Systems and methods for laser-based glass tube separation and sealing

Abstract

A system for finishing the ends of glass tubes or rods includes a conveyor operable to translate and rotate the glass tubes or rods, and a separation laser system including a laser source operable to produce a separation laser beam and a beam delivery system operable to modify the shape, power density, or power density distribution of the separation laser beam and direct the separation laser beam at the glass tube or rod. A method for cutting and finishing the ends of glass tubes or rods using the system includes 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 the separation laser beam while rotating the glass tube or rod, and applying a pulling force to the end of the glass tube or rod.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application No. 63 / 441,305, filed January 26, 2023, the contents of which are herein relied upon and incorporated by reference in their entirety.

[0002] The present specification relates generally to methods, apparatus, and systems for the continuous production of glass tubing and glass rods, and specifically to methods, apparatus, and systems for finishing the ends of lengths of glass bars and glass tubing produced from continuous hollow glass tubing. [Background technology]

[0003] Background technology Historically, glass has been used to produce a variety of articles. Specifically, due to its hermeticity, optical clarity, and superior chemical durability compared to other materials, glass is a preferred material for pharmaceutical applications, including, but not limited to, vials, syringes, ampoules, cartridges, bottles, and other glass articles. Producing these articles from glass begins with providing a glass tube that can be later formed and separated into multiple glass articles. Specifically, glass used in pharmaceutical packaging must have adequate mechanical and chemical durability so as not to affect the stability of the pharmaceutical formulations contained therein. Glasses with suitable chemical durability include those glass compositions within the ASTM standard "Type IA" and "Type IB" glass compositions, which have a proven track record of chemical durability.

[0004] Glass tubing used as a starting material for producing glass articles is produced from a continuous process, such as the Danner or Bellow process, to produce a continuous hollow glass cylinder. The continuous hollow glass cylinder is annealed and cut into sections of glass tubing of approximately the same length by a high-speed continuous cutter. After initially separating the continuous hollow glass cylinder into multiple glass tubes, each of the glass tubes is further processed to finish the ends of the glass tube, such as by cutting to length and polishing the ends to reduce breakage during shipping and handling. Glass rods can also be produced as continuous solid glass cylinders from a similar process and then cut to rough lengths. The ends of the glass rods are also further processed to finish the ends of the rods to cut to final length and reduce breakage during shipping and handling. Summary of the Invention

[0005] Therefore, there is a need for methods, apparatus, and systems for the continuous production of glass tubing or glass rods, and in particular for continuous finishing of the ends of lengths of glass tubing and glass rods.

[0006] According to one or more aspects of the present disclosure, a method for producing glass tubing 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 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 area of ​​the glass tube by exposing the target area of ​​the glass tube to a separation laser beam while rotating the glass tube, and applying a pulling force to at least one end of the glass tube while exposing the target area of ​​the glass tube to the separation laser beam. Applying the pulling force while exposing the target area to the separation laser beam may separate a section of the glass tube from at least one end of the glass tube and finish a new end of the glass tube.

[0007] A second embodiment may include the first embodiment, wherein finishing at least one end of the glass tube may reduce the length of the glass tube to a final length and polish the new end of the glass tube in a single manufacturing step. A third embodiment may include any of the aforementioned embodiments, wherein finishing at least one end of the glass tube may produce a new end that is an open end of the glass tube, such as having an opening through the glass tube. A fourth embodiment may include the first or second embodiment, wherein finishing at least one end of the glass tube may seal the new end of the glass tube to produce a sealed end of the glass tube. A fifth embodiment may include any of the aforementioned embodiments, wherein the new end of the glass tube may be substantially free of surface defects. A sixth embodiment may include any of the aforementioned embodiments, wherein the new end of the glass tube may be substantially free of fused glass particles, hydrocarbon combustion products, or both.

[0008] A seventh aspect may include any of the preceding aspects, wherein applying a pulling force to at least one end of the glass tube may transport a section of the glass tube axially away from the glass tube relative to a central axis of the glass tube, thereby separating the section from the glass tube.

[0009] An eighth embodiment may include any of the preceding embodiments, further including preheating a 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 disposed upstream of the separation laser beam. A ninth embodiment may include the eighth embodiment, wherein the preheating laser beam may be separated from the separation laser beam.

[0010] A tenth aspect may include any of the aspects described above, including 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. An eleventh aspect may include the tenth aspect, including finishing the first end and the second end of each of the plurality of glass tubes in parallel. A twelfth aspect may include the tenth aspect, further including finishing the second end with a second separate laser beam downstream from finishing the first end with the first separate laser beam.

[0011] A thirteenth aspect may include any of the preceding aspects, wherein the separation laser beam may be an elongated beam, and the method may include simultaneously exposing target regions of a subset of the plurality of glass tubes to the separation laser beam. A fourteenth aspect may include any of the preceding aspects, wherein the separation laser beam may have a beam width to overall length ratio of about 5 to about 2000 at a point along the beam path where the separation laser beam is incident on an outer surface of the subset of glass tubes. A fifteenth aspect may include any one of the thirteenth or fourteenth aspects, wherein exposing target regions of the plurality of glass tubes to the separation laser beam may include sequentially transporting each of the plurality of glass tubes through the elongated beam of the separation laser beam from a leading edge to a trailing edge of the separation laser beam. Transporting each of the plurality of glass tubes through the entire length of the major axis of the separation laser beam may heat the glass at the target region and separate a section from at least one end of each of the plurality of glass tubes, and the entire length of the separation laser beam may be sufficient to simultaneously contact each of the subset of glass tubes. A sixteenth aspect may include the fifteenth aspect, wherein sequentially transporting each of the plurality of glass tubes through the elongated beam may include arranging the plurality of glass tubes in parallel on a conveyor including a plurality of rollers and at least one belt, each glass tube may be disposed 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 belt may move the rollers and the plurality of glass tubes horizontally through the elongated beam.

[0012] A seventeenth aspect may include any one of the aforementioned aspects, wherein the separate laser beams may include infrared lasers. An eighteenth aspect may include any one of the aforementioned aspects, wherein the separate laser beams may be continuous laser beams or alternating laser beams. A nineteenth aspect may include any one of the aforementioned aspects, wherein the separate laser beams may include a laser power of 200 W to 2000 W. A twentieth aspect may include any one of the aforementioned aspects, wherein the separate laser beams may be elliptical beams. A twenty-first aspect may include any one of the aforementioned aspects, wherein the separate laser beams may be elliptical laser beams having a ratio of their major axis to their minor axis of about 5 to about 2000 at points along the beam path where the separate laser beams are incident on the outer surfaces of the plurality of glass tubes. A twenty-second aspect may include any one of the aforementioned aspects, wherein the separate laser beams may have a Gaussian power density distribution along their major axes. A twenty-third aspect may include any one of the preceding aspects, wherein the separated laser beam may have a flat-top power density distribution along a major axis of the separated laser beam.

[0013] A twenty-fourth aspect may include any one of the preceding aspects, wherein the separation laser beam may have a length of about 100 mm to about 1000 mm, and the length of the separation laser beam may be a distance from a leading edge to a trailing edge of the separation laser beam at a point along the beam path where the separation laser beam is incident on the outer surfaces of the plurality of glass tubes. A twenty-fifth aspect may include any one of the preceding aspects, wherein the separation laser beam may have a beam width of about 0.5 mm to about 20 mm at a point along the beam path where the separation laser beam is incident on the outer surfaces of the plurality of glass tubes. A twenty-sixth aspect may include any one of the preceding aspects, wherein the separation laser beam may have a beam width of 0.5 mm to 5 mm at a point along the beam path where the separation 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 separation laser beam may remove a section of at least one end of each glass tube to produce a new end with an opening. A 27th aspect may include any one of the 1st to 25th aspects, wherein the separation laser beam may have a beam width of about 3 mm to 20 mm at a point along the beam path where the separation laser beam is incident on an outer surface of the plurality of glass tubes, and exposing each of the plurality of glass tubes to the separation laser beam may remove a section of at least one end of each glass tube to produce a new end, and seal the new end to produce sealed ends of the glass tubes.

[0014] A twenty-eighth aspect may include any one of the preceding aspects, the twenty-eighth aspect further including determining to finish at least one end of the plurality of glass tubes to produce an open new end or a sealed new end; and varying one or more of a beam shape, a power, a power density distribution, or a combination thereof of the separation laser beam, wherein varying the beam shape, a power, a power density distribution, or a combination thereof of the separation laser beam may change a volume of heated glass within a target region of the plurality of glass tubes, wherein decreasing the volume of heated glass within the target region may produce a new end with an opening, and wherein increasing the volume of heated glass within the target region may produce a meniscus of glass that seals the new end when a section is removed from at least one end of the plurality of glass tubes. A 29th aspect may include the 28th aspect, wherein the 29th aspect includes transitioning from forming an open new end to forming a sealed new end, and the transitioning may include one or more of increasing a beam width of the separation laser beam, increasing a power density of the separation laser beam, changing a power density distribution from a Gaussian distribution to a flat-top distribution, or a combination thereof. A 30th aspect may include the 29th aspect, wherein the transitioning from forming an open new end to forming a sealed new end may include heating a volume of glass sufficient to form a meniscus of glass on the new ends of the plurality of glass tubes when a section is removed from at least one end of the plurality of glass tubes.

[0015] A thirty-first aspect may include any of the twenty-ninth or thirty-first aspects, and may include changing the beam shape of the separated laser beam by changing the beam width in a range of 3 mm to 20 mm. A thirty-second aspect may include the thirty-first aspect, and may include adjusting a spacing between lenses of the beam delivery system. A thirty-third aspect may include any one of the thirty-first or thirty-second aspects, and may include passing the separated laser beam through a variable beam expander. A thirty-fourth aspect may include any of the thirty-first to thirty-third aspects, and may include adjusting a distance between the beam delivery system and the plurality of glass tubes, thereby changing a point in the beam path where the separated laser beam contacts the outer surfaces of the plurality of glass tubes relative to the waist of the separated laser beam.

[0016] A thirty-fifth aspect may include any one of aspects twenty-eight to thirty-four, and may further include varying the power density of the separated laser beam at a point along the beam path where the separated laser beam contacts the outer surface of the plurality of glass tubes, and varying the power density of the separated laser beam may further include adjusting the output of a laser source to produce the separated laser beam, varying the vertical distance between the beam delivery system and the plurality of glass tubes, or both.

[0017] A thirty-sixth aspect may include any of the preceding aspects, further including varying a heating rate of the separation laser beam, where varying the heating rate of the separation laser beam may include varying the power density of the separation laser beam, varying the power density distribution of the separation laser beam, varying the speed of a conveyor that translates the plurality of glass tubes through the separation laser beam, or a combination thereof. A thirty-seventh aspect may include the thirty-sixth aspect, where varying the power density of the separation laser beam may include adjusting the output of a laser source to produce the separation laser beam, varying the vertical distance between the 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, wherein the thirty-eighth aspect includes varying the power density distribution of the separated laser beam, and wherein varying the power density distribution may include passing the separated laser beam through a cylindrical lens to produce a Gaussian power density distribution with a lower heating rate, or passing the separated laser beam through an aspherical cylindrical lens to produce a flat-top power density distribution with a greater heating rate.

[0018] A thirty-ninth aspect may include any one of the preceding aspects, further including changing the type of glass tube 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 a heating rate of the separation laser beam in response to the change in glass tube type. 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 of a conveyor that translates the plurality of glass tubes through the separation laser beam, or a combination thereof. A forty-first aspect may include any one of the thirty-ninth or fortieth aspects, wherein changing the heating rate does not require changing lenses of the beam delivery system.

[0019] A forty-second aspect may include any one of the preceding aspects, wherein the forty-second aspect further includes increasing the production rate of the glass tubes, wherein increasing the production rate of the glass tubes may include changing a speed of a conveyor that translates the plurality of glass tubes through a 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 production rate of the glass tubes may further include preheating target areas of the plurality of glass tubes using a preheating laser system.

