Metering structure for equivalent aperture of capillary tube
By designing a metering structure with capillary equivalent pore size, and using a gas flow meter and vacuum pump to measure the gas flow rate of the shear capillary, the problem of inaccurate measurement of capillary equivalent pore size in existing technologies is solved, and the accuracy of positive sample pore size and the reliability of detection are achieved.
Patent Information
- Application Number
- CN202423311111.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Existing technologies cannot accurately measure the equivalent pore size of capillaries after shearing, resulting in insufficient accuracy of positive samples in drug packaging seal testing.
Design a metering structure for the equivalent pore size of a capillary tube, including a gas flow meter, a vacuum pump, and adapters. The vacuum pump creates a negative pressure, and the gas flow meter measures the gas flow rate shearing the capillary tube to obtain the equivalent pore size.
It enables accurate measurement of the equivalent pore size of shear capillaries, is applicable to capillaries of different diameters, ensures the accuracy of pore size in positive samples, and contributes to drug leak detection research and commercial production.
Smart Images
Figure CN223784132U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of aperture measurement, specifically to a metering structure for the equivalent aperture of a capillary. Background Technology
[0002] Currently, in the application for consistency evaluation of injectable drugs, the sealing test is one of the important verification items. The "Technical Guidelines for Sealing Research of Packaging Systems for Injectable Chemical Drugs" (Trial Implementation) issued by the CDE on October 21, 2020, also clearly defines the requirements and methods for testing the sealing performance of packaging during the research, development, and production of injectable drugs. The testing methods must use positive samples with known defects to verify sensitivity. This is specifically reflected in USP 1207, where positive samples represent a range of packaging defect sizes and types, and there are multiple methods to prepare positive samples. When testing for defects in drug packaging, a basic understanding of leakage kinetics is extremely important for understanding the effects of different defect types and drug packaging materials.
[0003] Common methods for identifying defects in pharmaceutical packaging include laser perforation, capillary implantation, and glass micro-droplet implantation. Among these, in pharmaceutical packaging sealing studies and testing, the capillaries implanted into the packaging are hollow and vary in length, thus achieving different leakage pore sizes.
[0004] The capillary tube opening diameter is not the same as the capillary equivalent pore diameter. The opening diameter can be measured by a microscope or scanning electron microscope, while the equivalent pore diameter can only be measured by the gas flow rate. The longer the capillary tube is, the smaller its equivalent pore diameter will be, which will lead to a decrease in flow rate and a smaller equivalent pore diameter. In the study and testing of the sealing performance of pharmaceutical packaging, the equivalent pore diameter of the capillary tube is often used, rather than the actual opening diameter.
[0005] Positive samples are prepared using capillary implantation methods. The equivalent pore size of the capillary needs precise measurement. The capillary orifice diameter can be measured using an optical microscope. Capillary orifice diameters are often quite large, typically tens to hundreds of micrometers. However, the conventional pore size specifications used in pharmaceutical packaging sealing tests are mostly 0.5µm-15µm. Therefore, in practice, capillary tubes of tens of micrometers are usually used. Depending on the pharmaceutical packaging and pore size requirements, capillary tubes of different lengths are cut. The equivalent pore size of the cut capillary tubes is then precisely measured to obtain positive samples with different equivalent pore sizes. However, the flow rate of the cut capillary tube cannot be accurately obtained. Therefore, a metering structure capable of accurately determining the equivalent pore size of the cut capillary tube, in conjunction with a gas flow meter, is designed. Utility Model Content
[0006] The present invention aims to provide a metering structure that can accurately determine the equivalent pore size of the capillary after shearing when used in conjunction with a gas flow meter.
[0007] To achieve the above objectives, the present invention adopts the following technical solution:
[0008] 1) A metering structure for capillary equivalent aperture, comprising a gas flow meter, a vacuum pump, and an adapter, wherein the adapter has a gas space for positioning and shearing capillary, one end of the adapter has an inlet channel communicating with the gas space and the inlet channel communicating with the shearing capillary in the gas space, the other end of the adapter has an outlet channel communicating with the gas space, the outlet channel facing the gas flow meter and communicating with the inlet of the gas flow meter, and the outlet of the gas flow meter communicating with the vacuum pump.
