Integrated forming preparation method of glass tube with polygonal cross section

Abstract

The invention discloses an integral forming preparation method of a glass tube with a polygonal cross section, which comprises the following steps: S1, vertically arranging a solid metal mold with a polygonal cross section in a glass outer sleeve with a sealed bottom and an open top, and ensuring that the solid metal mold and the glass outer sleeve are coaxially positioned; s2, the glass outer sleeve is vacuumized, so that pressure difference is formed between the interior of the glass outer sleeve and the external atmosphere; s3, the to-be-formed part of the glass outer sleeve is heated to be softened, and the softened part is attached to the mold to be formed under the action of the internal and external pressure difference; s4, the formed glass outer sleeve is moved to the room temperature to be cooled, and the mold is separated from the formed glass outer sleeve according to the characteristics of thermal expansion and cold contraction; and S5, cutting the molded glass outer sleeve to obtain a glass tube with a polygonal cross section, and grinding and polishing the glass tube with the polygonal cross section. The preparation process is easy to operate, less in equipment use and simple in forming process, the production period can be greatly shortened, the preparation efficiency is improved, and the quality and performance of a finished product are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of glass tube production, and in particular to an integrated molding preparation method for a polygonal cross-section glass tube. Background Art

[0002] The preparation of existing square glass tubes with square cross-sections mainly involves the following steps: A. Batching: Mix various raw materials together according to the required formula; B. Melting: Put the batches into a high-temperature furnace to melt into glass liquid; C. Molding: The molten glass liquid is made into a glass tube through a mold or blowing. For the glass square tube, a specific mold is required to ensure the shape after molding. During the molding process, the glass gradually cools down from a liquid state, through a plastic state to a solid state. In this process, shearing, bonding, blowing, rolling and other operations are performed to form the required glass square tube; D. Annealing: The glass square tube is gradually cooled to eliminate its internal stress; E. Processing: The glass square tube is cut, polished and other processes are performed.

[0003] However, the existing preparation method has complicated operation, requires more equipment, and has a complex molding process, which is not conducive to improving the preparation efficiency of the glass square tube and ensuring the quality and performance of the finished product. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an integrated molding preparation method for a polygonal cross-section glass tube, which can not only prepare a polygonal cross-section glass tube, but also has high preparation efficiency and can effectively ensure the quality and performance of the finished product.

[0005] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows.

[0006] The one-piece molding preparation method of a polygonal cross-section glass tube comprises the following steps:

[0007] S1. A solid metal mold with a polygonal cross section is placed in a glass outer sleeve with a bottom seal and a top opening, and the two are coaxially positioned;

[0008] S2. Evacuate the glass outer tube to create a pressure difference between the inside of the glass outer tube and the outside atmosphere;

[0009] S3. The glass outer sleeve is heated to soften the portion to be formed, and the softened portion is attached to the mold under the pressure difference between the inside and outside;

[0010] S4. The formed glass outer sleeve is moved to room temperature for cooling, and the mold is separated from the formed glass outer sleeve according to the characteristics of thermal expansion and contraction;

[0011] S5. Cut the formed glass outer sleeve to obtain a glass tube with a polygonal cross section, and grind and polish the glass tube with a polygonal cross section.

[0012] Preferably, before step S1, the method further includes selecting a suitable glass outer sleeve and mold according to the size of the required polygonal cross-section glass tube, specifically selecting the mold according to the cross-sectional shape and inner wall size of the required polygonal cross-section glass tube, and selecting the glass outer sleeve according to the size and wall thickness of the required polygonal cross-section glass tube; the length of the mold is greater than the length of the required polygonal cross-section glass tube, and the length of the glass outer sleeve is greater than the length of the mold.

[0013] Preferably, in step S1, the cross-section of the glass outer sleeve is circular.

[0014] Preferably, in step S1, the method for ensuring the coaxial positioning of the glass outer sleeve and the mold is as follows: the bottom of the glass outer sleeve is arc-shaped with a consistent curvature, and the mold and the glass outer sleeve are coaxially positioned under the action of the mold's own gravity; in step S2, during the process of evacuating the glass outer sleeve, the mold and the glass outer sleeve are always coaxially positioned under the action of the mold's own gravity and the control of the vacuum degree.

[0015] Preferably, the method for ensuring the coaxial positioning of the glass outer sleeve and the mold in step S1 is: first, abutting the bottom of the mold against the bottom of the glass outer sleeve and ensuring that the mold and the glass outer sleeve are coaxially arranged; then, connecting the glass outer sleeve to the vacuum equipment through a connecting tube and supporting the mold from the top of the mold through a push rod arranged in the connecting tube to ensure that the mold and the glass outer sleeve are always coaxially positioned.