[0020] A 44th aspect may include any one of the preceding aspects, wherein the target area of ​​each glass tube may be within at least 100 mm of at least one end of the glass tube. A 45th aspect may include any one of the preceding aspects, wherein the section removed from at least one end of the plurality of glass tubes may have a length of less than 100 mm. A 46th aspect may include any one of the preceding aspects, further including conveying the plurality of glass tubes horizontally while rotating the plurality of glass tubes and finishing at least one end of each of the plurality of glass tubes. A 47th aspect may include any one of the preceding aspects, wherein exposing each of the plurality of glass tubes to the separate laser beams may include producing a laser beam using a laser source, passing the laser beam through an optical system that shapes the laser beam to produce separate laser beams and directs the separate laser beams toward the plurality of glass tubes, and passing each of the plurality of glass tubes in a beam path of the separate laser beam.

[0021] A forty-eighth aspect may include any one of the preceding aspects, wherein producing the continuous hollow glass cylinder may further include drawing the continuous hollow glass cylinder from a tube forming apparatus.A forty-ninth aspect may include any one 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 a plurality of glass tubes having an initial length, and transferring the plurality of glass tubes to a horizontal conveyor upstream of finishing at least one end of the plurality of glass tubes.

[0022] 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 translate the plurality of glass tubes or glass rods horizontally while also rotating each of the plurality of glass tubes or glass rods about a central axis of the glass tubes or glass rods; and a separation laser system, the separation laser system comprising: a laser source operable to produce 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 produce a separation laser beam and direct the separation laser beam toward the plurality of glass tubes or glass rods being translated and rotated by the conveyor. The system may further comprise one or more axial separation conveyors branching from the conveyor and operable to exert a pulling force on each end of the plurality of glass tubes or glass rods in at least an axial direction relative to the central axis.

[0023] A fifty-first aspect may include the fifty-first aspect, wherein the beam delivery system may include one or more beam expanding optics, shaping optics, and a rotating mirror. A fifty-second aspect may include any one of the fifty-first or fifty-first aspects, wherein the beam delivery system may further include one or more of a variable beam expander, a cylindrical lens, an aspherical cylindrical lens, a polygonal mirror, or a combination thereof for controlling the beam size, beam shape, beam power density distribution, or a combination thereof. A fifty-third aspect may include any one of the fifty-first to fifty-second aspects, wherein the beam delivery system may include at least one cylindrical lens operable to produce a separated laser beam having a Gaussian power density distribution. A fifty-fourth aspect may include any one of the fifty-third to fifty-third aspects, wherein the beam delivery system may include an aspherical cylindrical lens operable to produce a beam having a flat-top power density distribution. A fifty-fifth aspect may include any one of the fifty-fourth aspects, wherein the beam delivery system includes a variable beam expander.

[0024] A 56th aspect may include any one of aspects 50 to 55, and the 56th aspect may further include a preheating laser system disposed 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 may be operable to direct a preheating laser beam at a target area of ​​the multiple glass tubes or glass rods to preheat glass within the target area upstream of the separation laser beam.

[0025] A fifty-seventh aspect may include any one of aspects fifty to fifty-six, wherein the separation laser system may comprise: a first separation laser system operable to direct a first separation laser beam to a target area proximate a first end of the plurality of glass tubes or glass rods; and a second separation laser system operable to direct a second separation laser beam to a target area proximate a second end of the plurality of glass tubes or glass rods. A fifty-eighth aspect may include the fifty-seventh aspect, wherein the first separation laser system may comprise a first laser source and a first beam delivery system, and the second separation laser system may comprise a second laser source and a second beam delivery system.

[0026] A fifty-ninth aspect may include any one of the fifty-seventh or fifty-eighth aspects, the fifty-ninth aspect comprising a first preheating laser system disposed upstream of the first separation laser system and a second preheating laser system disposed upstream of the second separation laser system, each of the first preheating laser system and the second preheating laser system further comprising a preheating laser source and a preheating beam delivery system.

[0027] A 60th aspect may include any one of aspects 50 to 59, and the 60th aspect may further include a positioning system operably coupled to the separation laser system, and the positioning system may be operable to vary the distance between the separation laser system and the plurality of glass tubes or glass rods.

[0028] A sixty-first aspect may include any one of aspects fifty to sixty, wherein the laser source may be an infrared laser. A sixty-second aspect may include any one of aspects fifty to sixty-first, wherein the laser source may be a CO laser or a CO laser. A sixty-third aspect may include any one of aspects fifty to sixty-second, 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.

[0029] A sixty-fourth aspect may include any one of aspects fifty to sixty-third, wherein the conveyor may comprise a variable speed drive operatively coupled to one or more of the plurality of belts and operable to vary the speed of the conveyor for translating the plurality of glass tubes or glass rods through the beam path of the separation laser beam. A sixty-fifth aspect may include any one of aspects fifty to sixty-fourth, wherein the conveyor may comprise a plurality of rollers and a plurality of belts.

[0030] A sixty-sixth embodiment may be directed to a method for producing a glass rod, 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 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 area of ​​the glass rod by exposing the target area of ​​the glass rod to a separation laser beam while rotating the glass rod, and applying a pulling force to the at least one end of the glass rod while exposing the target area of ​​the glass rod to the separation laser beam, wherein applying the pulling force while exposing the target area to the separation laser beam may separate a section of the glass rod from the at least one end of the glass rod and may finish a new end of the glass rod.

[0031] Additional features and advantages of the systems and methods disclosed herein will be set forth in the following detailed description, and in part will become readily apparent to those skilled in the art from that description, or may be learned by practicing the embodiments described herein, including the following detailed description, the claims, and the accompanying drawings.

[0032] It is to be understood that both the foregoing general description and the following detailed description are intended to describe various embodiments and provide an overview or framework for understanding the nature and features 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 various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. [Brief explanation of the drawings]

[0033] [Figure 1] 1A and 1B schematically depict 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. [Figure 2] 1 schematically depicts a side perspective view of a glass tube according to one or more embodiments shown and described herein; [Figure 3] 1A and 1B schematically depict a top view of a process for continuously producing glass tubing according to one or more embodiments shown and described herein. [Figure 4] 4 schematically depicts a side view of the process of FIG. 3 for continuously producing glass tubing according to one or more embodiments shown and described herein. [Figure 5] 2 schematically depicts a top view of the system of FIG. 1 for finishing the ends of a plurality of glass tubes or glass rods according to one or more embodiments shown and described herein; [Figure 6] 10 graphically depicts relative beam intensity (y-axis) as a function of beam position (x-axis) for long beams having Gaussian and flat-top power density profiles according to one or more embodiments shown and described herein. [Figure 7] 2 schematically depicts another side view of the system of FIG. 1 with a positioning system, according to one or more embodiments shown and described herein; [Figure 8]2 schematically depicts a side perspective view of the system of FIG. 1 during operation of the system, according to one or more embodiments shown and described herein; [Figure 9] 1A and 1B schematically depict a front view of a system for finishing both ends of a glass tube or glass rod according to one or more embodiments shown and described herein. [Figure 10] FIG. 10 schematically depicts a side view of another system for finishing the end of a glass tube or glass rod having a separation laser system and a preheating laser system according to one or more embodiments shown and described herein. [Figure 11] 2 is a photograph of the end of a glass tube separated using the system of FIG. 1 according to one or more embodiments shown and described herein. [Figure 12] 2 is a photograph of the ends of glass tubes separated and sealed using the system of FIG. 1 according to one or more embodiments shown and described herein. DETAILED DESCRIPTION OF THE INVENTION

[0034] explanation Reference will now be made in detail to embodiments of apparatus, systems, and methods for continuously producing composite glass tubes or glass 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 parts. Referring now to FIG. 1 , a system 100 of the present disclosure for finishing one or both ends of glass tubes 102 or glass rods (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. System 100 further includes a separation laser system 120 comprising a laser source 130 operable to produce a separation laser beam 132 and a beam delivery system 140 operable to modify the shape and / or characteristics of the separation laser beam 132 and direct the separation laser beam 132 toward the plurality of glass tubes 102 or glass rods as the plurality of glass tubes 102 or glass rods are translated and rotated by conveyor 110. System 100 may further include one or more axial separation conveyors 180 branching from conveyor 110 and operable to exert a pulling force on an end of each of the plurality of glass tubes 102 or glass rods in at least an axial direction relative to a central axis A of each of the plurality of glass tubes 102 or glass rods.

[0035] The system 100 disclosed herein can be used in a method for finishing the end of a glass tube 102 or a glass rod. The method for finishing the end of a glass tube 102 or a glass rod includes rotating each glass tube 102 or glass rod about a central axis A, heating a target area of ​​the glass tube 102 or glass rod by exposing the target area of ​​the glass tube 102 or glass rod to a separation laser beam 132 while rotating the glass tube 102 or glass rod, and applying a pulling force to at least one end of the glass tube 102 or glass rod while exposing the target area of ​​the glass tube 102 or glass rod to the separation laser beam 132, wherein applying the pulling force while exposing the target area to the separation 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 finishing a new end of the glass tube 102 or glass rod. The methods disclosed herein for producing glass tubes 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 glass tubes 102. The methods disclosed herein for producing glass rods 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 glass tubes 102 or glass rods.

[0036] Unless otherwise expressly stated, it is never intended that any method described herein be construed as requiring its steps to be performed in a particular order, or that any apparatus require a particular orientation. Thus, if a method claim does not actually recite the order in which its steps are to be followed, or if any apparatus claim does not actually recite an order or orientation for individual components, or if the claim or specification does not specifically state that the steps are to be limited to a particular order or that no particular order or orientation for the apparatus components is recited, then no order or orientation is intended to be inferred in any respect. This holds for any possible implicit basis for interpretation, including logical matters regarding the arrangement of steps, workflow, component order, or component orientation, the apparent meaning derived from grammatical construction or punctuation, and the number or type of embodiments described in the specification.

[0037] Directional terms used herein, e.g., up, down, right, left, front, back, top, bottom, are used only with reference to the depicted figures and the coordinate axes provided therewith, and are not intended to imply absolute orientations.

[0038] 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.

[0039] As used herein, "axial direction" refers to a direction parallel to the central axis A of the glass tube or glass rod.

[0040] As used herein, the "beam waist" of a laser beam refers to the point along the beam path of the laser beam where the power density of the laser beam is greatest.

[0041] 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 through the manufacturing process. For example, if the glass tube encounters a first feature before encountering a 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.

[0042] As used herein, the terms "up beam" and "down beam" 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. A first component may be considered to be an up beam of a second component if the laser beam encounters the first component before encountering the second component. Conversely, a first component may be considered to be a down beam of a second component if the laser beam encounters the second component before encountering the first component.

[0043] Due to its airtightness, optical clarity, and superior chemical durability compared to other materials, glass is a preferred material for pharmaceutical applications, including, but not limited to, vials, syringes, ampoules, cartridges, bottles, and other glass articles. These pharmaceutical glass containers, as well as other types of glass articles, can be produced through a process in which lengths of glass tubing are converted into one or more glass articles through multiple heating and forming operations. Referring to FIG. 2 , one embodiment of a glass tube 102 for use as a starting point for fabricating multiple glass articles is schematically depicted. The glass tube 102 comprises a hollow cylinder of glass having an outer surface 104 and an inner surface 106. The inner surface 106 defines the interior of the glass tube 102. The glass tube 102 has a first end 107 and a second end 108 opposite the first end. The glass tube 102 is characterized by a tube length L, an outer diameter OD, and a thickness t. The tube length L is the distance from the first end 107 to the second end 108, and the thickness t refers to the average radial distance between the outer surface 104 and the inner surface 106 of the glass tube 102. The glass tube 102 further comprises a central axis A. Although described in the context of a glass tube 102, the separation and end finishing methods can be applied to the entire length of a glass rod with equal effect, and they can also be used to produce multiple glass articles.

[0044] The subject matter disclosed herein relates to a system and method for separating and finishing the ends of glass tubes or glass rods during a production process for producing glass tubes and glass rods. In production, molten glass is first formed into a continuous hollow glass cylinder using a glass tube forming process. The process for forming the molten glass into a continuous hollow glass cylinder may include the Danner process, the Bellow process, or other current or future developed processes for producing continuous hollow glass cylinders. The continuous hollow glass cylinder is then pulled through an annealing process and then cut into individual glass tubes having an initial length.

[0045] 3 and 4, one embodiment of a system 200 for producing a plurality of glass tubes 102 is schematically depicted. 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 drawer 250 downstream of the annealing section 240, a continuous tube cutter 260 downstream of the tube drawer 250, and a horizontal conveyor 110 disposed downstream of the continuous tube cutter 260.

