Systems and methods for measuring temperature of glass during tube conversion

Abstract

To provide systems and methods for measuring the temperature of a glass tube during glass tube conversion.SOLUTION: A system for producing articles from a glass tube includes a converter having a base with a plurality of processing stations and also having a turret moveable relative to the base. The turret indexes a plurality of holders for holding the glass tubes successively through the processing stations. The system further includes a thermal imaging system that includes a thermal imager coupled to the turret for movement with the turret. The thermal imaging system may also include a mirror coupled to the thermal imager and positioned to reflect infrared light from one of the holders to the thermal imager. The thermal imaging system may measure one or more characteristics of the glass tube during the conversion process. Processes for controlling the converter using the thermal imaging system to measure one or more process variables are also disclosed.SELECTED DRAWING: Figure 1

Description

Cross - Reference to Related Applications

[0001] This application claims the benefit of priority under 35 U.S.C. § 120 to U.S. Provisional Patent Application No. 62 / 476,408, entitled "Systems and Methods for Measuring the Temperature of Glass During Tube Conversion," filed on March 24, 2017, which is hereby incorporated by reference in its entirety. Further, this application is a divisional application of Japanese Patent Application No. 2023 - 142114, filed on September 1, 2023, which is a divisional application of Japanese Patent Application No. 2019 - 552485, filed on March 22, 2018, as the parent application.

Technical Field

[0002] This specification generally relates to systems and methods for measuring the temperature of glass during the conversion of a glass tube into a glass article.

Background Art

[0003] A glass tube can be converted into other glass articles. For example, a glass tube can be converted into various glass containers for pharmaceutical use, including but not limited to vials, syringes, ampoules, cartridges, and other glass articles. A glass tube can be converted, for example, by a "conversion machine." Conversion machines have been in use for over 75 years and are currently manufactured by various commercial and in - house equipment suppliers. These conversion machines typically use processes including framing, rotating and stationary tool forming, thermal separation or scoring, and impact cutting processes to remake a long glass tube length into multiple glass articles.

[0004] In the current glass conversion industry, conversion machines are operated by operators and technicians with extensive experience. These operators and technicians learn to operate the machines through experience and craftsman-like training. For example, the operation adjustments of burners and machine settings are usually carried out only by visual evaluation of the temperature and shape of partially formed or fully formed glass articles. The operating procedures and machine modification methods are strictly maintained by component manufacturers, and this approach has become a major barrier for new manufacturers to enter the high-end pharmaceutical product manufacturing market.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, alternative systems and methods for forming glass articles by tube conversion machines are needed.

[0006] Therefore, systems and methods for measuring the temperature of a glass tube during glass tube conversion for manufacturing glass articles are needed.

Means for Solving the Problems

[0007] In one or more aspects of the present disclosure, a system for manufacturing glass articles from a glass tube includes a base having a plurality of processing stations spaced apart within a circuit, and a turret movable relative to the base, the turret having a plurality of holders extending from the turret toward the plurality of processing stations, the plurality of holders being spaced apart from each other, and the turret being operable to index each of the plurality of holders and bring them into continuous proximity with each of the plurality of processing stations. The system may include a conversion machine including the turret. The system may further include a thermal imaging system including a thermal imager coupled to the turret for movement therewith, the thermal imager being arranged to capture infrared light emitted from a glass tube disposed in one of the plurality of holders.

[0008] In an embodiment, the thermal imager can be arranged to directly receive the infrared light emitted by the outer surface of the glass tube. The thermal imaging system can further include at least one mirror directed to reflect the infrared light emitted from the inner surface of the glass tube to the thermal imager. The at least one mirror can be a fixed mirror coupled to the base and directed to reflect the infrared light emitted from the inner surface of the glass tube to the thermal imager.

[0009] In some embodiments, the system can further include a mirror coupled to the thermal imager and directed to reflect infrared light from the glass tube to the thermal imager. The mirror can be directed to reflect the infrared light emitted from the outer surface of the glass tube to the thermal imager. The reflective surface of the mirror can have a reflectivity of 96% or more for light having a wavelength of 800 nanometers to 20 micrometers. In other embodiments, the mirror can be directed to reflect the infrared light emitted from the inner surface of the glass tube to the thermal imager.

[0010] In an embodiment, the system can include at least one auxiliary mirror coupled to the thermal imager, the mirror being directed to reflect the infrared light emitted from the outer surface of the glass tube to the thermal imager, and the auxiliary mirror being directed to reflect the infrared light emitted from the inner surface of the glass tube to the thermal imager. In other embodiments, the system can include at least one fixed mirror disposed vertically below one of the plurality of processing stations, the fixed mirror being arranged to reflect the infrared light emitted from the inner surface of the glass tube to the thermal imager when the thermal imager is indexed to a predetermined position of one of the plurality of processing stations by a turret.

[0011] In some embodiments, the thermal imager can be an infrared camera configured to receive infrared light having a wavelength of 4 micrometers to 14 micrometers or 5 micrometers to 14 micrometers. In an embodiment, the system can include a main turret and a secondary turret. The thermal imager can be coupled to the main turret to rotate with the main turret. The system can include a loading turret that is disposed above the main turret and rotatable with respect to the main turret. In some embodiments, the thermal imaging system can include a plurality of thermal imagers.

[0012] In some embodiments, the system can include a slip ring having a slip ring axis disposed above the turret and aligned with the central axis of the turret, and the slip ring electrically couples the thermal imager to a power source. The slip ring can operatively couple the thermal imager to a processor. The inner ring of the slip ring can include a central bore.

[0013] In other embodiments, the system can further include a power source coupled to the turret to rotate with the turret, and the power source is electrically coupled to the thermal imager to supply power to the thermal imager. The system can also include a wireless communication device coupled to the turret, and the wireless communication device communicatively couples the thermal imager to a processor.

[0014] In an embodiment, the system can include a cooling system including a cooling fluid supply, a rotary joint fluidly coupled to the cooling fluid supply and having a joint axis aligned with the central axis of the turret, and a supply conduit extending from the rotary joint to the thermal imaging system. The system can also include a cleaning system including at least one nozzle disposed to deliver fluid to a lens of the thermal imager. The thermal imaging system can include a mirror coupled to the thermal imager and directed to reflect infrared light from a glass tube disposed in one of a plurality of holders to the thermal imager, and the cooling system can include at least one nozzle disposed to deliver fluid to a reflective surface of the mirror.

[0015] In some embodiments, the system may include at least one processor communicatively coupled to a thermal imager, at least one memory module communicatively coupled to the processor, and machine-readable instructions stored in the at least one memory module that, when executed by the at least one processor, cause the thermal imaging system to perform at least the following: receive thermal image information from the thermal imager, process the thermal image information, and determine characteristics of the glass tube from the thermal image information. The characteristics may be the temperature of the glass tube, the temperature gradient through the thickness of the glass tube, the viscosity of the glass tube, the viscosity gradient through the thickness of the glass tube, the dimensions of the glass tube, the temperature profile of the glass tube, the temperature profile of the glass tube over time, at least one of the centerlines of the glass tube, or a combination thereof.

[0016] In an embodiment, the system may further include machine-readable instructions stored in the at least one memory module that, when executed by the at least one processor, cause the thermal imaging system to determine the temperature of the glass tube from the thermal image information, determine the viscosity of the glass tube from the thermal image information, or determine the dimensions of the glass tube from the thermal image information.

[0017] In some embodiments, the system may further include machine-readable instructions stored in the at least one memory module that, when executed by the at least one processor, cause the thermal imaging system to perform at least the following: determine a first characteristic of the glass tube at a first processing station, determine a second characteristic of the glass tube at a second processing station disposed downstream of the first processing station, calculate the difference between the first characteristic and the second characteristic, and transmit an output representing the difference between the first characteristic and the second characteristic.

[0018] In some embodiments, the processor may be communicatively coupled to a control device, and the system, when executed by at least one processor, causes the thermal imaging system to perform at least the following: compare the characteristics of the glass tube with the characteristics of a set point, determine a control variable from the comparison of the characteristics of the glass tube and the characteristics of the set point, and transmit a control signal representing the control variable to the control device, and may further include machine-readable instructions stored in at least one memory module.

[0019] In an embodiment, at least one of the plurality of processing stations may include a heating station having at least one heating element, and the control device is operatively coupled to the heating element to operate the heating of the glass tube by the heating element. The heating element may include a burner, and the control device may be one or more of a fuel control valve, an oxygen control valve, or an air control valve. The control variable may be one or more mass flow rates of fuel gas, oxygen, or air. Alternatively, the control variable may be the position of one or more of the fuel control valve, the oxygen control valve, or the air control valve.

[0020] In an embodiment, at least one of the processing stations may be a cooling station having at least one coolant control valve, and the control device is the coolant control valve. In an embodiment, at least one of the processing stations may be a forming station having one or more actuators for translating at least one forming tool to removably engage the glass tube, and the control device includes the one or more actuators. The control variable may be the contact time between at least one forming tool and the glass tube within the forming station.

[0021] In some embodiments, the system may further include a sizing system. The sizing system may include at least one of a vision image system, a laser reflectometer, a laser gauge, or an optical micrometer. The sizing system may be arranged to capture measurement data of the glass tube upstream of the converter. Alternatively, in some embodiments, the sizing system may be arranged to capture measurement data of the glass tube at one of a plurality of processing stations. The system may further include machine-readable instructions stored in at least one memory module that, when executed by at least one processor, cause the sizing system to perform at least the following: capture measurement data of the glass tube at one of a plurality of processing stations, process the measurement data of the glass tube, and determine physical attributes of the glass tube from the measurement data of the glass tube. The physical attributes are one or more of the diameter, thickness, or glass mass per unit length of the glass tube.

[0022] In some embodiments, the system may include machine-readable instructions stored in at least one memory module that, when executed by at least one processor, cause the system to perform at least the following: receive physical attributes of the glass tube from the sizing system, and determine a characteristic gradient across the thickness of the glass tube from the physical attributes and characteristics. The characteristic gradient may be a temperature gradient or a viscosity gradient.

[0023] In an embodiment, the system may include machine-readable instructions stored in at least one memory module that, when executed by at least one processor, cause the system to perform at least the following: compare the physical attributes of the glass tube with the physical attributes of a setpoint, and determine an adjustment value of a control variable from the comparison between the physical attributes of the glass tube and the physical attributes of the setpoint.

[0024] In another aspect, a method for controlling a glass tube changer may include indexing a glass tube removably coupled to a turret of the glass tube changer through a plurality of processing stations of the glass tube changer, wherein at least one of the plurality of processing stations includes a control device. The method may further include capturing a thermal image of the glass tube using a thermal imaging system coupled to the turret of the glass tube changer, the thermal imaging system including at least a thermal imager oriented to capture infrared light from the glass tube. The method may further include processing the thermal image, determining characteristics of the glass tube from the thermal image, comparing the characteristics of the glass tube to a setpoint, determining a control variable from the comparison of the characteristics of the glass tube and the setpoint, and transmitting a control signal representative of the control variable to the control device.

[0025] In some embodiments of the method, at least one of the plurality of processing stations may include a heating station having at least one heating element, and the control device may be operatively coupled to the heating element. The heating element may be a burner, and the control device may be one or more of a fuel control valve, an oxygen control valve, or an air control valve, and the control variable may be a mass flow rate of one or more of fuel gas, oxygen, or air. The control device may be one or more of a fuel control valve, an oxygen control valve, or an air control valve, and the control variable may be a position of one or more of the fuel control valve, the oxygen control valve, or the air control valve.

[0026] In an embodiment of the method, at least one of the processing stations may include a cooling station having at least one coolant control valve, and the control device may be the coolant control valve. In some embodiments of the method, at least one of the processing stations includes a forming station having one or more actuators for translating at least one forming tool into removable engagement with the glass tube, and the control device may be the one or more actuators. The control variable may be a contact time between at least one forming tool and the glass tube within the forming station.

[0027] In some embodiments, the converter may include a dimensional determination system having at least one of a vision image system, a laser reflectometer, a laser gauge, or an optical micrometer arranged to capture measurement data of a glass tube at one of a plurality of processing stations. The method may further include capturing measurement data of a glass tube at one of a plurality of processing stations, processing the measurement data of the glass tube, and determining a physical attribute of the glass tube from the measurement data of the glass tube. The physical attribute may be one or more of the diameter, thickness, or glass mass per unit length of the glass tube.

[0028] In an embodiment, the method may further include comparing the physical attribute of the glass tube with the physical attribute of a set point and determining an adjustment value of a control variable from the comparison between the physical attribute of the glass tube and the physical attribute of the set point. In other embodiments, the method may further include measuring a physical attribute of the glass tube, wherein the physical attribute may be one of the diameter, thickness, or mass per unit length of the glass tube, comparing the physical attribute of the glass tube with the physical attribute of a set point, and determining an adjustment value of a control variable from the comparison between the physical attribute of the glass tube and the physical attribute of the set point.

[0029] It should be understood that both the foregoing summary and the following detailed description are intended to describe various embodiments and to provide an overview or framework for understanding the nature and characteristics of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate the various embodiments described herein and, together with the specification, serve to explain the principles and operations of the claimed subject matter.

Brief Description of the Drawings

[0030]

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MODE FOR CARRYING OUT THE INVENTION

[0031] Here, embodiments of a system and method for controlling a tube conversion process will be described in detail. Examples thereof are shown in the accompanying drawings. As far as possible, the same reference numbers are used throughout the drawings for references to the same or identical parts. An embodiment of a system for manufacturing an article from a glass tube is shown in FIG. 1. In this embodiment, the system for manufacturing a glass article from the glass tube 102 includes a converter 100 and a thermal imaging system 120. The converter 100 includes a base 104 having a plurality of processing stations 106 spaced apart within a circuit, and a main turret 108 spaced apart from the base 104 and movable relative to the base 104. The main turret 108 includes a plurality of holders 130 extending from the main turret 108 towards the plurality of processing stations 106. The plurality of holders 130 are spaced apart from each other, and each of the plurality of holders 130 is aligned with one of the plurality of processing stations 106. The main turret 108 is operable to sequentially index each of the plurality of holders 130 and bring it into proximity with each of the plurality of processing stations 106. The thermal imaging system 120 may include a thermal imager 122, and the thermal imager 122 may be coupled to a portion of the main turret 108 and may translate with this portion of the main turret 108. The thermal imaging system 120 may also include a mirror 124 coupled to the thermal imager 122 and arranged to reflect infrared light from one of the plurality of holders 130 to the thermal imager 122. Various embodiments of the system and method for controlling the tube conversion process are described herein with particular reference to the accompanying drawings.

[0032] As used herein, directional terms (e.g., up, down, right, left, front, back, top, bottom) are described only with respect to the drawn figures and do not imply absolute orientation.

[0033] Unless otherwise expressly stated, any method described in this specification is not intended to require implementation in a particular order of its steps, nor is it ever intended to require a particular orientation in any device. 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 the order or orientation of individual components, or if the claims or the specification do not otherwise expressly state that the steps are limited to a particular order, or if the particular order or orientation of the components of the apparatus is not recited, it is not intended to imply any order or orientation in any sense. This applies to any possible non-expression-based basis for interpretation, including logical matters, simple meanings derived from grammar or punctuation regarding the arrangement of steps, flow of operations, order of components or orientation of components, and the number or type of embodiments described in this specification.

[0034] 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 embodiments having two or more such components unless the context clearly dictates otherwise.

[0035] Referring now to FIG. 1, a converter 100 for manufacturing glass articles from a glass tube 102 is schematically shown. The converter 100 can be used to convert the glass tube 102 into a plurality of glass articles such as, but not limited to, vials, syringes, cartridges, ampoules, or other glass articles. The converter 100 includes a base 104 having a plurality of processing stations 106, a main turret 108 disposed above the base 104 and rotatable about a central axis A with respect to the base 104, and a glass tube loading turret 110 disposed above the main turret 108 for supplying the glass tube 102 to the main turret 108. The converter 100 may also include a plurality of sub-processing stations 112 on the base 104 and a sub-turret 114 rotatable with respect to the base 104. A thermal imaging system 120 is coupled to the main turret 108 and rotates with the main turret 108. In an embodiment, the thermal imaging system 120 includes a thermal imager 122 and a mirror 124. An attachment device 126 may be used to couple the thermal imaging system 120 to the main turret 108. The thermal imaging system 120 can be used to capture thermal images of the glass tube 102 as the glass tube 102 is indexed by the main turret between the processing stations 106. From these thermal images, one or more temperatures or temperature profiles of the glass tube 102 can be extracted, used, and / or incorporated into one or more process control methods for studying the conversion process and / or controlling the converter 100.

[0036] As schematically shown in FIG. 1, the base 104 of the converter 100 is fixed, and the processing station 106 can be coupled to the upper portion 105 of the base 104. A plurality of processing stations 106 are spaced apart from each other and disposed within the main circuit 116. In one or more embodiments, the main circuit 116 can be circular such that rotation of the main turret 108 about the central axis A allows the main turret 108 to index the glass tube 102 through the plurality of processing stations 106. The type and / or shape of the article produced from the glass tube 102 can affect the number of processing stations 106 coupled to the base 104. The number of processing stations 106 of the main turret 108 can be from 14 processing stations 106 to 32 processing stations 106. The converter 100 and the conversion process are described herein in connection with a converter 100 having 16 processing stations 106 within the main circuit 116, but it should be understood that the converter 100 can have more or fewer than 16 processing stations 106 within the main circuit 116. The processing stations 106 can include, by way of example and without limitation, one or more heating stations, forming stations, polishing stations, cooling stations, separation stations, punching stations, measuring stations, supply stations or discharge stations or other processing stations for manufacturing glass articles from the glass tube 102. The type and / or shape of the article produced from the glass tube 102 can also affect the type and / or order of the processing stations 106 of the converter 100.

[0037] The main turret 108 can be disposed above the base 104 and rotatably coupled to the base 104 such that the main turret 108 is rotatable about a central axis A with respect to the base 104. A drive motor (not shown) can be used to rotate the main turret 108 with respect to the base 104. The main turret 108 includes a plurality of holders 130 configured to removably secure each glass tube 102 to the main turret 108. The holder 130 can be a clamp, chuck or other holding device or combination of holding devices. The holder 130 can orient each glass tube 102 such that the glass tube 102 is substantially parallel to the central axis A of the main turret 108 and substantially perpendicular to the upper portion 105 of the base 104. Although the converter 100 is described herein in connection with a converter 100 oriented vertically, it should be understood that the converter 100 can be oriented horizontally or at an angle. Each holder 130 extends in a direction from the bottom 109 of the main turret 108 toward the base 104 (i.e., in the -Z direction with respect to the coordinate axes in FIG. 1), and each holder 130 is oriented such that when the main turret 108 is indexed about the central axis A, the glass tube 102 is positioned within or proximate to each successive processing station 106 of the main circuit 116 of the base 104. The vertical orientation of the glass tubes 102 allows the lower protrusions of each glass tube 102 to be continuously circulated through the processing stations 106 of the main circuit 116. Each holder 130 can be individually rotatable with respect to the main turret 108 about a holder axis D that can be substantially parallel to the central axis A of the main turret 108. Each holder 130 can be operatively coupled to a motor (not shown), a continuous drive belt or other drive mechanism to rotate each holder 130 with respect to the main turret 108. Rotation of the holder 130 enables rotation of the glass tube 102 with respect to a fixed burner, shaping tool, cooling nozzle or other feature of the processing station 106.

[0038] Referring to FIGS. 1 and 2, the converter 100 may have a plurality of sub - processing stations 112 disposed at intervals within a secondary circuit 118 (FIG. 2), and a sub - turret 114 (FIG. 1) for indexing an article 103 (FIG. 1) separated from a glass tube 102 through the plurality of sub - processing stations 112. The sub - turret 114 may be rotatable relative to a base 104 about a second axis B. The second axis B may be substantially parallel to the central axis A of the main turret 108. The sub - turret 114 holds the glass article 103 so as to engage successively with each sub - processing station 112, and also includes a plurality of holders 130 for positioning the glass article 103. The sub - turret 114 may receive the article 103 from the separation station 206 (FIG. 2) of the main turret 108, index the article 103 through the plurality of sub - processing stations 112 by rotation of the sub - turret 114, and discharge the finished article from the converter 100.

