A preparation device and method for medium-borosilicate pharmaceutical glass tubes

Abstract

The present invention provides a preparation device and method for a medium-borosilicate pharmaceutical glass tube, relating to the technical field of pharmaceutical glass tube preparation. The preparation device provided by the present invention includes a melting system, a forming system and a cutting system. The forming system includes a muffle furnace, a shaping furnace and an annealing furnace which are vertically arranged from top to bottom. In the muffle furnace, between the material trough and the annular gap between the inner wall of the furnace body passage of the guiding tube, the glass liquid is pushed downward by its own gravity and the pushing force of the annular gap and enters the shaping furnace. The tube drawing system is provided with a traction roller and a guiding clamping ring to clamp and position the glass tube. The traction roller clamps the glass melt, so that the glass melt is continuously drawn under the combined action of its own gravity and the self-rotation force of the traction roller to form a glass tube. The glass tube prepared by this device has a uniform thickness, the whole preparation process is simple, avoiding complicated processes and ensuring the internal and external quality of the glass tube at the same time. The preparation device of the present invention has a simple structure and is convenient for maintenance, and also reduces the cost and energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of preparation of medicinal glass tubes, and in particular to a preparation device and method for medium-borosilicate medicinal glass tubes. Background Art

[0002] As the direct carrier of pharmaceuticals, pharmaceutical packaging materials have an important responsibility to ensure the quality and safety of pharmaceuticals. Glass has been proven to be the preferred packaging material in the pharmaceutical industry after nearly a hundred years of application and practice, thanks to its characteristics of being smooth, transparent, easy to disinfect, and having good sealing properties. In particular, medium-borosilicate glass has better impact resistance and chemical stability, becoming the internationally recognized safest pharmaceutical packaging material, and is widely used in the packaging of high-end infusions, antibiotics, lyophilized agents, vaccines, biological agents, and other pharmaceuticals.

[0003] The preparation of medium borosilicate pharmaceutical glass is all made by secondary processing of medium borosilicate glass tubes. The medium borosilicate tube drawing technology has become the core barrier of medium borosilicate tube bottles. At present, the mainstream methods of medium borosilicate tubes are Dana method and Vero method. The Vero method has a higher plant building and higher investment and energy consumption. The Dana method is more widely used, but the life of the rotating tube in the Dana method tube drawing restricts the tube drawing production efficiency, and regular replacement and maintenance virtually increase production consumption. Summary of the invention

[0004] In order to solve the problem that the tube drawing equipment used in the production process of preparing pharmaceutical glass tubes needs frequent replacement of consumables and regular maintenance, the present invention provides a device and method for preparing medium-borosilicate pharmaceutical glass tubes.

[0005] To achieve the above purpose, the following technical solutions are used:

[0006] A device for preparing a medium-borosilicate pharmaceutical glass tube, comprising:

[0007] The melting system includes a melting zone and a clarification zone which are arranged in sequence; the melting zone is used to melt the batch material into glass liquid and then feed it into the clarification zone; the clarification zone is used to bubble and homogenize the glass liquid, stir and remove bubbles, and feed the glass liquid into the material tank of the molding system through the feed pipe;

[0008] The forming system includes a muffle furnace, a shaping furnace, and an annealing furnace that are vertically arranged from top to bottom; the muffle furnace includes a material trough, the material trough is in the shape of an inverted frustum of a cone, a guiding tube is arranged below the material trough, the guiding tube extends from the muffle furnace to the lower end of the shaping furnace, a furnace body channel is arranged outside the guiding tube in the material trough and the muffle furnace, the furnace body channel is coaxially arranged with the material trough and the guiding tube and forms an annular gap; several groups of traction rollers and several guiding clamping rings are arranged in the shaping furnace for clamping and positioning the glass tube, the traction rollers are arranged on the clamping drive mechanism bracket, and both the clamping drive mechanism bracket and the guiding clamping rings are arranged on the furnace wall of the shaping furnace and are connected to an external servo motor; several groups of traction rollers and several guiding clamping rings are also arranged in the upper part of the annealing furnace;

[0009] The cutting system is arranged below the forming system and is used to cut the formed and annealed glass tube according to the specified length for application.

