube 102 to heat the glass without significantly passing through the glass. Because silicate-based glass has a strong absorption property for light having a wavelength greater than or equal to approximately 4 micrometers (μm), a variety of different laser sources may be used to generate the laser beam 131. The laser source 130 is operable to generate the laser beam 131 with a wavelength in the infrared wavelength region, such as the far infrared region. The laser source 130 is operable to generate a laser beam 131 having a wavelength greater than or equal to about 1 μm, greater than or equal to about 2 μm, greater than or equal to about 3 μm, greater than or equal to about 4 μm, or even greater than or equal to about 8 μm. The laser source 130 is operable to generate a laser beam 131 having a wavelength less than or equal to about 12 μm, or even less than or equal to about 11 μm. The laser source 130 is operable to generate a laser beam 131 having a wavelength of about 1 μm to about 12 μm, about 1 μm to about 11 μm, about 2 μm to about 12 μm, about 2 μm to about 11 μm, about 3 μm to about 12 μm, about 3 μm to about 11 μm, about 4 μm to about 12 μm, about 4 μm to about 11 μm, about 5 μm to about 12 μm, about 5 μm to about 11 μm, about 8 μm to about 12 μm, or about 8 μm to about 11 μm. The specific wavelength range may depend in part on the type of glass composition comprising the glass tube.

[0076] The laser source 130 is operable to generate a laser beam 131 that is an infrared laser beam. In embodiments, the laser source 130 may be a CO laser, a CO2 laser, a quantum cascade laser (QCL), or another suitable type of laser capable of generating a laser beam 131 having a wavelength within the aforementioned range. The laser source 130 is operable to generate a continuous or pulsed laser beam 131. Continuous lasers typically have lower peak power and gradually increase the glass surface temperature, while pulsed lasers typically have higher peak power and increase the glass surface temperature to a greater extent in a shorter period of time than continuous lasers. The laser beam 131 may be collimated or uncollimated.

[0077] Reference again Figure 1, the beam delivery system 140 can be positioned downstream of the laser source 130. The beam delivery system 140 can be operated to modify the characteristics of the laser beam 131, such as shape, power density distribution, other beam characteristics, or a combination thereof, to produce a separate laser beam 132. The beam delivery system 140 can further operate to direct the separate laser beam 132 to the plurality of glass tubes 102 as the glass tubes 102 are horizontally translated and rotated by the conveyor 110. The beam delivery system 140 can include one or more beam expansion optics, shaping optics, steering mirrors 150, or a combination thereof. In an embodiment, the beam delivery system 140 can include at least one expansion optic, at least one shaping optic, and at least one steering mirror 150.

[0078] The expanding optics, the shaping optics, or both may include one or more lenses, mirrors, or both operable to expand the laser beam 131, shape the laser beam 131 into an elongated laser beam, or both, to produce the separated laser beams 132. The laser beam 131 generated by the laser source 130 may be a circular Gaussian laser beam. The beam delivery system 140 may include optical components that transform the circular-shaped laser beam 131 into an elliptical beam, change the dimensions (e.g., length and width) of the laser beam 131, and / or change the power density distribution along one or two axes of the elliptical beam to produce the separated laser beams 132. In embodiments, the beam delivery system 140 may include one or more variable beam expanders (e.g., zoom telescope lenses), cylindrical lenses, aspheric cylindrical lenses, polygonal mirrors, or combinations thereof to modify the beam size, beam shape, beam power density distribution, or combinations thereof. In an embodiment, the beam delivery system 140 may include one or more zoom telescope lenses or other variable beam expanders operable to modify the beam size of the laser beam 131, for example, by increasing the beam size to produce the separate laser beams 132. In an embodiment, the beam delivery system 140 may include one or more cylindrical lenses operable to modify the shape of the laser beam 131, for example, by modifying the length, beam width, or both of the laser beam 131, to produce the separate laser beams 132. In an embodiment, the beam delivery system 140 may include multiple cylindrical lenses operable to transform the circular laser beam 131 into separate laser beams 132 having an elliptical shape. The multiple cylindrical lenses may also expand or compress the laser beam 131 to produce separate laser beams 132 having target dimensions (e.g., length and beam width) at the point where the separate laser beams 132 contact the glass tube 102.

[0079] In an embodiment, the beam delivery system 140 may include one or more lenses operable to change the power density distribution of the laser beam 131 to produce the separated laser beam 132. In an embodiment, the beam delivery system 140 may include one or more spherical cylindrical lenses operable to produce the separated laser beam 132 having a Gaussian power density distribution. In an embodiment, the beam delivery system 140 may include one or more aspherical cylindrical lenses operable to produce the separated laser beam 132 having a flat-top power density distribution. In an embodiment, the beam delivery system 140 may include one or more polygonal mirrors operable to modify the power density distribution of the laser beam 131 to produce the separated laser beam 132. In an embodiment, the separated laser beam 132 is an elliptical beam, and the cylindrical lens, aspherical cylindrical lens, or polygonal mirror may be configured to modify the power density distribution of the laser beam 131 along the long axis direction (i.e., the longitudinal direction, such as Figure 1 The power density distribution in the + / -X direction of the coordinate axis.

[0080] Now refer to Figure 6 , graphically depicts two different power density distributions for a split laser beam 132, with power density (y-axis) varying with beam position (x-axis). Figure 6 The position in the beam in the longitudinal direction (i.e., the direction along the long axis of an elliptical beam, such as Figure 1 The position of the coordinate axis in the + / -X direction). Figure 6 , a Gaussian power density profile 602 is characterized by a maximum laser power density at the center 600 of the separated laser beam 132 and a power density that decreases with increasing distance from the center 600 of the separated laser beam 132. In contrast, a flat-top power density profile 604 has a smaller maximum power density, but the power density is more uniform across most of the long axis of the laser beam.

[0081] The beam delivery system 140 may include any other optical components, such as, but not limited to, mirrors, lenses, prisms, filters, apertures, etc., operable to modify one or more characteristics of the laser beam 131 to produce the separation laser beam 132 upstream of the point where the separation laser beam 132 is incident on the glass tube 102. The beam delivery system 140 may provide for adjustment of the distances between the various components (e.g., lenses, mirrors, filters, prisms, etc.) within limits. Some adjustment of the distances between the optical components of the beam delivery system 140 may enable fine-tuning of the size and position of the separation laser beam 132 at the point where the separation laser beam 132 contacts the glass tube 102. In embodiments, the length and beam width of the separation laser beam 132 may be modified by varying the distances between the lenses in the beam delivery system 140.

[0082] Reference again Figure 1In an embodiment, the separation laser system 120 may be horizontal (ie, substantially parallel to Figure 1 The separating laser system 120 is mounted above the conveyor 110 (in the XY plane of the coordinate axes in the XY plane), and the beam delivery system 140 may include a steering mirror 150. The steering mirror 150 is operable to turn the separating laser beam 132 downward (i.e., in the -Z direction) toward the glass tube 102 on the conveyor 110. Although shown herein as being mounted horizontally above the conveyor 110, it should be understood that the separating laser system 120 may be mounted in any suitable location and may use one or more steering mirrors 150 to direct the separating laser beam 132 toward the glass tube 102.

[0083] The separation laser beam 132 may be an infrared laser beam having a wavelength of 1 μm to 12 μm, 1 μm to 10 μm, 2 μm to 12 μm, 2 μm to 10 μm, 3 μm to 12 μm, 3 μm to 10 μm, 4 μm to 12 μm, 4 μm to 10 μm, 8 μm to 12 μm, or 8 μm to 10 μm. The separation laser beam 132 may be a continuous laser beam or an alternating laser beam. The total laser power of the separation laser beam 132 may be greater than or equal to 200 watts (W), greater than or equal to 500 W, or even greater than or equal to 1000 W. In an embodiment, the total laser power of the separation laser beam 132 may be 200 W to 2000 W, such as 200 W to 1000 W, 500 W to 2000 W, 500 W to 1000 W, or 1000 W to 2000 W.

[0084] The split laser beam 132 can be characterized by a power density profile. In an embodiment, the split laser beam 132 generated by the beam delivery system 140 can have a Gaussian power density profile along the long axis (e.g., length) of the split laser beam 132. In an embodiment, the split laser beam 132 generated by the beam delivery system 140 can have a flat-top power density profile along the long axis (e.g., length) of the split laser beam 132.

[0085] In an embodiment, the separation laser beam 132 may be an elliptical beam having a major axis and a minor axis. The beam delivery system 140 may shape and guide the separation laser beam 132 so that the major axis of the separation laser beam 132 may be substantially parallel to the processing direction of the conveyor 110 (i.e., Figure 1 The + / -X direction of the coordinate axis of the conveyor 110), and the short axis of the separating laser beam 132 can be substantially parallel to the transverse processing direction of the conveyor 110 (e.g., Figure 1(+ / -Y direction of the coordinate axis of the glass tube 102). In an embodiment, the separating laser beam 132 may be an elongated elliptical beam having a major axis greater than or equal to 5 times the minor axis at the point along the beam path where the separating laser beam 132 is incident on the outer surface of the glass tube 102. In an embodiment, the separating laser beam 132 may be an elliptical laser beam having a major axis to minor axis ratio of about 5 to about 2000 at the point along the beam path where the separating laser beam 132 is incident on the outer surfaces of the plurality of glass tubes. When the separating laser beam 132 is an elongated elliptical beam, the separating laser beam 132 may be able to simultaneously and continuously contact and heat the plurality of glass tubes 102, thereby improving heating efficiency and reducing processing time during the end cutting and finishing processes.