[0046] In operation of system 200, glass 202 is introduced into melting furnace 210, which is operable to melt the glass to form molten glass 212. The molten glass 212 is then passed to glass tube former 220, which is operable to form the molten glass 212 into a continuous hollow glass cylinder 222. As shown in Figure 4, in an embodiment, glass tube former 220 may be a tube former used in a Danner process, where molten glass 212 flows from a feeder into a rotatable, tilted hollow cylinder and is drawn from the rotatable, tilted hollow cylinder by tube puller 250 into muffle furnace 230 to produce the continuous hollow glass cylinder 222. While the continuous hollow glass cylinder 222 is being drawn from the tube former 220, compressed air or other gas supplied to the center of the continuous hollow glass cylinder 222 through the tube former 220, along with a vacuum applied from the outside of the continuous hollow glass cylinder 222, helps control the tube diameter and prevent the continuous hollow glass cylinder 222 from collapsing before it cools enough to hold its shape. Although shown in Figure 4 as the Danner process, it is understood that the continuous hollow glass cylinder 222 may be made using the Vello process or any other current or future process for making continuous hollow glass cylinders.

[0047] 3 and 4 , after being formed, the continuous hollow glass cylinder 222 is then pulled by a tube puller 250 through a muffle furnace 230 and an annealing section 240. The annealing section 240 may be operable to anneal the continuous hollow glass cylinder 222 to produce an annealed continuous hollow glass cylinder 242. The tube puller 250 may include one or more sets of drive rollers 252 operable to exert a pulling force on 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 puller 250, the annealed continuous hollow glass cylinder 242 is passed to a tube cutter 260, where the annealed continuous hollow glass cylinder 242 is roughly cut into glass tubes 102 having an initial length.

[0048] The process for producing a glass rod is similar to the process for producing a glass tube, except for the apparatus and method for drawing the glass rod from the melting furnace 210. Once the continuous solid glass rod is formed from the molten glass, it is pulled by a rod puller through a muffle furnace and an annealing section. The annealed continuous solid glass cylinder is then cut into continuous rough lengths by a cutter to produce a glass rod having an initial length.

[0049] The first cut performed by the tube cutter 260 or rod cutter is a rough cut, followed by further processing of the glass tube 102 or glass rod to cut it to a final length and to finish the ends of the glass tube 102 or glass rod. Referring to FIG. 3 , after 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 a conventional tube manufacturing process, the glass tube 102 is cut to a final length in a second cut using a combination of a mechanical tool for crack (flaw) initiation, heating with a gas burner, and quenching the glass tube 102 to create a thermal shock condition and propagate the crack around the circumference of the glass tube 102, completing the separation of the section from the end of the glass tube 102. After the second cut is made at both ends, the edges at the ends of the glass tube are finished through flame polishing using a gas burner. Glass rods (not shown) may be processed in a similar manner to cut the glass rod to length and finish the ends. Conventional manufacturing processes for final cutting to length and edge finishing are well established but present many challenges and opportunities for improvement, especially in light of the current increasing demand for pharmaceutical products and increased focus on high quality, manufacturing efficiency, and environmental sustainability.

[0050] One of the challenges in existing tube or glass rod production processes is manufacturing throughput. As the drawing speed of continuous hollow or solid glass cylinders constantly increases, especially for thin-walled products, cutting and finishing steps must ensure high-quality tube or rod edges (free of glass defects, acceptable geometry, high strength) and precise final lengths to achieve low losses and high yields at high processing speeds. Existing cutting processes rely on the creation of an initial flaw on the surface of the tube or rod, performed by a cutting blade (or other mechanical tool), and the subsequent propagation of a crack. The creation of a fracture surface, which begins from an initial mechanical defect and propagates around the circumference of the glass tube due to thermal stress, is not very precise and requires several processing steps, which is inefficient. In addition, separation is followed by edge flame polishing, which is necessary to repair surface defects created by the scoring and breaking method. Edge or end flame polishing implies an additional process step and requires extra time to complete, further reducing the efficiency of the manufacturing process.

[0051] Pharmaceutical packaging products, such as vials, cartridges, syringes, ampoules, or other containers converted from glass tubes, require high levels of cleanliness. The mechanical crack initiation process used in current conventional tube finishing processes scratches the surface of the tube or rod, generating glass particles that contaminate the outer and inner surfaces of the glass tube or rod. These glass particles then need to be removed from the glass tube or rod through a thorough cleaning process. The cleaning process becomes more complicated when a large number of particles are generated during the manufacturing process, especially when the glass particles adhere to the surface, for example, by fusing to the glass surface during flame polishing of the edges of the glass tube or rod.

[0052] Additionally, conventional manufacturing processes for finishing the ends of glass tubes or glass rods further contaminate the final product by exposing 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. Specifically, interaction of the glass with combustion products from gas burners used in heat treating and flame polishing can contaminate the surface of the glass final product (e.g., the finished tube or rod). Combustion of fuel for the gas burners also creates process exhaust containing combustion products that can have adverse environmental effects.

[0053] Furthermore, certain glass tube products require sealed tube ends. In conventional glass tube manufacturing processes, sealing the ends of the glass tube is currently performed at the end of the conveyor line described above as an additional step performed using a gas burner after final cutting to length and edge polishing. The use of a gas burner to seal the ends of the glass tube 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 tube and create additional process emissions. Therefore, there is a need to improve current glass cutting and finishing processes to improve manufacturing efficiency and quality and reduce contamination and emissions during the production of glass tubes and glass rods.

[0054] The present application is directed to a new 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 also rotating each of the plurality of glass tubes or glass rods about a central axis. The system further includes a separation laser system comprising a laser source operable to produce a separation laser beam and a beam delivery system operable to shape 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 further include one or more axial separation conveyors branching from the conveyor and operable to apply a pulling force to the ends 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.

[0055] The laser-based method disclosed herein for finishing the ends of glass tubes or rods includes 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 separation laser beam produced by a separation laser system while rotating the glass tube or rod, and applying a pulling force to at least one end of the glass tube or rod while exposing the target area of ​​the glass tube or rod to the separation laser beam. Applying the pulling force while exposing the target area to the separation laser beam separates a section of the glass tube or rod from at least one end of the glass tube or rod and finishes a new end of the glass tube or rod.

[0056] The systems and methods disclosed herein can achieve cutting of glass tubes and glass rods to produce finished new ends. The methods allow for a more stable, precise, and controllable mode of heat delivery to the glass due to the well-defined area affected by the separate laser beam and the stability of the laser power over long periods of time. Precise heating by the laser system can minimize dimensional variations in the final part, reduce the number of rejects, and increase yields by tightly controlling the glass viscosity. In the case of glass tubes, the systems and methods can achieve cutting of the glass tube to produce new ends that are open ends, or, in tube cutting with sealing, producing new ends that are sealed. The systems and methods disclosed herein combine cutting and edge finishing into a one-step process. The systems and methods disclosed herein enable glass tube separation and bottom formation to be performed simultaneously. Furthermore, the systems and methods disclosed herein can enable switching of beam characteristics (e.g., length, beam width, power density, etc.) between a tube separation and finishing mode and a tube separation and bottom formation mode without changing the lenses of the beam delivery system.

[0057] Additionally, the design of the beam delivery system for the separation laser beam, the preheating laser beam, or both creates a long laser beam, which allows for continuous processing of multiple tubes or rods at the same time, increasing heating efficiency and reducing processing time. Heating of the tube or rod with the long laser beam occurs continuously and uninterrupted as the glass tube or rod is translated horizontally by the conveyor, which is advantageous over separate heating with multiple gas burners and allows for faster conveyor speeds. The heating rate of the glass tube or rod can be adjusted depending on the type and size of the glass tube or rod by varying the power density and / or power density profile along the length of the separation laser beam. The system and method 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 different glass types, diameters, and wall thicknesses of the glass tube or rod. The systems and methods may optionally use additional long laser beams (i.e., preheating the laser beam) to further enable preheating of target areas of the glass tube or glass rod to accelerate separation and / or process glass tubes or glass rods with larger diameters or glass tubes with larger sidewall thicknesses.

[0058] Furthermore, the systems and methods disclosed herein do not require mechanical initiation and quenching to create a thermal shock for crack propagation. Therefore, the systems and methods disclosed herein can reduce contamination of the surface of the glass tube or glass rod with fused 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 process.

[0059] Referring again to FIG. 1 , a 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 (shown in FIG. 5 ). The separation laser system 120 may include a laser source 130 operable to produce a laser beam 131 and a beam delivery system 140 operable to shape the laser beam 131 to produce a separation laser beam 132 and direct the separation laser beam 132 to a plurality of glass tubes 102 or glass rods that are translated and rotated by the 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 may be applied with equal effect to cutting and finishing the ends of glass rods.

[0060] In an embodiment, the conveyor 110 may include multiple rollers 112 and multiple belts 114. The conveyor 110 may be operable to translate the multiple glass tubes 102 horizontally (i.e., in the +X direction of the coordinate axes in FIG. 1 ) while also rotating each of the glass tubes 102 about its central axis A. The multiple rollers 112 may be arranged in parallel in the + / -X directions of the coordinate axes in FIG. 1 . In an embodiment, the rollers 112 may extend axially in the + / -Y directions, which may be parallel to the central axis A of the glass tube 102. The rollers 112 may be rotatable in the same rotational direction. After each of the glass tubes 102 has been cut to an initial length by the tube cutter 160 ( FIG. 3 ), it may be positioned within a convergent gap between two adjacent rollers 112 and supported through contact with the adjacent rollers 112. While the rollers 112 are rotating, contact between the outer surface 104 of the glass tube 102 and the surface of the rollers 112 may cause the glass tube 102 to rotate about the central axis A of the glass tube 102 .

[0061] The plurality of belts 114 may be operably coupled to a drive motor (not shown), which may move the belts 114 along the belt path. The belts 114 may contact portions of the rollers 112 such that contact between the belts 114 and the rollers 112 may translate the rollers 112 and the glass tubes 102 disposed between each of the rollers 112 horizontally (i.e., in the +X direction of the coordinate axis of FIG. 1 ) as the belts 114 are moved along the belt path. Contact of one or more of the belts 114 with the rollers 112 may further cause the rollers 112 to rotate, facilitating rotation of the glass tubes 102. In an embodiment, the drive motor operably coupled to the belts 114 may be a variable speed drive, which may be operable to vary the speed of the conveyor 110 to translate the plurality of glass tubes 102 horizontally through the beam path of the separated laser beam 132. Although described as having a plurality of rollers 112 and belts 114, it is understood that the conveyor 110 can have other configurations so long as the conveyor is operable to translate the glass tubes 102 horizontally while simultaneously rotating the glass tubes 102 about the central axis A of each glass tube.

[0062] The system 100 includes one or more devices operable to exert a pulling force on each end of the glass tubes at least axially relative to the central axis A of each of the plurality of glass tubes. Referring now to FIG. 5, in an embodiment, the system 100 may include one or more axial separation conveyors 180. The axial separation conveyor 180 may gradually diverge from the conveyor 110 in the longitudinal direction (i.e., the cross-machine direction, or the +Y or −Y direction of the coordinate axes in FIG. 5). In an embodiment, the axial separation conveyor 180 may include a plurality of rollers, and each end of the glass tubes 102 may be disposed in a gap between and supported by adjacent rollers. The axial separation conveyor 180 may also include a plurality of belts (not shown) and a drive motor (not shown) for driving the axial separation conveyor 180. The axial separation conveyor 180 may be operable to exert a pulling force on each end of the glass tubes 102 at least axially 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 exert a pulling force F on 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 102 during finishing of the glass tube 102. The second axial separation conveyor 180' may exert a pulling force F on the second end 108 of the glass tube 102, which may help separate the second section 194 from the second end 108 of the glass tube 102 during finishing of the glass tube 102. Instead of or in addition to the axial separation conveyor 180, a method or device other than the axial separation conveyor 180 may be used to generate a pulling force F on the ends of the glass tubes.