[0010] It also includes an on-line detection system, which is placed at the outlet of the annealing furnace and is used for real-time monitoring and feedback of the glass tube diameter and the state of the glass tube.

[0011] The side surface of the traction roller is a rotating surface, several traction rollers are arranged in a group at the same horizontal height in the shaping furnace, and the generatrices of the rotating surfaces of several traction rollers can form a circular ring to wrap the glass tube.

[0012] Heating devices are arranged outside the upper parts of the muffle furnace, the shaping furnace, and the annealing furnace; temperature measuring devices are also arranged outside the muffle furnace and the shaping furnace, and the temperature measuring devices outside the annealing furnace are arranged according to the temperature gradient in the furnace.

[0013] The depth of the inner barrel of the material trough is not less than 1 / 2 of the total height of the material trough and not greater than the total height of the material trough.

[0014] Positioning wheels are fixed at both ends of the traction roller.

[0015] The minimum diameter of the furnace body channel is 2 - 30 mm larger than the bottom diameter of the material trough.

[0016] The melting zone includes a melting furnace, a flue is arranged at the upper part of the front wall of the melting furnace, a feeding port is arranged at the lower part of the front wall of the melting furnace; the heating electrodes are arranged in a side stacking manner on the side walls of the melting furnace, burners are arranged on both sides of the breast wall of the melting furnace, and a discharging port is arranged at the bottom of the melting furnace.

[0017] The clarification zone includes a clarification channel and a homogenization tank, the clarification channel connects the melting furnace and the homogenization tank; a stirring device, a bottom bubbling device, and a discharging port are arranged in the homogenization tank, the bottom bubbling device is used to bubble into the glass liquid to promote the clarification of the glass liquid, the stirring device is used for homogenizing the glass liquid, and the discharging port is arranged at the bottom of the homogenization tank.

[0018] A method for preparing medium borosilicate pharmaceutical glass tubes using the above preparation device includes the following steps:

[0019] The batch material is put into a furnace for high-temperature glass melting. The molten viscosity of the glass liquid is 10 2 -10 2.3 dPa·s;

[0020] After melting, it is sent to a homogenizing tank for glass clarification, defoaming and homogenization. The viscosity of the clarified and homogenized glass liquid is 10 2.5 -10 3 dPa·s;

[0021] It is sent into a muffle furnace through a feeder pipe. When the glass liquid in the trough is full, it overflows simultaneously from the circular top of the trough, and along the outer edge of the trough, the annular gap formed between the furnace body channel and the trough makes the glass liquid flow evenly downward. The diameter of the glass tube gradually decreases until it enters the shaping furnace; it is clamped by several groups of traction rollers and several guiding clamping rings. Under the uniform pulling force of the traction rollers and the self-weight of the glass, it is drawn into a slender hollow glass tube with uniform thickness along the drawing tube system; the viscosity of the glass tube during forming and drawing is 10 4 -10 4.3 dPa·s;

[0022] It enters an annealing furnace to complete annealing and eliminate stress. The viscosity for stress elimination of the glass tube is not less than 10 9 dPa·s;

[0023] The annealed glass tube is sent into a cutting device and cut according to the preset size, and then inspection and packaging are completed.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] For the device for preparing medium-borosilicate medical glass tubes provided by the present invention, in the annular gap between the trough and the guide tube and the inner wall of the furnace body channel in the muffle furnace, the glass liquid advances downward by means of its own gravity and the pushing force of the annular gap and enters the shaping furnace. The drawing tube system is provided with traction rollers and guiding clamping rings to clamp and position the glass tube. The glass melt is continuously drawn under the combined action of its own gravity and the self-rotation force of the traction rollers to form a glass tube. The whole preparation process is simple, avoiding complicated processes and ensuring the internal and external quality of the glass tube at the same time. The preparation device of the present invention has a simple structure and is easy to maintain, and also reduces cost and energy consumption.