[0086] In an embodiment, the length of the separating laser beam 132 may be from about 100 mm to about 1000 mm, where the length of the separating laser beam 132 refers to the distance from the leading edge 154 to the trailing edge 156 of the separating laser beam 132 at the point on the beam path where the separating laser beam 132 impinges on the outer surface of the glass tube 102. As used herein, the length of the separating laser beam 132 refers to the maximum distance between the leading edge 154 and the trailing edge 156 at that point, rather than the average length taken over the beam width. For an elliptical beam, the beam width is equal to the length of the major axis of the elliptical beam. The upper limit of the length of the separating laser beam 132 may depend on the maximum available laser power. When the separating laser beam 132 is an elliptical beam, the length of the separating laser beam 132 may be equal to the distance across the separating laser beam 132 in a direction parallel to the major axis of the separating laser beam 132.

[0087] At the point along the beam path where splitting laser beam 132 impinges on the outer surface of glass tube 102, the beam width of splitting laser beam 132 may be from about 0.5 mm to about 20 mm. Beam width refers to the maximum width of the beam along its length. For an elliptical beam, the beam width is equal to the minor axis of the elliptical beam. In an embodiment, the beam width W of the separating laser beam 132 may be 0.5 mm to 10 mm, 0.5 mm to 7 mm, 0.5 mm to 5 mm, 0.5 mm to 3 mm, 0.5 mm to 2 mm, 1 mm to 20 mm, 1 mm to 10 mm, 1 mm to 7 mm, 1 mm to 5 mm, 1 mm to 3 mm, 1 mm to 2 mm, 2 mm to 20 mm, 2 mm to 10 mm, 2 mm to 7 mm, 2 mm to 5 mm, 2 mm to 3 mm, 3 mm to 20 mm, 3 mm to 10 mm, 3 mm to 7 mm, 3 mm to 5 mm, 5 mm to 20 mm, 5 mm to 10 mm, 5 mm to 7 mm, 7 mm to 20 mm, 7 mm to 10 mm, or even 10 mm to 20 mm at the point on the beam path where the separating laser beam 132 is incident on the outer surface of the glass tube 102. The beam width of the separating laser beam 132 may be adjusted based on the thickness, diameter, glass composition, or a combination thereof of the glass tube 102.

[0088] The beam width of the splitting laser beam 132 may also be selected depending on whether the end finishing process includes sealing the new end of the glass tube 102 or providing an open new end of the glass tube 102. In an embodiment, finishing the end of the glass tube 102 includes providing an open new end, and the beam width of the splitting laser beam 132 at the point along the beam path where the splitting laser beam 132 is incident on the outer surface of the glass tube 102 may be 0.5 mm to 5 mm, for example, 0.5 mm to 3 mm, 0.5 mm to 2 mm, 1 mm to 5 mm, 1 mm to 3 mm, or even 1 mm to 2 mm. Exposing each of the glass tubes 102 to the splitting laser beam 132 having a narrower beam width removes a section of the glass tube from the end of the glass tube 102 to produce a new end including an opening. The narrower beam width of the splitting laser beam 132, in the range of 0.5 mm to 5 mm, may result in heating a volume of glass in the target area that is insufficient to form a glass meniscus above the new end of the glass tube 102.

[0089] In an embodiment, finishing the end of the glass tube 102 may include sealing the end of the glass tube 102 to create a sealed or closed end. To seal the end of the glass tube 102, an additional volume of glass is heated so that when a pulling force is applied to the end of the glass tube 102 to separate the segment from the end of the glass tube 102, the larger volume of heated glass is sufficient to form a glass meniscus covering the end of the glass tube 102. By increasing the beam width of the separating laser beam 132, a larger volume of glass can be heated in the target area of ​​the glass tube 102. In an embodiment, finishing the end of the glass tube 102 may include sealing the end of the glass tube 102, and at the point in the beam path where the separating laser beam 132 impinges on the outer surface of the glass tube 102, the beam width of the separating laser beam 132 may be from about 3 mm to about 20 mm, for example, from 3 mm to 10 mm, from 5 mm to 20 mm, from 5 mm to 10 mm, from 7 mm to 20 mm, from 7 mm to 10 mm, or even from 10 mm to 20 mm. For larger beam widths, exposing each of the glass tubes 102 to a separate laser beam 132 having a larger beam width can remove a glass segment from the end of each of the glass tubes 102 to create a new end, and can seal the new end to create a sealed end of the glass tube 102. The range of beam widths of the separate laser beam 132 sufficient to heat a volume of glass sufficient to form a meniscus can depend on the thickness, diameter, and glass type of the glass tube. Increasing the beam width of the separate laser beam 132 can increase the volume of glass heated in the target area, which can result in a thicker meniscus forming at the end of the glass tube 102. Thus, the thickness of the sealed new end of the glass tube 102 can be varied by varying the beam width of the separate laser beam 132. The beam width and beam length of the separate laser beam 132 can be increased or decreased by changing the distance between two or more lenses of the beam delivery system 140, by changing the distance between the separate laser system 120 and the glass tube 102, or both. Thus, the length and beam width of the separation laser beam 132 at the point where the separation laser beam 132 contacts the glass tube 102 may be modified without changing the lenses of the beam delivery system 140 .

[0090] Now refer to Figure 7 In an embodiment, the system 100 may further include a positioner 170 operatively coupled to the separation laser system 120. The positioner 170 is operable to change the distance between the separation laser system 120 and the glass tube 102 supported on the conveyor 110. In an embodiment, the positioner 170 is operable to change the vertical distance D between the turning mirror 150 and the outer surface of the glass tube 102. LIn an embodiment, the positioner 170 may include at least one track 172, a laser support 174 coupled to the laser system 120, and an actuator 176 that movably secures the laser support 174 to the track 172. The actuator 176 is operable to Figure 7 The actuator 176 can be a stepper motor or can be operated to move the laser support 174 and the laser system 120 in the + / -Z direction along the track 172. Figure 7 Other means for moving the laser support 174 along the track 172 in the + / -Z direction of the coordinate axis in Figure 7 1 as having rails 172, laser support 174, and actuator 176, it should be understood that positioner 170 may include any other type of device, such as a hydraulic or pneumatic positioner, a scissor lift, pulleys, or other device or combination of devices suitable for moving separation laser system 120 relative to glass tube 102. In an embodiment, positioner 170 may be manually adjusted to change the position of laser support 174.

[0091] In an embodiment, the positioner 170 is operable to position the separation laser system 120 relative to the glass tube 102 so that the glass tube 102 is centered at the beam waist 158 ​​of the separation laser beam 132. The beam waist 158 ​​refers to the region of the beam path of the separation laser beam 132 where the power density of the separation laser beam 132 is greatest. In an embodiment, the positioner 170 can be adjusted to position the separation laser system 120 so that the glass tube 102 is positioned in a converging or diverging section of the separation laser beam 132 to reduce the power density of the separation laser beam 132. Changing the position of the separation laser system 120 to move the beam waist 158 ​​closer to the glass tube 102 can increase the power density of the separation laser beam 132 at the point where the separation laser beam 132 contacts the glass tube 102. Conversely, changing the position of the separation laser system 120 to move the beam waist 158 ​​further away from the glass tube 102 can reduce the power density of the separation laser beam 132 at the point where the separation laser beam 132 contacts the glass tube 102.

[0092] Additionally, moving the position of the separation laser system 120 to change the distance between the separation laser system 120 and the glass tube 102 can also change the beam size. For example, changing the distance between the separation laser system 120 and the glass tube 102 to move the beam waist 158 ​​of the separation laser beam 132 further away from the glass tube 102 (e.g., positioning the glass tube 102 further into the converging or diverging portion of the beam path) can result in the separation laser beam 132 having a greater beam width and length at the point in the beam path where the separation laser beam 132 impinges on the outer surface of the glass tube 102. Conversely, changing the distance between the separation laser system 120 and the glass tube 102 to move the beam waist 158 ​​of the separation laser beam 132 closer to the glass tube 102 can result in the separation laser beam 132 having a reduced beam width and length at the point in the beam path where the separation laser beam 132 impinges on the outer surface of the glass tube 102.

[0093] Now refer to Figure 8 The operation of the system 100 for finishing the first end 107 of the glass tube 102 will now be described in more detail. The separation laser system 120 can be positioned horizontally (i.e., along the Figure 8 The split laser beam 132 is incident on the outer surface 104 of the glass tube 102 at a target area 190 of the glass tube 102. The target area 190 of the glass tube 102 can be close to the end of the glass tube 102, for example, close to the first end 107 of the glass tube 102, such as Figure 8 In an embodiment, the target area 190 of each glass tube 102 may be located at least 100 mm from the end of the glass tube 102, such as Figure 8 As previously described, the separation laser system 120 can be positioned vertically (i.e., in the + / - Z direction) to provide a desired shape and power density of the separation laser beam 132 at the point on the beam path where the separation laser beam 132 impinges on the target area 190 of the glass tube 102.