[0039] The glass tube loading turret 110 is disposed above the main turret 108. In an embodiment, the glass tube loading turret 110 can be offset from the central axis A of the main turret 108. The glass tube loading turret 110 can be rotatable about an axis C that can be substantially parallel to the central axis A of the main turret 108. The glass tube loading turret 110 can be supported independently in a fixed position relative to the main turret 108, and the rotation of the glass tube loading turret 110 can be independent of the rotation of the main turret 108. Referring to FIGS. 1 and 2, in some embodiments, the glass tube loading turret 110 is disposed within a circular circuit 134 and can include a plurality of loading channels 132 configured to hold glass tubes 102. The glass tube loading turret 110 can be arranged to align one of the loading channels 132 vertically (i.e., in a direction parallel to the central axis A of the main turret 108 and / or parallel to the Z axis of FIG. 1) with a processing station 106 of the main circuit 116 of the converter 100 and a corresponding holder 130 on the main turret 108 determined through the processing station 106 of the main circuit 116. In one or more embodiments, the processing station 106 aligned with the glass tube loading turret 110 can be the tube loading station 214 (FIG. 2). When the converter 100 has converted all or a portion of a glass tube 102 at a particular holder position 136 into one or more articles, the glass tube loading turret 110 can deliver a new length of glass tube 102 through the top of the main turret 108 to the holder 130 at the holder position 136 when the holder position 136 is determined and aligned with the tube loading station 214 of the main circuit 116. In another embodiment, the converter 100 can include an arm (not shown) that is electromechanically movable between the main turret 108 and the glass tube loading turret 110. When the converter 100 has converted all or a portion of a glass tube 102 at a particular holder position 136, the arm can grasp a new length of glass tube 102 from the glass tube loading turret 110 or another glass tube staging device and deliver the new length of glass tube 102 to a particular holder position 136 on the main turret 108. Other methods of delivering a new length of glass tube 102 to the main turret 108 are contemplated.

[0040] Referring to FIG. 2, as described above, the plurality of processing stations 106 of the converter 100 may include one or more heating stations 202, forming stations 204, separating stations 206, polishing stations 208, cooling stations 210, punching stations 212, tube loading stations 214, discharging stations 216, measuring stations 218, tube length reduction stations 220 or other stations and / or combinations of these stations. FIG. 2 schematically shows the arrangement of the processing stations 106 of the converter 100 having a main circuit 116 of 16 processing stations 106 and a secondary circuit 118 of 8 secondary processing stations 112. As described, the processing stations 106 of the main circuit 116 are evenly spaced and evenly distributed in a circular circuit, and the secondary processing stations 112 of the secondary circuit 118 are also evenly spaced and evenly distributed in a circular circuit. FIG. 2 also schematically shows a glass tube loading turret 110 having a plurality of loading channels 132. In FIG. 2, for illustrative purposes, the glass tube loading turret 110 is shown at a position spaced from the main circuit 116. The glass tube loading turret 110 is shown as having 24 loading channels 132, but it should be understood that the glass tube loading turret may have more or fewer than 24 loading channels 132.

[0041] The main circuit 116 of the converter schematically shown in FIG. 2 may include one or more heating stations 202, a separation station 206, a flame piercing station 212, one or more forming stations 204, one or more cooling stations 210, a measurement station 218, a tube length reduction station 220, and a tube loading station 214. With respect to the direction of the indexing 222 of the main turret 108, the heating station 202 may be disposed in front of the separation station 206 and each forming station 204 to preheat the target region of the glass tube 102 to a target temperature at which the target region of the glass tube 102 can be effectively shaped or cut without causing the glass to crack or break plastically. At the separation station 206, the formed glass article 103 (FIG. 1) may be separated from the glass tube 102 (FIG. 1). The separation station 206 may also be a processing station 106 where the partially formed glass article 103 is transferred to a sub-turret 114 (FIG. 1) that is indexed through a sub-circuit 118 of the sub-processing station 112 when it is separated. The piercing station 212 may be disposed downstream of the separation station 206 in the direction of the indexing 222 of the main turret 108 of the main circuit 116. At the piercing station 212, the end of the glass tube 102 that was previously closed by the separation station 206 is pierced, thereby forming an opening in the glass tube 102.

[0042] The forming station 204 of the main turret 108 can be disposed downstream of the piercing station 212 in the direction of indexing 222. At the forming station 204, the glass tube 102 is repeatedly shaped into the desired shape of the finished glass article. As described above, one or more heating stations 202 can be disposed prior to each forming station 204 to preheat the target region of the glass tube 102 to a temperature at which the glass tube can be formed. The forming station 204 of the main turret 108 shapes one end of the glass article 103, and the forming station 204 of the sub-turret 114 shapes the other end of the glass article 103. In one or more embodiments, the converter 100 can be used to manufacture vials from the glass tube 102, and the forming stations 204 of the converter 100 can include one or more shoulder forming stations, one or more flange forming stations, and one or more flange finishing stations, with one or more heating stations 202 disposed before and between each forming station 204. The main circuit 116 can further include a measurement station 218, where a dimensional determination system 1310 (FIG. 13) can be used to measure one or more dimensions of the glass tube 102, such as diameter and thickness, and one or more dimensions of the features formed by the forming station 204. The dimensions of the features can include flange thickness, flange length, neck length, neck thickness, overall article length, dimensions of other features, or combinations thereof. The measurement station 218 can be disposed immediately downstream of the last forming station 204 such that the dimensions are measured while the glass tube 102 is still hot. Alternatively, the measurement station 218 can be disposed after one or more cooling stations 210 to measure the dimensions of the glass tube 102 and / or the glass article at a low temperature.

[0043] Referring further to FIG. 2, one or more cooling stations 210 may be disposed after the forming station 204 in the direction of the indexing 222 of the main turret 108. The tube length reduction station 220 may be disposed between the forming station 204 and the separation station 206, after the forming station 204, for shortening the partially formed glass tube 102 and for positioning it to be cut to the target length at the separation station 206. The main circuit 116 may also include a tube loading station 214 for loading a new length of glass tube 102 stock from the glass tube loading turret 110 into the main turret 108 (FIG. 1). In one or more embodiments, the tube loading station 214 may be incorporated into the cooling station 210. The tube loading station 214 may be disposed between the last forming station 204 and the separation station 206.

[0044] The forming station 204 of the main turret 108 forms features on the first end of the glass article 103. For example, the forming station 204 may form a shoulder 142 and a flange 144 on the top (first end) of the glass article 103 which is a vial or cartridge. When the glass article 103 is separated from the glass tube 102 at the separation station 206, the glass article 103 is transferred to the secondary processing station 112 of the secondary turret 114. The secondary processing station 112 may include one or more forming stations 204 for forming the second end of the glass article 103 opposite the first end of the glass article 103. For example, the forming station 204 of the secondary processing station 112 may form one or more features on the bottom (second end) of the glass article 103 which is a vial.

[0045] The sub - processing stations of the sub - circuit may include one or more heating stations 202, forming stations 204, polishing stations 208, cooling stations 210, discharging stations 216, or other stations or combinations of sub - processing stations 112. In one or more embodiments, the sub - processing stations 112 of the sub - circuit 118 may be used to form one or more features of a glass article 103, such as a vial, ampule, cartridge, or syringe, at an end of the glass article 103 opposite to the end formed, for example, by the main turret 108. For example, in some embodiments, the glass article 103 is a vial, and the forming station 204 of the sub - circuit 118 may form the bottom of the vial. Other features are contemplated, such as features indicative of characteristics of ampules, cartridges, syringes, etc. The sub - circuit 118 may include one or more polishing stations 208 for finishing the surface of the glass article. The sub - circuit 118 may further include a plurality of cooling stations 210 and a discharging station 216 where the finished glass article may be discharged from the converter 100.

[0046] The above description of the processing stations 106 of the main circuit 116 and the sub - processing stations 112 of the sub - circuit 118 may illustrate a typical converter 100 for manufacturing vials from a glass tube 102. However, it should be understood that more or fewer processing stations 106 and sub - processing stations 112 may be used to make other glass articles such as vials or cartridges, syringes, ampules, etc. having different shapes, or other glass articles. Additionally, it should be understood that the processing stations 106 and sub - processing stations 112 may be arranged in any of several different orders and / or configurations to manufacture glass articles of different shapes.

[0047] Referring now to FIG. 3A, the heating station 202 of the converter 100 is schematically shown. Each heating station 202 may include one or more heating elements 301. Examples of heating elements 301 may include, but are not limited to, fuel burners, lasers such as CO2 lasers, induction heaters, other heating devices, or combinations thereof. In some embodiments, a laser may be used to heat the glass tube 102. As shown in FIG. 3A, in an embodiment, the heating element 301 may include one or more burners 302 used to heat a target region of the glass tube 102 prior to the forming operation performed at the forming station 204 (FIG. 2) or the separation operation performed at the separation station 206 (FIG. 2). Although FIG. 3A shows one burner 302, it should be understood that two or more burners 302 may be used in one heating station 202. Each burner 302 may be fluidly coupled to a fuel supply 304, an oxygen supply 306, and optionally an air supply 308. Examples of burner fuels may include, but are not limited to, hydrogen, hydrocarbon fuel gases such as methane, propane, and butane, other fuels, or combinations thereof. Each burner 302 may include a fuel control valve 310 for controlling the mass flow rate of fuel gas to the burner 302. Each burner 302 may also include an oxygen control valve 312 for controlling the mass flow rate of oxygen to the burner 302. Each burner 302 may further include an air control valve 314 for optionally controlling the mass flow rate of air to the burner 302. The burner 302 burns the fuel gas in the presence of oxygen and / or air to generate a flame that heats at least the target region of the glass tube 102.

[0048] The heat of the flame generated by burner 302 can be increased or decreased by changing the mass flow rates of fuel gas, oxygen, and air to burner 302, and by changing the ratio of fuel gas to oxygen and / or the ratio of fuel gas to air supplied to burner 302. One or more of fuel control valve 310, oxygen control valve 312, or air control valve 314 can be adjusted to adjust the ratio of fuel to oxygen and / or air. Burner 302 can be combusted continuously, and glass tube 102 can be indexed into and out of contact with the flame generated by burner 302 by rotation of main turret 108 and / or sub-turret 114 for indexing glass tube 102 within and outside heating station 202. Each glass tube 102 can be rotated relative to burner 302 about holder axis D by holder 130 while disposed in heating station 202 so that glass tube 102 can be uniformly heated around the perimeter of glass tube 102 within the particular region being formed at downstream forming station 204 (Figure 2).

[0049] Referring now to FIG. 3B, the separation station 206 of the converter 100 is schematically shown. The separation station 206 is disposed after one or more heating stations 202 in the direction of the indexing 222 of the main turret 108. The heating station 202 disposed prior to the separation station 206 heats the glass tube 102 to make the glass plastically deformable. The separation station 206 may include a separation tool 320. While the glass tube 102, made plastically deformable by the previous heating station 202, is rotated about the holder axis D by the holder 130, the separation tool 320 may engage the outer surface 140 of the glass tube 102 to cut the glass tube 102 to a target length, thereby separating the article 103 (FIG. 1) from the glass tube 102. Alternatively, in some embodiments, the separation station 206 may include a burner, such as a hydrogen / oxygen burner, and / or a laser, such as a CO2 laser, to cut the glass tube 102 to a target length and separate the article 103 from the glass tube 102. In other embodiments, the separation station 206 may include the separation tool 320 and at least one of a hydrogen / oxygen burner or a laser. Once separated from the glass tube 102, the article 103 may be transferred to the sub-turret 114 (FIG. 1) or discharged from the converter 100.

[0050] Referring now to FIGS. 3C and 3D, an example of the forming station 204 of the converter 100 is schematically shown. Each forming station 204 may include one or more forming tools 324 rotatably coupled to the forming station 204. The forming tool 324 may be rotatable relative to the base 104 (FIG. 1) about a tool axis E that is generally parallel to the central axis A (FIG. 1) of the main turret 108 (FIG. 1). When indexed to the forming station 204, the glass tube 102 heated at the previous heating station 202 is rotated by the holder 130. The rotatable forming tool 324 engages the outer surface 140 of the glass tube 102. The forming tool 324 may be actuated by one or more actuators 326 to engage the outer surface 140 of the glass tube 102. The forming tool 324 continues to contact the glass tube 102 with a tool pressure maintained by the actuator 326 over the contact time. Contact of the forming tool 324 with the outer surface 140 of the heated glass tube 102 forms the glass tube 102 into the desired shape. When the contact time ends, the actuator 326 releases the forming tool 324 from engagement with the glass tube 102. In one or more embodiments, the contact time may be different from the dwell time of the converter 100.

[0051] Figure 3C schematically shows an embodiment of a forming station 204 for forming a shoulder 142 of a glass vial formed from a glass tube 102. Figure 3D schematically shows an exemplary embodiment of a forming station 204' for forming a flange 144 of a glass vial formed from a glass tube 102. The forming station 204' for forming the flange 144 includes three forming tools 324a, 324b, and 324c. Two forming tools 324a and 324b contact an outer surface 140 of the glass tube 102 to form an outer contour of the flange 144. A third forming tool 324c contacts an inner surface of the glass tube 102 radially inside the flange 144 and forms an inner diameter of the glass tube 102 at the flange 144. The third forming tool 324c also contacts an axial end of the glass tube 102 and forms an axial surface of the flange 144. In an embodiment, the third forming tool 324c can be fixed and the glass tube 102 is rotated about the third forming tool 324c by a holder 130. In an embodiment, a thin layer of a lubricant such as oil can be disposed, for example, between the glass tube 102 and the third forming tool 324c to space the glass tube 102 away from contact with the third forming tool 324c. Although described with respect to forming the structure of a vial, the forming station 204 can be configured to form other structures such as, for example, a shoulder, neck, or tapered tip of an ampoule or any other structure associated with an article other than a glass vial.

[0052] Figure 3E schematically shows a cooling station 210 having one or more cooling nozzles 340 arranged to direct a cooling fluid 342, such as cold air, or an inert gas, towards the glass tube 102. One or more of the cooling nozzles 340 can be arranged to direct the cooling fluid 342 to a particular region of the glass tube 102. One or more cooling fluid control valves 344 can be fluidly coupled to the cooling nozzles 340 to control a mass flow rate of the cooling fluid 342 to the cooling nozzles 340, enabling control of the cooling rate of the glass tube 102 as well as the temperature of the glass tube 102 and the temperature gradient of the glass tube 102.

[0053] Figures 3A - 3E include schematic diagrams of several different examples of the processing station 106 that can be used in the converter 100. However, it should be understood that other processing stations 106 having different structures, combinations of structures, or functions can be used to achieve the desired conversion of the glass tube 102 to one or more glass articles.

[0054] Referring again to FIG. 2, during operation, the main turret 108 indexes the glass tube 102 fixed to the holder 130 to the processing station 106. At each processing station 106, specific operations such as heating, forming, piercing, separating, cooling, reducing, supplying, etc. are performed on the glass tube 102. The dwell time is the time spent at a particular processing station 106 before the glass tube 102 is indexed by the main turret 108 to the next successive processing station 106. The converter 100 can be adjusted such that all processing stations 106 complete their operations within the dwell time. At the end of the dwell time, the main turret 108 indexes the glass tube 102 to the next processing station 106. The indexing time means the time it takes for the main turret 108 to index the glass tube 102 from one processing station 106 to the next processing station 106 and is measured in time units. The total time per part per station used in the present disclosure is the sum of the dwell time and the indexing time. The part speed (manufacturing speed) is the number of parts manufactured per unit time and is the reciprocal of the total time per part per station. In an embodiment, the indexing time of the main turret 108 can be 25% or less of the total time per part per station.

[0055] Examples of the converter 100 for converting the glass tube 102 into a glass vial include the Vial Forming Machine Model RP16 manufactured by AMBEG Dr. J. Dichter GmbH, which includes 16 processing stations 106 and 8 secondary processing stations 112 in the main circuit 116. Other examples include the Vial Forming Machine Model RP32 manufactured by AMBEG Dr. J. Dichter GmbH, which has 32 processing stations 106 in the main circuit 116 and two secondary circuits 118 each having 8 secondary processing stations 112, and the Zeta 098 Vial Forming Machine manufactured by Euromatic S.R.L., which has 36 processing stations 106. Another example may be the Zeta 103 Cartridge Forming Machine manufactured by Euromatic S.R.L., which is a converter for converting the glass tube 102 into a cartridge. The cartridge converter has similar features to the aforementioned vial converter 100 but is used for manufacturing glass articles in the form of cartridges rather than vials.

[0056] Although described in relation to the converter 100 for manufacturing a glass vial from the glass tube 102, it should be understood that the converter 100 can be configured to manufacture one or more other articles such as cartridges, syringes, ampoules or other glass articles by changing the order or configuration of the forming tool 324 and / or the processing stations 106 of the main circuit 116 or the secondary processing stations 112 of one or more secondary circuits 118.

[0057] A typical converter 100 for manufacturing articles from a glass tube 102 can operate at a manufacturing speed of 30 to 50 parts per minute. At these manufacturing speeds, the thermal gradient within the glass tube 102 is extremely high and dynamic. A short length of the glass tube 102 is generally heated from 200 °C to 1500 °C within a time period of 2 to 4 seconds. In particular, a heated length of the glass tube 102 can produce a temperature gradient of 100 °C per minute or less or 200 °C per minute or less along the length of the tube. Referring to FIG. 4, in the glass tube 102, the length L is measured in the +Z / -Z direction of the reference axis provided in FIG. 4. These large temperature gradients along the length L of the glass tube 102 facilitate precise dimensional control of thermal separation within the converter 100 and precise control of, for example, the thickness of the bottom of the glass article and the profile of the glass article.

[0058] The rapid heating of the glass tube 102 at one or more processing stations 106 can also induce a maximum temperature gradient through the thickness T of the heated glass tube 102. These temperature gradients can be, for example and without limitation, 200 °C per minute to 300 °C per minute. During the forming process for forming the shoulder 142 and flange 144 of the vial at the forming station 204, similar or higher temperature gradients can be induced. These high thermal gradients induced along the length L and through the thickness T of the glass tube 102 during conversion are important for understanding the mechanics of the conversion process, but are only poorly understood within the performance range of currently commercially available converters 100.

[0059] Referring now to FIGS. 5-6, an embodiment of the converter 100 described herein may use a thermal imaging system 120 to provide and / or enhance the automatic control of the converter 100 and the conversion process. The thermal imaging system 120 may be used to measure the surface temperature of one or more of the glass tubes 102 during the conversion process. The thermal imaging system 120 includes a thermal imager 122 and a mounting device 126 for mounting the thermal imager 122 to the main turret 108. In an embodiment, the thermal imaging system 120 may also include one or more mirrors 124 coupled to the thermal imager 122 by the mounting device 126. The mirror 124 may enable the thermal imager 122 to be oriented substantially vertically to reduce the spatial footprint of the converter 100. The thermal imaging system 120 is mounted to the main turret 108 such that the thermal imaging system 120 rotates with the main turret 108 and moves with the glass tube 102 through each processing station 106 (FIG. 1) of the converter 100. By moving with the glass tube 102 through each successive processing station 106, the thermal imaging system 120 can be used to generate a temperature profile of the glass tube 102 over the entire conversion process from the glass tube to the finished glass article. The temperature profile can be used to identify, investigate, and control the temperature gradient from one processing station 106 to the next.