[0026] Furthermore, the preparation device of the present invention is provided with a clarification channel for the first clarification, and the clarification and homogenization tank is provided with a bubbling device for the second clarification. Two-stage clarification is set, which is more beneficial to the clarification of the glass liquid; the side surface of the traction roller is a rotating curved surface to form a ring to clamp the glass melt, and the glass melt is subjected to a uniform traction force, ensuring that the thickness of the prepared glass tube is uniform. Description of the Drawings

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below:

[0028] Figure 1 This is a schematic structural diagram of the device for preparing medium-borosilicate medicinal glass tubes according to the present invention;

[0029] Figure 2 This is a schematic structural diagram of the traction roller in the tube drawing system of the device according to the present invention;

[0030] Figure 3 This is a schematic installation diagram of the traction roller in the tube drawing system of the device according to the present invention;

[0031] Figure 4 This is a schematic layout diagram of the traction roller in the tube drawing system of the device according to the present invention;

[0032] Figure 5 This is a schematic structural diagram of the guiding clamping ring in the tube drawing system of the device according to the present invention;

[0033] In the figure: 1, melting furnace; 2, flue; 3, feeding port; 4, heating electrode; 5, burner; 6, homogenizing tank; 7, stirring device; 8, bottom bubbling device; 9, feeding pipe; 10, muffle furnace; 11, shaping furnace; 12, trough; 13, furnace body passage; 14, heating device; 15, temperature measuring device; 16, traction roller; 17, guiding clamping ring; 18, annealing furnace; 19, on-line detection device; 20, glass tube; 21, traction roller positioning wheel; 22, clamping drive mechanism bracket; 23, guiding tube. Specific embodiments

[0034] The following further describes the present invention with reference to the accompanying drawings:

[0035] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0037] The present invention will be further described in detail below with reference to the accompanying drawings:

[0038] As Figure 1 shown, the present invention provides a preparation device for medium borosilicate pharmaceutical glass tubes, comprising a melting system, a forming system and a cutting system;

[0039] The melting system is used for glass melting and feeding. Glass melting includes high-temperature melting of the batch materials, stirring and defoaming, and bubbling and homogenization. The melting system is sequentially provided with a melting zone, a clarification zone and a feeding pipe 9 in the horizontal position.

[0040] The melting zone is used for melting the batch materials into glass liquid. The melting zone includes a furnace 1, in which a flue 2, a feeding port 3, heating electrodes 4, burners 5 and a discharging port are provided. The flue 2 is at the upper part of the front wall of the furnace 1, and the feeding port 3 is at the lower part of the front wall of the furnace 1; the heating electrodes 4 are made of molybdenum electrodes or tin oxide electrodes, and the heating electrodes 4 are arranged in a side wall stacking manner of the tank wall; the burners 5 are on both sides of the breast wall of the furnace 1; the discharging port is at the bottom of the furnace 1 and is used for discharging the glass liquid to remove sediment impurities. The furnace 1 adopts an all-electric heating method or an electric plus gas heating method to heat the batch materials.

[0041] The clarification zone includes a clarification channel and a homogenization tank 6; a stirring device 7, a bottom bubbling device 8 and a discharging port are provided in the homogenization tank 6. The clarification channel connects the furnace 1 and the homogenization tank 6. The bottom bubbling device 8 is used for bubbling into the glass liquid to enhance the convection of the glass liquid and promote the clarification of the glass liquid; the stirring device 7 is used for homogenizing the glass liquid; the discharging port is arranged at the bottom of the homogenization tank 6 and is used for intermittent discharging to remove sediment impurities of the glass liquid.

[0042] The feeding pipe 9 is used for conveying the molten glass liquid to the trough 12 of the forming system. One end of the feeding pipe 9 is communicated with the flowing liquid channel at the bottom side of the clarification zone, and the other end is above the trough 12.

[0043] The batch material composed of crushed glass powder and powder material is fed into the furnace 1 from the feeding port 3, melted into a melt at high temperature, and enters the clarification zone along the clarification channel after complete melting. The clarified and homogenized glass liquid flows into the trough 12 of the forming system along the feeding pipe 9.