[0094] During operation of the system, the conveyor 110 may be moved in a machine direction 116 (i.e., along Figure 8The plurality of glass tubes 102 are translated along the machine direction 116 of the conveyor 110 (in the +X direction of the coordinate axis in FIG), while rotating the glass tubes 102 about the central axis A of the glass tubes 102. The translation of the glass tubes 102 along the machine direction 116 of the conveyor 110 can cause the glass tubes 102 to pass through the beam path of the separation laser beam 132. The separation laser beam 132 can be incident on the target area 190 of the glass tubes 102, which can cause heating of the glass in the target area 190 of the glass tubes 102. When the separation laser beam 132 heats the target area 190 of the glass tubes 102, a tensile force F can be applied to the first end 107 of the glass tubes 102. In an embodiment, the axial separation conveyor 180 can apply a tensile force F to the end of the glass tubes (i.e., Figure 8 The axial separation conveyor 180 can apply the pulling force F to the end of the glass tube 102 by following a path that deviates from the conveyor 110, so that contact between the glass tube 102 and a surface of the axial separation conveyor 180 proximate to the first end 107 of the glass tube 102 applies an axial pulling force to the first end 107 of the glass tube 102.

[0095] Applying a pulling force F to at least one end of the glass tube 102 can convey a segment 192 of the glass tube 102 away from the glass tube 102 in an axial direction relative to the central axis A of the glass tube 102, which can separate the segment 192 from the glass tube 102. Specifically, as the temperature of the glass in the target region 190 increases due to the operation of the separation laser beam 132, the glass in the target region 190 can become viscous, and applying the pulling force F to the first end 107 of the glass tube 102 can cause the segment 192 of the glass tube 102 to be pulled away from the remainder of the glass tube 102 at the target region 190 and separated therefrom. The segment 192 can be large enough that the axial separation conveyor 180 or other device can generate sufficient pulling force F to separate the segment 192 from the glass tube 102. In embodiments, the axial length of the segment 192 removed from the at least one end of the plurality of glass tubes 102 is less than about 100 mm, for example, from about 13 mm to about 100 mm, or from about 10 mm to about 100 mm.

[0096] During separation, at the target region 190, the glass thins and stretches until the glass separates. Once separated, surface tension within the glass can cause the volume of viscous glass on either side of the separation point to flow back to the new end 196 of the glass tube 102 and the end of the segment 192, respectively. In embodiments, the volume of heated glass can be large enough so that the viscous glass flowing back to the new end 196 of the glass tube 102 can form a meniscus above the new end 196 of the glass tube 102. The formation of a glass meniscus above the new end 196 of the glass tube 102 can seal the new end 196 of the glass tube 102. In embodiments, the volume of glass heated by the separation laser beam 132 in the target region 190 may not be sufficient to form a meniscus, resulting in the new end 196 of the glass tube 102 being open, as shown in FIG. Figure 8 shown.

[0097] The characteristics of the separating laser beam 132, such as, but not limited to, beam shape, power density, power density distribution, or a combination thereof, can be modified to convert the system 100 from producing an open new end 196 of the glass tube 102 to producing a sealed new end 196 of the glass tube 102. The characteristics of the separating laser beam 132 can also be modified to adjust the heating rate, for example, in response to a change in the type of glass tube 102 (e.g., a change in glass composition, nominal diameter, average wall thickness, etc.), or to accommodate a change in the production rate. Modifying the characteristics of the separating laser beam 132 will be discussed in further detail herein.

[0098] In an embodiment, finishing the end of the glass tube 102 may produce a new end 196 that is an open end of the glass tube 102 , eg, having an opening therethrough. Figure 11 A photograph of the open new end 196 of the glass tube 102 is shown after the annular segment 192 is separated from the end of the glass tube 102. In an embodiment, finishing the end of the glass tube 102 can seal the new end 196 of the glass tube 102 to create a sealed end of the glass tube 102. Figure 12 A photograph of the sealed new end 196 of the glass tube 102 is shown after the ring segment is separated from the end of the glass tube 102. Whether the new end 196 is sealed or open, heating the glass by splitting the laser beam and separating the segment 192 from the end of the glass tube 102 can produce a polished and finished new end 196, such as Figure 11 and Figure 12 After segment 192 is separated from the end of glass tube 132, the finishing provided by heating with the separation laser beam and reflowing of the viscous glass can be equal to or better than the finishing provided by fire polishing the end according to conventional methods.

[0099] In embodiments, the new end 196 of the glass tube 102 produced by operation of the system can be substantially free of surface defects, such as, but not limited to, cracks, scratches, or any other surface inclusions. In embodiments, the acceptable quality level (AQL) of the new end 196 of the glass tube 102 produced by the systems and methods disclosed herein can be less than 0.25 for end cracks greater than 2 mm in length. The acceptable quality level (AQL) is defined in accordance with ISO 2859-1. An end crack is a crack occurring in the axial end of a glass tube. In embodiments, the AQL of the new end 196 of the glass tube 102 produced by the systems and methods disclosed herein can be less than or equal to 0.025 for surface cracks of any size and length. Surface cracks are cracks in the outer and / or inner surfaces (i.e., not the end face) of the glass tube 102. In embodiments, after finishing the end by separating the segments 192 using a separate laser beam, the new end 196 of the glass tube 102 and / or the entire glass tube 102 can be substantially free of molten glass particles, hydrocarbon combustion products, or both. In an embodiment, the glass tube 102 is free of glass particles greater than 0.5 mm in diameter attached to the inner or outer surface of the glass tube 102. In an embodiment, the glass tube 102 may have less than or equal to 5 glass particles with a diameter of 0.2 mm to less than 0.5 mm attached to the inner or outer surface of the glass tube 102. In an embodiment, the glass tube 102 produced by the systems and methods disclosed herein may have an AQL of less than 0.1 for impurities greater than 1 mm on the outer surface of the glass tube that are not easily removed. In an embodiment, the glass tube 102 produced by the systems and methods disclosed herein may have an AQL of less than 0.1 for impurities greater than 0.5 mm on the inner surface of the glass tube that are not easily removed. In an embodiment, the glass tube 102 produced by the systems and methods disclosed herein may be free of discoloration of the glass tube due to deposition of combustion products on the glass tube surface, visual deposits on the glass tube surface, or both.

[0100] Reference again Figure 8 , removing the segment 192 from the first end 107 of the glass tube 102 can finish the end of the glass tube 102 by reducing the length of the glass tube 102 to the final length of the glass tube 102 and providing a new, finished and polished end. The system 100 of the present disclosure can achieve both reducing the length of the glass tube 102 to the final length and providing a new, finished end of the glass tube 102 in a single step of removing the segment 192 from the end of the glass tube 102 by directing the split laser beam 132 to the target area 190 of the glass tube 102 while also applying a tensile force F to the end of the glass tube 102.

[0101] The second end 108 of the glass tube 102 can be cut and finished using the same methods described for cutting and finishing the first end 107 of the glass tube 102. Figure 9 In an embodiment, the system 100 may include a separate laser system 120 for each end of the glass tubes 102. In an embodiment, the system 100 may include a first separate laser system 120A and a second separate laser system 120B. The first separate laser system 120A and the second separate laser system 120B may have any of the components and / or features previously discussed with respect to the separate laser system 120. The first separate laser system 120A may include a first laser source and a first beam delivery system, and the second separate laser system 120B may include a second laser source and a second beam delivery system, both of which may be the same as or different from the first laser source and the first beam delivery system, respectively. The first separate laser system 120A is operable to direct a first separate laser beam 132A to a target area 190 proximate the first end 107 of the plurality of glass tubes 102. The second separate laser system 120B is operable to direct a second separate laser beam 132B to a target area 190 proximate the second end 108 of the plurality of glass tubes 102. The first separate laser beam 132A and the second separate laser beam 132B can each have any of the features and / or characteristics discussed previously herein with respect to the separate laser beams 132 .

[0102] In embodiments, the system 100 may further include a first laser system positioner 170A and a second laser system positioner 170B, which may each have any of the features and / or components previously described herein with respect to the laser system positioner 170. The first laser system positioner 170A may be operable to position the first separation laser system 120A relative to the glass tube 102, and the second laser system positioner 170 may be operable to position the second separation laser system 120B relative to the glass tube 102. In embodiments, the system 100 may include a single laser system positioner 170 that may support and position both the first separation laser system 120A and the second separation laser system 120B.

[0103] Now refer to Figure 10 In an embodiment, the system 100 may further include a preheating laser system 160 positioned upstream of the separation laser system 120. In some cases, the properties of the glass tube 102, such as the type of glass composition, average wall thickness, nominal diameter, or a combination thereof, may require additional heating to achieve separation of the segment 192 from the end of the glass tube 102. Additionally, the use of the preheating laser system 160 may increase the separation rate, thereby increasing the production rate of the finishing process, which may increase the drawing speed of the process for manufacturing a continuous hollow glass cylinder.

[0104] like Figure 10As shown, the preheating laser system 160 can be positioned upstream of the separation laser system 120. The preheating laser system 160 is operable to generate a preheating laser beam 162 and direct the preheating laser beam 162 toward the glass tube 102. The preheating laser system 160 can include a preheating laser source 164 and a preheating beam delivery system 166. The preheating laser system 160 can also include a steering mirror 168. The preheating laser source 164, the preheating beam delivery system 166, and the steering mirror 168 can have any of the features previously described herein with respect to the separation laser source 130, the beam delivery system 140, and the steering mirror 150. The preheating laser source 164 is operable to generate a laser beam 161. The preheating beam delivery system 166 is operable to modify the shape, power density, power density distribution, or other characteristics of the laser beam 161 to generate the preheating laser beam 162. The steering mirror 168 is operable to direct the preheating laser beam 162 toward the glass tube 102 at a position upstream of the separation laser beam 132 (i.e., relative to the position of the separation laser beam 132). Figure 10 The preheating laser beam 162 is directed toward the target area of ​​the glass tube 102 at a position in the -X direction of the mid-axis. The preheating laser beam 162 can have any of the features, properties, or characteristics previously described herein for the separation laser beam 132.