[0063] Referring again to FIG. 1 , the separation laser system 120 may include a laser source 130 and a beam delivery system 140 disposed down-beam from 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 produce a separation laser beam 132 and direct the separation laser beam 132 toward the glass tube 102. The laser source 130 may be operable to produce the laser beam 131. The laser beam 131 and the separation laser beam 132 produced therefrom may have a wavelength in a wavelength range that is absorbed by the glass of the glass tube 102, allowing the separation laser beam 132 to heat the glass, but does not significantly pass through the glass. Because silicate-based glass has a strong absorption of light having a wavelength of approximately 4 micrometers (μm) or greater, many different laser sources can be used to produce the laser beam 131. The laser source 130 may be operable to produce a laser beam 131 having a wavelength in the infrared wavelength range, such as the far infrared range. The laser source 130 may be operable to produce a laser beam 131 having a wavelength of about 1 μm or greater, about 2 μm or greater, about 3 μm or greater, about 4 μm or greater, or even about 8 μm or greater. The laser source 130 may be operable to produce a laser beam 131 having a wavelength of about 12 μm or less, or even about 11 μm or less. The laser source 130 may be operable to produce 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 particular wavelength range may depend in part on the type of glass composition comprising the glass tube.

[0064] Laser source 130 may be operable to produce laser beam 131, which is an infrared laser beam. In embodiments, laser source 130 may be a CO laser, a CO laser, a quantum cascade laser (QCL), or other type of suitable laser capable of producing laser beam 131 having a wavelength within the above range. Laser source 130 may be operable to produce continuous or pulsed laser beam 131. Continuous lasers generally have lower peak power and gradually increase the glass surface temperature, while pulsed lasers generally have higher peak power for a shorter length of time and increase the glass surface temperature to a greater extent compared to continuous lasers. Laser beam 131 may be collimated or uncollimated.

[0065] Referring again to FIG. 1 , the beam delivery system 140 may be positioned down the beam from the laser source 130. The beam delivery system 140 may be operable to modify the characteristics of the laser beam 131, such as the shape, power density distribution, other beam characteristics, or a combination thereof, to produce separate laser beams 132. The beam delivery system 140 may further be operable to direct the separate laser beams 132 to multiple glass tubes 102 as the glass tubes 102 are translated horizontally and rotated by the conveyor 110. The beam delivery system 140 may include one or more beam expanding optics, shaping optics, a rotating mirror 150, or a combination thereof. In an embodiment, the beam delivery system 140 may include at least one expanding optic, at least one shaping optic, and at least one rotating mirror 150.

[0066] The expanding optics, shaping optics, or both may include one or more lenses, mirrors, or both operable to expand laser beam 131, shape laser beam 131 into an elongated laser beam, or both, to produce separated laser beams 132. Laser beam 131 produced by laser source 130 may be a round, Gaussian laser beam. Beam delivery system 140 may include optical components that convert the round shape of laser beam 131 into an elliptical beam, vary the dimensions (e.g., length and width) of laser beam 131, and / or vary the power density distribution along one or both axes of the elliptical beam to produce separated laser beams 132. In embodiments, 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 change beam size, beam shape, beam power density distribution, or combinations thereof. In embodiments, the beam delivery system 140 may include one or more zoom telescope lenses or other variable beam expanders that may be operable to change the beam size, such as by increasing the beam size of the laser beam 131, to produce the separated laser beam 132. In embodiments, the beam delivery system 140 may include one or more cylindrical lenses that may be operable to change the shape of the laser beam 131, such as by changing the length, beam width, or both, of the laser beam 131 to produce the separated laser beam 132. In embodiments, the beam delivery system 140 may include multiple cylindrical lenses that are operable to transition the round laser beam 131 into the separated laser beam 132 having an elliptical shape. The multiple cylindrical lenses may also expand or compress the laser beam 131 to produce the separated laser beam 132 having target dimensions (e.g., length and beam width) at the point where the separated laser beam 132 contacts the glass tube 102.

[0067] In embodiments, 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 beams 132. In embodiments, the beam delivery system 140 may include one or more spherical cylindrical lenses operable to produce the separated laser beams 132 having a Gaussian power density distribution. In embodiments, the beam delivery system 140 may include one or more aspherical cylindrical lenses operable to produce the separated laser beams 132 having a flat-top power density distribution. In embodiments, the beam delivery system 140 may include one or more polygon mirrors operable to change the power density distribution of the laser beam 131 to produce the separated laser beams 132. In embodiments, the separated laser beams 132 are elliptical beams, and the cylindrical lenses, aspherical cylindrical lenses, or polygon mirrors may be configured to change the power density distribution in the direction of the major axis (i.e., the longitudinal direction, such as the + / −X direction of the coordinate axes in FIG. 1 ).

[0068] Referring now to FIG. 6, a graph depicts power density (y-axis) as a function of position within the beam (x-axis) for two different power density distributions of the separated laser beam 132. The position within the beam in FIG. 6 refers to the position within the beam in the longitudinal direction (i.e., along the major axis of the elliptical beam, such as the + / -X direction of the coordinate axes in FIG. 1). As shown in FIG. 6, the Gaussian power density distribution 602 is characterized by a maximum laser power density at the center 600 of the separated laser beam 132 and a decreasing power density with increasing distance from the center 600 of the separated laser beam 132. In contrast, the flat-top power density distribution 604 has a smaller maximum power density, but the power density is more uniform across most of the major axis of the laser beam.

[0069] 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 laser beam 131 to produce separated laser beam 132 at the up-beam at the point where separated laser beam 132 enters glass tube 102. Beam delivery system 140 may provide, within limits, adjustment of the distance between various components (e.g., lenses, mirrors, filters, prisms, etc.). Some adjustment of the distance between optical components of beam delivery system 140 may allow fine adjustment of the size and position of separated laser beam 132 at the point where separated laser beam 132 contacts glass tube 102. In embodiments, the length and beam width of separated laser beam 132 can be changed by changing the distance between lenses in beam delivery system 140.

[0070] 1 , in an embodiment, the separation laser system 120 may be mounted horizontally above the conveyor 110 (i.e., generally parallel to the XY plane of the coordinate axes in FIG. 1 ), and the beam delivery system 140 may include a rotating mirror 150. The rotating mirror 150 may be operable to rotate the separation laser beam 132 downward (i.e., in the −Z direction) toward the glass tubes 102 on the conveyor 110. Although shown herein as being mounted horizontally above the conveyor 110, it will be understood that the separation laser system 120 may be mounted in any suitable location, and one or more rotating mirrors 150 may be utilized to direct the separation laser beam 132 toward the glass tubes 102.

[0071] The separated 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 separated laser beam 132 may be a continuous laser beam or an alternating laser beam. The separated laser beam 132 may have a total laser power of 200 watts (W) or more, 500 W or more, or 1000 W or more. In embodiments, the separated laser beam 132 may have a total laser power of 200 W to 2000 W, e.g., 200 W to 1000 W, 500 W to 2000 W, 500 W to 1000 W, or 1000 W to 2000 W.

[0072] The separated laser beam 132 may be characterized by a power density distribution. In an embodiment, the separated laser beam 132 produced by the beam delivery system 140 may have a Gaussian power density distribution along the major axis (e.g., length) of the separated laser beam 132. In an embodiment, the separated laser beam 132 produced by the beam delivery system 140 may have a flat-top power density distribution along the major axis (e.g., length) of the separated laser beam 132.

[0073] In embodiments, the separated laser beams 132 may be elliptical beams having a major axis and a minor axis. The beam delivery system 140 may shape and direct the separated laser beams 132 such that the major axis of the separated laser beams 132 may be generally parallel to the machine direction of the conveyor 110 (i.e., the + / -X direction of the coordinate axes in FIG. 1 ) and the minor axis of the separated laser beams 132 may be generally parallel to the cross-machine direction of the conveyor 110 (e.g., the + / -Y direction of the coordinate axes in FIG. 1 ). In embodiments, the separated laser beams 132 may be elongated elliptical beams having a major axis that is five or more times larger than the minor axis at the point along the beam path where the separated laser beams 132 are incident on the outer surface of the glass tube 102. In embodiments, the separated laser beams 132 may be elliptical laser beams having a ratio of the major axis to the minor axis of about 5 to about 2000 at the point along the beam path where the separated laser beams 132 are incident on the outer surfaces of the glass tubes. When the separation laser beam 132 is an elongated elliptical beam, the separation laser beam 132 may be able to continuously contact and heat multiple glass tubes 102 simultaneously, increasing the heating efficiency and reducing the processing time of the end cutting and finishing process.

[0074] In embodiments, the separated laser beam 132 may have a length of about 100 mm to about 1000 mm, where the length of the separated laser beam 132 refers to the distance from the leading edge 154 to the trailing edge 156 of the separated laser beam 132 at a point along the beam path where the separated laser beam 132 is incident on the outer surface of the glass tube 102. As used herein, the length of the separated laser beam 132 refers to the maximum distance between the leading edge 154 and the trailing edge 156 at a point, rather than the average length taken across the beam width. In the case of an elliptical beam, the beam length is equal to the length of the major axis of the elliptical beam. The upper limit of the length of the separated laser beam 132 may depend on the maximum available laser power. When the separated laser beam 132 is an elliptical beam, the length of the separated laser beam 132 may be equal to the distance across the separated laser beam 132 in a direction parallel to the major axis of the separated laser beam 132.

[0075] The separated laser beam 132 may have a beam width of about 0.5 mm to about 20 mm at the point along the beam path where the separated laser beam 132 is incident on the exterior surface of the glass tube 102. The 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 embodiments, the separated laser beam may have a beam width of 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 along the beam path where the separated laser beam 132 is incident on the exterior surface of the glass tube 102. The beam width of the split laser beam 132 can be adjusted based on the thickness, diameter, glass composition, or a combination thereof of the glass tube 102 .

[0076] The beam width of the separation laser beam 132 may also be selected depending on whether the end finishing includes sealing the new end of the glass tube 102 or providing the new end of the glass tube 102 with an opening. In an embodiment, finishing the end of the glass tube 102 may include providing the new end with an opening, and the separation laser beam 132 may have a beam width of 0.5 mm to 5 mm, e.g., 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, at the point along the beam path where the separation laser beam 132 is incident on the exterior surface of the glass tube 102. Exposing each of the glass tubes 102 to the separation laser beam 132 with the narrower beam width removes a section of glass tube from the end of the glass tube 102 to produce a new end with an opening. A narrower beam width of the detached laser beam 132 in the range of 0.5 mm to 5 mm may result in heating the volume of glass in the target area insufficient to form a glass meniscus above the new end of the glass tube 102.

[0077] In embodiments, finishing the end of the glass tube 102 may include sealing the end of the glass tube 102 to produce a sealed or closed end. To seal the end of the glass tube 102, an additional volume of glass is heated such that when a pulling force is applied to the end of the glass tube 102 to separate a section from the end of the glass tube 102, the larger volume of heated glass is sufficient to form a meniscus of glass covering the end of the glass tube 102. By increasing the beam width of the separation laser beam 132, a larger volume of glass can be heated within the target area of ​​the glass tube 102. In embodiments, finishing the ends of the glass tubes 102 may include sealing the ends of the glass tubes 102, and the separation laser beam 132 may have a beam width of about 3 mm to about 20 mm, e.g., 3 mm to 10 mm, 5 mm to 20 mm, 5 mm to 10 mm, 7 mm to 20 mm, 7 mm to 10 mm, or even 10 mm to 20 mm, at the point along the beam path where the separation laser beam 132 is incident on the exterior surface of the glass tube 102. At larger beam widths, exposing each of the glass tubes 102 to the separation laser beam 132 having a larger beam width may remove a section of glass from the end of each glass tube 102 to create a new end, and may seal the new end to create a sealed end of the glass tube 102. The range of beam widths of the separation laser beam 132 sufficient to form a meniscus and heat a volume of glass may depend on the thickness, diameter, and glass type of the glass tube. Increasing the beam width of the separation laser beam 132 may increase the volume of glass heated in the target area, which may result in a thicker meniscus forming on the end of the glass tube 102. Therefore, the thickness of the new sealed end of the glass tube 102 can be changed by varying the beam width of the separation laser beam 132. The beam width and beam length of the separation laser beam 132 may be increased or decreased by changing the distance between two or more lenses in the beam delivery system 140, by changing the distance between the separation laser system 120 and the glass tube 102, or both.Therefore, the length and beam width of the separated laser beam 132 at the point where it contacts the glass tube 102 can be changed without changing the lenses of the beam delivery system 140 .