[0016] Preferably, the step S2 is specifically as follows: connecting the glass outer sleeve with the built-in coaxial positioning mold to the vacuum equipment through a liftable connecting tube and longitudinally setting the glass outer sleeve at the bottom of the connecting tube, and then vacuuming the glass outer sleeve through the vacuum equipment.

[0017] Preferably, a furnace body for heating is arranged below the longitudinally arranged glass outer sleeve, and a work station opening which is connected to the heating chamber in the furnace body and is used for the glass outer sleeve to penetrate into the heating chamber in the furnace body is opened at the top of the furnace body opposite to the glass outer sleeve; in the step S3, the glass outer sleeve is driven to move downward through the work station opening into the furnace body by the liftable connecting tube, and the part of the glass outer sleeve to be formed is the part where the glass outer sleeve penetrates into the heating chamber in the furnace body and the top of the mold is not lower than the top of this part.

[0018] Preferably, in step S4, the glass outer sleeve is driven to move upward by the liftable connecting pipe so that the formed part is moved from inside the furnace to outside the furnace for room temperature cooling after forming.

[0019] Due to the adoption of the above technical scheme, the technical progress achieved by the present invention is as follows.

[0020] The one-piece molding preparation method of a polygonal cross-section glass tube provided by the present invention can not only prepare a glass tube with a polygonal cross-section, but also has simple preparation operation, less equipment usage, and a simple molding process, which can greatly shorten the production cycle, improve preparation efficiency, and ensure the quality and performance of the finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of the present invention;

[0022] Figure 2 It is a schematic diagram of vacuuming of the present invention;

[0023] Figure 3 It is a heating schematic diagram of the present invention.

[0024] Among them: 1. Vacuuming equipment, 2. Connecting pipe, 3. Glass outer sleeve, 4. Mold, 5. Furnace body, 51. Work station opening, 52. Heating chamber. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] A method for preparing a polygonal cross-section glass tube in one piece, wherein a solid metal mold is coaxially positioned in a glass outer sleeve, and then the glass outer sleeve is vacuumed and heated to prepare the polygonal cross-section glass tube in one piece, and the method is combined with Figure 1 As shown, the following steps are included:

[0027] S1. Place a solid metal mold with a polygonal cross section in a glass outer sleeve with a sealed bottom and an open top, and ensure that the two are coaxially positioned.

[0028] Before this step, it also includes selecting a suitable glass outer sleeve and mold according to the size of the required polygonal cross-section glass tube, specifically selecting a mold according to the cross-sectional shape and inner wall size of the required polygonal cross-section glass tube. If the required polygonal cross-section glass tube is a square tube, a square cross-sectional mold is selected. Because the mold is a metal mold, it will expand after being heated, so its cross-sectional size should be smaller than the inner wall cross-sectional size of the required polygonal cross-section glass tube; the glass outer sleeve is the raw material for preparing the required one-piece polygonal cross-section glass tube, and the glass outer sleeve is selected according to the size and wall thickness of the required polygonal cross-section glass tube. At the same time, the length of the mold is greater than the length of the required polygonal cross-section glass tube, and the length of the glass outer sleeve is greater than the length of the mold, so that the prepared one-piece polygonal cross-section glass tube meets the length requirements and is convenient for vacuuming the glass outer sleeve later.

[0029] In this method, a glass outer sleeve with a circular cross section is selected to ensure the uniformity of the wall thickness of the finished product.

[0030] Methods to ensure the coaxial positioning of the glass outer sleeve and the mold include but are not limited to the following two:

[0031] ① The bottom of the glass outer sleeve is arc-shaped with consistent curvature, and the mold and the glass outer sleeve are coaxially positioned under the action of the mold's own gravity; in the later process of evacuating the glass outer sleeve, the mold and the glass outer sleeve are always coaxially positioned under the action of the mold's own gravity and the control of the vacuum degree.

[0032] ② The method for ensuring the coaxial positioning of the glass outer sleeve and the mold can also be: first, the bottom of the mold is abutted against the bottom of the glass outer sleeve and the mold and the glass outer sleeve are ensured to be coaxially arranged; Figure 2 As shown, the glass outer sleeve 3 is then connected to the vacuum equipment 1 through the connecting tube 2. The connecting tube 2 is a hard tube body. A push rod is provided in the connecting tube 2. The mold 4 is supported from the top of the mold 4 by the push rod, so that the mold 4 and the glass outer sleeve 3 are always coaxially positioned.