[0105] During operation of the system 100, the conveyor 110 can move the glass tube 102 through the beam path of the preheating laser beam 162. The preheating laser beam 162 can heat a target area of ​​the glass tube 102 by contacting the preheating laser beam 162 with the outer surface of the glass tube 102. The conveyor 110 can then move the glass tube 102 out of the beam path of the preheating laser beam 162 and into the beam path of the separation laser beam 132, which can complete the heating and separation of the annular segment from the end of the glass tube 102.

[0106] In an embodiment, the system 100 may include multiple preheat laser systems 160. In an embodiment, the system 100 may include a preheat laser system 160 positioned upstream of each of the separate laser systems 120 (i.e., one at each end of the glass tube 102). In an embodiment, the system 100 may include a first preheat laser system ( Figure 9 ) and a second preheating laser system ( Figure 9 ). In an embodiment, the system 100 may include a plurality of preheating laser systems 160 arranged in series upstream of each of the separation laser systems 120. Referring again to Figure 10 In an embodiment, each of the preheat laser systems 160 may include one of the laser system positioners 170 operable to Figure 10The preheat laser system 160 is positioned in the + / -Z direction (e.g., in the vertical direction) of the coordinate axis in FIG. The laser system positioner 170 is operable to change the distance between the preheat laser system 160 and the glass tube 102 along the + / -Z direction, thereby changing one or more characteristics of the preheat laser beam 162, such as, but not limited to, the power density or shape at the point where the preheat laser beam 162 contacts the glass tube 102.

[0107] In an embodiment, the system 100 for cutting and finishing the ends of the glass tubes 102 does not include a gas burner. In an embodiment, the system 100 for cutting and finishing the ends of the glass tubes 102 does not include any mechanical tool for scoring the surfaces of the plurality of glass tubes 102.

[0108] Reference again Figure 3 and Figure 8 , a method of producing a glass tube 102 using the system 100 disclosed herein will now be described in more detail. Figure 3 The method for producing the glass tube 102 of the present disclosure may include producing a continuous hollow glass cylinder 222 or an annealed continuous hollow glass cylinder 242, cutting the continuous hollow glass cylinder 222 or the annealed continuous hollow glass cylinder 242 into a plurality of individual glass tubes 102 having an initial length, and finishing at least one end (e.g., the first end 107, the second end 108, or both) of the plurality of glass tubes 102. Now referring to Figure 8 Finishing the ends of the glass tubes 102 includes: rotating each glass tube 102 about a central axis A of the glass tube 102; heating a target region 190 of the glass tube 102 by exposing the target region 190 to a split laser beam 132 while rotating the glass tube 102; and applying a laser beam to at least one end of the glass tube 102 (e.g., Figure 8 Applying the pulling force F while exposing the target area 190 to the separation laser beam 132 can separate the annular section 192 of the glass tube 102 from the end of the glass tube 102 to produce a new end 196 of the glass tube 102, and the new end 196 of the glass tube 102 can be finished.

[0109] Finishing the end of the glass tube 102 reduces the length of the glass tube 102 to a final length. In embodiments, finishing the end of the glass tube 102 using the split laser beam 132 can produce a new end 196 that is polished and exhibits minimal surface defects. In embodiments, the new end 196 of the glass tube 102 can be substantially free of surface defects. In embodiments, the new end 196 of the glass tube 102 can be substantially free of molten glass particles, hydrocarbon combustion products, or both. In embodiments, finishing the end of the glass tube 102 can include forming the new end 196 of the glass tube 102 as an open end, e.g., having an opening therethrough. In embodiments, finishing the end of the glass tube 102 can seal the new end 196 of the glass tube 102 to produce a sealed new end of the glass tube 102. Finishing the ends of the glass tubes 102 may include heating a volume of glass in the target region 190 sufficient to form a glass meniscus above each new end 196 of each glass tube 102 during separation of the segments 192 from the ends of the glass tubes 102 .

[0110] refer to Figure 8 Exposing each of the plurality of glass tubes 102 to the split laser beam 132 may include: generating a laser beam 131 using a laser source 130; passing the laser beam 131 through a beam delivery system 140, the beam delivery system including an optical device that modifies the shape or properties of the laser beam 131 to generate a split laser beam 132 and directs the split laser beam 132 toward the plurality of glass tubes; and passing each of the plurality of glass tubes 102 through a beam path of the split laser beam 132. In an embodiment, passing each of the glass tubes 102 through the beam path of the split laser beam 132 may further include moving the plurality of glass tubes horizontally (i.e., along the beam path) while passing each of the glass tubes 102. Figure 8 The +X direction of the coordinate axis of the laser beam 132 is transmitted through the beam path of the separated laser beam 132.

[0111] In an embodiment, applying a tensile force F to the end of the glass tube 102 can transport the segment 192 of the glass tube 102 away from the glass tube 102 in an axial direction relative to the central axis A of the glass tube 102. Transporting the segment 192 axially away from the glass tube 102 can separate the segment 192 from the glass tube 102. In an embodiment, the segment 192 can be transported in a transverse machine direction (i.e., Figure 8 The tensile force F is applied in the + / -Y direction of the median coordinate axis, wherein the transverse machine direction is parallel to the central axis A of the glass tube 102 and perpendicular to the horizontal travel direction of the conveyor 110 (e.g., Figure 8Applying the pulling force F to the end of the glass tube 102 may include providing one or more axial separation conveyors 180, each of which may be positioned to support the end of the glass tube 102 and may be separated from the conveyor 110 along a path 181. Contact between the glass tube 102 and the rollers of the axial separation conveyors 180 and separation of the axial separation conveyors 180 from the conveyor 110 along the path 181 may apply the pulling force F to the end of the glass tube 102 in an axial direction (e.g., a + / - Y direction).

[0112] Now refer to Figure 9 In an embodiment, the methods disclosed herein may include finishing both ends of the glass tubes 102. Specifically, the methods may include finishing the first end 107 of each of the plurality of glass tubes 102 with a first separate laser beam 132A, and finishing the second end 108 of each of the plurality of glass tubes 102 with a second separate laser beam 132B. In an embodiment, the methods may include finishing the first end 107 and the second end 108 of each of the plurality of glass tubes 102 in parallel. In an embodiment, the methods may include finishing the second end 108 with the second separate laser beam 132B downstream of finishing the first end 107 with the first separate laser beam 132A.

[0113] Reference again Figure 8In an embodiment, the method may include processing multiple glass tubes 102 at a time. In an embodiment, the separating laser beam 132 may be an elongated beam, and the method may include simultaneously exposing a target region 190 of a subset of the multiple glass tubes 102 to the separating laser beam 132. In an embodiment, a ratio of the total length of the separating laser beam 132 to the beam width at a point along the beam path where the separating laser beam 132 impinges on the outer surface of the subset of glass tubes 102 may be from about 5 to about 2000. In an embodiment, exposing the target region 190 of the multiple glass tubes 102 to the separating laser beam 132 may include sequentially passing each of the multiple glass tubes 102 through the elongated beam of the separating laser beam 132, from a leading edge 154 to a trailing edge 156 of the separating laser beam 132. Passing each of the multiple glass tubes 102 through the total length of the separating laser beam 132 may gradually heat the glass at the target region 190 while applying a tensile force F, and may cause a segment 192 to separate from the end of each of the multiple glass tubes 102. The total length of the separating laser beam 132 may be sufficient to simultaneously contact each of the subset of glass tubes 102. In an embodiment, sequentially conveying each of the plurality of glass tubes 102 through the elongated beam of the separating laser beam 132 may include arranging the plurality of glass tubes 102 side by side on a conveyor 110 comprising a plurality of rollers 112 and at least one conveyor belt, wherein each glass tube 102 is arranged between two adjacent rollers 112 of the conveyor 110. The rollers 112 of the conveyor 110 may rotate each of the plurality of glass tubes 102, and the at least one conveyor belt may move the rollers 112 and the plurality of glass tubes 102 horizontally (i.e., along the conveyor belt). Figure 8 The +X direction of the coordinate axis) moves through the separated laser beam 132.

[0114] Now refer to Figure 10 In an embodiment, the method disclosed herein may further include preheating a target region 190 of the glass tube 102 before exposing the target region 190 of the glass tube 102 to the separating laser beam 132. Preheating the target region 190 of the glass tube 102 may include rotating each glass tube 102 and exposing each glass tube 102 to a preheating laser beam 162 positioned upstream of the separating laser beam 132. The preheating laser beam 162 may be separate from the separating laser beam 132. The method may further include varying a distance between the preheating laser system 160 and the glass tube 102 to vary a shape or power density of the preheating laser beam 162.

[0115] In embodiments, the methods disclosed herein may further include varying the heating rate of the separating laser beam 132. Varying the heating rate of the separating laser beam 132 may include varying the power density of the separating laser beam 132, varying the power density distribution of the separating laser beam 132, varying the speed at which the conveyor 110 translates the plurality of glass tubes 102 through the separating laser beam 132, or a combination thereof. In embodiments, varying the heating rate of the separating laser beam 132 may include varying the power density of the separating laser beam 132 at the point along the beam path where the separating laser beam 132 contacts the glass tubes 102. In embodiments, varying the power density of the separating laser beam 132 at the point where the separating laser beam 132 contacts the glass tubes 102 may include adjusting the power of the laser source 130 used to generate the laser beam 131, varying the distance between the beam delivery system 140 and the plurality of glass tubes 132, or both.