[0060] In an embodiment, the thermal imager 122 can be a two-dimensional infrared thermal image camera capable of capturing light having wavelengths in the infrared spectrum. In particular, in some embodiments, the thermal imager 122 can receive long-wave infrared light having wavelengths of 4 micrometers to 14 micrometers, 4 micrometers to 10 micrometers, 4 micrometers to 8 micrometers, 4 micrometers to 7 micrometers, 5 micrometers to 14 micrometers, 5 micrometers to 10 micrometers, 5 micrometers to 8 micrometers, 5 micrometers to 7 micrometers, 7 micrometers to 14 micrometers, 7 micrometers to 10 micrometers, or 7 micrometers to 8 micrometers. Infrared light includes wavelengths in the broad spectrum of 700 nanometers (nm) to 1 millimeter. However, infrared light with longer wavelengths generally represents infrared light emitted by the outer surface 140 of the glass tube 102, which is the surface directly heated. Infrared light with shorter wavelengths of 700 nm to about 4 micrometers can be transmitted at least in part through the glass composition of the glass tube 102. Therefore, the shorter-wavelength infrared light received by the thermal imager 122 may be emitted by the inner portion of the glass tube 102 or by an external structure located behind the glass tube 102 with reference to the position of the thermal imager 122. Thus, shorter-wavelength infrared light of less than about 4 micrometers does not represent the surface of the glass tube 102. For long-wavelength infrared light, such as infrared light having wavelengths exceeding about 14 micrometers, at least a portion of the long-wavelength infrared light emitted from the surface of the glass tube 102 can be reflected away from the thermal imaging system. The glass composition of the glass tube 102 converted by the converter 100 exhibits a low transmittance and a low reflectance of infrared light having wavelengths of 4 micrometers to 14 micrometers, and thus a high emissivity of infrared light in this wavelength range. For example, the glass tube 102 exhibits a 0% transmittance and a mere 3% reflectance of infrared light having a wavelength of about 5 micrometers. Therefore, the emissivity of infrared light having a wavelength of about 5 micrometers from the glass tube 102 is about 97%.In another example, the reflectivity of infrared light having a wavelength of about 7.5 micrometers from the glass tube 102 is about 10%, and the emissivity is 90%. By capturing infrared light having a wavelength in the range of about 4 micrometers to about 14 micrometers, for example, infrared light having a wavelength of 4 micrometers to 7.5 micrometers or about 5 micrometers, the error in the surface temperature measurement value can be reduced by avoiding the integration of the temperature gradient through the thickness of the glass tube 102. The transmittance of infrared light in the glass tube 102 and the reflectivity of infrared light from the glass tube 102 introduce errors into the thermal image data captured by the thermal imager 122. A thermal imager 122 capable of capturing infrared light having a wavelength of 4 micrometers to 14 micrometers can show an improvement in the temperature accuracy of the thermal image obtained by the thermal imager 122. In one or more embodiments, the thermal imager 122 may have an object temperature range of 100°C to 2000°C or 300°C to 2000°C.

[0061] The thermal imager 122 may have an image capture speed of at least 30 Hertz (Hz). In some embodiments, the thermal imager 122 may have an image capture speed of 30 Hz to 60 Hz or 30 Hz to 50 Hz. In addition, the thermal imager 122 may comply with one or more interface protocols, such as GigE Vision, to enable the imager to communicate with one or more image analysis systems having image analysis software, such as LabVIEW (trademark) sold by National Instruments, for example, via an Ethernet (registered trademark) connection, and to transmit high-speed imaging data to this system. The thermal imager 122 may have an internal temperature sensor (not shown) incorporating a self-calibration system that enables the thermal imager 122 to measure the temperature of the infrared sensor set and adjust the image data to compensate for the temperature change of the thermal imager 122.

[0062] As described above, the thermal imager 122 is attached to the main turret 108 of the converter 100 using the attachment device 126. Referring to FIG. 6, the attachment device 126 can be attached to the outer portion 128 of the main turret 108 such that the attachment device 126 and the thermal imager 122 rotate with the main turret 108. In an embodiment, the main turret 108 of the converter 100 can be housed within a housing such as a steel mesh housing 127. In these embodiments, the steel mesh housing 127 is the outer portion 128 of the main turret 108. The attachment device 126 can be attached to the steel mesh housing 127 by a rail support system 129 (FIG. 5). In some embodiments, the attachment device 126 can allow for the temporary removal of the thermal imager 122 and / or the mirror 124 from the turret 108 of the converter 100.

[0063] The attachment device 126 positions the thermal imager 122 and the mirror 124 at a fixed angular position 138 on the main turret 108 such that the thermal imager 122 and the mirror 124 follow a single holder 130 and the glass tube 102 throughout the entire cycle of the converter 100. The attachment device 126 can include an imager support 502 and a mirror support 504. The thermal imager 122 can be removably coupled to the imager support 502. The imager support 502 can be adjustable in one or more directions to orient the thermal imager 122 with respect to the holder 130 and / or the glass tube 102. For example, the imager support 502 can include vertical adjustment (i.e., moving up or down parallel to the central axis A of the main turret 108), radial adjustment with respect to the main turret 108 (i.e., moving the thermal imager 122 closer to or away from the outer portion 128 of the main turret 108), angular adjustment (i.e., adjusting the angular position of the thermal imager 122 with respect to one of the holders 130), rotational adjustment (i.e., adjustably rotating the camera to change the angle formed between the optical centerline OC of the camera in FIG. 6 and the XY plane of the axis), or other adjustments.

[0064] In some embodiments, the imager support 502 may be configured to position the thermal imager 122 to directly capture an image of the glass tube 102 while the glass tube 102 is being processed. In this configuration, the optical centerline OC of the thermal imager 122 may be aligned within the XY plane of the coordinate axes of FIGS. 5 and 6. However, in a typical converter 100, the space around the processing station 106 of the main circuit 116 and / or the secondary processing station 112 of the secondary circuit 118 is limited, and when the thermal imager 122 is positioned such that the optical centerline OC of the thermal imager 122 is within the XY plane and radially aligned with the glass tube 102, the thermal imager 122 may extend radially outward from the main turret 108. This can cause the thermal imager 122 and / or the mounting device 126 to contact the components of the converter 100 or interfere with the operation of the converter 100 when the thermal imager 122 rotates with the rotation of the main turret 108. Additionally, in this configuration, the thermal imager 122 extends radially outward from the rotating main turret 108, which may create a dangerous situation during operation.

[0065] To avoid these spatial issues, in some embodiments, the imager support 502 may be adjustable to direct the thermal imager 122 such that the optical centerline OC of the thermal imager 122 forms a non-zero angle with respect to the XY plane of the coordinate axes of FIGS. 5 and 6. In one or more embodiments, the thermal imager 122 may be positioned such that the optical centerline OC of the thermal imager 122 is parallel to the central axis A of the main turret 108 (i.e., substantially perpendicular to the XY plane of the coordinate axes of FIGS. 5 and 6). Alternatively, the thermal imager 122 may be positioned such that the optical centerline OC forms a non-zero angle of less than 90° with respect to the axial plane of the main turret 108. Mounting the thermal imager 122 at a non-zero angle with respect to the axial plane of the main turret 108 can help avoid interfering with the operation of the converter 100 and / or creating a dangerous situation.

[0066] The mirror support portion 504 can be coupled to the imager support portion 502, and the mirror 124 can be arranged to reflect infrared light from the glass tube 102 toward the lens 506 of the thermal imager 122. In an embodiment, the mirror support portion 504 can arrange the mirror 124 in alignment with the optical center line OC of the thermal imager 122. In one or more embodiments, the mirror support portion 504 can enable one or more of vertical (i.e., along the +Z / -Z axes of the coordinate axes in FIGS. 5 and 6), radial, angular, rotational, or other directional adjustments of the mirror 124 with respect to the thermal imager 122.

[0067] Referring to FIG. 5, mirror 124 can be coupled to mounting device 126 and can be positioned within the field of view of thermal imager 122 such that mirror 124 reflects infrared light toward lens 506 of thermal imager 122. In one or more embodiments, mirror 124 can be positioned such that the optical centerline OC of thermal imager 122 intersects the reflective surface 508 of the mirror. Alternatively, mirror 124 can be positioned within the field of view of thermal imager 122 such that reflective surface 508 reflects infrared light to lens 506, but the optical centerline OC of thermal imager 122 does not intersect reflective surface 508 of mirror 124. Mirror 124 can be angled with respect to the optical centerline OC of thermal imager 122 to reflect infrared light emitted from the outer surface 140 of glass tube 102 at a particular holder position 136 to thermal imager 122. Referring to FIG. 7, generally, mirror 124 is angled such that the reflective surface 508 of mirror 124 forms a non-zero angle α less than 90° with the optical centerline OC of thermal imager 122. In other words, the reflective surface 508 of mirror 124 can be angled such that the reflective surface 508 is not perpendicular to the optical centerline OC of thermal imager 122. In one or more embodiments, mirror 124 can be positioned to reflect infrared light from holder position 136 that is directly radially inward from thermal imager 122 with respect to the central axis A of main turret 108 to thermal imager 122. Alternatively, in other embodiments, mirror 124 can be positioned to reflect infrared light from holder position 136 that is one or more positions in the clockwise or counterclockwise direction from the position of thermal imager 122 (i.e., one or more positions upstream / forward or downstream / rearward of the position where thermal imager 122 is mounted to main turret 108). Although specific orientations of mirror 124 and thermal imager 122 have been described herein, it should be understood that mirror 124 and thermal imager 122 can be arranged and oriented in any of a number of configurations depending on the configuration of the particular converter 100.

[0068] In an embodiment, the reflective surface 508 of the mirror 124 can be highly reflective of infrared light. In one or more embodiments, the reflective surface 508 of the mirror 124 can have an average reflectivity of 96% or more, 97% or more, 98% or more, or 99% or more of infrared light having a wavelength of 4 micrometers (μm) to 14 μm. In one or more embodiments, the reflective surface 508 of the mirror 124 can have an average reflectivity of 96% or more of light having a wavelength of 4 μm to 14 μm. Referring to FIG. 17, the mirror 124 can include a mirror substrate 510 and a reflective coating 512 applied to the mirror substrate 510 to create the reflective surface 508. The mirror substrate 510 can be thermally stable to avoid distorting the image. In an embodiment, the mirror substrate 510 can be quartz, such as fused quartz, for example. In some embodiments, the reflective coating 512 can be a gold coating, for example.

[0069] Referring to FIG. 7A, as described above, in some embodiments, the thermal imager 122 can be arranged to directly receive infrared light emitted from the outer surface 140 of the glass tube 102 at a specific holder position 135 of the main turret 108. In particular, the thermal imager 122 can be arranged such that infrared light emitted from the outer surface 140 of the glass tube 102 moves directly along path 710 to the lens 506 of the thermal imager 122 without being reflected by a mirror such as the mirror 124. The thermal imager 122 receives the infrared light emitted by the outer surface 140 of the glass tube 102 and captures a thermal image representing the wavelength and intensity of the infrared light received by the thermal imager 122. The thermal imager 122 moves with the main turret 108 such that the thermal imaging system 120 captures thermal image data of the outer surface 140 of the glass tube 102 at a specific holder position 136 as the glass tube 102 is indexed through each successive processing station 106 (FIG. 1). Capturing thermal image data from the infrared light emitted by the outer surface 140 of the glass tube 102 can enable profiling of the temperature of the outer surface 140 of the glass tube 102 over the course of the conversion process.

[0070] Referring to FIG. 7B, in an embodiment, the thermal imager 122 may be arranged to directly receive infrared light emitted by the outer surface 140 of the glass tube 102. Additionally, one or more fixed mirrors 700 may be coupled to the base 104 of the converter 100 at the processing station 106 to reflect infrared light emitted by the inner surface 146 of the glass tube 102 to the thermal imager 122. In some embodiments, each fixed mirror 700 may be disposed vertically below the processing station 106 (i.e., in the -Z direction of the coordinate axes of FIG. 7B with respect to the processing station 106). By disposing the fixed mirror 700 vertically below the processing station 106, when the thermal imager 122 is positioned at a predetermined position of the processing station 106, the fixed mirror 700 enables infrared light emitted by the inner surface 146 (FIG. 4) of the glass tube 102 to be reflected towards the lens 506 of the thermal imager 122. By reflecting the infrared light emitted from the inner surface 146 of the glass tube 102 towards the thermal imager 122, the thermal imaging system 120 may be able to profile or determine the temperature of the inner surface 146 of the glass tube 102. The infrared light emitted from the inner surface 146 of the glass tube 102 may move along a path 712 extending substantially downward (i.e., in the -Z direction of the coordinate axes of FIG. 7B) from the inner surface 146 of the glass tube 102 and be reflected from the fixed mirror 700 towards the lens 506 of the thermal imager 122. The thermal imager 122 is coupled to the main turret 108 and rotates with the main turret 108. Therefore, the thermal imager 122 is sent to a predetermined position for receiving infrared light emitted by the inner surface 146 of the glass tube 102 and reflected from a specific fixed mirror 700 only once per cycle of the main turret 108 through the entire main circuit 116 of the processing station 106. In an embodiment, during each cycle of the main turret 108, the fixed mirror 700 may be disposed at a plurality of processing stations 106 so that the thermal imager 122 can capture thermal image data from the inner surface 146 of the glass tube 102 at the plurality of processing stations 106.

[0071] Referring to FIG. 7C, as described above, the thermal imager 122 can be arranged such that the lens 506 of the thermal imager 122 is not oriented to directly receive infrared light from the outer surface 140 of the glass tube 102. In FIG. 7C, the thermal imager 122 is shown oriented substantially vertically (i.e., in the + / −Z direction of the coordinate axes of FIG. 7C). In an embodiment, the thermal imager 122 can be oriented such that the optical center line OC of the thermal imager 122 is substantially parallel to the center line C of the glass tube 102. As described above, the mounting device 126 can allow the thermal imager 122 to rotate, tilt, or be angled with respect to the center line C of the glass tube 102. The mirror 124 is coupled to the mounting device 126 such that the mirror 124 moves with the thermal imager 122 when the main turret 108 is indexed through the processing station 106. The mirror 124 can be arranged to reflect infrared light from the outer surface 140 of the glass tube 102 toward the lens 506 of the thermal imager 122. In this configuration, when the glass tube 102 is rotated to each successive processing station 106 (FIG. 1) and between each successive processing station 106, both the mirror 124 and the thermal imager 122 move with the main turret 108 such that the thermal imaging system 120 captures thermal image data of the outer surface 140 of the glass tube 102 at a particular holder position 136. In particular, the mirror 124 can be arranged to reflect infrared light radially outwardly emitted by the outer surface 140 of the glass tube 102 to the thermal imager 122, and the thermal imager 122 receives the infrared light reflected from the mirror 124 and captures a thermal image representing the wavelength and intensity of the infrared light received by the thermal imager 122. The infrared light moves outwardly from the outer surface 140 of the glass tube 102 along path 714 and is reflected from the mirror 124 toward the lens 506 of the thermal imager 122. L can be oriented such that the optical center line OC of the thermal imager 122 is substantially parallel to the center line C of the glass tube 102. As described above, the mounting device 126 can allow the thermal imager 122 to rotate, tilt, or be angled with respect to the center line C of the glass tube 102. L can be oriented such that the optical center line OC of the thermal imager 122 is substantially parallel to the center line C of the glass tube 102. As described above, the mounting device 126 can allow the thermal imager 122 to rotate, tilt, or be angled with respect to the center line C of the glass tube 102.

[0072] Referring now to FIG. 7D, mirror 124 can be arranged to reflect infrared light emitted by the outer surface 140 of glass tube 102 and infrared light emitted by the inner surface 146 of glass tube 102 toward lens 506 of thermal imager 122. Infrared light emitted from the outer surface 140 of glass tube 102 moves outward from the outer surface 140 of glass tube 102 along path 714 and is reflected from mirror 124 toward lens 506 of thermal imager 122. Infrared light emitted from the inner surface 146 moves along path 716 from the inner surface 146 of glass tube 102 to mirror 124 and is reflected by mirror 124 toward lens 506 of thermal imager 122. Since mirror 124 moves with thermal imager 122 when thermal imager 122 is indexed through a plurality of processing stations 106, mirror 124 can enable thermal imager 122 to capture thermal image data from the outer surface 140 and the inner surface 146 of glass tube 102 at each processing station 106. In an embodiment, thermal imager 122 can capture thermal image data from the outer surface 140 and the inner surface 146 of glass tube 102 simultaneously, for example, with a single thermal image.

[0073] Referring to FIG. 7E, in an embodiment, the thermal imaging system 120 may include an auxiliary mirror 125 that may be coupled to the mounting device 126 such that the auxiliary mirror 125 moves with the thermal imager 122 and the mirror 124. In these embodiments, the infrared light emitted from the outer surface 140 of the glass tube 102 moves from the outer surface 140 of the glass tube 102 along path 714 to the mirror 124 and is reflected by the mirror 124 towards the lens 506 of the thermal imager 122. The infrared light emitted from the inner surface 146 of the glass tube 102 moves from the inner surface 146 of the glass tube 102 along path 718 to the auxiliary mirror 125 and is reflected by the auxiliary mirror 125 towards the lens 506 of the thermal imager 122. In some embodiments, the auxiliary mirror 125 may be disposed vertically below the mirror 124 (i.e., in the -Z direction of the coordinate axes in FIG. 7E). Since both the mirror 124 and the auxiliary mirror 125 move with the thermal imager 122 when the thermal imager 122 is indexed through the plurality of processing stations 106, the mirror 124 and the auxiliary mirror 125 may enable the thermal imager 122 to capture thermal image data from the outer surface 140 and the inner surface 146 of the glass tube 102 at each processing station 106. In an embodiment, the thermal imager 122 may capture thermal image data from the outer surface 140 and the inner surface 146 of the glass tube 102 simultaneously.

[0074] Referring to FIG. 7F, in an embodiment, one or more fixed mirrors 700 may be coupled to the base 104 of the converter 100 at the processing station 106. In an embodiment, each fixed mirror 700 may be disposed vertically below the processing station 106. The fixed mirror 700 may be angled to reflect infrared light emitted by the inner surface 146 of the glass tube 102 to the thermal imager 122 when the thermal imager 122 is indexed to a predetermined position of the processing station 106. The infrared light emitted from the inner surface 146 of the glass tube 102 may travel substantially downward along path 720 (i.e., in the substantially -Z direction of the coordinate axes of FIG. 7F) to the fixed mirror 700 and is reflected by the fixed mirror 700 toward the lens 506 of the thermal imager. The thermal imager 122 is coupled to the main turret 108 and rotates with the main turret 108 as the main turret 108 indexes each holder 130 through a plurality of processing stations 106. Thus, the thermal imager 122 is sent to a predetermined position to receive the infrared light reflected from the fixed mirror 700 once per cycle of the main turret 108 through the entire main circuit 116 of the processing station 106. The infrared light reflected by the fixed mirror 700 to the thermal imager 122 may be captured by the thermal imager 122 only once per cycle of the main turret 108. By disposing the fixed mirror 700 below the processing station 106, the fixed mirror 700 is enabled to reflect infrared light emitted by one or more inner surfaces 146 (FIG. 4) of the glass tube 102, and the thermal imaging system 120 may be enabled to profile or determine the temperature of one or more inner surfaces 146 of the glass tube 102.

[0075] Referring to FIG. 7G, in an embodiment, the fixed mirror 700 can be oriented to reflect infrared light from the inner surface 146 of the glass tube 102 toward the mirror 124 coupled to the mounting device 126. In these embodiments, the infrared light from the inner surface 146 of the glass tube 102 moves along path 722 from the inner surface 146 of the glass tube 102 to the fixed mirror 700, is reflected from the fixed mirror 700 toward the mirror 124, and then is reflected from the mirror 124 toward the lens 506 of the thermal imager 122. At the same time, the infrared light emitted from the outer surface 140 of the glass tube 102 moves along path 714 from the outer surface 140 of the glass tube 102 toward the mirror 124 and is reflected from the mirror 124 toward the lens 506 of the thermal imager 122. To obtain different configurations or different viewing angles of the glass tube 102 at one or more stages of the conversion process, other fixed mirrors 700 can be coupled to the base 104 under other processing stations 106, and other auxiliary mirrors 124 can be coupled to the main turret 108 or the mounting device 126.

[0076] In some embodiments, the thermal imaging system 120 can include a plurality of thermal imagers 122. The plurality of thermal imagers 122 can be coupled to the main turret 108, the secondary turret 114, or both to rotate with the main turret 108 or the secondary turret 114. In some embodiments, each of the plurality of thermal imagers 122 can be arranged to capture thermal image data from a separate holder position 136. In an embodiment, the thermal imaging system 120 includes one or more thermal imagers 122 coupled to the base 104 of the converter 100 or to another fixed structure (e.g., the floor, wall, or another structure adjacent to the converter 100) at a fixed position to capture thermal image data from a particular processing station 106 and / or a secondary processing station 112 when the glass tube 102 is indexed through the particular processing station 106 and / or the secondary processing station 112.