[0033] Specifically, the glass outer sleeve 3 using the first method of coaxially positioning the glass outer sleeve 3 and the mold 4 is also connected to the vacuum equipment 1 through the connecting tube 2. At this time, the ejector rod may not be provided in the connecting tube 2.

[0034] S2. Evacuate the glass outer tube to create a pressure difference between the inside of the glass outer tube and the outside atmosphere.

[0035] The connecting tube 2 is connected to a lifting drive mechanism, and the lifting drive mechanism is used to realize the lifting of the connecting tube 2. The lifting drive mechanism is a prior art, and its specific structure is not limited or repeated here. In this step, the glass outer sleeve 3 with the coaxial positioning mold 4 built in is connected to the vacuum device 1 through the lifting connecting tube 2, and the glass outer sleeve 3 is longitudinally arranged at the bottom of the connecting tube 2, and then the glass outer sleeve 3 is vacuumed by the vacuum device 1.

[0036] S3. The part of the glass outer sleeve to be formed is heated until it softens, and the softened part is attached to the mold under the action of the internal and external pressure difference to be formed.

[0037] A furnace body 5 is disposed below the longitudinally arranged glass outer sleeve 3, and the furnace body 5 is used to heat the to-be-formed portion of the glass outer sleeve 3. A station opening 51 is provided at the top of the furnace body 5 opposite to the glass outer sleeve 3, and the station opening 51 is communicated with a heating chamber 52 in the furnace body 5, and the station opening 51 is used for the glass outer sleeve 3 to pass through the heating chamber 52 in the furnace body 5.

[0038] like Figure 3As shown, in this step, the glass outer sleeve 3 is driven by the liftable connecting tube 2 to move downward through the work station opening 51 and enter the furnace body 5. The part of the glass outer sleeve 3 to be formed is the part where the glass outer sleeve 3 penetrates into the heating chamber 52 in the furnace body 5, and the top of the mold 4 is not lower than the top of this part. This part is softened by heat and will be attached to the mold 4 to be formed under the action of the internal and external pressure difference.

[0039] S4. The formed glass outer sleeve is moved to room temperature for cooling, and the mold is separated from the formed glass outer sleeve according to the characteristics of thermal expansion and contraction.

[0040] In this step, the glass outer sleeve is driven to move upward by the lifting connecting pipe, so that the forming part is moved from the furnace body to the outside of the furnace body for room temperature cooling after forming. The cooling can toughen the forming part and improve its hardness. At the same time, because the mold is made of metal and the glass outer sleeve is made of glass, the expansion coefficient of metal is higher than that of glass, and the glass has an expansibility. During the cooling process, the mold shrinks faster and more than the forming part of the glass outer sleeve, so that a gap is generated between the mold and the forming part, and then the mold is naturally and slowly separated from the forming part. After the cooling is completed, the glass outer sleeve is removed as a whole. Because the part of the glass outer sleeve that does not enter the furnace body heating cavity cannot reach the softening temperature during the heating process in step S3, the shape of this part of the glass outer sleeve will not change, and the mold can be withdrawn from the top opening of the formed glass outer sleeve.

[0041] S5. Cut the formed glass outer sleeve to obtain a glass tube with a polygonal cross section, and grind and polish the glass tube with a polygonal cross section.

[0042] The present invention can complete the preparation of an integrally formed polygonal cross-section glass tube, and the preparation process is simple to operate, requires less equipment, and has a simple forming process, which can greatly shorten the production cycle, improve the preparation efficiency, and ensure the quality and performance of the finished product.

[0043] Embodiment 1

[0044] Choose the appropriate glass outer tube and mold according to the size of the required product. For example, if you want to produce a 3mm×3mm square glass tube, choose a 2mm×2mm×40mm rectangular solid stainless steel mold and a 3mm diameter glass outer tube. The length of the glass outer tube is about 130mm according to the required length of the production equipment.

[0045] S1. Place the selected mold vertically in the selected glass outer sleeve and ensure that the two are coaxially positioned.

[0046] S2. Insert the glass outer sleeve into the bottom of the liftable connecting pipe and fix it, and connect it to the vacuum equipment through the connecting pipe to evacuate the glass outer sleeve. After the negative pressure reaches about 10,000 Pa, prepare for molding.

[0047] S3. The part of the glass outer sleeve to be formed is inserted into the heating chamber of the furnace body through the liftable connecting pipe, and then the temperature is raised to the glass softening point between 600° and 800°. The product will be formed in this temperature range.

[0048] S4. Move the molded glass outer sleeve to room temperature for cooling, and invert the glass outer sleeve to remove the mold.