[0044] The forming system includes a muffle furnace 10, a shaping furnace 11, and an annealing furnace 18 that are vertically arranged from top to bottom.

[0045] The muffle furnace 10 includes the trough 12, the furnace body channel 13, and the upper part of the guiding pipe 23. The trough 12 is in the shape of an inverted frustum of a cone. The depth of the inner barrel of the trough 12 is not less than 1 / 2 of the total height of the trough 12 and not greater than the total height of the trough 12. The guiding pipe 23 is in the shape of a cylinder. The guiding pipe 23 is arranged below the trough 12 and extends from the muffle furnace 10 to the lower end of the shaping furnace 11. The bottom of the trough 12 is connected to the upper end of the guiding pipe 23 through an arc. The upper opening diameter of the furnace body channel 13 is larger than the upper cross-sectional diameter of the trough 12. The furnace body channel 13 is coaxially arranged with the trough 12 and the guiding pipe 23 in the muffle furnace 10, so that an annular gap is formed between the inner wall of the furnace body channel 13 and the trough 12 and the guiding pipe 23 in the muffle furnace 10. The diameter of the annular gap gradually decreases from top to bottom until it reaches the guiding pipe 23 and then remains unchanged. The minimum diameter of the furnace body channel 13 is 2 - 30 mm larger than the bottom diameter of the trough 12.

[0046] As Figures 1-5 shown, the shaping furnace 11 is provided with a tube drawing system. The tube drawing system includes a traction roller 16, a guiding and clamping ring 17, a clamping transmission mechanism support 22, and the lower part of the guiding pipe 23. The clamping transmission mechanism support 22 is arranged on the furnace wall of the shaping furnace 11. The traction roller 16 is arranged on the clamping transmission mechanism support 22 and can rotate on the clamping transmission mechanism support 22. Positioning wheels 21 are provided at both ends of the traction roller 16 to prevent the traction roller 16 from moving horizontally on the clamping transmission mechanism support 22. The clamping transmission mechanism support 22 is also connected to a servo motor, and the servo motor controls and drives the traction roller 16 on the clamping transmission mechanism support 22 to rotate automatically in the direction of glass flow. The side surface of the traction roller 16 is a rotating surface. Several traction rollers 16 are arranged in a group at the same horizontal height in the shaping furnace 11. The generatrices of the rotating surfaces of several traction rollers 16 can form a circular ring to wrap the glass tube 20. Several groups of traction rollers 16 clamp the glass melt, so that the glass melt is continuously drawn under the combined action of its own gravity and the self-rotation force of the traction roller 16 to form the glass tube 20. The guiding and clamping ring 17 is arranged on the furnace wall of the shaping furnace 11 and is connected to an external servo motor, and can be moved by the servo motor according to actual process requirements. Several guiding and clamping rings 17 and traction rollers 16 are arranged alternately to play a guiding and positioning role during the stretching process of the glass melt.

[0047] In one embodiment of the present invention, four traction rollers 16 are arranged in a group to form a circular ring to wrap the glass tube 20.

[0048] A number of groups of traction rollers 16 and guiding clamping rings 17 are also arranged in the annealing furnace 18, and are centrally arranged at the upper part of the annealing furnace 18.

[0049] As Figure 1 shown, heating devices 14 are uniformly arranged on the exteriors of the muffle furnace 10 and the shaping furnace 11 for heating and heat preservation of the furnace bodies. The heating devices 14 are also centrally arranged at the upper part of the annealing furnace 18 to make the temperature in the annealing furnace 18 decrease in a gradient manner, aiming to remove the internal stress of the glass and make the internal structure of the glass tube 20 formed by pulling through the drawing system more dense. The heating device 14 is a heating rod or a heating wire wound around the outer wall of the furnace; temperature measuring devices 15 are uniformly arranged on the exteriors of the muffle furnace 10 and the shaping furnace 11, and the temperature measuring devices 15 are arranged along the temperature gradient in the furnace on the exterior of the annealing furnace 18. The temperature measuring device 15 is a thermocouple.