[0077] Referring now to FIG. 8A, coupling the thermal imaging system 120 to the main turret 108 such that the thermal imaging system 120 moves within a continuous circuit centered about the central axis A of the main turret 108 presents unique challenges with respect to delivering power and cooling fluid to the thermal imaging system 120 and receiving data from the thermal imaging system 120. Thus, in embodiments, the thermal imaging system 120 may include one or more rotary electrical and / or gas joints that may enable power feeding, data exchange, and cooling of the thermal imaging system. In one or more embodiments, the thermal imaging system may include a slip ring 802 (also sometimes referred to as a rotary electrical connection) that may provide a rotary connection for enabling power transmission and data transfer to and from the thermal imaging system 120. The slip ring 802 may operatively couple the thermal imager 122 to the processor 900 (FIG. 9). The slip ring 802 may be a double-ring structure having an inner ring 804 and an outer ring 806. The inner ring 804 or the outer ring 806 may be fixed, and the other of the inner ring 804 or the outer ring 806 rotates relative to the fixed ring. The slip ring 802 may have a rotation axis parallel to and aligned with the central axis A of the main turret 108. Aligning the axis of the slip ring 802 with the central axis A of the main turret 108 may prevent the electrical cable 808 and the data cable 810 extending from the slip ring 802 to the thermal imaging system 120 from winding up during rotation of the main turret 108.

[0078] The slip ring 802 may include a plurality of circuits (not shown) formed between an inner ring 804 and an outer ring 806. While the inner ring 804 and the outer ring 806 rotate relative to each other, power (e.g., 24 volts of power as an example) and data may be transmitted radially electronically between the radial inner surface of the outer ring 806 and the radial outer surface of the inner ring 804. The outer ring 806 may be electrically connected to a power source and / or may also be communicatively coupled to a processor 900 (FIG. 9). The inner ring 804 is electrically connected to the thermal imager 122, can deliver power to the thermal imager 122, and is communicatively coupled to the thermal imager 122 to transmit and receive data from the thermal imager 122. Power may be transmitted from the slip ring 802 to the thermal imager 122 by one or more electrical cables 808. Additionally, data may be transmitted between the slip ring 802 and the thermal imager 122 via one or more data cables 810, such as, for example, an Ethernet cable. The slip ring 802 communicatively couples the thermal imager 122 to a processor 900 (FIG. 9) that may be located in a fixed position remotely (i.e., at a distance) from the thermal imager 122 and may facilitate the transfer of data to and from the thermal imager 122. The processor 900 (FIG. 9) may be temperature sensitive, and by remotely positioning the processor 900 and the ability to effectively transfer data to the processor 900, it may be possible to avoid incorporating a special heat-resistant structure or cooling system for further protecting the processor 900.

[0079] In one or more embodiments, the rotating portion of the slip ring 802 (e.g., shown as the inner ring 804 in FIG. 8A) may be coupled to the main turret 108 and supported by a support 812, such as a wire conduit or bracket, that rotates with the main turret 108. The stationary component of the slip ring 802 (e.g., shown as the outer ring 806 in FIG. 8A) may be coupled to a stationary support 814 attached to a fixed non-rotating surface (not shown) separate from the main turret 108. The stationary support 814 may be, for example, a wire conduit, bracket, or other support structure. Additionally, in one or more embodiments, the inner ring 804 of the slip ring 802 may have a central bore 816 that provides access to one or more fluid conduits 818. The central bore 816 may be centered on the axis of rotation of the slip ring 802 that is aligned with the central axis A of the main turret 108. The fluid conduits 818 may pass through the central bore 816 of the inner ring 804 and deliver a cooling fluid or other fluid to the thermal imaging system 120 or other components of the main turret 108. In some embodiments, the slip ring 802 is rotatable freely with respect to the fluid conduits 818 (i.e., the slip ring 802 is not coupled to the fluid conduits 818).

[0080] Referring to FIG. 8B, in another embodiment, the thermal imaging system 120 may include a power source 840, such as a battery, removably coupled to the main turret 108 and rotatable with the main turret 108. The power source 840 may be electrically coupleable to the thermal imager 122 to supply power to the thermal imager 122. The power source 840 may be removable from the main turret 108 so that the power source 840 can be replaced and / or recharged. In one or more embodiments, the thermal imager 122 may be communicatively coupled to the processor 900 via one or more wireless communication devices 842 that use one or more wireless communication protocols. The wireless communication devices 842 may be coupled to the main turret 108 and rotate with the main turret 108. The wireless communication devices 842 may be communicatively coupled to the thermal imager 122. In embodiments, the thermal imaging data may be transmitted between the thermal imager 122 and the processor 900 using one or more wireless communication devices and / or protocols.

[0081] Referring again to FIG. 8A, in an embodiment, the thermal imaging system 120 may also include a cooling system 820 for cooling the thermal imager 122. The cooling system 820 may include a cooling fluid source 822, a fluid rotary joint 824 in fluid communication with the cooling fluid source 822, and a fluid conduit 818 in fluid communication with the fluid rotary joint 824. The cooling fluid may be, for example, compressed gas such as filtered air, nitrogen or other gas or combination of gases. In an embodiment, to avoid introducing contaminants that may adversely affect the performance of the thermal imaging system 120 into the thermal imaging system 120, the cooling fluid may be clean dry air (i.e., air from which moisture, particulates, dust, oil or other contaminants have been removed). Alternatively, the cooling fluid may be nitrogen. In an embodiment, the cooling system 820 may include at least one of a regulator, a moisture remover, a particulate filter, a coalescing filter or a combination thereof. The cooling fluid source 822 may include a compressed gas storage tank, a gas compressor or other compressed gas system or combination of cooling fluid sources.

[0082] The fluid rotary joint 824 includes a fixed portion 826 fluidly coupled to the cooling fluid source 822 and a rotating portion 828 rotatably coupled to the fixed portion 826 and rotatable relative to the fixed portion 826. The fluid rotary joint 824 includes a joint axis parallel to and aligned with the central axis A of the main turret 108 such that the rotating portion 828 of the fluid rotary joint 824 can rotate with the rotation of the main turret 108. The rotating portion 828 of the fluid rotary joint 824 may be fluidly coupled to a fluid conduit 818 that extends from the fluid rotary joint 824 to the thermal imager 122 to deliver cooling fluid to the thermal imager 122.

[0083] The cooling system 820 may further include one or more cooling fluid conduits 830 arranged to deliver a cooling fluid in fluid communication with the fluid conduit 818 to a part of the thermal imaging system 120. In one or more embodiments, one or more of the cooling fluid conduits 830 may be arranged to deliver a cooling fluid to the thermal imager 122. In an embodiment, the thermal imager 122 may be maintained at a temperature of less than about 50 °C to maintain the accurate operation of the set of infrared sensors within the thermal imager 122. A combustion gas hood (not shown) integrated with the converter 100 may operate to draw the combustion gas and the surplus heat generated by the heating element 301 (FIG. 3A) towards the central axis A of the main turret 108 and discharge it from the converter 100. Thus, the thermal imager 122 is generally not exposed to most of the heat from the heating element 301 (FIG. 3A). However, the thermal imager 122 may be exposed to some heat from the conversion process and may generate additional heat internally due to the operation of the set of sensors and electronics of the thermal imager 122. The cooling fluid directed to the thermal imager 122 may operate to maintain the temperature of the thermal imager 122 at 50 °C or less. In some embodiments, the cooling system 820 is independent of the cooling station 210 (FIG. 3E) of the converter 100. However, in one or more embodiments, the cooling station 210 (FIG. 3E) and the cooling system 820 may share a common cooling fluid source 822.

[0084] In some embodiments, the thermal imaging system 120 may include a cleaning system 832 for purging the lens 506 of the thermal imager 122, the reflective surface 508 of the mirror 124, or both. During operation of the converter 100 and the thermal imaging system 120, oil and combustion products may deposit on the lens 506 of the thermal imager 122 and the reflective surface 508 of the mirror 124, such as by oil condensing on the mirror 124 or the lens 506, reducing the reflectivity of the mirror 124 and potentially preventing infrared light from passing through the lens 506 of the thermal imager 122, introducing errors and inaccuracies into the image data collected by the thermal imager 122. In an embodiment, the cleaning system 832 may include one or more nozzles 834 arranged to deliver fluid to the lens 506 of the thermal imager 122 to purge oil, dust, and other contaminants from the lens 506. The nozzle 834 may be fluidly coupled to a fluid delivery conduit 836 that delivers fluid from a fluid source (not shown) to the nozzle 834. In an embodiment, one or more of the nozzles 834 may be arranged to deliver fluid to the reflective surface 508 of the mirror 124 to purge oil, dust, and other contaminants from the reflective surface 508 of the mirror 124. A fluid free of particulates, dust, oil, or other contaminants may be used to purge the lens 506 of the thermal imager 122, the reflective surface 508 of the mirror 124, or both to avoid further contamination of the lens 506 and the mirror 124. For example, the fluid may be nitrogen, clean air, other gases, or combinations thereof. In some embodiments, the cleaning system 832 may be fluidly coupled to a cooling system 820 such that a cooling fluid is delivered to the nozzles 834 and used as the fluid for cleaning the lens 506 of the thermal imager 122, the mirror 124, or both.

[0085] The thermal imaging system 120 described herein can be adapted for use with the secondary turret 114 of the converter 100. Referring to FIGS. 18A and 18B, the secondary turret 114 can include a thermal imaging system 120 that is coupled to the secondary turret 114 and rotates with the secondary turret 114. In some embodiments, the thermal imaging system 120 can be coupled to the shaft 1806 of the secondary turret 114 such that the thermal imaging system 120 is disposed at the center of the secondary turret 114. As described above, the thermal imaging system 120 includes a thermal imager 122 and a mounting device 126. The thermal imaging system 120 coupled to the secondary turret 114 can capture thermal image data from the inner surface 146 and / or the outer surface 140 of the glass tube 102 when the glass tube 102 is indexed by the secondary turret 114 through the secondary processing station 112 of the secondary circuit 118. Referring to FIG. 18A, in some embodiments, the thermal imager 122 is disposed at the center of the secondary turret 114 such that the optical centerline OC of the thermal imager 122 is substantially parallel to the central axis B of the secondary turret 114 and can be oriented vertically (i.e., in the + / -Z direction of the coordinate axes of FIG. 18A). In this configuration, the mirror 124 can be disposed and oriented to reflect infrared light from the outer surface 140 and / or the inner surface 146 of the glass tube 102. Referring to FIG. 18B, in other embodiments, the thermal imager 122 can be oriented substantially horizontally (i.e., within the XY plane of the coordinate axes of FIG. 18B) such that the thermal imager 122 directly receives infrared light from the outer surface 140 of the glass tube 102. In these embodiments, the thermal imager 122 can face substantially radially outward from the centerline B of the secondary turret 114. In this orientation, the infrared light emitted by the outer surface 140 of the glass tube 102 can move directly from the glass tube 102 radially inward to the thermal imager 122. Other configurations of the thermal imaging system 120, including embodiments using an auxiliary mirror 125 (FIG. 7E), a fixed mirror 700 (FIG. 7B), or a combination of mirrors 124, 125, 700 to reflect infrared light from the inner surface 146 or the outer surface 140 of the glass tube 102 to the thermal imager 122 as described herein, can be adapted for the secondary turret 114.

[0086] Referring again to FIG. 9, the thermal imaging system 120 may include a processor 900, one or more memory modules 902 communicatively coupled to the processor 900, and machine-readable instructions stored in the one or more memory modules 902. The processor 900 may be communicatively coupled to the thermal imager 122 via a communication path 904 that includes a data cable 810 (FIG. 8) and / or one or more wireless communication devices 842 (FIG. 8B) using standard wireless communication protocols. Suitable wireless communication protocols may include 802.11-based protocols, Bluetooth® protocols, ZigBee IEEE 802 standard protocols, and the like. FIG. 8A shows a communicative coupling of the processor 900 to the thermal imager 122 using a data cable 810 through a slip ring 802 or other rotary electrical coupler. The data cable 810 may be a wire, an optical fiber data cable, or other data cable. FIG. 8B shows a communicative coupling of the processor 900 to the thermal imager 122 using a wireless communication device 842.

[0087] Processor 900 may enable automatic analysis of the image data collected by thermal imager 122. By executing machine-readable instructions stored in memory module 902, processor 900 may cause thermal imaging system 120 to receive the image data captured by thermal imager 122, process the image data, and determine at least one characteristic of glass tube 102. Characteristics of glass tube 102 determined from the thermal image data may include one or more surface temperatures, temperature gradients, dimensions of glass tube 102 (i.e., dimensions of the physical boundaries of the glass tube), viscosities of glass tube 102 at various locations, temperature profiles of the glass tube over time, centerlines of the glass tube, other characteristics, or combinations thereof. The machine-readable instructions, when executed by processor 900, may also cause thermal imaging system 120 to store the thermal image data and / or characteristics of glass tube 102 determined from the thermal image data, or to display the data and / or characteristics of glass tube 102 on one or more displays 906. In one or more embodiments, the machine-readable instructions stored in memory module 902 may include one or more image analysis software packages. An example of an image analysis software package may include, for example, LabVIEW™ sold by National Instruments. Other commercially available or otherwise modified commercial image analysis software may also be used with thermal imaging system 120.

[0088] When executed by the processor 900, the machine-readable instructions may cause the thermal imaging system 120 to perform at least the following: capture thermal image information of the glass tube 102 using the thermal imager 122; transmit the thermal image information from the thermal imager 122 to the processor 900; receive the thermal image information from the thermal imager 122 at the processor 900; process the thermal image information; and determine one or more characteristics of the glass tube 102 from the thermal image information. In some embodiments, when executed by the processor 900, the machine-readable instructions may further cause the thermal imaging system 120 to determine one or more physical boundaries of the glass tube 102 from the thermal image data. In some embodiments, when further executed by the processor 900, the machine-readable instructions may cause the thermal imaging system 120 to identify the centerline of the glass tube 102 from the thermal image information, draw the centerline on the thermal image captured by the thermal imager 122, convert infrared wavelength data to temperature data, compile the temperature data to determine one or more temperature profiles and / or temperature gradients of the glass tube 102, and / or determine a temperature profile of the glass tube 102 over time (e.g., a graph plot or data table). In some embodiments, when executed by the processor 900, the machine-readable instructions may cause the thermal imaging system 120 to calculate the viscosity of the glass at a particular location of the glass tube 102 from the temperature of the glass tube 102 and a viscosity according to the temperature model of the glass tube 102. In some embodiments, the thermal imaging system 120 may calculate a viscosity gradient through the thickness of the glass tube 102.

[0089] In some embodiments, when executed by the processor 900, the machine-readable instructions may cause the thermal imaging system 120 to calculate at least one metric from the processed thermal image information. The at least one metric may be obtained from the at least one metric by a control algorithm that can calculate at least one process control variable, such as a controlled variable, or a process control parameter, such as a gain constant or other process control parameter.

[0090] Indirect capture of a thermal image by reflecting infrared light to the thermal imager 122 using the mirror 124 introduces an error due to the mirror compared to a direct image obtained without using the mirror 124. In processing the thermal image information, when the machine-readable instructions are executed by the processor 900, the thermal imaging system 120 may be caused to apply one or more correction factors to the thermal image information to correct for the error introduced by the mirror 124. When one or more fixed mirrors 700 (FIG. 7) are used with the thermal imaging system 120, when the machine-readable instructions are executed by the processor 900, the thermal imaging system 120 may be caused to apply a plurality of correction factors to the thermal image information.

[0091] In one or more embodiments, when the machine-readable instructions stored in one or more memory modules 902 are executed by the processor 900, the thermal imaging system 120 may be caused to perform at least the following: determining a first characteristic or temperature of the glass tube 102 at the first processing station 106, determining a second characteristic or temperature of the glass tube 102 at a second processing station 106 disposed downstream of the first processing station 106, calculating a difference between the first characteristic or temperature and the second characteristic or temperature, and transmitting an output representing the difference between the first characteristic or temperature and the second characteristic or temperature. In some embodiments, the first and second characteristics are temperatures measured at a particular physical location or region of the outer surface 140 (FIG. 4) or inner surface 146 (FIG. 4) of the glass tube 102 or the glass article 103 (e.g., the temperature of the outer surface 140 of the shoulder 142 shown in FIG. 4). Alternatively, in other embodiments, the first and second characteristics may be the average temperature of the glass tube 102. For example, in some embodiments, the first and second characteristics may mean the average temperature of the centerline of the glass tube 102. Additionally, the first and second characteristics may be average temperatures obtained over a region of the glass tube 102 or the glass article 103. The first and second characteristics may be the inner surface temperature or the outer surface temperature of the glass tube 102 or the glass article 103.

[0092] In one or more embodiments, when the machine-readable instructions are executed by the processor 900, the thermal imaging system 120 may be caused to store thermal image data in one or more of the memory modules 902. In one or more embodiments, the machine-readable instructions may be used by the thermal imaging system 120 as set points for one or more process control methods for facilitating startup of the machine and / or controlling the converter 100, and may be used to develop baseline targets and / or metrics for the operating parameters of the converter 100, and may store and maintain a database of thermal image data and / or data on the characteristics of the glass tube determined from the thermal image data. In some embodiments, when the machine-readable instructions are executed by the processor 900, the thermal imaging system 120 may be caused to store data from a particular glass article in one or more of the memory modules 902 and index the data from the particular glass article according to component identification so that the thermal history of the particular component may be accessible for further analysis and study.

[0093] Normal errors generated by the mirror 124 may be introduced into the image data captured by the thermal imager 122. In one or more embodiments, when the machine-readable instructions are executed by the processor 900, the thermal imaging system 120 may be caused to apply one or more data filters to the thermal image data. In one or more embodiments, when the machine-readable instructions are executed by the processor 900, the thermal imaging system 120 may be caused to receive thermal image data from the thermal imager 122 at a target sampling rate. The target sampling rate may be varied to affect the overall capture rate of the thermal imaging system 120.

[0094] Referring further to FIG. 9, the thermal imaging system 120 may further include a display 906 communicatively coupled to the processor 900. The memory module 902 may include machine-readable instructions that, when executed by the processor 900, cause the thermal imaging system 120 to display on the display 906 one or more outputs (e.g., a thermal image, a graph plot, and / or a data table including glass tube temperature data from the thermal image). The output may be one or more graphical outputs such as a graph of the surface temperature of the glass tube 102 at a particular location over time as shown in FIG. 10 or a thermal image of the glass tube 102 as shown in FIGS. 11A-11D. The output to the display 906 may also include one or more data tables that provide a numerical representation of the temperature data generated by the thermal imaging system 120 rather than a graph.

[0095] Referring to FIGS. 7 and 9, during operation, the thermal imager 122 is arranged to capture thermal image data from the glass tube 102 removably secured within the holder 130 of the main turret 108. As the glass tube 102 is indexed through the plurality of processing stations 106, the glass tube 102 is heated and cooled. When heated to a high temperature, one or more outer surfaces 140 or inner surfaces 146 (FIG. 4) of the glass tube 102 emit infrared radiation outwardly in a radial, axial, or other direction from the glass tube 102. This infrared light can be reflected by the reflective surface 508 (FIG. 6) of the mirror 124 toward the lens 506 (FIG. 6) of the thermal imager 122. Alternatively, the thermal imager 122 may be arranged to directly capture the infrared light emitted from the glass tube 102 without the mirror 124. The thermal imager 122 uses a plurality of sensors to capture the infrared light and outputs thermal image data including the wavelength and intensity of the infrared light received by the thermal imager 122. As shown in FIG. 9, the thermal image data output by the thermal imager 122 is transferred from the thermal imager 122 to the processor 900 via a communication path 904 that may be wired or wireless. The processor 900 receives the thermal image data, processes the thermal image data, and outputs one or more attributes (e.g., temperature) of the glass tube 102 determined by the processing of the thermal image data.

[0096] In one or more embodiments, the thermal imaging system 120 may be configured to capture thermal image data of the glass tube 102 at a particular stage of the conversion process or at the processing station 106, such as at the beginning or end of the dwell time at the heating station 202 (FIG. 2), at the beginning or end of the dwell time of the forming operation at the forming station 204 (FIG. 2), or at other stages in the conversion process. The thermal image data may be captured at the beginning of the dwell time, in the middle of the dwell time, at the end of the dwell time, or while the glass tube 102 is being transferred by the main turret 108 between one processing station 106 and the next processing station 106.