[0116] refer to Figure 7 In an embodiment, changing the power density of the separation laser beam 132 at the point where the separation laser beam 132 contacts the glass tube 102 includes changing the distance D between the separation laser system 120 and the glass tube 102. L , which changes the position of the beam waist 158 ​​of the separation laser beam 132 relative to the glass tube 102. Changing the distance D L Moving the beam waist 158 ​​closer to the glass tube 102 can increase the power density of the separation laser beam 132 at the point where the separation laser beam 132 contacts the glass tube 102. Conversely, changing the distance D L Moving the beam waist 158 ​​away from the glass tube 102 can reduce the power density of the separation laser beam 132 at the point where the separation laser beam 132 contacts the glass tube 102 .

[0117] In an embodiment, changing the heating rate of the split laser beam 132 may include changing the power density distribution of the split laser beam 132. Changing the power density distribution of the split laser beam 132 may include passing the laser beam 131 through a cylindrical lens to produce the split laser beam 132 having a Gaussian power density distribution, which has a lower heating rate, or passing the laser beam 131 through an aspherical cylindrical lens to produce the split laser beam 132 having a flat-top power density distribution, which has a higher heating rate. In an embodiment, changing the heating rate of the split laser beam 132 does not require changing the lens of the beam delivery system 140.

[0118] Reference again Figure 10In embodiments, the methods disclosed herein can include varying the heating rate of the preheating laser beam 162. Varying the heating rate of the preheating laser beam 162 can include varying the power density of the preheating laser beam 162, varying the power density distribution of the preheating laser beam 162, varying the speed at which the conveyor 110 translates the plurality of glass tubes 102 through the preheating laser beam 162, or a combination thereof. In embodiments, varying the heating rate of the preheating laser beam 162 can include varying the power density of the preheating laser beam 162 at the point along the beam path where the preheating laser beam 162 contacts the glass tubes 102. In embodiments, varying the power density of the preheating laser beam 162 at the point where the preheating laser beam 162 contacts the glass tubes 102 can include adjusting the power of the preheating laser source 164 used to generate the preheating laser beam 162, varying the distance between the preheating beam delivery system 166 and the plurality of glass tubes 132, or both, which can be similar to the previously discussed methods of varying the power density of the separation laser beam 132. In an embodiment, changing the heating rate of the preheating laser beam 162 may further include changing the power density distribution, such as by using a cylindrical lens to produce a Gaussian distribution with a lower heating rate or using an aspheric cylindrical lens to produce a flat-top power density distribution with a higher heating rate. In an embodiment, changing the heating rate of the preheating laser beam 162 does not require changing the lens of the preheating beam delivery system 166.

[0119] The methods disclosed herein can be modified to finish the new end 196 of the glass tube 102, such that the new end 196 is open or sealed. In one embodiment, finishing the end of the glass tube 102 can include forming the new end 196 as an open end, meaning that the new end 196 of the glass tube 102 is annular. In one embodiment, at the point along the beam path where the separating laser beam 132 impinges on the outer surfaces of the plurality of glass tubes 132, the beam width of the separating laser beam 132 can be 0.5 mm to 5 mm, and exposing each of the glass tubes 102 to the separating laser beam 132 can remove the annular segment 192 from the end of each of the glass tubes 102 to produce a new end including an opening. To form the open end on the glass tube 102, the beam width of the separating laser beam 132 can be reduced, which reduces the volume of glass heated during the separation of the annular segment 192 from the end of the glass tube 102. The reduction in glass volume caused by reducing the beam width of the separation laser beam 132 may not be sufficient to form a stable meniscus on the end of the glass tube 102, which may cause surface tension to cause the viscous heated glass to flow back to the sidewall at the new end 196 of the glass tube 102 after the annular segment is separated from the glass tube 102. This leaves the new end 196 as an open end.

[0120] In an embodiment, finishing the end of the glass tube 102 may include forming the new end 196 as a sealed end, meaning that the new end 196 is surrounded or covered by a glass film or glass wall. Finishing the end of the glass tube 102 may seal the new end 196 of the glass tube 102 to create a sealed end of the glass tube. In an embodiment, the beam width of the separating laser beam 132 may be approximately 3 mm to 20 mm at the point in the beam path where the separating laser beam 132 impinges on the outer surface of the glass tube 102, and exposing each of the glass tubes 102 to the separating laser beam 132 may remove the annular segment 192 from the end of the glass tube 102 to create the new end 196, and seal the new end 196 to create a sealed end of the glass tube 102. To form a sealed end on the glass tube 102, the beam width of the separating laser beam 132 may be increased, which increases the volume of glass heated during the separation of the annular segment 192 from the end of the glass tube 102. The increased volume of glass resulting from increasing the beam width of the separating laser beam 132 can be sufficient to form a stable glass meniscus on the end of the glass tube 102. The volume of glass in the glass meniscus formed above the end can be sufficient to resist surface tension, which causes the meniscus to cover the new end 196 of the glass tube 102 and cool to form a sealed end of the glass tube 102.

[0121] The methods disclosed herein can include adjusting the system 100 to switch between forming an open end of the glass tube 102 and forming a sealed end of the glass tube. In an embodiment, the method can include determining whether to finish the end of the glass tube 102 to produce an open or sealed new end, and changing one or more of the beam shape (e.g., beam width), power, power density distribution, or a combination thereof of the separating laser beam 132. Changing the beam shape, power, power density distribution, or a combination thereof of the separating laser beam 132 can change the volume of glass heated in the target region 190 of the plurality of glass tubes 102. As previously described, when the annular segment 192 is removed from the end of the glass tube 102, reducing the volume of glass heated in the target region 190 can produce a new end having an opening, and increasing the volume of glass heated in the target region 190 can produce a glass meniscus that seals the new end 196.

[0122] Changing the beam shape can include adjusting the spacing between two or more lenses of the beam delivery system 140, adjusting the distance between the beam delivery system 140 and the plurality of glass tubes 102, or a combination thereof. In an embodiment, changing the beam shape can include adjusting the distance between the beam delivery system 140 and the glass tubes 102, which changes the point within the beam path at which the separating laser beam 132 contacts the outer surfaces of the plurality of glass tubes 102 relative to the beam waist 158 ​​of the separating laser beam 132. In an embodiment, transitioning between forming an open end and forming a sealed end can include changing the power density of the separating laser beam 132 at the point along the beam path at which the separating laser beam 132 contacts the outer surfaces of the glass tubes 102. Changing the power density of the separating laser beam 132 at the point at which it contacts the glass tubes 102 can include adjusting the power of the laser source 130 used to generate the separating laser beam 132, changing the distance between the beam delivery system 140 and the plurality of glass tubes 102, or both. To produce a sealed end, the method may include adjusting the distance between the beam delivery system 140 and the glass tube 102 to move the beam waist 158 ​​of the separating laser beam 132 closer to the glass tube 102, which may increase the power density of the separating laser beam 132 at the point where the separating laser beam 132 contacts the glass tube 102. To produce an open end, the method may include adjusting the distance between the beam delivery system 140 and the glass tube 102 to move the beam waist 158 ​​of the separating laser beam 132 away from the glass tube 102, which may decrease the power density of the separating laser beam 132 at the point where the separating laser beam 132 contacts the glass tube 102.

[0123] In an embodiment, the method may include transitioning from forming an open new end 196 to forming a sealed new end, wherein the transition includes one or more of: increasing the beam width of the separating laser beam 132; increasing the power density of the separating laser beam 132; changing the power density profile of the separating laser beam 132 from a Gaussian power density profile to a flat-top power density profile; or a combination thereof. In an embodiment, transitioning from forming an open new end to forming a sealed new end may include heating a volume of glass sufficient to form a glass meniscus above the new ends of the plurality of glass tubes when the segment is removed from at least one end of the plurality of glass tubes. In an embodiment, transitioning from forming an open new end to forming a sealed new end may include changing the beam shape of the separating laser beam 132 by increasing the beam width to a range of 3 mm to 20 mm.

[0124] In an embodiment, the method may include transitioning from forming a sealed new end 196 to forming an open new end, wherein the transition includes one or more of: reducing the beam width of the separating laser beam 132; reducing the power density of the separating laser beam 132; changing the power density profile of the separating laser beam 132 from a flat top power density profile to a Gaussian power density profile; or a combination thereof. In an embodiment, transitioning between forming a sealed new end and forming an open new end may include reducing the volume of glass heated in the target area as the segment is removed from each of the glass tubes to prevent formation of a glass meniscus above the new ends of the plurality of glass tubes. In an embodiment, transitioning from forming a sealed new end to forming an open new end may include changing the beam shape of the separating laser beam 132 by reducing the beam width to a range of 0.5 mm to 5 mm.

[0125] When the system 100 includes the preheat laser system 160, the transition between forming an open end and forming a sealed end can further include modifying properties of the preheat laser beam 162. In embodiments, the transition between forming an open end and forming a sealed end can include changing one or more of the beam shape (e.g., thickness), power, power density distribution, or a combination thereof of the preheat laser beam 162. Changing the beam shape, power, power density distribution, or a combination thereof of the preheat laser beam 162 can change the volume of glass heated in the target region 190 of the plurality of glass tubes 102.