[0078] 7, in an embodiment, the system 100 may further include a positioner 170 operably coupled to the separation laser system 120. The positioner 170 may be operable to vary the distance between the separation laser system 120 and the glass tube 102 supported on the conveyor 110. In an embodiment, the positioner 170 adjusts the vertical distance D between the rotating mirror 150 and the outer surface of the glass tube 102. L 7 along the rail 172 in the + / -Z direction of the coordinate axis in FIG. 7 . The actuator 176 may be operable to translate the laser support 174 and the laser system 120 along the rail 172 in the + / -Z direction of the coordinate axis in FIG. 7 . The actuator 176 may be a stepper motor or other device operable to move the laser support 174 along the rail 172 in the + / -Z direction of the coordinate axis in FIG. 7 . Although depicted in FIG. 7 as having the rail 172, the laser support 174, and the actuator 176, it is understood that the positioner 170 may include any other type of apparatus, such as a hydraulic or pneumatic positioner, a scissor lift, a pulley, or other device, or combination of devices suitable for moving the separation laser system 120 relative to the glass tube 102. In an embodiment, the positioner 170 may be manually adjusted to change the position of the laser support 174 .

[0079] In embodiments, the positioner 170 may be operable to position the separation laser system 120 relative to the glass tube 102 so that the glass tube 102 is positioned at the center of the beam waist 158 ​​of the separated laser beam 132. The beam waist 158 ​​refers to the region of the beam path of the separated laser beam 132 where the power density of the separated laser beam 132 is greatest. In embodiments, the positioner 170 may be adjusted to position the separation laser system 120 so that the glass tube 102 is disposed at a converging or diverging section of the separated laser beam 132 to reduce the power density of the separated laser beam 132. Changing the position of the separation laser system 120 to move the beam waist 158 ​​closer to the glass tube 102 may increase the power density of the separated laser beam 132 at the point where the separated laser beam 132 contacts the glass tube 102. Conversely, changing the position of the separation laser system 120 to move the beam waist 158 ​​farther away from the glass tube 102 may reduce the power density of the separation laser beam 132 at the point where the separation laser beam 132 contacts the glass tube 102.

[0080] In addition, 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 farther 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 cause the separation laser beam 132 to have a larger beam width and length at the point in the beam path where the separation laser beam 132 is incident 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 waist 158 ​​of the separation laser beam 132 closer to the glass tube 102 can cause the separation laser beam 132 to have a reduced beam width and length at the point in the beam path where the separation laser beam 132 is incident on the outer surface of the glass tube 102.

[0081] Referring now to FIG. 8 , the operation of the system 100 for finishing the first ends 107 of the glass tubes 102 will be described in further detail. The separation laser system 120 may be positioned horizontally (i.e., in the + / −Y direction of the coordinate axes in FIG. 8 ) so that the separation laser beam 132 is incident on the outer surface 104 of the glass tube 102 within a target area 190 of the glass tube 102. The target area 190 of the glass tube 102 may be proximate to an end of the glass tube 102, such as proximate to the first end 107 of the glass tube 102, as shown in FIG. 8 . In an embodiment, the target area 190 of each glass tube 102 may be within at least 100 mm of the end of the glass tube 102, such as the first end 107 of the glass tube 102 in FIG. 8 . As previously discussed, the separation laser system 120 can be positioned vertically (i.e., positioned in the + / -Z direction) to provide the desired shape and power density of the separation laser beam 132 at the point along the beam path where the separation laser beam 132 is incident on the target area 190 of the glass tube 102.

[0082] During operation of the system, the conveyor 110 may translate the multiple glass tubes 102 in a machine direction 116 (i.e., the +X direction of the coordinate axes in FIG. 8 ) while rotating the glass tubes 102 about their central axes A. The translation of the glass tubes 102 in the machine direction 116 of the conveyor 110 may cause the glass tubes 102 to pass through the beam path of the separation laser beam 132. The separation laser beam 132 may be incident on a target region 190 of the glass tube 102, which may cause heating of the glass within the target region 190 of the glass tube 102. As the separation laser beam 132 heats the target region 190 of the glass tube 102, a pulling force F may be applied to the first end 107 of the glass tube 102. In an embodiment, the axial separation conveyor 180 may exert the pulling force F on the end of the glass tube (i.e., the first end 107 in FIG. 8 ). The axial separation conveyor 180 can exert a pulling force F on the end of the glass tube 102 by following a path that branches away from the conveyor 110 such that contact between the glass tube 102 and the surface of the axial separation conveyor 180 near the first end 107 of the glass tube 102 exerts an axial pulling force F on the first end 107 of the glass tube 102.

[0083] Applying a pulling force F to at least one end of the glass tube 102 may transport a section 192 of the glass tube 102 axially away from the glass tube 102 relative to the central axis A of the glass tube 102, which may separate the section 192 from the glass tube 102. Specifically, as the temperature of the glass in the target region 190 increases through the action of the separation laser beam 132, the glass in the target region 190 may become viscous, and applying a pulling force F to the first end 107 of the glass tube 102 may cause the section 192 of the glass tube 102 to pull away from the remainder of the glass tube 102 in the target region 190 and separate. The section 192 may be large enough to allow the axial separation conveyor 180 or other device to produce a pulling force F sufficient to separate the section 192 from the glass tube 102. In embodiments, the section 192 removed from at least one end of the plurality of glass tubes 102 has an axial length of less than about 100 mm, for example, from about 13 mm to about 100 mm, or from about 10 mm to about 100 mm.

[0084] During separation, the glass in the target area 190 thins and stretches until the glass separates. Once separated, surface tension within the glass may cause the volume of viscous glass on either side of the separation point to return to the new end 196 of the glass tube 102 and the end of the section 192, respectively. In embodiments, the volume of heated glass may be large enough so that the viscous glass returning to the new end 196 of the glass tube 102 may form a meniscus on the new end 196 of the glass tube 102. Forming a meniscus of glass on the new end 196 of the glass tube 102 may 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 area 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. 8 .

[0085] The properties of the separation laser beam 132, such as, but not limited to, beam shape, power density, power density distribution, or a combination thereof, can be altered to transition the system 100 from producing a new end 196 of the glass tube 102 that is open to producing a new end 196 of the glass tube 102 that is sealed. The properties of the separation laser beam 132 can also be altered to adjust the heating rate, for example, to respond to changes in the type of glass tube 102 (e.g., changes in glass composition, nominal diameter, average wall thickness, etc.) or to adjust for changes in production rate. Altering the properties of the separation laser beam 132 is discussed in more detail herein.

[0086] In embodiments, finishing the end of the glass tube 102 may produce a new end 196 that is an open end of the glass tube 102, such as having an opening through the glass tube 102. FIG. 11 shows a photograph of the new end 196 of the glass tube 102 that is open after the annular section 192 has been separated from the end of the glass tube 102. In embodiments, finishing the end of the glass tube 102 may seal the new end 196 of the glass tube 102 to produce a sealed end of the glass tube 102. FIG. 12 shows a photograph of the new end 196 of the glass tube 102 that is sealed after the annular segment has been separated from the end of the glass tube 102. Whether the new end 196 is sealed or open, heating the glass with the separation laser beam and separating the section 192 from the end of the glass tube 102 may produce a new end 196 that is already polished and finished, as shown in FIGS. 11 and 12. The finish provided by heating and returning the viscous glass using a separating laser beam after separating section 192 from the end of glass tube 132 can be comparable to or superior to the finish provided by flame polishing the end according to conventional methods.

[0087] In embodiments, the new end 196 of the glass tube 102 resulting from operation of the system may be substantially free of surface defects, such as, but not limited to, cracks, scratches, or any other surface inclusions. In embodiments, the new end 196 of the glass tube 102 resulting from the systems and methods disclosed herein may have an Acceptable Quality Level of less than 0.25 for end cracks having a crack length greater than 2 mm. Acceptable Quality Level (AQL) is defined in accordance with ISO 2859-1. End cracks refer to cracks that appear at the axial end of the glass tube. In embodiments, the new end 196 of the glass tube 102 resulting from the systems and methods disclosed herein may have an AQL of 0.025 or less for surface cracks of any size and any length. Surface cracks refer to cracks on the exterior and / or interior surfaces (i.e., not the end faces) of the glass tube 102. In embodiments, the new end 196 of the glass tube 102 and / or the entire glass tube 102 may be substantially free of fused glass particles, hydrocarbon combustion products, or both after finishing the end by separating the section 192 using a separation laser beam. In embodiments, the glass tube 102 has zero glass particles with a diameter greater than 0.5 mm attached to the inner or outer surface of the glass tube 102. In embodiments, the glass tube 102 may have five or fewer 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 embodiments, 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 in size that are on the outer surface of the glass tube and are not easily removed. In embodiments, 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 in size that are on the inner surface of the glass tube and are not easily removed. In embodiments, the glass tube 102 produced by the systems and methods disclosed herein may be free of discoloration of the glass tube, visible deposits on the surface of the glass tube, or both, caused by the deposition of combustion products on the surface of the glass tube.

[0088] 8 , removal of section 192 from first end 107 of glass tube 102 may finish the end of glass tube 102 by reducing the length of glass tube 102 to its final length and by providing a finished, polished new end. The system 100 of the present disclosure may accomplish reducing the length of glass tube 102 to its final length and providing a finished new end of glass tube 102 in a single step by directing a separation laser beam 132 to a target region 190 of glass tube 102 while also applying a pulling force F to the end of glass tube 102.

[0089] The second end 108 of the glass tube 102 may be cut and finished using the same methods described for cutting and finishing the first end 107 of the glass tube 102. Referring now to Figure 9, in an embodiment, the system 100 may include a separation laser system 120 for each end of the glass tube 102. In an embodiment, the system 100 may include a first separation laser system 120A and a second separation laser system 120B. The first separation laser system 120A and the second separation laser system 120B may have any of the components and / or features previously discussed for the separation laser system 120. The first separation laser system 120A may comprise a first laser source and a first beam delivery system, and the second separation laser system 120B may comprise 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 first beam delivery system, respectively. The first separation laser system 120A may be operable to direct the first separation laser beam 132A to a target area 190 proximate the first ends 107 of the plurality of glass tubes 102. The second separation laser system 120B may be operable to direct the second separation laser beam 132B to a target area 190 proximate the second ends 108 of the plurality of glass tubes 102. First separated laser beam 132A and second separated laser beam 132B may each have any of the characteristics and / or properties previously discussed herein for separated laser beam 132.

[0090] In embodiments, system 100 may further include a first laser system positioner 170A and a second laser system positioner 170B, each of which may have any of the features and / or components previously described herein for laser system positioner 170. First laser system positioner 170A may be operable to position first separation laser system 120A relative to glass tube 102, and second laser system positioner 170 may be operable to position second separation laser system 120B relative to glass tube 102. In embodiments, system 100 may include a single laser system positioner 170 that may support and position both first separation laser system 120A and second separation laser system 120B.

[0091] 10 , in embodiments, the system 100 may further include a preheating laser system 160 disposed upstream from the separation laser system 120. In some examples, the characteristics of the glass tube 102, such as the type of glass composition, the average wall thickness, the nominal diameter, or a combination thereof, may require additional heating to achieve separation of the section 192 from the end of the glass tube 102. In addition, the use of the preheating laser system 160 may allow for an increased separation speed and therefore an increased production rate of the finishing process, which may allow for an increased drawing speed of the process to create a continuous hollow glass cylinder.

[0092] 10 , a preheating laser system 160 may be disposed upstream of the separation laser system 120. The preheating laser system 160 may be operable to produce a preheating laser beam 162 and direct the preheating laser beam 162 toward the glass tube 102. The preheating laser system 160 may include a preheating laser source 164 and a preheating beam delivery system 166. The preheating laser system 160 may further include a turning mirror 168. The preheating laser source 164, the preheating beam delivery system 166, and the turning mirror 168 may have any of the features previously described herein for the separation laser source 130, the beam delivery system 140, and the turning mirror 150. The preheating laser source 164 may be operable to produce a laser beam 161. The preheating beam delivery system 166 may be operable to modify the shape, power density, power density distribution, or other characteristics of the laser beam 161 to produce the preheating laser beam 162. The rotating mirror 168 may be operable to direct the preheating laser beam 162 toward a target area of ​​the glass tube 102 at a location upstream of the separated laser beam 132 (i.e., a location in the −X direction of the coordinate axes in FIG. 10 relative to the location of the separated laser beam 132). The preheating laser beam 162 may have any of the characteristics, properties, or properties described earlier herein for the separated laser beam 132.