[0097] Alternatively, in other embodiments, the thermal imaging system 120 may be configured to capture thermal image data of the glass tube 102 at set time intervals throughout the conversion process. As described above, the thermal imager 122 may have an image capture speed within the range of 30 Hz to 60 Hz. The overall capture speed of the thermal imaging system 120 can be defined as the speed at which the thermal imaging system 120 generates an output data set and may include the capture speed of the thermal imager 122 as well as the time required to transfer the thermal image data to the processor 900, process the thermal image data, and output the thermal image data to the memory module 902, the display 906, the process controller, or other devices. The minimum overall capture speed of the thermal imaging system 120 is the fastest speed at which the thermal imaging system 120 can capture, transfer, process, and output thermal image data. The minimum overall capture speed of the thermal imaging system 120 can be generally above about 10 Hz. In other embodiments, the minimum overall capture speed of the thermal imaging system 120 can be at least 20 Hz. For example, the minimum overall capture speed of the thermal imaging system 120 can be 10 Hz to 50 Hz, 10 Hz to 40 Hz, 10 Hz to 30 Hz, 10 Hz to 20 Hz, 20 Hz to 50 Hz, 20 Hz to 40 Hz, 20 Hz to 30 Hz, 30 Hz to 50 Hz, or 30 Hz to 40 Hz. The minimum overall capture speed of at least 10 Hz of the thermal imaging system 120 can facilitate capturing very high temperature gradients generated during a particular stage of the conversion process. In one or more embodiments, one or more data filters may be used to increase the overall capture speed of the thermal imaging system 120. In one or more embodiments, the sampling speed may be adjusted to change the overall capture speed of the thermal imaging system 120.

[0098] Referring to FIGS. 11A - 11D, a thermal image captured by the imager is provided. Regions on the glass tube 102 that are hotter are shown as lighter colors, and regions that are cooler are shown as darker colors. FIG. 11A shows a preheating step in which the glass tube 102 is heated prior to being separated. In FIG. 11B, the glass tube 102 is cut and separated from the glass tube stock. The region of the cut 1102 of the glass tube at the separation station 206 is very hot, as indicated by the very light - colored region between the two portions of the glass tube 102. In an embodiment, the temperature of the glass tube 102 in the region of the cut 1102 can reach a temperature of 1500°C or higher. The color contrast shows a high temperature gradient from the region of the cut 1102 to the opposite end 1104 of the glass tube 102. FIGS. 11C and 11D show thermal images captured during the forming operations of the shoulder 142 and flange 144 of the glass tube 102 that is formed into a vial. Similarly, the changing color contrast between the lighter colors of the forming regions (e.g., shoulder 142 and flange 144) and the darker colors towards the opposite end 1104 of the glass tube 102 shows a high temperature gradient along the length L of the glass tube 102.

[0099] Temperature data for generating the temperature history of the glass tube 102 over the entire conversion process in the converter 100 can be extracted from a series of images similar to those in FIGS. 11A - 11D. The wavelength of the infrared light captured within the thermal image correlates to the temperature of the glass tube 102 that emits infrared light of the specific wavelength captured. FIG. 10 shows an example of the temperature history of the surface of the glass tube 102 processed by the converter 100 and captured by the thermal imaging system 120. FIG. 10 shows a first temperature 1002 of the glass tube 102 determined at a first portion of the surface of the glass tube 102. Additionally, the thermal imaging system 120 can also be used to extract temperature information from different regions of the article, such as the flange 144 and the neck 145 regions of the partially formed glass tube 102 during the forming of the flange 144 and the neck 145 (FIG. 3A). In FIG. 10, a second temperature 1004 is determined at a second portion of the surface of the glass tube 102, and a third temperature 1006 is determined at a third portion of the surface of the glass tube 102. In some embodiments, the second temperature 1004 and the third temperature 1006 can be determined at portions of the glass tube 102 corresponding to the flange 144 and the neck 145, respectively.

[0100] The operating experience with the tube component converter 100 indicates that the conversion process is highly interactive (in the sense that a slight temperature change at one processing station 106 of the converter 100 can equally affect the glass temperature and the forming process throughout the converter 100). The thermal imaging system 120 enables the monitoring of the temperature of one glass tube 102 through all processing stations 106 and the operations performed at each processing station 106 so as to observe and investigate the impact of temperature changes at one processing station 106 on the downstream forming operations. Since the thermal imaging system 120 moves with the main turret 108 when the main turret 108 is indexed between processing stations 106, the thermal imaging system 120 can capture thermal images of the glass tube 102 between processing stations 106 and investigate the impact of the cooling of the glass tube 102 between processing stations 106.

[0101] Referring again to FIGS. 7A-7G, as described above, the thermal imaging system 120 can be configured to acquire thermal image data of the outer surface 140 of the glass tube 102. Additionally, the thermal imaging system 120 can be configured to acquire thermal image data of one or more inner surfaces 146 (FIG. 4) of the glass tube 102, and thus surface temperature data. The ability to measure the surface temperature of the inner surface 146 can be useful for characterizing component conversion processes in which temperature gradients of several hundred degrees Celsius (i.e., 200° C. to 300° C. or more) are measured through the thickness T (FIG. 4) of the glass tube 102. Additionally, in one or more embodiments, the measurement of the temperature of the inner surface 146 of the glass tube 102 can facilitate the identification of temperature ranges leading to quality defects. For example, during a flange forming operation performed at the forming station 204 of the converter 100 for making the vial, small cracks can occur on the inner surface 146 of the flange 144 (FIG. 3D) at certain inner surface temperatures. The measurement of the inner surface temperature of the glass tube 102 can be used to identify these inner surface temperatures leading to cracks so that changes can be made to prevent cracks in the conversion process.

[0102] Multiple mirror paths can be configured to acquire thermal image data of the inner surface 146 (FIG. 4) of the glass tube 102. As described above, multiple fixed mirrors 700 can be used to configure the thermal imaging system 120 to acquire a thermal image of an end view of the glass tube 102. The end view of the open end of the glass tube 102 can enable the thermal imaging system 120 to determine one or more inner temperatures of the glass tube 102, such as the temperature of the inner surface 146. To capture the end view of the open end of the glass tube 102, one or more fixed independent thermal imaging devices (not shown) can be mounted directly below one or more of the processing stations 106 of the converter 100. The optical centerline of the fixed thermal imaging device is the centerline C of the glass tube 102 for capturing the end view of the glass tube 102 Lcan be aligned. Mounting a plurality of individual thermal imaging devices under a plurality of processing stations 106 can be expensive and may be prohibitively costly. In another configuration, a fixed imaging device (not shown) can be mounted at a radially outer position from the processing station 106, and the fixed mirror 700 can be mounted under the processing station 106 to reflect an end face observation image of the glass tube 102 to the lens (not shown) of the thermal imaging device. In this configuration, a plurality of thermal imaging devices are required at different processing stations 106 to capture thermal data of the inner surface 146 of the glass tube 102.

[0103] Instead, in one or more embodiments, the thermal imaging system 120 coupled to the main turret 108, as described above herein, can be used with one or more fixed mirrors 700 that can each be disposed under one of the plurality of processing stations 106. As shown in FIG. 7, the mirror 124 can be arranged to reflect infrared light emitted radially outward from the outer surface 140 of the glass tube 102 toward the lens 506 of the thermal imager 122, and the fixed mirror 700 can be axially downward (i.e., along the center line C of the glass tube 102) from the inner surface 146 of the glass tube 102 toward the lens 506 of the thermal imager 122. LIt can be arranged to reflect the emitted infrared light (directed in a direction parallel to and towards the base 104). When the thermal imager 122 is indexed by the main turret 108 and aligned (e.g., angular alignment) with the fixed mirror 700, both the mirror 124 and the fixed mirror 700 can reflect the infrared light to the lens 506 of the thermal imager 122, enabling the thermal imager 122 to simultaneously capture thermal images of the outer surface 140 and the inner surface 146 of the glass tube 102. FIG. 12 shows a thermal image obtained by the thermal imaging system 120 having the mirror 124 and the fixed mirror 700. The thermal image of FIG. 9 shows a single thermal image that simultaneously captures the thermal data of the outer surface 140 and the thermal data of the inner surface 146. The single thermal image can enable the thermal imaging system 120 to determine one or more outer surface temperatures and one or more inner temperatures from a single thermal image data set. Although described using the combination of the mirror 124 and the fixed mirror 700, the capture of the infrared light emitted from the inner surface 146 of the glass tube 102 can be accomplished by arranging the mirror 124 to reflect the infrared light from both the outer surface 140 and the inner surface 146 of the glass tube 102 towards the thermal imager 122, as previously described in this disclosure, or by coupling an auxiliary mirror 125 to the mounting device 126 to reflect the infrared light from the inner surface 146 of the glass tube towards the thermal imager 122.

[0104] Although the thermal imaging system 120 has been described with respect to the converter 100 oriented vertically such that the central axis A of the main target 108 is substantially perpendicular to the ground, it should be understood that the thermal imaging system 120 may also be adapted for use with a horizontally oriented converter or an angled converter. Although the thermal imaging system 120 has been described herein with respect to the converter 100 having a substantially circular main target 108 for indexing the glass tube 102 in the substantially circular main circuit 116 of the processing station 106, it should be understood that the thermal imaging system 120 may be used with a converter 100 having any non-circular continuous loop or track for indexing the glass tube 102 through a plurality of processing stations 106. The processing stations 106 may be laid out in any convenient pattern. As described above, it should also be understood that the thermal imaging system 120 may be used with the vial converter 100 and other converters for manufacturing other articles such as cartridges, ampoules, syringes or other glass articles from the glass tube 102.

[0105] The thermal imaging system 120 described in this disclosure may assist in the basic understanding of the converter 100 and the development of process measurements, mathematical models and experiments for building glass-centered characterization and the conversion process thereby implemented. By developing a better understanding of the conversion process through the use of the thermal imaging system 120, the dependence on technology and experience and the ability to move seamlessly between conversion platforms for guiding the setup, tooling, and process configuration of the converter 100 is reduced. The thermal imaging system 120 also enables the quantitative mapping of process windows and process limits. The thermal imaging system 120 enables the automatic analysis of thermal images and the location of the centerline C L of the glass tube 102 and / or the article made from the glass tube 102. In addition, the thermal imaging system 120 enables the easier adaptation of the converter 100 and the conversion process to incorporate another glass formulation.

[0106] The thermal imaging system 120 also provides process temperature measurements that can be incorporated into a control system for controlling the converter 100. At a particular processing station 106, measurements of the surface temperature of the glass tube 102 determined through the processing station 106 exhibit significant short-term and long-term variations in the surface temperature of the glass tube 102. The short-term variations in the surface temperature of the glass tube 102 (which are variations from one individual part to the next) can be attributed to manufacturing tolerances in the tube drawing process that result in variations in tube dimensions such as the tube diameter W (FIG. 4) and wall thickness T (FIG. 4) along the length L of the glass tube 102 stock. The mass variation per tube can be from + / - 2.5 percent (%) to + / - 5%. The heating element 301 (FIG. 3A) of the glass tube converter 100 is arranged to heat a specific region of the glass tube 102. Thus, the change in the mass of the glass in that specific region resulting from these manufacturing variations for each glass tube 102 directly results in corresponding variations in the surface temperature of the glass tube 102. Other factors such as mechanical timing uncertainties and variations can also contribute to the short-term variations in surface temperature, but the manufacturing variability of the glass tube 102 stock most significantly contributes to these short-term variabilities. Conventional converter machines do not have a system for compensating for these short-term variations in the surface temperature of the glass tube 102.

[0107] The long-term variability of the surface temperature of the glass tube 102 (i.e., measured per cycle, minute, and / or time) can be attributed to several factors that cause variations in the thermal state of the conversion process. Conditions that can potentially cause long-term variability in the glass surface temperature can include the heating of the machine when the converter 100 raises the temperature from room temperature conditions to steady-state operating conditions. The heating process can take from 2 hours to 12 hours. Long-term variations in surface temperature can also result from changes in the calorific value of the fuel (variations in the composition of the fuel gas received from the natural gas supplier), deterioration of the burner 302, changes in manifold pressure (i.e., fuel gas, air, oxygen), room temperature conditions, variations in the exhaust hood flow rate, other factors, and / or combinations of factors. Conventional converter machine systems have to be manually adjusted to account for these long-term variations in surface temperature.

[0108] Referring to FIG. 13, a control system 1300 for a glass tube converter 100 is disclosed that can provide a system and method for compensating for both short-term and long-term variations in surface temperature to provide a more consistent and efficient operation of the converter 100. The control system 1300 includes the converter 100, a thermal imaging system 120, and a controller 1302.

[0109] The converter 100 can have any of the features of the converter 100 described above herein. As described above, one or more heating stations 202 can include heating elements 301 that are operable to vary the amount of heat applied to the glass tube 102 and thus vary the temperature of the glass tube 102. For example, in an embodiment, the heating element 301 can be a burner 302 having a fuel control valve 310, an oxygen control valve 312, and optionally a combustion air control valve 314 (which can all be operated to vary the heat of the flame generated by the burner 302 and thus vary the temperature of the glass tube 102 as the glass tube 102 passes through the heating station 202). Alternatively, in other embodiments, the heating element 301 can be a laser, such as a carbon dioxide laser, for example. The power input to the laser, the exposure time of the glass tube 102 to the laser, or both can be operated to vary the degree of heating of the glass tube 102 and thus vary the temperature of the glass tube 102. Referring to FIG. 3E, as described above, the converter 100 can also have one or more cooling stations 210, and the one or more cooling stations 210 can include one or more coolant control valves 344 for controlling the mass flow rate of a coolant fluid 342 that can also affect the temperature of the glass tube 102 as it passes through the cooling station 210.

[0110] The thermal imaging system 120 may measure and be used to determine one or more process variables for use by the control system 1300. The thermal imaging system 120 may have any of the features described herein with respect to the thermal imaging system 120 that is coupled to the main target 108 and rotates with the main target 108. As described above, the thermal imaging system 120 includes at least one thermal imager 122, a processor 900 communicatively coupled to the thermal imager 122, and one or more memory modules 902 having machine-readable instructions for receiving and processing the thermal image data captured by the thermal imager 122. The thermal imaging system 120 may also include at least one mirror 124 arranged to reflect infrared light from the glass tube 102 to the thermal imager 122. In some embodiments, one processor may serve as both the controller 1300 of the control system 1300 and the processor 900 of the thermal imaging system 120. The thermal imaging system 120 may also have one or more fixed mirrors 700 (FIG. 7) arranged vertically below one or more processing stations 106 such that when the thermal imager 122 is positioned to receive light reflected from the fixed mirror 700, infrared light emitted by the inner surface 146 (FIG. 4) of the glass tube 102 is reflected to the thermal imager 122. In one or more embodiments, multiple thermal imagers 122 may be coupled to the main target 108 to simultaneously measure the process variables of multiple processing stations 106 or sub-processing stations 112.

[0111] The thermal imaging system 120 may output one or more process variables that can be used by the control system 1300 to control the converter 100 and the conversion process. Alternatively, the thermal imaging system 120 may store one or more process variables in the memory module 902 for retrieval by the controller 1302. In one or more embodiments, the process variables determined by the thermal imaging system 120 may include the one or more temperatures on the outer surface 140 of the glass tube 102 at one or more locations and at one or more stages of the conversion process. In an embodiment, the process variables determined by the thermal imaging system 120 may include the one or more temperatures on the inner surface 146 of the glass tube 102 at one or more locations and at one or more stages of the conversion process of the inner surface 146 (FIG. 4) of the glass tube 102. In an embodiment, the process variable may be the centerline peak glass temperature (i.e., the highest temperature of the glass tube 102 along the centerline C L of the glass tube 102). In other embodiments, the process variable may also be one or more dimensions of the glass tube 102 in one or more regions of the glass tube 102, the viscosity of the glass tube 102 in one or more regions of the glass tube 102, the temperature profile of the glass tube 102 over time, other properties of the glass tube 102, or combinations thereof.

[0112] The control system 130 may receive other process variables of the converter 100. For example, the control system 130 may receive information regarding other physical attributes such as the dimensions or outer diameter, inner diameter, and / or thickness of the glass tube 102. The dimensions of the glass tube 102 or other process variables may be received by the control system 130 from an external source or from other measurement systems incorporated into the converter 100 and / or the control system 1300. Referring to FIG. 13, in some embodiments, the control system 1300 may include a dimensioning system 1310 for measuring the diameter W and thickness T of the glass tube 102 and determining the glass mass per unit length of the glass tube 102 from the diameter W, thickness T, and density of the glass. Any one of the diameter W, thickness T, or the glass mass per unit length of the glass tube 102 may be used as a process variable by the control system 1300.

[0113] The dimension determination system 1310 may include at least one of a visual image system, a laser reflectometer, a laser gauge, other measurement devices, or combinations thereof. Alternatively, the dimension determination system 1310 may include an optical micrometer, such as a micrometer that includes a collimated beam of light emitted from a light source on one side of the glass tube 102, and a light receiver, such as a camera or a light sensor, disposed on the opposite side of the glass tube. As shown in FIG. 13, in some embodiments, the dimension determination system 1310 may include a visual image system 1312 having a visual image device configured to capture a visual image of the glass tube 102. In some embodiments, the visual image device of the visual image system 1312 may be fixed and may be focused on one processing station 106. In an embodiment, the visual image system 1312 may be coupled to the base 104 of the converter 100. In an embodiment, the visual image system 1312 may be arranged to capture a visual image of the glass tube 102 at the processing station 106 immediately after the final forming station 204 (FIG. 2) in the main circuit 116 (FIG. 2). Alternatively, in other embodiments, the visual image system 1312 may be arranged at the processing station 106 located before the first forming station 204 of the converter 100. In yet another embodiment, the visual image system 1312 may be arranged to capture a visual image of the glass tube 102 before the glass tube 102 is loaded into the holder 130. The visual image obtained from the visual image system 1312 may be used to obtain the outer diameter W of the glass tube 102.

[0114] In some embodiments, the sizing system 1310 may further include a laser reflectometer 1314 attached at a fixed position relative to the base 104 of the converter 100. The laser reflectometer 1314 may be oriented to measure the thickness T (i.e., wall thickness) of the glass tube 102 at one of the processing stations 106. In one or more embodiments, the laser reflectometer 1314 may be arranged as a visual image system 1312 at the same processing station 106. Alternatively, the laser reflectometer 1314 may be arranged at a processing station 106 different from the processing station 106 at which the visual image system 1312 is directed. In some embodiments, the visual image system 1312 may be arranged and oriented to capture a visual image of the glass tube 102, such as an end-face observation image of the glass tube 102, from which the outer diameter W and inner diameter of the glass tube can be determined. Thus, the visual image system 1312 may determine the thickness T and mass per unit length of the glass tube 102 using the outer and inner diameters of the glass tube 102. The sizing system 1310 is described herein as having the visual image system 1312, the laser reflectometer 1314, or both, but it is contemplated that other dimensional measurement devices for determining the dimensions and mass per unit length of the glass tube 102 may be incorporated into the sizing system 1310.

[0115] In another embodiment, one or more elements of the sizing system 1310, such as the visual image system 1312, the laser reflectometer, or other sizing devices, may be arranged upstream of the processing station 106 of the converter 100 to measure the dimensions of the glass tube stock before supplying the glass tube stock to the converter 100. For example, the sizing system 1310 may be arranged in a tube loading device, such as the glass tube loading turret 110 (FIG. 1) or a glass tube loading arm (not shown), to measure the dimensions of the glass tube 102 before loading the glass tube 102 into the converter 100.