[0050] The on-line detection system 19 is located at the outlet of the annealing furnace 18 for real-time monitoring and feedback of the glass tube diameter and the state of the glass tube.

[0051] The cutting system is arranged below the shaping system and is used to cut the formed and annealed glass tube 20 according to the specified fixed-length dimension for application. The cut end is rounded by a round mouth burner flame or polished flat. The cut glass tubes 20 are stacked and coiled for packing.

[0052] The preparation method of the middle borosilicate pharmaceutical glass tube using the above device includes the following steps:

[0053] Weigh the batch materials according to the raw material ratio, and add the batch materials into a mixer and mix evenly;

[0054] The evenly mixed batch materials are melted into glass at high temperature in the melting furnace 1, and the molten viscosity of the glass liquid is 10 2 -10 2.3 dPa·s;

[0055] After melting, it is sent to the homogenizing tank 6 for glass clarification, bubble removal and homogenization; the viscosity of the glass clarification and homogenization is 10 2.5 -10 3 dPa·s.

[0056] It is sent into the muffle furnace 10 through the feeding pipe 9. When the glass liquid in the material tank 12 is full, it overflows simultaneously from the circular top of the material tank 12, and flows down evenly along the outer edge of the material tank 12. Along the outside of the material tank 12, the diameter of the glass tube 20 gradually decreases, and the caliber of the glass liquid gradually decreases, and it enters the shaping furnace 11; it is clamped by a number of groups of traction rollers 16 and a number of guiding clamping rings 17 of the drawing system. Under the uniform pulling force of the traction rollers 16 and the self-weight of the glass, it is drawn into a slender hollow glass tube with uniform thickness along the traction of the drawing system; the viscosity of the glass tube forming and drawing is 10 4 -10 4.3dPa·s.

[0057] Enter an annealing furnace 18 with a viscosity of not less than 10 9 dPa·s for annealing to eliminate stress;

[0058] Feed the annealed glass tube into a cutting device and cut it according to a preset size, then complete inspection and packaging. After inspection, it directly enters the secondary processing process of pharmaceutical glass to complete the processing of pharmaceutical glass bottles such as ampoules and vials.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still modify the specific implementation manners of the present invention or make equivalent replacements. Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the scope of the claims of the present invention pending approval.

Claims

1. A preparation device for medium-borosilicate pharmaceutical glass tubes, characterized in that, Including: A melting system, which includes a melting zone and a clarification zone arranged in sequence; the melting zone is used to melt the batch material into molten glass and then send it to the clarification zone, and the clarification zone is used to bubble and homogenize the molten glass, stir and remove bubbles, and send the molten glass into the trough (12) of the forming system through a feeding pipe (9); A forming system, including a muffle furnace (10), a shaping furnace (11) and an annealing furnace (18) arranged vertically from top to bottom; the muffle furnace (10) includes a trough (12), the trough (12) is in the shape of an inverted frustum of a cone, a guiding pipe (23) is arranged below the trough (12), the guiding pipe (23) extends from the muffle furnace (10) to the lower end of the shaping furnace (11), and a furnace body passage (13) is arranged outside the guiding pipe (23) in the trough (12) and the muffle furnace (10), and the furnace body passage (13) is coaxially arranged with the trough (12) and the guiding pipe (23) to form an annular gap; several groups of traction rollers (16) and several guiding and clamping rings (17) are arranged in the shaping furnace (11) for clamping and positioning the glass tube (20), the traction rollers (16) are arranged on a clamping transmission mechanism bracket (22), and both the clamping transmission mechanism bracket (22) and the guiding and clamping rings (17) are arranged on the furnace wall of the shaping furnace (11) and are connected to an external servo motor; several groups of traction rollers (16) and several guiding and clamping rings (17) are also arranged in the upper part of the annealing furnace (18); A cutting system, arranged below the forming system, for cutting the formed and annealed glass tube (20) according to the application fixed-length dimension; The side surface of the traction roller (16) is a rotating surface, several traction rollers (16) are arranged in a group at the same horizontal height in the shaping furnace (11), and the generatrices of the rotating surfaces of several traction rollers (16) can form a circular ring to wrap the glass tube (20).