[0093] During operation of the system 100, the conveyor 110 may move the glass tube 102 through the beam path of the preheating laser beam 162. The preheating laser beam 162 may heat a target area of ​​the glass tube 102 through contact between the preheating laser beam 162 and the outer surface of the glass tube 102. The conveyor 110 may then pass the glass tube 102 from the beam path of the preheating laser beam 162 to the beam path of the separation laser beam 132, which may complete the heating and separation of the annular section from the end of the glass tube 102.

[0094] In an embodiment, the system 100 may include multiple preheating laser systems 160. In an embodiment, the system 100 may include a preheating laser system 160 disposed upstream from each of the separation laser systems 120 (i.e., one for each end of the glass tube 102). In an embodiment, the system 100 may include a first preheating laser system disposed upstream of the first separation laser system 120A ( FIG. 9 ) and a second preheating laser system disposed upstream of the second separation laser system 120B ( FIG. 9 ). In an embodiment, the system 100 may include multiple preheating laser systems 160 disposed in series upstream of each of the separation laser systems 120. Referring again to FIG. 10 , in an embodiment, each of the preheating laser systems 160 may include one of the laser system positioners 170, which may be operable to position the preheating laser system 160 in the + / −Z direction of the coordinate axis in FIG. 10 (e.g., the vertical direction). The laser system positioner 170 may be operable to vary the distance in the + / -Z direction between the preheating laser system 160 and the glass tube 102 to vary one or more characteristics of the preheating laser beam 162, such as, but not limited to, the power density or shape at the point where the preheating laser beam 162 contacts the glass tube 102.

[0095] 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 tools for scoring the surfaces of the plurality of glass tubes 102.

[0096] 3 and 8, a method for producing glass tubes 102 using the system 100 disclosed herein will now be described in further detail. Referring now to FIG. 3, the disclosed method for producing glass tubes 102 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. 8 , finishing the ends of the glass tubes 102 includes rotating each glass tube 102 about its central axis A, heating a target area 190 on the glass tube 102 by exposing the target area 190 to the separation laser beam 132 while rotating the glass tube 102, and applying a pulling force F to at least one end of the glass tube 102 (e.g., the first end 107 in FIG. 8 ) while exposing the target area 190 to the separation laser beam 132. Applying the pulling force F while exposing the target area 190 to the separation laser beam 132 may 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 may finish the new end 196 of the glass tube 102.

[0097] 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 isolated laser beam 132 may produce a new end 196 that is polished and exhibits minimal surface imperfections. In embodiments, the new end 196 of the glass tube 102 may be substantially free of surface imperfections. In embodiments, the new end 196 of the glass tube 102 may be substantially free of fused glass particles, hydrocarbon combustion products, or both. In embodiments, finishing the end of the glass tube 102 may include forming the new end 196 of the glass tube 102 to be open-ended, such as having an opening through the glass tube 102. In embodiments, finishing the end of the glass tube 102 may 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 sufficient volume of glass within the target area 190 to form a meniscus of glass on each new end 196 of each glass tube 102 during separation of the section 192 from the end of the glass tube 102.

[0098] 8, exposing each of the plurality of glass tubes 102 to the separation laser beam 132 may include producing a laser beam 131 using a laser source 130, passing the laser beam 131 through a beam delivery system 140, the beam delivery system 140 comprising an optical system that changes the shape or characteristics of the laser beam 131 to produce the separation laser beam 132 and directs the separation laser beam 132 to the plurality of glass tubes, and passing each of the plurality of glass tubes 102 through a beam path of the separation laser beam 132. In an embodiment, passing each of the glass tubes 102 through the beam path of the separation laser beam 132 may further include transporting the plurality of glass tubes horizontally (i.e., in the +X direction of the coordinate axis of FIG. 8) through the beam path of the separation laser beam 132 while rotating the glass tubes 102.

[0099] In embodiments, applying a pulling force F to the end of the glass tube 102 may transport a section 192 of the glass tube 102 axially away from the glass tube 102 relative to a central axis A of the glass tube 102. Transporting the section 192 axially away from the glass tube 102 may separate the section 192 from the glass tube 102. In embodiments, the pulling force F may be applied in a cross-machine direction (i.e., the + / -Y direction of the coordinate axes in FIG. 8 ), where the cross-machine direction is parallel to the central axis A of the glass tube 102 and perpendicular to the horizontal direction of travel of the conveyor 110 (e.g., the +X direction of the coordinate axes in FIG. 8 ). Applying 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 branch off from the conveyor 110 along a path 181. Contact between the glass tubes 102 and the rollers of the axial separation conveyor 180, and the branching of the axial separation conveyor 180 from the conveyor 110 along path 181, can exert a pulling force F on the ends of the glass tubes 102 in the axial direction (e.g., in the + / -Y direction).

[0100] 9 , in embodiments, the methods disclosed herein may include finishing both ends of the glass tubes 102. Specifically, the method may include finishing the first end 107 of each of the plurality of glass tubes 102 using a first separated laser beam 132A and finishing the second end 108 of each of the plurality of glass tubes 102 using a second separated laser beam 132B. In embodiments, the method may include finishing the first end 107 and the second end 108 of each of the plurality of glass tubes 102 in parallel. In embodiments, the method may include finishing the second end 108 using the second separated laser beam 132B downstream from finishing the first end 107 using the first separated laser beam 132A.

[0101] Referring again to FIG. 8 , in embodiments, the method may include processing multiple glass tubes 102 at a time. In embodiments, the separation laser beam 132 may be an elongated beam, and the method may include simultaneously exposing target areas 190 of a subset of the multiple glass tubes 102 to the separation laser beam 132. In embodiments, the separation laser beam 132 may have a beam width to overall length ratio of about 5 to about 2000 at the point along the beam path where the separation laser beam 132 is incident on the exterior surface of the subset of glass tubes 102. In embodiments, exposing the target areas 190 of the multiple glass tubes 102 to the separation laser beam 132 may include sequentially transporting each of the multiple glass tubes 102 through the elongated beam of the separation laser beam 132 from the leading edge 154 to the trailing edge 156 of the separation laser beam 132. Conveying each of the plurality of glass tubes 102 through the entire length of the separation laser beam 132 may gradually heat the glass in the target region 190 and, when a pulling force F is applied, may separate the section 192 from the end of each of the plurality of glass tubes 102. The entire length of the separation laser beam 132 may be sufficient to simultaneously contact each of a subset of the glass tubes 102. In an embodiment, sequentially conveying each of the plurality of glass tubes 102 through the elongated beam of the separation laser beam 132 may include placing the plurality of glass tubes 102 in parallel on a conveyor 110 comprising a plurality of rollers 112 and at least one belt, where each glass tube 102 is disposed between two adjacent rollers 112 of the conveyor 110. The rollers 112 of the conveyor 110 may rotate each of the multiple glass tubes 102, and at least one belt may move the rollers 112 and the multiple glass tubes 102 horizontally (i.e., in the +X direction of the coordinate axis in FIG. 8) through the separation laser beam 132.

[0102] 10 , in embodiments, the method disclosed herein may further include preheating a target area 190 of the glass tube 102 prior to exposing the target area of ​​the glass tube 102 to the separation laser beam 132. Preheating the target area 190 of the glass tube 102 may include rotating each of the glass tubes 102 and exposing each of the glass tubes 102 to a preheating laser beam 162 disposed upstream of the separation laser beam 132. The preheating laser beam 162 may be separated from the separation laser beam 132. The method may further include varying the distance between the preheating laser system 160 and the glass tube 102 to vary the shape or power density of the preheating laser beam 162.

[0103] In embodiments, the methods disclosed herein may also include varying the heating rate of the separation laser beam 132. Varying the heating rate of the separation laser beam 132 may include varying the power density of the separation laser beam 132, varying the power density distribution of the separation laser beam 132, varying the speed of the conveyor 110 that translates the plurality of glass tubes 102 through the separation laser beam 132, or a combination thereof. In embodiments, varying the heating rate of the separation laser beam 132 may include varying the power density of the separation laser beam 132 at a point along the beam path where the separation laser beam 132 contacts the glass tube 102. In embodiments, varying the power density of the separation laser beam 132 at a point where the separation laser beam 132 contacts the glass tube 102 may include adjusting the power of the laser source 130 that produces the laser beam 131, varying the distance between the beam delivery system 140 and the plurality of glass tubes 132, or both.

[0104] Referring to FIG. 7, in an embodiment, varying the power density of the separated laser beam 132 at the point where the separated laser beam 132 contacts the glass tube 102 can be achieved by varying the distance D between the separated laser system 120 and the glass tube 102. L, which changes the position of the waist 158 ​​of the split laser beam 132 relative to the glass tube 102. To move the waist 158 ​​closer to the glass tube 102, the distance D L Varying distance D can increase the power density of the detached laser beam 132 at the point where it contacts the glass tube 102. Conversely, varying ... L Varying the power density of the detached laser beam 132 may reduce the power density of the detached laser beam 132 at the point where the detached laser beam 132 contacts the glass tube 102 .

[0105] In embodiments, varying the heating rate of the separated laser beam 132 may include varying the power density distribution of the separated laser beam 132. Varying the power density distribution of the separated laser beam 132 may include passing the laser beam 131 through a cylindrical lens to produce a separated laser beam 132 with a Gaussian power density distribution with a lower heating rate, or passing the laser beam 131 through an aspheric cylindrical lens to produce a separated laser beam 132 with a flat-top power density distribution with a higher heating rate. In embodiments, varying the heating rate of the separated laser beam 132 does not require changing the lenses of the beam delivery system 140.

[0106] 10 , in embodiments, the methods disclosed herein may include varying the heating rate of the preheating laser beam 162. Varying the heating rate of the preheating laser beam 162 may 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 of the conveyor 110 that 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 may include varying the power density of the preheating laser beam 162 at a 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 tube 102 may include adjusting the power of the preheating laser source 164 for producing 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 may be similar to the method of varying the power density of the separated laser beam 132 discussed above. In embodiments, varying the heating rate of the preheating laser beam 162 may also include varying the power density distribution, for example, by using a cylindrical lens to produce a Gaussian distribution with a lower heating rate, or by using an aspherical cylindrical lens to produce a flat-top power density distribution with a higher heating rate. In embodiments, varying the heating rate of the preheating laser beam 162 does not require changing the lens of the preheating beam delivery system 166.

[0107] The methods disclosed herein can be modified to finish the new ends 196 of the glass tubes 102 so that the new ends 196 are open or sealed. In embodiments, finishing the ends of the glass tubes 102 can include forming the new ends 196 as open ends, meaning that the new ends 196 of the glass tubes 102 are annular. In embodiments, the separation laser beam 132 can have a beam width of 0.5 mm to 5 mm at the point along the beam path where the separation laser beam 132 is incident on the exterior surfaces of the glass tubes 102, and exposing each of the glass tubes 102 to the separation laser beam 132 can remove the annular section 192 from the end of each glass tube 102 to produce a new end with an opening. To form an open end on the glass tubes 102, the beam width of the separation laser beam 132 can be reduced, which reduces the volume of glass heated during separation of the annular section 192 from the end of the glass tube 102. The reduced glass volume resulting from reducing the beam width of the detachment laser beam 132 may not be sufficient to form a stable meniscus across the end of the glass tube 102, which results in surface tension pulling the viscous heated glass back to the sidewall of the new end 196 of the glass tube 102 after the annular section is separated from the glass tube 102. This results in the new end 196 being an open end.