[0126] Reference again Figure 8 and Figure 10 The method of the present disclosure may include changing the type of glass tube 102 from a first type of glass tube 102 to a second type of glass tube 102, and in response to the change in the type of glass tube 102, changing the heating rate of the separating laser beam 132, the preheating laser beam 162, or both. Changing the type of glass tube 102 from the first type of glass tube to the second type of glass tube may include changing the glass composition, nominal diameter, sidewall thickness, or a combination thereof of the plurality of glass tubes 102 produced by the glass tube forming process. The heating rate of the separating laser beam 132, the preheating laser beam 162, or both may be changed by any of the methods previously discussed herein. In an embodiment, changing the heating rate of the separating laser beam 132, the preheating laser beam 162, or both may include: changing the power density of the separating laser beam 132, the preheating laser beam 162, or both; changing the power density distribution of the separating laser beam 132, the preheating laser beam 162, or both; changing the speed at which the conveyor 110 translates the plurality of glass tubes 102 past the separating laser beam 132, or the separating laser beam 132 and the preheating laser beam 162; or a combination thereof. In an embodiment, changing the heating rate of the separating laser beam 132, the preheating laser beam 162, or both does not require changing the lens of the beam delivery system 140 or the preheating beam delivery system 166.

[0127] The disclosed systems and methods can increase the throughput rate of a glass tube forming process. The methods disclosed herein can include increasing the throughput rate of a system 100 for cutting and finishing the ends of glass tubes 102, which can result in an overall increase in the throughput rate of the tube forming process. In embodiments, increasing the throughput rate of the system 100 for cutting and finishing the ends of glass tubes 102 can include increasing the speed at which the conveyor 110 translates the plurality of glass tubes 102 through the beam path of the separating laser beam 132, and increasing the heating rate of the separating laser beam 132, the preheating laser beam 162, or both. The heating rate of the separating laser beam 132, the preheating laser beam 162, or both can be altered by any of the methods previously discussed herein. In embodiments, increasing the heating rate of the separating laser beam 132, the preheating laser beam 162, or both can include increasing the power density of the separating laser beam 132, the preheating laser beam 162, or both; changing the power density profile of the separating laser beam 132, the preheating laser beam 162, or both from a Gaussian power density profile to a flat-top power density profile; or a combination thereof. In an embodiment, increasing the production rate of the system 100 for cutting and finishing the end of the glass tube 102 may include preheating a target area of ​​the glass tube 102 with the preheat laser system 160 .

[0128] Reference again Figure 3 and Figure 4 The method disclosed herein for producing the glass tube 102 may include producing a continuous hollow glass cylinder 222, cutting the continuous hollow glass cylinder 222 into a plurality of glass tubes 102, and finishing the ends of the glass tubes 102. Producing the continuous hollow glass cylinder may include pulling the continuous hollow glass cylinder from the tube forming apparatus 220. In an embodiment, producing the continuous hollow glass cylinder may include: forming the continuous hollow glass cylinder 222 from molten glass in the tube forming apparatus 220; pulling the continuous hollow glass cylinder 222 from the tube forming apparatus 220 through an annealing section 240; annealing the continuous hollow glass cylinder 222 in the annealing section 240 to produce an annealed continuous hollow glass cylinder 242; cutting the annealed continuous hollow glass cylinder 242 to produce a plurality of glass tubes 102 having an initial length; and transferring the plurality of glass tubes 102 to the conveyor 110 of the system 100 to finish the ends of the glass tubes 102.

[0129] The systems and methods disclosed herein can also be applied to cutting and finishing the ends of glass rods. Specifically, the system 100 disclosed herein, including the conveyor 110 and the separating laser system 120, as well as any one of the preheating laser system 160 and the axial separating conveyor 180, or a combination thereof, can be used to cut and finish the ends of glass rods downstream of the glass rod forming process. When cutting and finishing glass rods, the system 100 can include any of the components or features previously discussed herein in connection with cutting and finishing glass tubes.

[0130] Products used for pharmaceutical packaging, such as, but not limited to, vials, cartridges, syringes, ampoules, jars, or other containers, are converted from glass tubes, such as those produced by the systems and methods previously discussed herein. During the conversion process, the glass tubes are indexed through multiple stations where heating and forming contact are applied to transform the glass tubes into the final product, which is a glass article. The laser systems and methods disclosed herein can be further incorporated into the conversion process for producing glass articles from glass tubes. Specifically, laser systems, such as separation laser systems and / or preheating laser systems, can be incorporated into the conversion process in place of one or more gas burners to heat the glass prior to forming or separating the partially formed glass article from the working end of the glass tube. The laser systems and methods disclosed herein can enable the formation of infrared laser beams with varying shapes and spatial power distributions. Furthermore, the superposition of beams and the control of the exposure time of the glass article and glass tube to the laser beam can allow for precise energy delivery to the glass, enabling targeted manipulation of heat and stress patterns as selected by the operator to improve process accuracy and repeatability, thereby enhancing the quality of the final product. An experimental platform consisting of multiple laser modules integrated with tube processing equipment can be used to simulate the use of laser systems and methods on a glass tube converter for manufacturing glass products from glass tubes. In addition, in some embodiments, the conversion process can be a hybrid conversion process that includes a combination of gas burner and laser-assisted heating.

[0131] A method for producing a glass article from a glass tube may include: rotating the glass tube about a central axis of the glass tube; heating a target region of the glass tube to a forming temperature while rotating the glass tube, wherein the target region may be proximate to a working end of the glass tube; after heating the target region of the glass tube, forming at least one feature of the glass article at the target region of the glass tube while rotating the glass tube; and separating the glass article from the working end of the glass tube at a separation region of the glass tube. Heating the target region of the glass tube, separating the glass article from the working end of the glass tube, or both may include exposing the target region of the glass tube, the separation region, or both to a laser beam having a wavelength in a range of about 1 μm to about 12 μm. Exposing the target region, the separation region, or both to the laser beam may heat the glass at the target region, the separation region, or both to a temperature greater than or equal to about 1000°C.

[0132] In an embodiment, heating the target area of ​​the glass tube may include exposing the target area to a laser beam, wherein the laser beam may be a heating laser beam. In an embodiment, the heating laser beam may have a circular cross-section. In an embodiment, the heating laser beam may have a Gaussian power density distribution.

[0133] In an embodiment, separating the glass article from the working end of the glass tube may include exposing the separation region of the glass tube to a laser beam, wherein the laser beam may be a separation laser beam. In an embodiment, separating the glass article from the working end of the glass tube may include applying a tensile force to the glass article while exposing the separation region of the glass tube to the laser beam, wherein the tensile force may cause the glass article to move away from the glass tube in an axial direction relative to a central axis of the glass tube. In an embodiment, the glass tube may be vertically oriented with the working end of the glass tube facing downward, and the tensile force may include gravity. In an embodiment, the separation laser beam may have an elliptical cross-section having a major axis and a minor axis.

[0134] In an embodiment, separating the glass article from the working end of the glass tube may include forming an open end on a bottom portion of the glass article, wherein the bottom portion of the glass article may be an end of the glass article previously coupled to the glass tube prior to separation. In an embodiment, the beam width of the separation laser beam may be approximately 0.5 mm to approximately 5 mm. In an embodiment, the beam length of the separation laser beam may be approximately 20 mm to approximately 35 mm. In an embodiment, the separation laser beam may be an elliptical beam having a major axis to minor axis ratio of approximately 4 to approximately 70.

[0135] In an embodiment, separating the glass article from the working end of the glass tube may further include forming a thin bottom of the glass article. In an embodiment, the beam width of the separating laser beam may be about 5 mm to about 10 mm. In an embodiment, the separating laser beam may be an elliptical beam having a ratio of a major axis to a minor axis of about 2 to about 7. In an embodiment, separating the glass article from the working end of the glass tube may include forming a thick bottom of the glass article. In an embodiment, the beam width of the separating laser beam may be about 3 mm to about 7 mm. In an embodiment, the separating laser beam may be an elliptical beam having a ratio of a major axis to a minor axis of about 2.5 to about 12. In an embodiment, the separating laser beam may be an elliptical beam, and the major axis of the separating laser beam may be parallel to the central axis of the glass tube.

[0136] In some embodiments, heating a target region of a glass tube, separating a glass article from a working end of the glass tube, or both may include exposing the target region, the separation region, or both of the glass tube with a first laser beam; and simultaneously exposing the target region, the separation region, or both of the glass tube with a second laser beam, wherein the first laser beam and the second laser beam may be superimposed on the target region or the separation region of the glass tube. In some embodiments, the first laser beam may have a circular beam cross-section, and the second laser beam may have an elliptical beam cross-section. In some embodiments, the method may include modifying the axial position of the second laser beam relative to the axial position of the first laser beam.

[0137] In some embodiments, the method may further include finishing a bottom portion of the glass article, wherein the bottom portion of the glass article may include an end portion of the glass article formed by separating the glass article from a working end of a glass tube. In some embodiments, finishing the bottom portion of the glass article may include exposing the bottom portion of the glass article to a finishing laser beam. In some embodiments, shaping may include contacting a surface of the glass tube in a target region with one or more shaping tools while rotating the glass tube, wherein contact between the shaping tools and the surface of the glass tube changes the shape of the glass tube in the target region.

[0138] In an embodiment, a method may include operating a converter to produce a plurality of glass products from a plurality of glass tubes. The converter may include a plurality of processing stations, the plurality of processing stations including at least one heating station, at least one forming station, and a separation station. Operating the converter may include sequentially translating each of the plurality of glass tubes through each of the plurality of processing stations. At least one heating station, at least one separation station, or both may include exposing each of the glass tubes to a laser beam to heat each of the glass tubes at a target region, a separation region, or both.