2. The preparation device for a medium-borosilicate pharmaceutical glass tube according to claim 1, wherein It also includes an on-line detection system (19), and the on-line detection system (19) is placed at the outlet of the annealing furnace (18) for real-time monitoring and feedback of the glass tube diameter and the state of the glass tube.

3. The preparation device for a medium-borosilicate medicinal glass tube according to claim 1, wherein, Heating devices (14) are arranged outside the upper parts of the muffle furnace (10), the shaping furnace (11) and the annealing furnace (18); temperature measuring devices (15) are also arranged outside the muffle furnace (10) and the shaping furnace (11), and temperature measuring devices (15) are arranged outside the annealing furnace (18) along with the temperature gradient in the furnace.

4. The preparation device for a medium-borosilicate medicinal glass tube according to claim 1, wherein, The depth of the inner barrel of the trough (12) is not less than 1 / 2 of the total height of the trough (12) and not greater than the total height of the trough (12).

5. The preparation device for a medium-borosilicate pharmaceutical glass tube according to claim 1, characterized in that, Positioning wheels (21) are fixed at both ends of the traction roller (16).

6. The preparation device for a medium-borosilicate medicinal glass tube according to claim 1, characterized in that, The minimum diameter of the furnace body passage (13) is 2 - 30 mm larger than the bottom diameter of the trough (12).

7. The preparation device for a medium-borosilicate pharmaceutical glass tube according to claim 1, characterized in that, The melting zone includes a melting furnace (1), a flue (2) is arranged at the upper part of the front wall of the melting furnace (1), a feeding port (3) is arranged at the lower part of the front wall of the melting furnace (1); the heating electrodes (4) are arranged in a side-piled manner on the side wall of the pool, burners (5) are arranged on both sides of the breast wall of the melting furnace (1), and a discharge port is arranged at the bottom of the melting furnace (1).

8. The preparation device for a medium-borosilicate medicinal glass tube according to claim 1, characterized in that, The clarification area includes a clarification channel and a homogenization tank (6). The clarification channel is connected to the melting furnace (1) and the homogenization tank (6). A stirring device (7), a bottom bubbling device (8) and a discharging opening are arranged in the homogenization tank (6). The bottom bubbling device (8) is used for bubbling into the glass liquid to promote the clarification of the glass liquid. The stirring device (7) is used for homogenizing the glass liquid. The discharging opening is arranged at the bottom of the homogenization tank (6).

9. A method for preparing a medium borosilicate pharmaceutical glass tube using the preparation device according to any one of claims 1-8, characterized in that, It includes the following steps: The batch material is put into the melting furnace (1) for high-temperature glass melting, and the molten viscosity of the glass liquid is 10 2 -10 2.3 dPa·s; After melting, it is sent to the homogenizing tank (6) for glass clarification, defoaming and homogenization. The viscosity of the clarified and homogenized glass liquid is 10 2.5 -10 3 dPa·s; It is fed into the muffle furnace (10) through the feeding pipe (9). When the glass liquid in the material storage tank (12) is full, it overflows simultaneously from the circular top of the material storage tank (12), and flows uniformly downward along the outer edge of the material storage tank (12). In the annular gap formed by the furnace body channel (13) and the material storage tank (12), the glass liquid flows uniformly downward. The diameter of the glass tube (20) gradually decreases until it enters the shaping furnace (11); it is clamped by several groups of traction rollers (16) and several guiding clamping rings (17). Under the uniform pulling force of the traction rollers (16) and the self-weight of the glass, it is drawn into a slender hollow glass tube with a uniform thickness along the traction of the tube drawing system; the viscosity of the glass tube during forming and drawing is 10 4 -10 4.3 dPa·s; Enter the annealing furnace (18) to complete annealing and eliminate stress, and the viscosity of the glass tube after stress elimination is not less than 10 9 dPa·s; Feed the annealed glass tube (20) into a cutting device, cut it according to a preset size, and complete inspection and packaging.

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