[0116] The dimension determination system 1310 may further include a dimension determination processor 1316 having one or more dimension determination memory modules 1318. When executed by the dimension determination processor 1316, the one or more dimension determination memory modules 1318 cause the dimension determination system 1310 to receive measurement data from at least one dimension determination device, process the measurement data, and determine the diameter W and thickness T of the glass tube from the measurement data. For example, in some embodiments, when executed by the dimension determination processor 1316, the machine-readable instructions cause the dimension determination system 1310 to receive visual image data from the visual image system 1312, receive thickness information from the laser reflectometer 1314, process the visual image data, determine the diameter W of the glass tube 102, process the thickness information from the laser reflectometer 1314, and determine the thickness T of the glass tube 102. Alternatively, in other embodiments, when executed by the dimension determination processor 1316, the machine-readable instructions cause the dimension determination system 1310 to receive visual image data from the visual image system 1312, determine the outer diameter W of the glass tube 102, determine the thickness, and determine the mass per unit length of the glass tube 102 from the thickness T and the outer diameter W. The machine-readable instructions may include commercially available visual image processing software such as the aforementioned image processing program. When executed by the dimension determination processor 1316, the machine-readable instructions may cause the dimension determination system 1310 to store and / or output the thickness T and diameter W of the glass tube 102. In an embodiment, when executed by the dimension determination processor 1316, the machine-readable instructions cause the dimension determination system 1310 to determine the mass of the glass per unit length of the glass tube 102 (i.e., the mass per unit length of the glass tube 102) from the measured diameter W and thickness T of the glass tube 102. The dimension determination system 1310 may store the mass per unit length of the glass tube in one or more dimension determination memory modules 1318 or output the mass per unit length of the glass tube 102.

[0117] In an embodiment, the control system 1300 can determine a temperature gradient across the thickness T of the glass tube 102 from the thickness T determined by the sizing system 1310 and the surface temperatures such as the temperatures of the outer surface 140 and the inner surface 146 of the glass tube 102 determined by the thermal imaging system 120. The temperature gradient can be used as a process variable in one or more control methods. In some embodiments, the control system 130 can determine a viscosity gradient of the glass across the thickness T of the glass tube 102 from the temperature information from the thermal imager 122 and the thickness T of the glass tube 102 determined by the sizing system 1310. In some embodiments, the viscosity gradient can be used as a process variable. The process variable can also include the indexing time of the turret.

[0118] Referring further to FIG. 13, the controller 1302 of the control system 1300 can include a control processor 1304 and one or more control memory modules 1306 in which machine-readable instructions are stored, and when the machine-readable instructions are executed by the control processor 1304, cause the control system 1300 to implement one or more control methods for controlling the converter 100. This control method is further described herein. The controller 1302 can have a plurality of inputs communicatively coupled to one or more of the thermal imaging system 120, the sizing system 1310, or other sensors. The controller 1302 can have a plurality of outputs communicatively coupled to one or more control devices, and the one or more control devices can include one or more of the fuel control valve 310, the oxygen control valve 312, the air control valve 314, the coolant flow control valve 344 (FIG. 3E), the forming tool actuator 326 (FIG. 3D), or other control devices associated with one or more of the heating stations 202, the forming stations 204, the cooling stations 210, or other processing stations 106. In an embodiment, the controller 1302 can be a proportional integral derivative (PID) controller.

[0119] When the machine-readable instructions stored in one or more control memory modules 1306 are executed by a control processor 1304, the control system 1300 can be caused to receive process variables from a thermal imaging system 120, such as temperature, viscosity, dimensions, temperature gradient, viscosity gradient, other properties, or combinations of properties of the glass tube 102, compare the process variables with setpoints stored in memory, determine a control variable based on the comparison of the process variables with the setpoints, and transmit a control signal representing the control variable to one or more control devices. In an embodiment, the controller 1302 can receive one or more process variables, such as the diameter W, thickness T, and / or glass mass per unit length of the glass tube 102, from a dimensioning system 1310. In one or more embodiments, when the machine-readable instructions are executed by the control processor 1304, the controller 1302 can be caused to obtain process variables from the thermal imaging system 120, the dimensioning system 1310, or other sensors or sensor systems.

[0120] The setpoint of the process variable can be determined from a database of historical process variable measurements collected during operation of the converter 100. In an embodiment, the database can include process variable measurements and operating conditions representative of acceptable manufacturing conditions. In an embodiment, the database can include a dataset of process variable measurements and operating conditions that match a collected representative cycle that characterizes typical variations of the converter 100. The process variable measurements in the database can be used to create setpoints for one or more process variables. The variations in the process variable measurements can be determined from the database to define control parameters, such as one or more gain constants, to maximize thermal uniformity and avoid over-control of the converter 100. In an embodiment, the setpoint can be calculated as a rolling average of process variables acquired over a specific time period, such as at least 3 minutes, at least 30 minutes, at least 60 minutes, at least 3 hours, at least 10 hours, or even at least 3 days.

[0121] Referring now to FIG. 14, one embodiment of a temperature feedback control method 1400 is schematically shown. A process variable 1402 of the converter 100 is measured and sent to the controller 1302. A control processor 1304 of the controller 1302 compares the process variable 1402 with a setpoint 1404 and calculates an error 1406 that may be the difference between the setpoint 1404 and the process variable 1402. The control processor 1304 may then calculate one or more control variables 1408 and send one or more control signals representing the control variables 1408 back to the converter 100, particularly to a control device 1410 of the converter 100. In an embodiment, the process variable 1402 may be one or more temperatures of the glass tube 102 measured by the thermal imaging system 120. In some embodiments, the temperature of the glass tube 102 may be used by the controller 1302 to control one or more control devices 1410 associated with the heating station 202 (FIG. 3A) and to control the heating of the glass tube 102 at the heating station 202. The control processor 1304 may calculate the control variable 1408 using one or more proportional, integral, or derivative calculation techniques. The calculation of the control variable 1408 may include applying a gain constant 1409 to the control variable 1408 to adjust the sensitivity of the conversion process to changes in the control variable 1408. In particular, in some embodiments, the control variable 1408 may be determined by multiplying the error 1406 by the gain constant 1409. Alternatively, the control processor 1304 may incorporate other control strategies for determining the control variable 1408, such as modeling, e.g., heat transfer modeling, system-level control methods, or the like.

[0122] The temperature measured by the thermal imaging system 120 can be one temperature of the glass tube 102 obtained at a specific position of the glass tube 102 at a specific stage of the conversion process, such as the end-of-cycle temperature, the end-of-stay temperature (i.e., the temperature of the glass tube 102 immediately before the main target 108 transfers the glass tube 102 to the next processing station 106 at the end of the operation in the processing station 106), the start-of-stay temperature (i.e., the temperature of the glass tube 102 at the start of the stay time in the processing station 106), or any other temperature of the glass tube 102 at any position of the glass tube 102 and at any stage of the conversion process. In some embodiments, the temperature measured by the thermal imaging system 120 can be the centerline maximum temperature at the end of the cycle and / or the centerline maximum temperature at any processing station 106. The process variable 1402 can include the temperature of the outer surface 140 (FIG. 4) of the glass tube 102 or the temperature of the inner surface 146 (FIG. 4) of the glass tube 102. In some embodiments, the process variable 1402 can include one or more average temperatures, such as, for example, the average temperature of the centerline of the glass tube 102.

[0123] In some embodiments, the process variable 1402 can be the difference between any two temperatures of the glass tube 102 measured by the thermal imaging system 120. For example, in some embodiments, the process variable 1402 can be the difference between the centerline temperature of the glass tube 102 at the beginning of the residence time at a processing station 106 (FIG. 1), such as the heating station 202 or the forming station 204, and the centerline temperature of the glass tube 102 at the end of the residence time at the same processing station 106. In some embodiments, the process variable 1402 can be the difference between the end-of-cycle temperature of the glass tube 102 (i.e., the temperature of the glass tube 102 measured at the end of the last processing station of the conversion process) and the start-of-cycle temperature of the glass tube 102 (i.e., the temperature of the glass tube 102 measured at the first processing station of the conversion process). The process variable 1402 can be the difference between the temperatures of the glass tube 102 at the same holder position 136 (FIG. 2) at different stages of the conversion process. Alternatively, the process variable 1402 can include the difference between the temperature of one position of the glass tube 102 and the temperature of a second position of the glass tube 102 at the same stage of the conversion process. For example, the process variable 1402 can include the difference between the temperature of the outer surface 140 (FIG. 4) of the glass tube 102 and the temperature of the inner surface 146 (FIG. 4) of the glass tube 102 at the same processing station 106. The process variable 1402 can represent a temperature gradient between two positions of the glass tube 102, such as a temperature gradient through the thickness T of the glass tube 102. The process variable 1402 can also be a physical dimension of the glass tube 102 determined from the thermal imaging data. The process variable can also be the viscosity of the glass tube 102 or a viscosity gradient through the thickness T of the glass tube 102. The process variable 1402 can be any other process variable or characteristic of the glass tube 102 described herein.

[0124] The process variable 1402 (e.g., the temperature of the glass tube) can be compared with a setpoint 1404 that can be stored in one or more control memory modules 1306 of the controller 1302. The setpoint 1404 can be updated periodically in the control memory module 1306 based on the measured process variable 1402 and the observed changes from the continuous accumulation of the operating conditions in the database of the aforementioned operating conditions.

[0125] In some embodiments, the control variable 1408 can include one or more variables that affect the heating of the glass tube 102 by the heating element 301 (FIG. 3A) at one or more heating stations 202 (FIG. 3A). For example, in an embodiment, the control variable 1408 can include the positions of one or more of the fuel control valve 310 (FIG. 3A), the oxygen control valve 312 (FIG. 3A), and the air control valve 314 (FIG. 3A) for one or more burners 302 (FIG. 3A) of one or more heating stations 202 of the converter 100. By communicatively coupling the fuel control valve 310, the oxygen control valve 312, and / or any air control valve 314 of one or more heating stations 202 to the output of the controller 1302, the controller 1302 can control the heating station 202 by manipulating the mass flow rate of the fuel gas to one or more of the burners 302 (FIG. 3) by a proportional change in the flow rate of oxygen and / or air.

[0126] In some embodiments, the ratio of the mass flow rate of oxygen and / or air to the mass flow rate of the fuel gas can be fixed and constant such that when the mass flow rate of the fuel gas is adjusted, the corresponding mass flow rate of oxygen and / or air changes. In these embodiments, the controller 1302 can be configured to operate the fuel control valve 310, the oxygen control valve 312, and / or the air control valve 314 to maintain a constant stoichiometric ratio of the fuel gas sent to the burner. For example, in embodiments where both air and pure oxygen are supplied to the burner, the ratio of the air flow rate to the pure oxygen flow rate must also be maintained to maintain stoichiometry. When burner combustion is supplied by multiple flows, such as in the case of air and oxygen, the mass flow rates of both air and pure oxygen are maintained at a constant ratio, and the concentration of the oxidizer in the burner 302, which refers to the total oxygen concentration combining the air and oxygen flows, is maintained constant. Thus, in embodiments where fuel gas, pure oxygen gas, and air are supplied to the burner 302, the stoichiometry of the oxidation of the fuel gas is maintained by maintaining the ratio of the fuel gas flow rate to the pure oxygen flow rate and by maintaining the ratio of the air flow rate to the pure oxygen flow rate. During operation, the controller 1302 can send a control signal to the fuel control valve 310 to change the mass flow rate of the fuel gas to the burner 302. To maintain stoichiometry, the controller 1302 also makes corresponding changes to the pure oxygen flow rate and the air flow rate to maintain a constant ratio of the air flow rate to the pure oxygen flow rate and a constant ratio of the fuel gas flow rate to the pure oxygen flow rate. By maintaining a constant stoichiometric ratio of the fuel gas sent to the burner 302, the heating level of the burner 302 in response to an increase in the fuel flow can be maintained, and the predictability of the temperature control response to changes in the control variable 1408 can be enhanced.

[0127] Alternatively, in other embodiments, the mass flow rate of the fuel gas and the mass flow rate of oxygen and / or air may be adjusted independently of each other such that the ratio of oxygen and / or air to the fuel gas can be adjusted in response to a control signal from the controller 1302. For example, the adjustment of the ratio of the fuel gas to the oxidant introduced into the burner 302 at the heating station 202 can be used to adjust the amount of heating performed at the heating station 202 and thus can affect the temperature of the glass tube 102. In some embodiments, the fuel control valve 310 can be controlled to control the heating at the heating station 202, and the oxygen control valve 312 and / or the air control valve 314 can be controlled to maintain a constant stoichiometric ratio of fuel gas to oxygen at the burner 302 of the heating station 202. Additionally, in a heating station 202 having a plurality of burners 302, the ratio of the mass flow rate of the fuel gas between each burner 302 can be fixed such that a change in the mass flow rate of the fuel gas of one burner 302 results in a proportional change in the mass flow rate of the fuel gas of the other burners 302. In an embodiment, each burner 302 can be independently controlled by the controller 1302. In another embodiment, the heating station 202 can include one or more laser heating elements, and the control variable 1408 can be the power output to the laser or the exposure time of the glass tube 102 to the laser light.

[0128] The gain constant 1409 can be determined by performing a series of bump tests at the individual processing stations 106 (FIG. 1). Generally, a bump test refers to a process of applying small step changes to one or more control variables 1408, measuring the process variable 1402, and determining the response of the process variable 1402 to the small step changes of the control variable 1408. For example, the mass flow rate of the fuel gas and / or oxygen can be changed in very small increments, and the thermal responsiveness of the converter 100 to the change in the mass flow rate of the fuel and / or oxygen can be measured using the thermal imaging system 120. In the glass converter 100, since the heating stations 202 (FIG. 2) are very highly coupled, the bump tests can be performed individually for each heating station 202 while maintaining very small changes in the mass flow rates of the fuel and oxygen.

[0129] The feedback control method 1400 shown in FIG. 14 can operate to maintain a constant surface temperature of the glass tube 102 averaged over the period of two to three full rotations of the main target 108 (FIG. 1). By configuring the control system 1300 to maintain a constant surface temperature through the feedback control method 1400 of FIG. 14, the influence of the aforementioned long-term variation sources of the surface temperature can be reduced or eliminated.

[0130] However, the feedback control method 1400 may not effectively reduce or eliminate short-term variations such as those caused by variations in the glass mass per unit length of the glass tube 102 as described above. For example, in a converter 100 having a thermal imaging system 120 with N processing stations 106 and a single thermal imager 122, the thermal imager 122 can measure the process variable 1402 (i.e., temperature) of one glass tube 102 as this glass tube 102 is routed through the N processing stations 106. Accordingly, the adjustment of the control variable 1408 based on the temperature of one glass tube 102 is maintained through the next (N - 1) glass tubes until the thermal imager 122 cycles back to measure the process variable 1402 again. Thus, the operating conditions for the (N - 1) glass tubes are maintained constant between cycles of the thermal imager 122. In larger converters 100 having more than 18 processing stations 106, such as 36 or more stations, the control of the converter 100 in response to one measurement of the process variable 1402 of one glass tube 102 per N glass tubes may not address short-term variations in the process. Additionally, the dimensions and / or masses of the (N - 1) glass tubes can vary, potentially introducing more variations into the process between cycles of the thermal imager 122. In some embodiments, the thermal imaging system 120 can include a plurality of thermal imagers 122 distributed around the holder position. By incorporating a plurality of thermal imagers 122, the measurement frequency of the process variable 1402 can be increased, and the control of the converter 100 can be improved.

[0131] Instead, to address short-term variations such as variations in the glass mass per unit length of the glass tube 102, a cascade control method 1500, such as the method schematically shown in FIG. 15, may be implemented in the control system 1300 (FIG. 13). In the cascade control method 1500, between cycles of the thermal imager 122, a second process variable 1516 for at least (N - 1) glass tubes 102 may be measured or provided from an external source. The cascade control method 1500 provides the ability to compensate for short-term variations such as variations in the mass and / or dimensions of the glass tubes on a per-tube basis. Thus, the cascade control method 1500 may enable the control system 1300 to compensate for temperature changes at holder positions where the temperature is not measured by the visual image system 120. The cascade control method 1500 may provide improved and / or enhanced process control of the converter 100 compared to the feedback control method 1400, which may rely on a single measurement of the process variable by the thermal image system 120 per cycle of the thermal imager 122 through the processing station 106.

[0132] Referring to FIG. 15, in the first feedback loop 1502, a first process variable 1506 of the conversion process is measured and sent to the controller 1302. The controller 1302 compares the first process variable 1506 with a first setpoint 1508 associated with the first process variable 1506, and calculates a first error 1510 that can be the difference between the first setpoint 1508 and the first process variable 1506. Thereafter, the controller 1302 can calculate an intermediate control variable (not shown) and adjust the intermediate control variable by applying a first gain constant 1514. In the second feedback loop 1504, a second process variable 1516 of the converter 100 is measured and sent to the controller 1302. The controller 1302 compares the second process variable 1516 with a second setpoint 1518 associated with the second process variable 1516, and calculates a bias (i.e., a second error, not shown). Thereafter, the controller 1302 can adjust the control variable 1512 determined by the controller 1302 in the first feedback loop 1502 using this bias and a second gain constant 1522 to generate the control variable 1512. Thereafter, the controller 1302 can send one or more control signals representing the control variable 1512 to one or more control devices 1410 of the converter 100.

[0133] In an embodiment, the first process variable 1506 can be one or more temperatures of the glass tube 102 measured by the thermal imaging system 120, and the second process variable 1516 can be a physical dimension of the glass tube 102, such as the diameter, thickness, or glass mass per unit length, measured by the sizing system 1310. The temperature of the glass tube 102 and the physical dimension of the glass tube 102 can be used by the controller 1302 to control heating in one or more of the heating stations 202 (FIG. 3A) in the cascade control method 1500. The first feedback loop 1502 having the first process variable 1506 that is the temperature of the glass tube 102 can enable the control system 1300 to control the converter 100 on a per-cycle basis in order to reduce or eliminate the influence of the aforementioned long-term sources of surface temperature variation. The second feedback loop 1504 having the second process variable 1516 that is the physical dimension of the glass tube 102 can enable the control system 1300 to control the converter 100 on a per-glass-tube basis in order to reduce or eliminate the influence of short-term sources of surface temperature variation, such as the variation in the dimensions of the glass tube 102 described above in this specification.

[0134] In one or more embodiments, the first feedback loop 1502 of the cascade control method 1500 can be the same as the feedback loop shown in and described above in connection with FIG. 14. Similarly, the first process variable 1506, the first setpoint 1508, the first gain constant 1514, and the control variable 1512 can be similar to the process variable 1402, the setpoint 1404, the gain constant 1409, and the control variable 1408 described above in connection with FIG. 14.

[0135] Referring again to FIG. 15, a second process variable 1516, which can be a physical attribute of the glass tube 102, can be measured and / or calculated by a sizing system 1310 (FIG. 13). The second process variable 1516 (e.g., diameter, thickness, or glass mass per unit length of the glass tube) can be compared to a second setpoint 1518 that can be stored in one or more control memory modules 1306 of the controller 1302. In an embodiment, the second setpoint 1518 can be a nominal tube mass per unit length. The second setpoint 1518 can be updated periodically in the control memory module 1306 based on changes observed from the continuous accumulation of process variable measurements and operating conditions in the database. A bias (not shown) can be calculated for each glass tube 102 being processed, and the control variable 1512 can be adjusted for each tube. The bias can be calculated using a mathematical model related to the mass per unit length of the glass tube 102 and the temperature profile of the glass tube 102. The mathematical model can include a heat transfer model or can be determined experimentally from the thermal data history stored by the thermal imaging system 120.

[0136] As described above, the control variable 1512 can include the position of one or more of the fuel control valve 310 (FIG. 3A), oxygen control valve 312 (FIG. 3A), and / or air control valve 314 (FIG. 3A) of one or more of the heating stations 202 of the converter 100.

[0137] Referring again to FIG. 13, as described herein, the thermal imaging system 120 follows one glass tube 102 through the converter 100, and at the fixed position 138 on the main turret 108 corresponding to the thermal imaging system 120, the control system 1300 operates in a full cascade mode (i.e., in accordance with the cascade control method 1500 shown in FIG. 15). However, for the glass tube 102 at the holder position 136 that does not correspond to the fixed position 138 of the thermal imaging system 120, the control system 1300 may operate as a single-loop feedback control method controlled based on a second process variable 1516 (FIG. 15) that may be the physical attributes of the glass tube 102 (e.g., the diameter, thickness, or glass mass per unit length of the glass tube 102). For the holder position 136 between the fixed positions 138 of the thermal imaging system 120, the heating flow rate is continuously changed based on the physical attributes of the glass tube. As described above, in one or more embodiments, two or more thermal imaging systems 120 are coupled to the main turret 108 of the converter 100, and the measurement of the first process variable 1506 at two fixed positions 138 on the main turret 108 can be performed, enabling the measurement of the first process variable 1506 at a frequency exceeding once per cycle.