[0139] In embodiments, the method may further include securing the glass tube in a holder of a converter comprising a plurality of processing stations, the plurality of processing stations comprising at least one heating station, at least one forming station, and a separation station, wherein the converter sequentially translates the holder and the glass tube through each of the processing stations. The method may further include forming one or more features of a glass article at a working end of the glass tube by translating the glass tube through the at least one heating station and the at least one forming station; and separating the glass article from the working end of the glass tube in the separation station. Heating a target region of the glass tube may include exposing the target region of the glass tube to a laser beam in the at least one heating station, or separating the glass article from the working end of the glass tube may include exposing a separation region of the glass tube to a laser beam in the separation station. In embodiments, the glass article may be a pharmaceutical container. In embodiments, the pharmaceutical container may include a vial, a syringe, a cartridge, an ampoule, or a canister.

[0140] In embodiments, exposing the target area or separation area of ​​the glass tube to a laser beam may include: generating the laser beam using a laser source; passing the laser beam through an optical device that modifies the shape or power density distribution of the laser beam; and directing the laser beam toward the target area or separation area of ​​the glass tube. In embodiments, the laser beam may be a continuous laser beam or a pulsed laser beam. In embodiments, the laser beam may be a collimated or non-collimated laser beam. In embodiments, the separation laser beam may have a laser power of 50 W to 2000 W. In embodiments, the laser beam may be an elliptical beam or a circular beam.

[0141] In embodiments, the method may further include changing the shape of the laser beam, wherein changing the shape of the laser beam may change the volume of glass heated in the target region or separation region of the glass tube. In embodiments, the method may further include changing the power density distribution of the laser beam, wherein changing the power density distribution may change the heating rate of the laser beam. In embodiments, the method may further include changing the power density of the laser beam, wherein changing the power density may change the heating rate of the laser beam. In embodiments, the method may include controlling the time the glass tube is exposed to the laser beam by adjusting the time a laser source used to generate the laser beam is turned on and off during heating the target region of the glass tube, separating the glass article from the working end of the glass tube, or both. In embodiments, exposing the target region, separation region, or both of the glass tube may include superimposing two or more laser beams at the target region, separation region, or both at once.

[0142] In an embodiment, the method may include rotating the glass tube at a rotational speed of 60 rpm to 400 rpm. In an embodiment, the laser beam may heat the glass tube at a rate of 200°C / second to 400°C / second. In an embodiment, the conversion rate of the glass tube to the glass article may be greater than or equal to 30 parts / minute. In an embodiment, heating the target area of ​​the glass tube or separating the glass article from the working end of the glass tube may include exposing the glass tube to a gas burner to heat the glass. In an embodiment, the target area may be located within 50 mm of the working end of the glass tube.

[0143] In an embodiment, a system for producing a glass article from a glass tube may include a converter comprising a plurality of processing stations spaced apart in a circuit, and at least one holder. The plurality of processing stations may include at least one heating station, at least one forming station, and a separation station. The at least one holder is operable to hold a working end of the glass tube and rotate the glass tube about a central axis. The converter is operable to sequentially translate the at least one holder, in which the glass tube is secured, through each of the plurality of processing stations. The system may further include at least one laser system positioned in at least one heating station or a separation station. The at least one laser system may include a laser source and a beam delivery system. The laser system is operable to generate a laser beam, modify one or more properties of the laser beam, and direct the laser beam to the glass tube in at least one heating station of the separation station. The laser system may include any of the components, features, or characteristics previously described herein with respect to the separation laser system 120. In an embodiment, the at least one laser system may include a plurality of laser systems, wherein the plurality of laser systems may include at least one heating laser system positioned in the at least one heating station and a separation laser system positioned in the separation station.

[0144] While various embodiments of the system 100 and methods of using the system 100 to cut and finish the end of the glass tube 102 have been described herein, it should be understood that each of these embodiments and techniques are contemplated for use alone or in combination with one or more embodiments and techniques.

[0145] It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Therefore, this specification is intended to cover modifications and variations of the various embodiments described herein, provided that such modifications and variations fall within the scope of the appended claims and their equivalents.

Claims

1. A method for producing a glass tube, the method comprising: Producing continuous hollow glass cylinders; cutting the continuous hollow glass cylinder into glass tubes having an initial length; Finishing at least one end of a plurality of glass tubes, wherein finishing at least one end of the plurality of glass tubes comprises: rotating each glass tube about a central axis of the glass tube; heating a target area of ​​the glass tube by exposing the target area of ​​the glass tube to separate laser beams while rotating the glass tube; and While exposing the target area of ​​the glass tube to the separation laser beam, applying a tensile force to the at least one end of the glass tube, wherein applying the tensile force while exposing the target area to the separation laser beam separates a section of the glass tube from the at least one end of the glass tube and finishes the new end of the glass tube.

2. The method of claim 1 , wherein finishing the at least one end of the glass tube reduces the length of the glass tube to a final length and polishes the new end of the glass tube in a single manufacturing step.

3. The method of claim 1, wherein finishing the at least one end of the glass tube produces the new end, the new end being an open end of the glass tube, such as having an opening therethrough.

4. The method of claim 1, wherein the at least one end of the glass tube is finished to seal the new end of the glass tube to produce a sealed end of the glass tube.

5. The method of claim 1, wherein the new end of the glass tube is substantially free of surface defects.

6. The method of claim 1, wherein the new end of the glass tube is substantially free of molten glass particles, hydrocarbon combustion products, or both.

7. The method of claim 1 , wherein applying the tensile force to the at least one end of the glass tube conveys the segment of the glass tube away from the glass tube in an axial direction relative to the central axis of the glass tube, which separates the segment from the glass tube.

8. The method of claim 1 , further comprising preheating the target area of ​​each of the plurality of glass tubes, wherein preheating the target area of ​​each of the plurality of glass tubes comprises rotating each of the glass tubes and exposing each of the glass tubes to a preheating laser beam positioned upstream of the separating laser beam.

9. The method according to claim 8, wherein the preheating laser beam is separated from the separation laser beam.

10. The method of claim 1, comprising finishing a first end of each of the plurality of glass tubes with a first separate laser beam and finishing a second end of each of the plurality of glass tubes with a second separate laser beam.

11. The method of claim 10, comprising finishing the first end and the second end of each of the plurality of glass tubes in parallel.

12. The method of claim 10, comprising finishing the second end with the second separate laser beam downstream of finishing the first end with the first separate laser beam.

13. The method of claim 1, wherein the separating laser beam is an elongated beam and the method comprises simultaneously exposing the target areas of a subset of the plurality of glass tubes to the separating laser beam.

14. The method of claim 13, wherein a ratio of a total length of the split laser beam to a beam width at a point on the beam path where the split laser beam impinges on the outer surface of the subset of glass tubes is from about 5 to about 2000.

15. The method of claim 13, wherein: Exposing the target area of ​​the plurality of glass tubes to the split laser beam includes sequentially passing each of the plurality of glass tubes through the elongated beam of the split laser beam from a leading edge to a trailing edge of the split laser beam; passing each of the plurality of glass tubes through the total length of the long axis of the separation laser beam to gradually heat the glass at the target area and separate the segment from the at least one end of each of the plurality of glass tubes; and The total length of the split laser beams is sufficient to contact each of the subset of glass tubes simultaneously.

16. The method of claim 15, wherein conveying each of the plurality of glass tubes sequentially through the elongated light beam comprises arranging the plurality of glass tubes side by side on a conveyor comprising a plurality of rollers and at least one conveyor belt, wherein: Each glass tube is placed between two adjacent rollers of the conveyor; The plurality of rollers of the conveyor rotate each of the plurality of glass tubes; and The at least one conveyor belt moves the drum and the plurality of glass tubes horizontally through the elongated light beam.

17. The method of claim 1, wherein the separate laser beam comprises an infrared laser.

18. The method according to claim 1, wherein the separate laser beams are continuous laser beams or alternating laser beams.

19. The method of claim 1, wherein the separation laser beam comprises a laser power of 200W to 2000W.

20. The method of claim 1, wherein the split laser beam is an elliptical beam.

21. The method of claim 1, wherein at the point on the beam path where the split laser beam is incident on the outer surfaces of the plurality of glass tubes, the split laser beam is an elliptical laser beam having a ratio of a major axis to a minor axis of about 5 to about 2000.

22. The method of claim 1, wherein the split laser beam has a Gaussian power density distribution along a long axis of the split laser beam.

23. The method of claim 1, wherein the split laser beam has a flat-top power density distribution along a long axis of the split laser beam.

24. The method of claim 1 , wherein the length of the separating laser beam is from about 100 mm to about 1000 mm, wherein the length of the separating laser beam is the distance from a leading edge to a trailing edge of the separating laser beam at a point on a beam path where the separating laser beam is incident on the outer surfaces of the plurality of glass tubes.

25. The method of claim 1, wherein a beam width of the separating laser beam at a point on the beam path where the separating laser beam is incident on the outer surfaces of the plurality of glass tubes is about 0.5 mm to about 20 mm.

26. The method of claim 1 , wherein a beam width of the separating laser beam is 0.5 mm to 5 mm at a point on the beam path where the separating laser beam is incident on the outer surfaces of the plurality of glass tubes, and exposing each of the plurality of glass tubes to the separating laser beam removes the segment of the at least one end of each glass tube to produce the new end including the opening.

27. The method of claim 1 , wherein the beam width of the splitting laser beam is approximately 3 mm to 20 mm at a point on the beam path where the splitting laser beam impinges on the outer surfaces of the plurality of glass tubes, and exposing each of the plurality of glass tubes to the splitting laser beam removes the segment of the at least one end of each glass tube to produce the new end, and the new end is sealed to produce a sealed end of the glass tube.