[0049] S5. Cut the formed glass outer sleeve to obtain a glass tube with a polygonal cross section, and grind and polish the glass tube with a polygonal cross section.

[0050] The one-piece polygonal cross-section glass tube prepared by this method can be used to make glass cavity products for medical equipment and aerospace consumables. Currently, such glass cavity products need to be bonded on six sides, and the six sides of glass need to be ground and polished each time, which is time-consuming and labor-intensive, with low production efficiency and a long production cycle. Moreover, the six-sided bonded cavity is prone to air leakage. By using the one-piece polygonal cross-section glass tube prepared by this method to make glass cavity products, the six-sided bonding and grinding and polishing can be reduced to two sides, which significantly improves efficiency and shortens the production cycle. At the same time, it also reduces the air leakage problem of the cavity.

Claims

1. An integrated molding preparation method for a polygonal cross-section glass tube, characterized in that: The following steps are involved: S1. A solid metal mold with a polygonal cross section is placed in a glass outer sleeve with a bottom seal and a top opening, and the two are coaxially positioned; S2. Evacuate the glass outer tube to create a pressure difference between the inside of the glass outer tube and the outside atmosphere; S3. The glass outer sleeve is heated to soften the portion to be formed, and the softened portion is attached to the mold under the pressure difference between the inside and outside; S4. The formed glass outer sleeve is moved to room temperature for cooling, and the mold is separated from the formed glass outer sleeve according to the characteristics of thermal expansion and contraction; S5. Cut the formed glass outer sleeve to obtain a glass tube with a polygonal cross section, and grind and polish the glass tube with a polygonal cross section.

2. The method for integrally forming a polygonal cross-section glass tube according to claim 1, characterized in that: Before step S1, the method also includes selecting a suitable glass outer sleeve and mold according to the size of the required polygonal cross-section glass tube, specifically selecting the mold according to the cross-sectional shape and inner wall size of the required polygonal cross-section glass tube, and selecting the glass outer sleeve according to the size and wall thickness of the required polygonal cross-section glass tube; the length of the mold is greater than the length of the required polygonal cross-section glass tube, and the length of the glass outer sleeve is greater than the length of the mold.

3. The method for integrally forming a polygonal cross-section glass tube according to claim 1, characterized in that: In the step S1, the cross section of the glass outer sleeve is circular.

4. The method for integrally forming a polygonal cross-section glass tube according to claim 1, characterized in that: The method for ensuring the coaxial positioning of the glass outer sleeve and the mold in step S1 is as follows: the bottom of the glass outer sleeve is arc-shaped with a consistent curvature, and the mold and the glass outer sleeve are coaxially positioned under the action of the mold's own gravity; in step S2, during the process of evacuating the glass outer sleeve, the mold and the glass outer sleeve are always coaxially positioned under the action of the mold's own gravity and the control of the vacuum degree.

5. The method for integrally forming a polygonal cross-section glass tube according to claim 1, characterized in that: The method for ensuring the coaxial positioning of the glass outer sleeve and the mold in step S1 is: first, the bottom of the mold is abutted against the bottom of the glass outer sleeve to ensure that the mold and the glass outer sleeve are coaxially arranged; then, the glass outer sleeve is connected to the vacuum pumping equipment through a connecting tube and the mold is supported from the top of the mold by a push rod arranged in the connecting tube to ensure that the mold and the glass outer sleeve are always coaxially positioned.

6. The method for integrally forming a polygonal cross-section glass tube according to claim 1, characterized in that: The step S2 is specifically as follows: connecting the glass outer sleeve with the coaxial positioning mold built in it to the vacuum equipment through a liftable connecting tube and vertically arranging the glass outer sleeve at the bottom of the connecting tube, and then vacuuming the glass outer sleeve through the vacuum equipment.

7. The method for integrally forming a polygonal cross-section glass tube according to claim 6, characterized in that: A furnace body for heating is arranged below the longitudinally arranged glass outer sleeve, and a work station opening which is connected to the heating chamber in the furnace body and is used for the glass outer sleeve to penetrate into the heating chamber in the furnace body is provided at the top of the furnace body opposite to the glass outer sleeve. In the step S3, the glass outer sleeve is driven to move downward through the work station opening into the furnace body by the liftable connecting pipe, and the part of the glass outer sleeve to be formed is the part where the glass outer sleeve penetrates into the heating chamber in the furnace body, and the top of the mold is not lower than the top of this part.

8. The method for integrally forming a polygonal cross-section glass tube according to claim 7, characterized in that: In step S4, the glass outer sleeve is driven to move upward by the liftable connecting pipe so that the formed part is moved from the furnace body to the outside of the furnace body for room temperature cooling after forming.

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