[0108] In embodiments, finishing the ends of the glass tubes 102 may include forming a new end 196 that is a sealed end, meaning that the new end 196 is surrounded or covered by a film or wall of glass. Finishing the ends of the glass tubes 102 may seal the new end 196 of the glass tubes 102 to produce a sealed end of the glass tube. In embodiments, the separation laser beam 132 may have a beam width of approximately 3 mm to 20 mm at the point along the beam path where the separation laser beam 132 is incident on the exterior surface of the glass tubes 102, and exposing each of the glass tubes 102 to the separation laser beam 132 may remove the annular section 192 from the end of the glass tube 102 to produce the new end 196 and seal the new end 196 to produce a sealed end of the glass tube 102. To form a sealed end on the glass tube 102, the beam width of the separation laser beam 132 may be increased, which increases the volume of glass heated during separation of the annular section 192 from the end of the glass tube 102. The increased volume of glass resulting from the increased beam width of the separation laser beam 132 may be sufficient to form a stable glass meniscus over the end of the glass tube 102. The volume of glass within the glass meniscus formed over the end may 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 the sealed end of the glass tube 102.

[0109] The methods disclosed herein may include adjusting the system 100 to switch between forming open ends and forming sealed ends of the glass tubes 102. In embodiments, the methods may include determining whether to finish the ends of the glass tubes 102 to produce an open new end or a sealed new end, and varying one or more of the beam shape (e.g., beam width), power, power density distribution, or a combination thereof of the separation laser beam 132. Varying the beam shape, power, power density distribution, or a combination thereof of the separation laser beam 132 may vary the volume of heated glass within the target region 190 of the multiple glass tubes 102. As previously discussed, decreasing the volume of heated glass within the target region 190 may produce a new end with an opening, and increasing the volume of heated glass within the target region 190 may produce a meniscus of glass that seals the new end 196 when the annular section 192 is removed from the end of the glass tube 102.

[0110] Varying the beam shape may 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, varying the beam shape may include adjusting the distance between the beam delivery system 140 and the glass tubes 102, which varies the point in the beam path where the separated laser beam 132 contacts the outer surface of the plurality of glass tubes 102 relative to the waist 158 ​​of the separated laser beam 132. In an embodiment, the transition between forming an open end and forming a sealed end may include varying the power density of the separated laser beam 132 at the point along the beam path where the separated laser beam 132 contacts the outer surface of the glass tube 102. Varying the power density of the separated laser beam 132 contacting the glass tube 102 may include adjusting the output power of the laser source 130 producing the separated laser beam 132, varying 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 waist 158 ​​of the detached laser beam 132 closer to the glass tube 102, which may increase the power density of the detached laser beam 132 at the point where the detached 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 waist 158 ​​of the detached laser beam 132 away from the glass tube 102, which may decrease the power density of the detached laser beam 132 at the point where the detached laser beam 132 contacts the glass tube 102.

[0111] In embodiments, the method may include transitioning from forming the open new end 196 to forming a sealed new end, where transitioning includes one or more of increasing the beam width of the separation laser beam 132, increasing the power density of the separation laser beam 132, changing the power density distribution of the separation laser beam 132 from a Gaussian power density distribution to a flat-top power density distribution, or combinations thereof. In embodiments, transitioning between forming the open new end and forming the sealed new end may include heating a volume of glass sufficient to form a glass meniscus on the new end of the plurality of glass tubes as a section is removed from at least one end of the plurality of glass tubes. In embodiments, transitioning from forming the open new end to forming the sealed new end may include changing the beam shape of the separation laser beam 132 by increasing the beam width to a range of 3 mm to 20 mm.

[0112] In embodiments, the method may include transitioning from forming the sealed new end 196 to forming an open new end, where the transitioning includes one or more of: decreasing the beam width of the separation laser beam 132; decreasing the power density of the separation laser beam 132; changing the power density distribution of the separation laser beam 132 from a flat-top power density distribution to a Gaussian power density distribution; or a combination thereof. In embodiments, the transitioning between forming the sealed new end and forming the open new end may include reducing the volume of heated glass in the target area to prevent the formation of a glass meniscus on the new end of the multiple glass tubes when a section is removed from each of the glass tubes. In embodiments, the transitioning from forming the sealed new end to forming the open new end may include changing the beam shape of the separation laser beam 132 by decreasing the beam width to a range of 0.5 mm to 5 mm.

[0113] Transitioning between forming an open end and forming a sealed end may also include changing characteristics of the preheating laser beam 162 if the system 100 includes a preheating laser system 160. In embodiments, transitioning between forming an open end and forming a sealed end may include changing one or more of the beam shape (e.g., thickness), power, power density distribution, or a combination thereof of the preheating laser beam 162. Changing the beam shape, power, power density distribution, or a combination thereof of the preheating laser beam 162 may change the volume of heated glass within the target region 190 of the multiple glass tubes 102.

[0114] 8 and 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 changing the heating rate of the separation laser beam 132, the preheating laser beam 162, or both, in response to the change in type of glass tube 102. Changing the type of glass tube 102 from a first type of glass tube to a 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 separation laser beam 132, the preheating laser beam 162, or both, may be changed by any of the methods previously discussed herein. In embodiments, varying the heating rate of the separation laser beam 132, the preheating laser beam 162, or both may include varying the power density of the separation laser beam 132, the preheating laser beam 162, or both, varying the power density distribution of the separation laser beam 132, the preheating laser beam 162, or both, varying the speed of the conveyor 110 that translates the plurality of glass tubes 102 through the separation laser beam 132 or the separation laser beam 132 and the preheating laser beam 162, or a combination thereof. In embodiments, varying the heating rate of the separation laser beam 132, the preheating laser beam 162, or both does not require changing the lenses of the beam delivery system 140 or the preheating beam delivery system 166.

[0115] The systems and methods of the present disclosure may enable increased production rates of glass tube forming processes. The methods disclosed herein may include increasing the production rate of the system 100 for cutting and finishing the ends of glass tubes 102, which may enable increased production rates of the entire tube forming process. In embodiments, increasing the production rate of the system 100 for cutting and finishing the ends of glass tubes 102 may include increasing the speed of the conveyor 110, which translates the plurality of glass tubes 102 through the beam path of the separation laser beam 132, and increasing the heating rate of the separation laser beam 132, the preheating laser beam 162, or both. The heating rate of the separation laser beam 132, the preheating laser beam 162, or both may be varied by any of the methods previously discussed herein. In embodiments, increasing the heating rate of the separation laser beam 132, the preheating laser beam 162, or both may include increasing the power density of the separation laser beam 132, the preheating laser beam 162, or both, changing the power density distribution of the separation 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 embodiments, increasing the production rate of the system 100 for cutting and finishing the end of a glass tube 102 may include preheating a target area of ​​the glass tube 102 with the preheating laser system 160.

[0116] 3 and 4, the methods disclosed herein for producing glass tubing 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 drawing the continuous hollow glass cylinder from a tube forming apparatus 220. In an embodiment, producing a continuous hollow glass cylinder may include forming a continuous hollow glass cylinder 222 from molten glass in a 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 a conveyor 110 of the system 100 for finishing the ends of the glass tubes 102.

[0117] 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 separation laser system 120, as well as the preheating laser system 160, the axial separation conveyor 180, or any 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 have any of the components or features previously discussed herein with respect to cutting and finishing glass tubes.

[0118] Pharmaceutical packaging products such as vials, cartridges, syringes, ampoules, bottles, or other containers are converted from glass tubes, such as those produced by the systems and methods previously discussed herein. In the conversion process, the glass tube is indexed through various stations and subjected to heating and forming contacts to convert the glass tube into a final product, a glass article. The laser systems and methods disclosed herein can be further incorporated into the conversion process to produce glass articles from glass tubes. Specifically, laser systems, such as a separation laser system and / or a preheating laser system, can be incorporated into the conversion process in place of one or more gas burners to heat the glass before forming it or to separate a 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 different shapes and spatial power distributions. Additionally, beam overlap and control of the exposure time of the glass article and glass tube to the laser beam can enable precise energy delivery to the glass, allowing for targeted thermal and stress pattern manipulation at the operator's discretion, improving process precision and repeatability and, consequently, the quality of the final product. An experimental platform consisting of multiple laser modules integrated with tube handling equipment can be used to model the use of laser systems and methods on glass tube converters to create glass articles from glass tubes. Additionally, in embodiments, the conversion process can be a hybrid conversion process that includes a combination of gas burners and laser-assisted heating.

[0119] 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, where the target region may be proximate a working end of the glass tube; forming at least one feature of a glass article in the target region of the glass tube while rotating the glass tube after heating the target region of 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 the 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 in the target region, the separation region, or both, to a temperature of about 1000° C. or greater.

[0120] In embodiments, heating the target area of ​​the glass tube may include exposing the target area to a laser beam, where the laser beam may be a heating laser beam. In embodiments, the heating laser beam may have a circular cross-section. In embodiments, the heating laser beam may have a Gaussian power density distribution.

[0121] In embodiments, separating the glass article from the working end of the glass tube may include exposing the separated region of the glass tube to a laser beam, where the laser beam may be a separation laser beam. In embodiments, separating the glass article from the working end of the glass tube may include applying a pulling force to the glass article while exposing the separated region of the glass tube to the laser beam, where the pulling force may move the glass article axially away from the glass tube relative to a central axis of the glass tube. In embodiments, the glass tube may be oriented vertically with the working end of the glass tube facing downward, and the pulling force may include a force due to gravity. In embodiments, the separation laser beam may have an elliptical cross-section having a major axis and a minor axis.

[0122] In embodiments, separating the glass article from the work end of the glass tube may further include forming an open end at the bottom of the glass article, where the bottom of the glass article may be the end of the glass article that was previously attached to the glass tube prior to separation. In embodiments, the separating laser beam may have a beam width of about 0.5 mm to about 5 mm. In embodiments, the separating laser beam may have a beam length of about 20 mm to about 35 mm. In embodiments, the separating laser beam may be an elliptical beam having a ratio of the major axis to the minor axis of about 4 to about 70.

[0123] In embodiments, separating the glass article from the working end of the glass tube may further include forming a thin bottom portion of the glass article. In embodiments, the separating laser beam may have a beam width of about 5 mm to about 10 mm. In embodiments, the separating laser beam may be an elliptical beam having a ratio of the major axis to the minor axis of about 2 to about 7. In embodiments, separating the glass article from the working end of the glass tube may further include forming a thick bottom portion of the glass article. In embodiments, the separating laser beam may have a beam width of about 3 mm to about 7 mm. In embodiments, the separating laser beam may be an elliptical beam having a ratio of the major axis to the minor axis of about 2.5 to about 12. In embodiments, 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.

[0124] In embodiments, heating a target area of ​​the glass tube, separating the glass article from the work end of the glass tube, or both, may include exposing the target area, the separation area, or both of the glass tube with a first laser beam and simultaneously exposing the target area, the separation area, or both of the glass tube with a second laser beam, where the first laser beam and the second laser beam may be superimposed on the target area or the separation area of ​​the glass tube. In 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 embodiments, the method may include varying the axial position of the second laser beam relative to the axial position of the first laser beam.

[0125] In embodiments, the method may further include finishing a bottom portion of the glass article, where the bottom portion of the glass article may include an end portion of the glass article formed from separating the glass article from the working end of the glass tube. In 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 embodiments, forming may include contacting a surface of the glass tube in the target area with one or more forming tools while rotating the glass tube, where contact between the forming tools and the surface of the glass tube changes the shape of the glass tube in the target area.

[0126] In embodiments, a method may include operating a converter to produce a plurality of glass articles from a plurality of glass tubes. The converter may include a 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. The at least one heating station, the 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 in a target region, a separation region, or both.

[0127] In embodiments, the method may further include securing the glass tube in a holder of a converter having multiple processing stations, the multiple processing stations including at least one heating station, at least one forming station, and a separation station, where 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 at least one heating station and at least one forming station, and separating the glass article from the working end of the glass tube in a separation station. Heating a target area of ​​the glass tube may include exposing the target area of ​​the glass tube to a laser beam in at least one heating station, or separating the glass article from the working end of the glass tube may include exposing a separation area of ​​the glass tube with a laser beam in a separation station. In embodiments, the glass article may be a pharmaceutical container. In embodiments, the pharmaceutical container may include a vial, syringe, cartridge, ampule, or bottle.

[0128] In embodiments, exposing the target or separated area of ​​the glass tube to a laser beam may include producing a laser beam using a laser source, passing the laser beam through an optical system that modifies the shape or power density distribution of the laser beam, and directing the laser beam toward the target or separated 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 uncollimated laser beam. In embodiments, the separated laser beam may include a laser power of 50 W to 2000 W. In embodiments, the laser beam may be an elliptical beam or a round beam.