28. The method of claim 1, further comprising: determining whether to finish the at least one end of the plurality of glass tubes to produce an open or sealed new end; as well as changing one or more of the beam shape, power, power density distribution, or a combination thereof of the split laser beam, wherein: varying the beam shape, power, power density distribution, or a combination thereof of the split laser beam to vary the volume of glass heated in the target region of the plurality of glass tubes; reducing the volume of the glass heated in the target area to produce the new end having an opening; and Increasing the volume of the glass heated in the target region creates a glass meniscus that seals the new end when the segment is removed from the at least one end of the plurality of glass tubes.

29. The method of claim 28, comprising transitioning from forming the new end as open to forming the new end as sealed, wherein the transition comprises one or more of: increasing the beam width of the separated laser beam; increasing the power density of the split laser beam; changing the power density distribution from a Gaussian distribution to a flat-top distribution; or Its combination.

30. The method of claim 29, wherein the transitioning from forming the new end as open to forming the new end as sealed comprises heating a volume of glass sufficient to form a glass meniscus above the new end of the plurality of glass tubes as the segment is removed from the at least one end of the plurality of glass tubes.

31. The method of claim 28, comprising changing the beam shape of the split laser beam by changing the beam width to a range of 3 mm to 20 mm.

32. The method of claim 31 , wherein changing the beam shape comprises adjusting a spacing between lenses of a beam delivery system.

33. The method of claim 31 , wherein changing the beam shape comprises passing the split laser beam through a variable beam expander.

34. The method of claim 31 , wherein changing the beam shape comprises adjusting a distance between a beam delivery system and the plurality of glass tubes, which changes the point within the beam path at which the splitting laser beam contacts the outer surfaces of the plurality of glass tubes relative to a beam waist of the splitting laser beam.

35. The method of claim 28 , comprising varying the power density of the separating laser beam at a point along the beam path where the separating laser beam contacts outer surfaces of the plurality of glass tubes, wherein varying the power density of the separating laser beam comprises adjusting a power of a laser source used to generate the separating laser beam, varying a vertical distance between a beam delivery system and the plurality of glass tubes, or both.

36. The method of claim 1 , further comprising varying a heating rate of the separating laser beam, wherein varying the heating rate of the separating laser beam comprises varying the power density of the separating laser beam, varying the power density distribution of the separating laser beam, varying a speed at which a conveyor translates the plurality of glass tubes through the separating laser beam, or a combination thereof.

37. The method of claim 36 , comprising varying the power density of the separating laser beam, wherein varying the power density of the separating laser beam comprises adjusting a power of a laser source used to generate the separating laser beam, varying a vertical distance between a beam delivery system and the plurality of glass tubes, or both.

38. The method of claim 36 , comprising changing the power density distribution of the split laser beam, wherein changing the power density distribution comprises passing the split laser beam through a cylindrical lens to produce a Gaussian power density distribution with a lower heating rate, or passing the split laser beam through an aspheric cylindrical lens to produce a flat-top power density distribution with a larger heating rate.

39. The method of claim 1, further comprising: changing the type of glass tubes from a first type to a second type by changing the glass composition, nominal diameter, thickness, or a combination thereof of the plurality of glass tubes; as well as The heating rate of the split laser beam is changed in response to a change in the glass tube type.

40. The method of claim 39, wherein varying the heating rate comprises varying the power density of the separating laser beam, varying the power density distribution of the separating laser beam, varying a speed at which a conveyor translates the plurality of glass tubes through the separating laser beam, or a combination thereof.

41. The method of claim 39, wherein changing the heating rate does not require changing the lens of a beam delivery system.

42. The method of claim 1 , further comprising increasing a rate of production of the glass tubes, wherein increasing the rate of production of the glass tubes comprises changing a speed at which a conveyor translates the plurality of glass tubes through a beam path of the separating laser beam, and increasing a power density of the separating laser beam, changing a power density profile from a Gaussian power density profile to a flat-top power density profile, or both.

43. The method of claim 42, wherein increasing the production rate of the glass tubes further comprises preheating the target area of ​​the plurality of glass tubes with a preheat laser system.

44. The method of claim 1, wherein the target area of ​​each glass tube is located within at least 100 mm from the at least one end of the glass tube.

45. The method of claim 1, wherein the length of the segment removed from the at least one end of the plurality of glass tubes is less than 100 mm.

46. ​​The method of claim 1, further comprising horizontally transferring the plurality of glass tubes while rotating the plurality of glass tubes, and finishing the at least one end of each of the plurality of glass tubes.

47. The method of claim 1 , wherein exposing each of the plurality of glass tubes to the separate laser beam comprises: generating a laser beam using a laser source; passing the laser beam through an optical device that shapes the laser beam to produce the separate laser beams and directs the separate laser beams toward the plurality of glass tubes; as well as Each of the plurality of glass tubes is passed through a beam path of the separate laser beam.

48. The method of claim 1, wherein producing the continuous hollow glass cylinder further comprises pulling the continuous hollow glass cylinder from a tube forming apparatus.

49. The method of claim 1 , wherein producing the continuous hollow glass cylinder comprises: forming the continuous hollow glass cylinder from molten glass in a tube forming apparatus; pulling the continuous hollow glass cylinder from the tube forming apparatus through an annealing process; annealing the continuous hollow glass cylinder; cutting the continuous hollow glass cylinder to produce the plurality of glass tubes having an initial length; as well as The plurality of glass tubes are transferred to a horizontal conveyor upstream of finishing the at least one end of the plurality of glass tubes.

50. A system for finishing the ends of a plurality of glass tubes or glass rods, the system comprising: a conveyor operable to horizontally translate the plurality of glass tubes or glass rods while also rotating each of the plurality of glass tubes or glass rods about a central axis of the glass tube or glass rod; A separation laser system comprising: a laser source operable to generate a laser beam; as well as a beam delivery system operable to modify the shape, power density, power density distribution, or a combination thereof of the laser beam to produce and direct separate laser beams to the plurality of glass tubes or rods being translated and rotated by the conveyor; and One or more axially separate conveyors are separate from the conveyor and operable to apply a pulling force to a distal end of each of the plurality of glass tubes or rods in at least an axial direction relative to the central axis.

51. The system of claim 50, wherein the beam delivery system comprises one or more beam expansion optics, shaping optics, and steering mirrors.

52. The system of claim 51, wherein the beam delivery system further comprises one or more of a variable beam expander, a cylindrical lens, an aspheric cylindrical lens, a polygonal mirror, or a combination thereof to control the beam size, beam shape, beam power density distribution, or a combination thereof.

53. The system of claim 52, wherein the beam delivery system comprises at least one cylindrical lens operable to produce a split laser beam having a Gaussian power density distribution.

54. The system of claim 52, wherein the beam delivery system comprises an aspheric cylindrical lens operable to produce a beam having a flat-top power density distribution.

55. The method of claim 51 , wherein the beam delivery system comprises a variable beam expander.

56. The system of claim 50, further comprising a preheat laser system positioned upstream of the separation laser delivery system, wherein the preheat laser system comprises a preheat laser source and a preheat beam delivery system and is operable to direct a preheat laser beam to a target area of ​​the plurality of glass tubes or glass rods to preheat glass in the target area upstream of the separation laser beam.

57. The system of claim 50, wherein the split laser system comprises: a first split laser system operable to direct a first split laser beam to a target area proximate a first end of the plurality of glass tubes or rods; as well as A second separate laser system is operable to direct a second separate laser beam to a target area proximate second ends of the plurality of glass tubes or rods.

58. The system of claim 57, wherein the first separate laser system comprises a first laser source and a first beam delivery system, and the second separate laser system comprises a second laser source and a second beam delivery system.

59. The system of claim 57, further comprising: a first preheating laser system positioned upstream of the first separation laser system; as well as A second preheating laser system is positioned upstream of the second separate laser system, wherein each of the first preheating laser system and the second preheating laser system includes a preheating laser source and a preheating beam delivery system.

60. The system of claim 50, further comprising a positioning system operatively coupled to the separation laser system, wherein the positioning system is operable to change a distance between the separation laser system and the plurality of glass tubes or glass rods.

61. The system of claim 50, wherein the laser source is an infrared laser.

62. The system of claim 61, wherein the laser source is a CO laser or a CO2 laser.

63. The system of claim 50, wherein the system does not include a gas burner and does not include a mechanical tool for scoring the surface of the plurality of glass tubes or glass rods.

64. The system of claim 50, wherein the conveyor comprises a variable speed drive operatively coupled to one or more of the plurality of conveyor belts and operable to vary the speed at which the conveyor translates the plurality of glass tubes or rods through the beam path of the separating laser beam.

65. The system of claim 50, wherein the conveyor comprises a plurality of rollers and a plurality of conveyor belts.

66. A method for producing a glass rod, the method comprising: Producing a continuous solid glass cylinder; cutting the continuous solid glass cylinder into glass rods having an initial length; Finishing at least one end of a plurality of glass rods, wherein finishing at least one end of the plurality of glass rods comprises: rotating each glass rod about a central axis of the glass rod; heating a target region of the glass rod by exposing the target region of the glass rod to separate laser beams while rotating the glass rod; and While exposing the target area of ​​the glass rod to the separating laser beam, applying a tensile force to the at least one end of the glass rod, wherein applying the tensile force while exposing the target area to the separating laser beam separates a section of the glass rod from the at least one end of the glass rod and finishes the new end of the glass rod.

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