[0138] Referring to FIG. 16, an embodiment of a single-loop feedback control method 1600 based on per-glass control of one or more heating elements 301 (FIG. 3A) of a heating station 202 (FIG. 3A) in response to a change in glass mass per unit length of a glass tube 102 measured by a sizing system 1310 is shown. In the embodiment of FIG. 16, the process variable 1602 can be a physical attribute of the glass tube 102 such as the diameter, thickness, or glass mass per unit length of the glass tube 102. The process variable 1602 can be compared to a setpoint 1604 that can be the nominal outside diameter, nominal thickness, or nominal glass mass per unit length of the glass tube 102. Using an error 1606, which can be the difference between the process variable 1602 and the setpoint 1604, and a gain constant 1609, a control variable 1608, which can be the position of one or more of a fuel control valve 310, an oxygen control valve 312, and / or an air control valve 314 that together control the mass flow rate of fuel, oxygen, and / or air to a burner 302 (FIG. 3) of one or more heating stations 202, can be determined. The single-loop feedback control method 1600 of FIG. 16 can show the operation of a control system 1300 (FIG. 13) with respect to a glass tube 102 at a holder position 136 that is not a fixed position 138, which is the holder 130 where a thermal imaging system 120 is disposed. At the fixed position 138, the control system 1300 operates in a full cascade mode as described above and as shown in FIG. 15.

[0139] In some embodiments, in any of the control methods shown in FIGS. 14 - 16, the control variables 1408, 1512, 1608 can be the position of a coolant flow control valve 344 that controls the mass flow rate of a coolant fluid 342 (FIG. 3E) to one or more cooling stations 210 (FIG. 3E). In these embodiments, the coolant flow control valve 344 (FIG. 3E) for the cooling stations 210 can be communicatively coupled to the control system 1300. Additionally, in embodiments, the control variables 1408, 1512, 1608 can also include the indexing time of a main turret 108 of a converter 100.

[0140] In an embodiment, the contact time between the forming tool 324 (Figs. 3C - 3D) and the glass tube 102 at the forming station 204 (Figs. 3C - 3D) can be controlled using the feedback control method 1400 (Fig. 14) or the cascade control method 1500 (Fig. 15). The contact time can be controlled as control variables 1408, 1512 in response to process variables 1402, 1506 such as the temperature of the glass tube 102 measured using the thermal imaging system 120 or physical attributes of the glass tube 102 such as the diameter, thickness, or glass mass per unit length of the glass tube 102 that can be measured by the dimension determination system 1310 (Fig. 13). The contact time between the forming tool 324 and the glass tube 102 can be increased or decreased in response to the process variables 1402, 1506.

[0141] In one or more embodiments, the control variable 1408 can be the contact time. When the measured surface temperature reaches the target surface temperature, the controller 1302 can set the contact time to a period that starts when the forming tool 324 first engages the glass tube 102 and ends at the time when the measured surface temperature reaches the target surface temperature. When the main target 108 indexes the glass tube 102 through the forming station 204, the controller 1302 maintains the control variable 1408 equal to the contact time determined by the controller 1302 until the thermal imaging system 120 returns to a predetermined position of the forming station 204 to measure the process variable 1402 again. In these embodiments, the contact time can vary from cycle to cycle and can be effective in reducing or eliminating the influence of long - term sources of variation in the surface temperature on the contact time.

[0142] In one or more embodiments, as shown in FIG. 15, the cascade control method 1500 described above in the present disclosure can be adapted to control the contact time between the forming tool 324 and the glass tube 102 based on not only the surface temperature of the glass tube 102 but also the physical properties of the glass tube 102. In these embodiments, the first process variable 1506 can be the surface temperature of the glass tube 102 measured by the thermal imaging system 120. The second process variable 1516 can be the glass mass per unit length of the glass tube 102 determined by the sizing system 1310. The control variable 1512 can be the contact time. The contact time (control variable 1512) is initially set for a cycle based on a comparison between the measured surface temperature (first process variable 1506) provided by the thermal imaging system 120 and the target surface temperature (first setpoint 1508) stored in the control memory module 1306. Thereafter, the contact time can be further adjusted for each glass tube based on a comparison between the glass mass per unit area (second process variable 1516) measured by the sizing system 1310 and the target glass mass per unit area (second setpoint 1518). Implementing the cascade control method 1500 can further enable the control system 1300 to reduce and / or eliminate the effects of short-term sources of variation in the glass tube temperature, such as variations in the dimensions of the glass tube 102.

[0143] Based on the foregoing, it should be understood here that the embodiments described herein relate to a thermal imaging system 120 and a control system 1300 for use with a converter 100 for manufacturing a plurality of glass articles from a glass tube 102. The thermal imaging system 120 and the control system 1300 described herein can be implemented to change or minimize the existing converter's dependence on the operator's experience and skills when fine-tuning the thermal conditions of the glass tube converter 100. The thermal imaging system 120 and the converter control system 1300 can minimize the requirements for experience and shorten the learning curve for new component manufacturers to achieve high-quality and stable manufacturing. The thermal imaging system 120 and the control system 1300 can also enable a more rapid process adjustment for the manufacture of new products or the introduction of different glass compositions. The control system 1300 can also enable the manufacturer to maximize the yield and processing capacity of the converter 100.

[0144] The present disclosure can be embodied in hardware and / or software (including firmware, resident software, microcode, etc.). As previously described herein, the thermal imaging system 120 and / or the control system 1300 can include at least one processor and a computer-readable medium (i.e., a memory module). A computer-usable or computer-readable medium or memory module can be any medium that can be used by, or included, stored, communicated, propagated, or transported with, an instruction execution system, apparatus, or device.

[0145] A computer-usable or computer-readable medium or memory module can be, for example, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of computer-readable media include the following: an electrical connection having one or more wires, a portable computer diskette, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), an optical fiber, and a portable compact disc read-only memory (CD-ROM). It should be noted that a program can be electronically captured, for example, by optical scanning of paper or other media, and then, if necessary, compiled, interpreted, or otherwise processed in a suitable manner and then stored in a computer memory, so a computer-usable or computer-readable medium can further be paper or another suitable media on which a program is printed.

[0146] The computer program code for performing the operations of the present disclosure can be written in a high-level programming language such as C or C++ for development convenience. Additionally, the computer program code for performing the operations of the present disclosure can also be written in other programming languages such as, but not limited to, an interpreter-type language. Some modules or routines can be written in assembly language or even microcode to improve performance and / or memory usage. However, the software embodiments of the present disclosure do not depend on the implementation of a specific programming language. It will further be recognized that some or all of the functions of a program module can also be implemented using discrete hardware components, one or more application-specific integrated circuits (ASICs), or programmed digital signal processors or microcontrollers.

[0147] Although various embodiments of the thermal imaging system 120 and techniques for using the thermal imaging system 120 for the investigation, startup, optimization, and control of the glass tube converter 100 have been described herein, it should be understood that these embodiments and techniques may be used separately or in combination with one or more of the embodiments and techniques.

[0148] It will be apparent to those skilled in the art that various modifications and changes can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Accordingly, this specification is intended to cover 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.

[0149] Hereinafter, preferred embodiments of the present invention will be described item by item.

[0150] Embodiment 1 In a system for manufacturing glass articles from glass tubes, a converter, a base having a plurality of processing stations spaced apart within a circuit, a turret movable relative to the base, the turret having a plurality of holders extending toward the plurality of processing stations, the plurality of holders being spaced apart from each other, and the turret being operable to index each of the plurality of holders and bring them into continuous proximity with each of the plurality of processing stations, the turret; a converter including; a thermal imaging system including a thermal imager coupled to the turret for movement therewith, the thermal imager being arranged to capture infrared light emitted from the glass tube disposed in one of the plurality of holders, the thermal imaging system; a system characterized by including.

[0151] Embodiment 2 The system according to Embodiment 1, wherein the thermal imager is arranged to directly receive infrared light emitted by the outer surface of the glass tube.

[0152] Embodiment 3 The system according to Embodiment 1 or 2, further comprising at least one mirror directed to reflect infrared light emitted from the inner surface of the glass tube to the thermal imager.

[0153] Embodiment 4 The system according to Embodiment 3, wherein the at least one mirror includes a fixed mirror coupled to the base and directed to reflect infrared light emitted from the inner surface of the glass tube to the thermal imager.

[0154] Embodiment 5 The system according to Embodiment 1, further comprising a mirror coupled to the thermal imager and directed to reflect infrared light from the glass tube to the thermal imager.

[0155] Embodiment 6 The system according to Embodiment 5, wherein the reflective surface of the mirror has a reflectivity of 96% or more with respect to light having a wavelength of 800 nanometers to 20 micrometers.

[0156] Embodiment 7 The system according to Embodiment 6, wherein the reflective surface of the mirror includes a gold coating.

[0157] Embodiment 8 The system according to Embodiment 6 or 7, wherein the mirror includes a quartz substrate having a gold coating.

[0158] Embodiment 9 The system according to any one of Embodiments 5 to 8, wherein the mirror is oriented to reflect infrared light emitted from an outer surface of the glass tube to the thermal imager.

[0159] Embodiment 10 The system according to any one of Embodiments 5 to 8, wherein the mirror is oriented to reflect infrared light emitted from an inner surface of the glass tube to the thermal imager.

[0160] Embodiment 11 The system according to any one of Embodiments 1 to 10, further comprising at least one auxiliary mirror coupled to the thermal imager, wherein the mirror is oriented to reflect infrared light emitted from an outer surface of the glass tube to the thermal imager, and the auxiliary mirror is oriented to reflect infrared light emitted from an inner surface of the glass tube to the thermal imager.

[0161] Embodiment 12 The system according to any one of Embodiments 1 to 11, further comprising at least one fixed mirror disposed vertically below one of the plurality of processing stations, wherein the fixed mirror is arranged to reflect infrared light emitted from an inner surface of the glass tube to the thermal imager when the thermal imager is indexed to the predetermined position of the one of the plurality of processing stations by the turret.

[0162] Embodiment 13 The system according to any one of Embodiments 1 to 12, wherein the thermal imager is an infrared camera configured to receive infrared light having a wavelength of 4 micrometers to 14 micrometers.

[0163] Embodiment 14 The system according to any one of Embodiments 1 to 13, wherein the thermal imager is an infrared camera configured to receive infrared light having a wavelength of 5 micrometers to 14 micrometers.

[0164] Embodiment 15 The system according to any one of Embodiments 1 to 14, comprising a main turret and a sub-turret.

[0165] Embodiment 16 The system according to Embodiment 15, wherein the thermal imager is coupled to the main turret to rotate with the main turret.

[0166] Embodiment 17 The system according to any one of Embodiments 1 to 16, wherein the thermal imaging system includes a plurality of thermal imagers.

[0167] Embodiment 18 The system according to any one of Embodiments 1 to 17, further comprising a slip ring having a slip ring axis disposed above the turret and aligned with the central axis of the turret, the slip ring electrically coupling the thermal imager to a power source.

[0168] Embodiment 19 The system according to Embodiment 18, wherein the slip ring operatively couples the thermal imager to a processor.

[0169] Embodiment 20 The system according to Embodiment 18 or 19, wherein the inner ring of the slip ring includes a central bore.

[0170] Embodiment 21 The system according to any one of Embodiments 1 to 20, further comprising a power source coupled to the turret for rotation with the turret, the power source being electrically coupled to the thermal imager to supply power to the thermal imager.

[0171] Embodiment 22 The system according to any one of Embodiments 1 to 21, further comprising a wireless communication device coupled to the turret, the wireless communication device communicatively coupling the thermal imager to a processor.

[0172] Embodiment 23 A cooling fluid supply unit, A rotary joint fluidly coupled to the cooling fluid supply unit and having a joint axis aligned with the central axis of the turret, A supply conduit extending from the rotary joint to the thermal imaging system The system according to any one of Embodiments 1 to 22, further comprising a cooling system including the above.

[0173] Embodiment 24 The system according to any one of Embodiments 1 to 23, further comprising a cleaning system including at least one nozzle arranged to deliver fluid to a lens of the thermal imager.

[0174] Embodiment 25 The thermal imaging system further includes a mirror coupled to the thermal imager and directed to reflect infrared light from a glass tube disposed in one of the plurality of holders to the thermal imager, and the cooling system further includes at least one nozzle arranged to deliver fluid to a reflective surface of the mirror. The system according to Embodiment 23.

[0175] Embodiment 26 At least one processor communicatively coupled to the thermal imager, At least one memory module communicatively coupled to the processor When executed by the at least one processor, cause the thermal imaging system to perform at least the following: Receive thermal image information from the thermal imager, Process the thermal image information, and Determine characteristics of the glass tube from the thermal image information Machine-readable instructions stored in the at least one memory module that cause the above to be performed, and The system according to any one of Embodiments 1 to 25, further comprising

[0176] Embodiment 27 The characteristics include at least one of the temperature of the glass tube, the temperature gradient through the thickness of the glass tube, the viscosity of the glass tube, the viscosity gradient through the thickness of the glass tube, the dimensions of the glass tube, the temperature profile of the glass tube, the temperature profile of the glass tube over time, at least one of the centerlines of the glass tube, or a combination thereof, according to the system of Embodiment 26

[0177] Embodiment 28 The system according to Embodiment 26 or 27, further comprising machine-readable instructions stored in the at least one memory module that, when executed by the at least one processor, cause the thermal imaging system to determine the temperature of the glass tube from the thermal image information

[0178] Embodiment 29 The system according to any one of Embodiments 26 to 28, further comprising machine-readable instructions stored in the at least one memory module that, when executed by the at least one processor, cause the thermal imaging system to determine the viscosity of the glass tube from the thermal image information

[0179] Embodiment 30 When executed by the at least one processor, the system according to any one of embodiments 26 to 29, further comprising machine-readable instructions stored in the at least one memory module that cause the thermal imaging system to determine the dimensions of the glass tube from the thermal image information.

[0180] Embodiment 31 When executed by the at least one processor, the thermal imaging system is caused to perform at least the following: Determine a first characteristic of the glass tube at a first processing station; Determine a second characteristic of the glass tube at a second processing station disposed downstream of the first processing station; Calculate a difference between the first characteristic and the second characteristic; and Transmit an output representing the difference between the first characteristic and the second characteristic. The system according to any one of embodiments 26 to 30, further comprising machine-readable instructions stored in the at least one memory module that cause the above to be performed when executed by the at least one processor.

[0181] Embodiment 32 The processor is communicatively coupled to a control device, and when executed by the at least one processor, the thermal imaging system is caused to perform at least the following: Compare the characteristic of the glass tube with a characteristic of a set point; Determine a control variable from the comparison between the characteristic of the glass tube and the characteristic of the set point; and Transmit a control signal representing the control variable to the control device. The system according to any one of embodiments 26 to 31, further comprising machine-readable instructions stored in the at least one memory module that cause the above to be performed when executed by the at least one processor.

[0182] Embodiment 33 At least one of the plurality of processing stations includes a heating station having at least one heating element, and the control device is operatively coupled to the heating element to operate the heating of the glass tube by the heating element, according to Embodiment 32 of the system.

[0183] Embodiment 34 The heating element includes a burner, and the control device is one or more of a fuel control valve, an oxygen control valve, or an air control valve, according to Embodiment 33 of the system.

[0184] Embodiment 35 The control variable is one or more mass flow rates of fuel gas, oxygen, or air, according to Embodiment 34 of the system.

[0185] Embodiment 36 The control variable is one or more positions of the fuel control valve, the oxygen control valve, or the air control valve, according to Embodiment 34 of the system.

[0186] Embodiment 37 At least one of the processing stations includes a cooling station having at least one coolant control valve, and the control device is the coolant control valve, according to Embodiment 32 of the system.

[0187] Embodiment 38 At least one of the processing stations includes a forming station having one or more actuators for translating at least one forming tool to removably engage the glass tube, and the control device includes the one or more actuators, according to Embodiment 32 of the system.

[0188] Embodiment 39 The control variable is the contact time between the at least one forming tool and the glass tube within the forming station, according to Embodiment 38 of the system.

[0189] Embodiment 40 The system according to any one of Embodiments 32 to 39, further comprising a dimension determination system.

[0190] Embodiment 41 The system according to Embodiment 40, wherein the dimension determination system includes at least one of a visual image system, a laser reflectometer, a laser gauge, or an optical micrometer.

[0191] Embodiment 42 The system according to Embodiment 40 or 41, wherein the dimension determination system is arranged to capture measurement data of the glass tube upstream of the converter.

[0192] Embodiment 43 The system according to any one of Embodiments 40 to 42, wherein the dimension determination system is arranged to capture measurement data of the glass tube at one of the plurality of processing stations.

[0193] Embodiment 44 When executed by the at least one processor, the dimension determination system is caused to perform at least the following: Capturing measurement data of the glass tube at the one of the plurality of processing stations, Processing the measurement data of the glass tube, and Determining physical attributes of the glass tube from the measurement data of the glass tube The system according to Embodiment 43, further comprising machine-readable instructions stored in the at least one memory module that cause the dimension determination system to perform the above.

[0194] Embodiment 45 The system according to Embodiment 44, wherein the physical attributes are one or more of the diameter, thickness, or glass mass per unit length of the glass tube.

[0195] Embodiment 46 When executed by the at least one processor, the system performs at least the following: Receiving the physical attributes of the glass tube from the sizing system, and Determining a characteristic gradient across the thickness of the glass tube from the physical attributes and the characteristics The system according to embodiment 44 or 45, further comprising machine-readable instructions stored in the at least one memory module that cause the system to perform the above.

[0196] Embodiment 47 The system according to embodiment 46, wherein the characteristic gradient is a temperature gradient or a viscosity gradient.

[0197] Embodiment 48 When executed by the at least one processor, the system performs at least the following: Comparing the physical attributes of the glass tube with the physical attributes of a set point, and Determining an adjustment value of the control variable from a comparison between the physical attributes of the glass tube and the physical attributes of the set point The system according to any one of embodiments 43 to 47, further comprising machine-readable instructions stored in the at least one memory module that cause the system to perform the above.

[0198] Embodiment 49 In a method for controlling a glass tube converter, Indexing a glass tube removably coupled to a turret of the glass tube converter through a plurality of processing stations of the glass tube converter, wherein at least one of the plurality of processing stations includes a control device; Capturing a thermal image of the glass tube using a thermal imaging system coupled to the turret of the glass tube converter, the thermal imaging system including at least a thermal imager directed to capture infrared light from the glass tube; Processing the thermal image; The step of determining the characteristics of the glass tube from the thermal image; The step of comparing the characteristics of the glass tube with a set point; The step of determining a control variable from the comparison between the characteristics of the glass tube and the set point; The step of transmitting a control signal representing the control variable to a control device A method characterized by including the above.

[0199] Embodiment 50 The method according to embodiment 49, wherein at least one of the plurality of processing stations includes a heating station having at least one heating element, and the control device is operatively coupled to the heating element.

[0200] Embodiment 51 The method according to embodiment 50, wherein the heating element is a burner, and the control device is one or more of a fuel control valve, an oxygen control valve, or an air control valve, and the control variable is one or more mass flow rates of fuel gas, oxygen, or air.

[0201] Embodiment 52 The method according to embodiment 50, wherein the heating element is a burner, and the control device is one or more of a fuel control valve, an oxygen control valve, or an air control valve, and the control variable is one or more positions of the fuel control valve, the oxygen control valve, or the air control valve.

[0202] Embodiment 53 The method according to any one of embodiments 50 to 52, wherein the heating element is a burner, and the control device is one or more of a fuel control valve, an oxygen control valve, or an air control valve, and the method further includes the step of maintaining a certain stoichiometric ratio between the fuel introduced into the burner and air, oxygen, or air and oxygen.

[0203] Embodiment 54 At least one of the processing stations includes a cooling station having at least one coolant control valve, and the control device is the coolant control valve, according to the method of Embodiment 49.

[0204] Embodiment 55 At least one of the processing stations includes a forming station having one or more actuators for translating at least one forming tool to removably engage the glass tube, and the control device includes the one or more actuators, according to the method of Embodiment 49.