[0129] In embodiments, the method may further include changing the shape of the laser beam, where changing the shape of the laser beam may change the volume of glass heated in the target area or the separation area of ​​the glass tube. In embodiments, the method may further include changing the power density distribution of the laser beam, where 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, where changing the power density may change the heating rate of the laser beam. In embodiments, the method may include controlling the exposure time of the glass tube to the laser beam while heating the target area of ​​the glass tube, separating the glass article from the working end of the glass tube by adjusting the time a laser source producing the laser beam is turned on and off, or both. In embodiments, exposing the target area, the separation area, or both of the glass tube may include overlapping two or more laser beams at once in the target area, the separation area, or both.

[0130] In embodiments, the method may include rotating the glass tube at a rotational speed of 60 rpm to 400 rpm. In embodiments, the laser beam may have a heating rate of 200°C / sec to 400°C / sec. In embodiments, the conversion rate of the glass tube to glass articles may be 30 or more per minute. In embodiments, heating a target area of ​​the glass tube or separating a 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 embodiments, the target area may be within 50 mm of the working end of the glass tube.

[0131] In an embodiment, a system for producing glass articles from glass tubes may include a converter including 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 may be operable to hold a working end of the glass tube and rotate the glass tube about a central axis. The converter may be operable to sequentially translate the at least one holder with the glass tube secured therein through each of the plurality of processing stations. The system may further include at least one laser system disposed in at least one heating station or separation station. The at least one laser system may include a laser source and a beam delivery system. The laser system may be operable to generate a laser beam, modify one or more characteristics 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 for the separation laser system 120. In an embodiment, the at least one laser system may include a plurality of laser systems, where the plurality of laser systems may include at least one heating laser system disposed in the at least one heating station and a separation laser system disposed in the separation station.

[0132] While various embodiments of the system 100 and methods for cutting and finishing the end of a glass tube 102 using the system 100 are described herein, it is understood that it is contemplated that each of these embodiments and techniques may be used separately or in conjunction with one or more other embodiments and techniques.

[0133] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the present specification cover the modifications and variations of the various embodiments described herein, provided that such modifications and variations come within the scope of the appended claims and their equivalents.

Claims

1. 1. A method for producing a glass tube, the method comprising: 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, wherein finishing the at least one end of the plurality of glass tubes comprises: rotating each glass tube around 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 a separate laser beam while rotating the glass tube; applying a pulling force to the at least one end of the glass tube while exposing the target area of ​​the glass tube to the separation laser beam, wherein applying the pulling force while exposing the target area to the separation laser beam separates the section of glass tube from the at least one end of the glass tube and finishes a new end of the glass tube.

2. 2. The method of claim 1, wherein the finishing of 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 being an open end of the glass tube, such as having an opening through the glass tube.

4. The method of claim 1 , wherein finishing the at least one end of the glass tube comprises sealing 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 fused glass particles, hydrocarbon combustion products, or both.

7. 2. The method of claim 1, wherein applying the pulling force to the at least one end of the glass tube conveys the section of the glass tube axially away from the glass tube relative to the central axis of the glass tube, thereby separating the section from the glass tube.

8. 2. 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 disposed upstream of the separating laser beam.

9. The method of claim 8 , wherein the preheating laser beam is separate from the separation laser beam.

10. 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, further comprising finishing the first end and the second end of each of the plurality of glass tubes parallel.

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

13. 10. The method of claim 1, wherein the separate laser beams are elongated beams, the method comprising simultaneously exposing the target areas of a subset of the plurality of glass tubes to the separate laser beams.

14. 14. The method of claim 13, wherein the separated laser beams have a ratio of overall length to beam width of about 5 to about 2000 at points along the beam path where the separated laser beams are incident on the exterior surfaces of the subset of glass tubes.

15. exposing the target areas of the plurality of glass tubes to the separation laser beam includes sequentially transporting each of the plurality of glass tubes through the elongated beam from a leading edge to a trailing edge of the separation laser beam; conveying each of the plurality of glass tubes through the entire length of the longitudinal axis of the separating laser beam gradually heats the glass in the target area and separates the section from the at least one end of each of the plurality of glass tubes; 14. The method of claim 13, wherein the total length of the separated laser beam is sufficient to simultaneously contact each of the subset of glass tubes.

16. sequentially conveying each of the plurality of glass tubes through the elongated beam includes placing the plurality of glass tubes in parallel on a conveyor including a plurality of rollers and at least one belt; Each glass tube is disposed between two adjacent rollers of the conveyor; the plurality of rollers of the conveyor rotate each of the plurality of glass tubes; 16. The method of claim 15, wherein the at least one belt moves the roller and the plurality of glass tubes horizontally through the elongated beam.

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

18. The method of claim 1 , wherein the separated laser beams are continuous or alternating laser beams.

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

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

21. 10. The method of claim 1, wherein the separated laser beams are elliptical laser beams having a ratio of a major axis to a minor axis of about 5 to about 2000 at points along a beam path where the separated laser beams are incident on the exterior surfaces of the plurality of glass tubes.

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

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

24. 2. The method of claim 1, wherein the separated laser beams have lengths of about 100 mm to about 1000 mm, the lengths of the separated laser beams being distances from leading edges to trailing edges of the separated laser beams at points along a beam path where the separated laser beams are incident on the outer surfaces of the plurality of glass tubes.

25. 10. The method of claim 1, wherein the separated laser beams have a beam width of about 0.5 mm to about 20 mm at points along their beam paths where the separated laser beams are incident on the exterior surfaces of the plurality of glass tubes.

26. 2. The method of claim 1, wherein the separation laser beam has a beam width of 0.5 mm to 5 mm at a point along a beam path where the separation laser beam is incident on an outer surface of the plurality of glass tubes, and wherein exposing each of the plurality of glass tubes to the separation laser beam removes the section of the at least one end of each glass tube to produce the new end with an opening.

27. 2. The method of claim 1, wherein the separation laser beam has a beam width of about 3 mm to 20 mm at a point along a beam path where the separation laser beam is incident on an outer surface of the plurality of glass tubes, and wherein exposing each of the plurality of glass tubes to the separation laser beam removes the section of the at least one end of each glass tube to produce the new end and seals the new end to produce a sealed end of the glass tube.

28. determining to finish the at least one end of the plurality of glass tubes to produce an open new end or a sealed new end; Varying one or more of the beam shape, power, power density distribution, or combinations thereof of the separated laser beam; Varying the beam shape, power, power density distribution, or combination thereof of the separated laser beams varies the volume of heated glass within the target region of the plurality of glass tubes; reducing the volume of heated glass within the target area to produce the new edge having an opening; 10. The method of claim 1, wherein increasing the volume of heated glass within the target area produces a meniscus of glass that seals the new end when the section is removed from the at least one end of the plurality of glass tubes.

29. transitioning from forming the new end being open to forming the new end being sealed, the transitioning increasing the beam width of the separated laser beam; increasing the power density of the separated laser beam; changing the power density distribution from a Gaussian distribution to a flat-top distribution; or 30. The method of claim 28, comprising one or more of:

30. 30. The method of claim 29, wherein the transition from forming the new end that is open to forming the new end that is sealed comprises heating a volume of glass sufficient to form a meniscus of glass on the new end of the plurality of glass tubes when the section is removed from the at least one end of the plurality of glass tubes.

31. 29. The method of claim 28, comprising varying the beam shape of the separated laser beam by varying a beam width in the range of 3 mm to 20 mm.

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

33. 32. The method of claim 31 , wherein varying the beam shape comprises passing the separated laser beam through a variable beam expander.

34. 32. The method of claim 31 , wherein varying the beam shape includes adjusting a distance between a beam delivery system and the plurality of glass tubes, thereby varying a point in the beam path where the separated laser beam contacts an outer surface of the plurality of glass tubes relative to a waist of the separated laser beam.

35. 29. The method of claim 28, comprising varying the power density of the separated laser beams at points along a beam path where the separated laser beams contact the outer surfaces of the plurality of glass tubes, wherein varying the power density of the separated laser beams comprises adjusting the output of a laser source for producing the separated laser beams, varying the vertical distance between a beam delivery system and the plurality of glass tubes, or both.

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

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

38. 37. The method of claim 36, comprising: varying the power density distribution of the separated laser beam, wherein varying the power density distribution comprises passing the separated laser beam through a cylindrical lens to produce a Gaussian power density distribution with a lower heating rate, or passing the separated laser beam through an aspherical cylindrical lens to produce a flat-top power density distribution with a greater heating rate.

39. Varying the type of glass tube 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; The method of claim 1 , further comprising: varying the heating rate of the separating laser beam in response to the change in type of the glass tube.

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

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

42. 2. The method of claim 1, further comprising increasing a production rate of the glass tubes, wherein increasing the production rate of the glass tubes comprises changing the speed of a conveyor that translates 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.

43. 43. The method of claim 42, wherein increasing the production rate of the glass tubes further comprises preheating the target areas of the plurality of glass tubes using a preheating laser system.

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

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

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

47. exposing each of the plurality of glass tubes to the separate laser beams producing a laser beam using a laser source; passing the laser beam through an optical system that shapes the laser beam to produce the separate laser beams and directs the separate laser beams toward the plurality of glass tubes; and passing each of the plurality of glass tubes through a beam path of the separated laser beam.

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

49. Producing the continuous hollow glass cylinder comprises: forming said 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; 2. The method of claim 1, further comprising: transferring the plurality of glass tubes to a horizontal conveyor upstream of finishing the at least one end of the plurality of glass tubes.

50. 1. A system for finishing the ends of a plurality of glass tubes or glass rods, the system comprising: a conveyor operable to translate the plurality of glass tubes or glass rods horizontally while also rotating each of the plurality of glass tubes or glass rods about a central axis of the glass tube or glass rod; 1. A separation laser system, comprising: a laser source operable to produce a laser beam; a beam delivery system operable to modify the shape, power density, power density distribution, or combinations thereof of the laser beam to produce separate laser beams and direct the separate laser beams to the plurality of glass tubes or glass rods being translated and rotated by the conveyor; one or more axial separation conveyors branching off from the conveyor and operable to exert a pulling force on the ends of each of the plurality of glass tubes or glass rods in at least an axial direction relative to the central axis.

51. 51. The system of claim 50, wherein the beam delivery system includes one or more beam expanding optics, shaping optics, and a rotating mirror.

52. 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 polygon mirror, or combinations thereof for controlling beam size, beam shape, beam power density distribution, or combinations thereof.

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

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

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

56. 51. The system of claim 50, further comprising a preheating laser system disposed upstream of the separation laser delivery system, the preheating laser system comprising a preheating laser source and a preheating beam delivery system, and operable to direct a preheating laser beam at the target area of ​​the plurality of glass tubes or glass rods to preheat the glass within the target area upstream of the separation laser beam.

57. the separate laser system a first separation laser system operable to direct a first separation laser beam to a target area proximate a first end of the plurality of glass tubes or glass rods; a second separation laser system operable to direct a second separation laser beam to a target area proximate a second end of the plurality of glass tubes or glass rods.

58. 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. a first preheating laser system disposed upstream of the first separation laser system; 58. The system of claim 57, further comprising: a second preheating laser system disposed 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.

60. 51. The system of claim 50, further comprising a positioning system operably coupled to the separation laser system, the positioning system operable to vary the distance between the separation laser system and the plurality of glass tubes or glass rods.

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

62. The laser source is a CO laser or a CO ２ 62. The system of claim 61, which is a laser.

63. 51. 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. 51. The system of claim 50, wherein the conveyor comprises a variable speed drive operably coupled to one or more of the plurality of belts and operable to vary the speed of the conveyor to translate the plurality of glass tubes or glass rods through the beam path of the separation laser beam.

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

66. 1. 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; and finishing at least one end of a plurality of the glass rods, wherein finishing the at least one end of the plurality of glass rods comprises: rotating each glass rod around a central axis of the glass rod; heating a target area of ​​the glass rod by exposing the target area of ​​the glass rod to a separate laser beam while rotating the glass rod; applying a pulling force to the at least one end of the glass rod while exposing the target area of ​​the glass rod to the separation laser beam, wherein applying the pulling force while exposing the target area to the separation laser beam separates a section of the glass rod from the at least one end of the glass rod and finishes a new end of the glass rod.

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