[0205] Embodiment 56 The control variable is the contact time between at least one forming tool and the glass tube in the forming station, according to the method of Embodiment 55.

[0206] Embodiment 57 The conversion machine includes a dimensional determination system including at least one of a visual image device, a laser reflectometer, a laser gauge, or an optical micrometer arranged to capture measurement data of the glass tube in one of the plurality of processing stations, according to any one of Embodiments 49 to 56.

[0207] Embodiment 58 The step of capturing measurement data of the glass tube in one of the plurality of processing stations; The step of processing the measurement data of the glass tube; The step of determining physical attributes of the glass tube from the measurement data of the glass tube and further includes, according to the method of Embodiment 57.

[0208] Embodiment 59 The physical attributes are one or more of the diameter, thickness, or glass mass per unit length of the glass tube, according to the method of Embodiment 58.

[0209] Embodiment 60 a step of comparing the physical property of the glass tube with the physical property of a set point; a step of determining an adjustment value of the control variable from a comparison between the physical property of the glass tube and the physical property of the set point The method according to embodiment 57 or 58, further comprising the above.

[0210] Embodiment 61 a step of measuring the physical property of the glass tube, wherein the physical property is one of the diameter, thickness or mass per unit length of the glass tube; a step of comparing the physical property of the glass tube with the physical property of a set point; a step of determining an adjustment value of the control variable from a comparison between the physical property of the glass tube and the physical property of the set point The method according to any one of embodiments 49 to 60, further comprising the above.

[0211] Embodiment 62 In a system for manufacturing glass articles from a glass tube, a converter, a base having a plurality of processing stations arranged at intervals in a circuit; a turret movable relative to the base, the turret having a plurality of holders extending from the turret towards the plurality of processing stations, the plurality of holders being arranged at intervals from each other, the turret being operable to index each of the plurality of holders and bring them into successive proximity with each of the plurality of processing stations; a turret; a converter including the above; a thermal imaging system including a thermal imager coupled to the turret for moving with the turret, the thermal imager being arranged to capture infrared light emitted from the glass tube disposed in one of the plurality of holders; a thermal imaging system; A system characterized by including the above.

[0212] Embodiment 63 The system according to Embodiment 62, further comprising at least one mirror directed to reflect infrared light emitted from the inner surface of the glass tube to the thermal imager.

[0213] Embodiment 64 The system according to Embodiment 62, further comprising a mirror coupled to the thermal imager and directed to reflect infrared light from the glass tube to the thermal imager.

[0214] Embodiment 65 The system according to Embodiment 64, further comprising at least one auxiliary mirror coupled to the thermal imager, the mirror being directed to reflect infrared light emitted from the outer surface of the glass tube to the thermal imager, and the auxiliary mirror being directed to reflect infrared light emitted from the inner surface of the glass tube to the thermal imager.

[0215] Embodiment 66 The system according to any one of Embodiments 62 to 65, further comprising at least one fixed mirror disposed vertically below one of the plurality of processing stations, the fixed mirror being arranged to reflect infrared light emitted from the inner surface of the glass tube to the thermal imager when the thermal imager is indexed to the predetermined position of the one of the plurality of processing stations by the turret.

[0216] Embodiment 67 The system further comprises a cleaning system including at least one nozzle arranged to deliver fluid to the lens of the thermal imager, The thermal imaging system further comprises a mirror coupled to the thermal imager and directed to reflect infrared light from a glass tube disposed in one of the plurality of holders to the thermal imager, and The cleaning system according to any one of embodiments 62 to 66, further comprising at least one nozzle arranged to deliver a fluid to the reflective surface of the mirror.

[0217] Embodiment 68 At least one processor communicatively coupled to the thermal imager, At least one memory module communicatively coupled to the processor, When executed by the at least one processor, cause the thermal imaging system to perform at least the following: Receiving thermal image information from the thermal imager, Processing the thermal image information, and Determining characteristics of the glass tube from the thermal image information Machine-readable instructions stored in the at least one memory module that, when executed by the at least one processor, cause the thermal imaging system to perform the above, The system according to any one of embodiments 62 to 67, further comprising.

[0218] Embodiment 69 The characteristics include at least one of the temperature of the glass tube, the temperature gradient through the thickness of the glass tube, the viscosity of the glass tube, the viscosity gradient through the thickness of the glass tube, the dimensions of the glass tube, the temperature profile of the glass tube, the temperature profile of the glass tube over time, the centerline of the glass tube, or a combination thereof, according to the system of embodiment 68.

[0219] Embodiment 70 The system according to embodiment 68 or embodiment 69, further comprising machine-readable instructions stored in the at least one memory module that, when executed by the at least one processor, cause the thermal imaging system to determine the viscosity of the glass tube from the thermal image information.

[0220] Embodiment 71 When executed by the at least one processor, cause the thermal imaging system to perform at least the following: Determining a first characteristic of the glass tube at a first processing station; Determining a second characteristic of the glass tube at a second processing station disposed downstream of the first processing station; Calculating a difference between the first characteristic and the second characteristic; and Transmitting an output representing the difference between the first characteristic and the second characteristic The system according to any one of embodiments 68 to 70, further comprising machine-readable instructions stored in the at least one memory module that cause the above to be performed.

[0221] Embodiment 72 The processor is communicatively coupled to a control device, and when the system is executed by the at least one processor, the thermal imaging system is caused to perform at least the following: Comparing the characteristic of the glass tube with the characteristic of a set point; Determining a control variable from a comparison between the characteristic of the glass tube and the characteristic of the set point; and Transmitting a control signal representing the control variable to the control device The system according to any one of embodiments 68 to 71, further comprising machine-readable instructions stored in the at least one memory module that cause the above to be performed.

[0222] Embodiment 73 At least one of the plurality of processing stations includes a heating station having at least one heating element, and the control device is operatively coupled to the heating element to operate the heating of the glass tube by the heating element. The system according to embodiment 72, characterized in that.

[0223] Embodiment 74 At least one of the processing stations includes a forming station having one or more actuators for translating at least one forming tool to removably engage the glass tube, the control device includes the one or more actuators, and the control variable is the contact time between the at least one forming tool and the glass tube forming station, according to Embodiment 72 of the system.

[0224] Embodiment 75 In a method for controlling a glass tube converter, feeding a glass tube removably coupled to a turret of the glass tube converter successively through a plurality of processing stations of the glass tube converter, the plurality of processing stations including at least one heating station, at least one forming station, and at least one separation station, at least one of the plurality of processing stations including a control device; capturing a thermal image of the glass tube using a thermal imaging system coupled to the turret of the glass tube converter, the thermal imaging system including at least one thermal imager oriented to capture infrared light from the glass tube; processing the thermal image; determining characteristics of the glass tube from the thermal image; comparing the characteristics of the glass tube with a setpoint; determining a control variable from the comparison of the characteristics of the glass tube and the setpoint; transmitting a control signal representing the control variable to a control device A method characterized by including.

[0225] Embodiment 76 At least one of the plurality of processing stations includes a heating station having at least one heating element, and the control device is operatively coupled to the heating element, according to Embodiment 75 of the method.

[0226] Embodiment 77 The heating element is a burner, and the control device is one or more of a fuel control valve, an oxygen control valve, or an air control valve, and the control variable is a mass flow rate of one or more of fuel gas, oxygen, or air. The method according to embodiment 76.

[0227] Embodiment 78 The heating element is a burner, and the control device is one or more of a fuel control valve, an oxygen control valve, or an air control valve, and the control variable is a position of one or more of the fuel control valve, the oxygen control valve, or the air control valve. The method according to embodiment 76.

[0228] Embodiment 79 The heating element is a burner, and the control device is one or more of a fuel control valve, an oxygen control valve, or an air control valve, and the method further includes maintaining a constant stoichiometric ratio of fuel introduced into the burner to air, oxygen, or air and oxygen. The method according to any one of embodiments 76 to 78.

[0229] Embodiment 80 The at least one of the processing stations includes a cooling station having at least one coolant control valve, and the control device is the coolant control valve. The method according to embodiment 75.

[0230] Embodiment 81 The at least one of the processing stations includes a forming station having one or more actuators for translating at least one forming tool to removably engage the glass tube, and the control device includes the one or more actuators. The method according to embodiment 75.

[0231] Embodiment 82 The control variable is a contact time between the at least one forming tool and the glass tube within the forming station. The method according to embodiment 81.

[0232] Embodiment 83 The glass tube converter includes a dimension determination system including at least one of a visual image device, a laser reflectometer, a laser gauge, or an optical micrometer arranged to capture measurement data of the glass tube at one of the plurality of processing stations, according to any one of Embodiments 75 to 82.

[0233] Embodiment 84 A step of capturing measurement data of the glass tube at the one of the plurality of processing stations, A step of processing the measurement data of the glass tube, A step of determining a physical attribute of the glass tube from the measurement data of the glass tube, and The method according to Embodiment 83, further comprising:

[0234] Embodiment 85 The physical attribute is one or more of a diameter, a thickness, or a glass mass per unit length of the glass tube, according to the method of Embodiment 84.

[0235] Embodiment 86 A step of comparing the physical attribute of the glass tube with a physical attribute of a set point, A step of determining an adjustment value of the control variable from a comparison between the physical attribute of the glass tube and the physical attribute of the set point, and The method according to Embodiment 83 or Embodiment 84, further comprising:

[0236] Embodiment 87 A step of measuring a physical attribute of the glass tube, wherein the physical attribute is one of a diameter, a thickness, or a mass per unit length of the glass tube, A step of comparing the physical attribute of the glass tube with a physical attribute of a set point, A step of determining an adjustment value of the control variable from a comparison between the physical attribute of the glass tube and the physical attribute of the set point, and The method according to any one of Embodiments 75 to 86, further comprising

[0237] Embodiment 88 A system for manufacturing glass articles from a glass tube, comprising A converter including a plurality of processing stations including at least one heating station, at least one forming station, and at least one separation station, the converter being operable to move a glass tube continuously through the plurality of processing stations during conversion; A thermal imaging system, a dimensional determination system, one or more sensors, or a combination thereof; One or more control devices; A control system, comprising A control processor; A control memory module communicatively coupled to the control processor; Computer-readable executable instructions stored in the control memory module; One or more inputs communicatively coupled to the thermal imaging system, the dimensional determination system, one or more sensors, or a combination thereof; One or more outputs communicatively coupled to one or more control devices; A control system including Including When the computer-readable executable instructions are executed by the control processor, the control system automatically Receives process variables from the thermal imaging system, the dimensional determination system, the sensors, or a combination thereof; Compares the process variables with setpoints; Determines control variables based on the comparison; and Transmits a control signal representing the control variable to the one or more control devices, causing the one or more control devices to change state by the control signal and changing the operation of the converter.

[0238] Embodiment 89 The system according to embodiment 88, wherein the control system is a proportional integral derivative controller.

[0239] Embodiment 90 The system according to embodiment 88, wherein when the computer-readable executable instructions are executed by the control processor, the control system is caused to automatically calculate the control variable using one or more proportional, integral, or derivative calculation methods.

[0240] Embodiment 91 When the computer-readable executable instructions are executed by the control processor, the control system is caused to automatically determine the setpoint from a database of historical process variable measurement values, and save the setpoint in the control memory module, the system according to embodiment 88.

[0241] Embodiment 92 When the computer-readable executable instructions are executed by the control processor, the control system is caused to automatically update the setpoint periodically based on changes observed from continuous accumulation of process variable measurement values, the system according to embodiment 88.

[0242] Embodiment 93 The process variable is determined at a point downstream of the control device, When the computer-readable executable instructions are executed by the control processor, the control system is caused to automatically perform feedback control of the control device based on the value of the process variable, the system according to embodiment 88.

[0243] Embodiment 94 When the computer-readable executable instructions are executed by the control processor, the control system is caused to automatically measure the process variable, determine an error from a comparison between the process variable and the setpoint, and The system according to Embodiment 93, which calculates the control variable from the error.

[0244] Embodiment 95 When the computer-readable executable instructions are executed by the control processor, the control system is automatically caused to determine a gain constant, and multiply the error by the gain constant to calculate the control variable, the system according to Embodiment 94.

[0245] Embodiment 96 The system according to Embodiment 95, wherein when the computer-readable executable instructions are executed by the control processor, the control system is automatically caused to determine the gain constant from the variability of past operation data of the converter.

[0246] Embodiment 97 The system according to Embodiment 95, wherein when the computer-readable executable instructions are executed by the control processor, the control system is automatically caused to execute one or more bump tests to determine the gain constant.

[0247] Embodiment 98 When the computer-readable executable instructions are executed by the control processor, the control system is automatically caused to apply a step change to the control variable, after applying the step change to the control variable, measure a process variable, and determine the gain constant from the change in the process variable in response to the change in the control variable, the system according to Embodiment 97.

[0248] Embodiment 99 The computer-readable executable instructions, when executed by the control processor, cause the control system to automatically determine the control variable for each full rotation of the main turret of the transducer or for every n full rotations of the main turret of the transducer, and to transmit the control signal to one or more of the control devices, the system according to Embodiment 88.

[0249] Embodiment 100 The computer-readable executable instructions, when executed by the control processor, cause the control system to automatically determine the control variable for each glass tube and to transmit the control signal to the one or more control devices, the system according to Embodiment 88.

[0250] Embodiment 101 The computer-readable executable instructions, when executed by the control processor, cause the control system to automatically perform cascade control of the control device based on the value of the process variable, the system according to Embodiment 88.

[0251] Embodiment 102 The computer-readable executable instructions, when executed by the control processor, cause the control system to automatically measure a first process variable, transmit the first process variable to the control system, compare the first process variable with a first setpoint related to the first process variable, determine a first gain constant for the control variable based on a response to a change in the first process variable, determine an intermediate control variable from the comparison and the first gain constant, measure a second process variable, transmit the second process variable to the control system, compare the second process variable with a second setpoint related to the second process variable, determine a second gain constant for the control variable based on a response to a change in the second process variable, and The system according to embodiment 101, which calculates the control variable from the intermediate control variable, the comparison of the second process variable and the second setpoint, and the second gain constant.

[0252] Embodiment 103 The system according to embodiment 88, wherein the process variable is at least one of the temperature of the outer surface of the glass tube, the temperature of the inner surface of the glass tube, the center line peak glass temperature of the glass tube, the average glass temperature of the center line of the glass tube, the glass viscosity of the glass tube, the temperature profile of the glass tube over time, the temperature gradient of the glass through the thickness of the glass tube, the dimensions of the glass tube, or a combination thereof.

[0253] Embodiment 104 The system according to embodiment 103, wherein the control system is communicatively coupled to the sizing system and the process variable is the dimension of the glass tube.

[0254] Embodiment 105 The system according to embodiment 88, wherein the control system is communicatively coupled to the thermal imaging system and the process variable is the difference between a first temperature and a second temperature of the glass tube.

[0255] Embodiment 106 The system according to embodiment 88, wherein the control variable includes one or more of the positions of one or more fuel control valves, the positions of one or more oxygen control valves, the positions of one or more air control valves, the position of a coolant control valve, the indexing time of the main turret of the converter, the contact time of one or more forming tools in contact with the glass tube, or a combination of these.

Claims

1. 1. A system for producing a glass article from a glass tube, comprising: a converter including a plurality of processing stations including at least one heating station, at least one forming station, and at least one separation station, the converter being operable to move the glass tube through the plurality of processing stations in succession during conversion; a thermal imaging system, a sizing system, one or more sensors, or a combination thereof; one or more control devices; 1. A control system comprising: A control processor; a control memory module communicatively coupled to the control processor; computer readable executable instructions stored in said control memory module; one or more inputs communicatively coupled to the thermal imaging system, the dimensioning system, one or more sensors, or a combination thereof; one or more outputs communicatively coupled to the one or more controllers; A control system including Including, The computer readable executable instructions, when executed by the control processor, cause the control system to automatically: receiving a process variable from the thermal imaging system, dimensioning system, sensor, or combination thereof; Comparing the process variable to a set point; determining a control variable based on said comparison; and A system for transmitting control signals representative of the control variables to the one or more controllers, the control signals causing the one or more controllers to change state and alter operation of the converter.

2. The system of claim 1 , wherein the control system is a proportional-integral-derivative controller.

3. The system of claim 1 , wherein the computer readable executable instructions, when executed by the control processor, cause the control system to automatically calculate the controlled variables using one or more proportional, integral or derivative calculation techniques.

4. The computer readable executable instructions, when executed by the control processor, cause the control system to automatically: determining said set points from a database of historical past process variable measurements; and The system of claim 1 , further comprising: storing said set points in said control memory module.

5. 2. The system of claim 1, wherein the computer readable executable instructions, when executed by the control processor, cause the control system to automatically update the set point periodically based on changes observed from a continuous accumulation of process variable measurements.

6. The process variable is determined at a point downstream of the control device; The system of claim 1 , wherein the computer readable executable instructions, when executed by the control processor, cause the control system to automatically perform feedback control of the controller based on the value of the process variable.

7. The computer readable executable instructions, when executed by the control processor, cause the control system to automatically: Measuring said process variable; determining an error from a comparison of the process variable to the set point; and The system of claim 6 , further comprising: a step of calculating the control variable from the error.

8. The computer readable executable instructions, when executed by the control processor, cause the control system to automatically: Determine the gain constant, and The system of claim 7 , further comprising: multiplying said error by said gain constant to calculate said controlled variable.

9. 9. The system of claim 8, wherein the computer readable executable instructions, when executed by the control processor, cause the control system to automatically determine the gain constant from variability in historical operating data of the converter.

10. The system of claim 8 , wherein the computer readable executable instructions, when executed by the control processor, cause the control system to automatically perform one or more bump tests to determine the gain constants.

11. The computer readable executable instructions, when executed by the control processor, cause the control system to automatically: subjecting the controlled variable to a step change; measuring a process variable after subjecting the step change to the controlled variable; and The system of claim 10 , further comprising determining the gain constant from a change in the process variable in response to a change in the control variable.

12. 2. The system of claim 1, wherein the computer readable executable instructions, when executed by the control processor, cause the control system to automatically determine the control variables and send the control signals to one or more of the controllers for every full rotation of the main turret of the converter or every n full rotations of the main turret of the converter.

13. The system of claim 1 , wherein the computer-readable executable instructions, when executed by the control processor, cause the control system to automatically determine the control variables for each glass tube and send the control signals to the one or more controllers.

14. The system of claim 1 , wherein the computer readable executable instructions, when executed by the control processor, cause the control system to automatically implement cascade control of the controllers based on values ​​of the process variables.

15. The computer readable executable instructions, when executed by the control processor, cause the control system to automatically: Measuring a first process variable; transmitting the first process variable to the control system; comparing the first process variable to a first set point associated with the first process variable; determining a first gain constant for the controlled variable based on the response to changes in a first process variable; determining an intermediate control variable from said comparison and said first gain constant; Measuring a second process variable; transmitting the second process variable to the control system; comparing the second process variable to a second set point associated with the second process variable; determining a second gain constant for the controlled variable based on the response to changes in a second process variable; and 15. The system of claim 14, further comprising: calculating the control variable from the intermediate control variable, the comparison of the second process variable and the second set point, and the second gain constant.

16. 2. The system of claim 1, wherein the process variables are at least one of a temperature of an exterior surface of the glass tube, a temperature of an interior surface of the glass tube, a peak glass temperature at the centerline of the glass tube, an average glass temperature at the centerline of the glass tube, a viscosity of glass in the glass tube, a temperature profile of the glass tube as a function of time, a temperature gradient of glass through a thickness of the glass tube, a dimension of the glass tube, or a combination thereof.

17. 17. The system of claim 16, wherein the control system is communicatively coupled to the dimensioning system and the process variable is a dimension of the glass tube.

18. 2. The system of claim 1, wherein the control system is communicatively coupled to the thermal imaging system, and the process variable is a difference between a first temperature of the glass tube and a second temperature of the glass tube.

19. 2. The system of claim 1, wherein the control variables include one or more of a position of one or more fuel control valves, a position of one or more oxygen control valves, a position of one or more air control valves, a position of a cooling fluid control valve, an index time of the main turret of the converter, a contact time of one or more forming tools in contact with the glass tube, or a combination thereof.

Images