[0009] Before use, the shearing capillary is placed into the gas space of the adapter through the air inlet channel, and the shearing capillary is positioned and fixed by the gas space. During use, the vacuum pump is started, and a negative pressure is formed at the outlet of the gas flow meter connected to the vacuum pump. Under the negative pressure at the outlet of the gas flow meter, external gas is allowed to enter the shearing capillary through the air inlet channel of the adapter. The airflow in the shearing capillary flows to the outlet channel of the adapter, and the airflow flows into the gas flow meter through the outlet channel of the adapter. The gas flow rate of the airflow is obtained by the gas flow meter, thereby obtaining the gas flow rate in the capillary and accurately obtaining the equivalent aperture of the shearing capillary.
[0010] 2) A metering structure for the equivalent pore size of a capillary tube as described in 1), wherein:
[0011] The adapter includes a tube body, one end of which is snapped with an outer sleeve. The outer sleeve has an air inlet channel for inserting a shearing capillary tube. An air inlet communicating with the air inlet channel is opened at the end of the outer sleeve away from the tube body. The other end of the tube body is snapped with a quick-connect block. The quick-connect block has an air outlet channel for gas flow. The position of the air outlet channel corresponds to the position of the shearing capillary tube. An exhaust port communicating with the air outlet channel is opened at the end of the quick-connect block away from the tube body. An inner sleeve forming a gas space is provided between the outer sleeve and the quick-connect block.
[0012] This invention employs an outer sleeve, a quick-connect block, and an inner sleeve connected adjacently to form a tube. The outer sleeve connects to the outside atmosphere through its air inlet, allowing outside air to be introduced into the air inlet channel. The air inlet channel also provides a space for inserting a shearing capillary. After insertion, the shearing capillary's position corresponds to the outlet channel, ensuring that the airflow within the shearing capillary flows towards the outlet channel. The airflow within the shearing capillary can be measured by a gas flow meter, thus obtaining the gas flow rate of the shearing capillary. The equivalent orifice diameter of the shearing capillary is then determined from the gas flow rate.
[0013] 3) A metering structure for the equivalent pore size of a capillary tube as described in 2), wherein:
[0014] The inner sleeve is provided with a sealing sleeve at the end facing the outer sleeve. The sealing sleeve has a limiting hole for clamping and shearing capillary tube. The limiting hole is connected to the air inlet channel and the gas space respectively. The end of the sealing sleeve facing the gas space is conical.
[0015] This invention fixes the shearing capillary through the limiting hole of the sealing sleeve and places the shearing capillary in the gas space of the inner sleeve; at the same time, the end of the sealing sleeve facing the gas space is designed as a cone, thereby clamping, fixing and locking the shearing capillary and maintaining the stability of the shearing capillary's position.
[0016] 4) A metering structure for the equivalent pore size of a capillary tube as described in 3), wherein:
[0017] The outer surface of the inner sleeve has a first external thread groove, the inner surface of the outer sleeve has a first internal thread groove, the sealing sleeve is embedded in the end of the inner sleeve facing the outer sleeve, and the thickness of the sealing sleeve is less than the length of the shear capillary.
[0018] In this invention, a sealing sleeve connects the inner sleeve and the outer sleeve. By rotating the threads between the first internal thread groove of the outer sleeve and the first external spiral groove of the inner sleeve, a tightening pressure is applied to the sealing sleeve located between the outer sleeve and the inner sleeve, forming a sealed state for the shearing capillary. At the same time, the thickness of the sealing sleeve is less than the length of the shearing capillary, thereby clamping and fixing a portion of the shearing capillary. This allows other parts of the shearing capillary to transmit their own gas flow without being subjected to any compressive force, ensuring the accuracy of the detected gas flow data of the shearing capillary.
[0019] 5) A metering structure for the equivalent pore size of a capillary tube as described in 2), wherein:
[0020] The end of the quick-connect block away from the inner sleeve has a tapered connector. An air pipe is provided between the connector and the gas flow meter. One end of the air pipe is for the connector to be inserted, and the other end is connected to the air inlet of the gas flow meter.
[0021] The conical connector designed in this invention facilitates the insertion of the quick-connect block into the end of the air tube, making operation simple and convenient. At the same time, the quick-connect block is connected to the gas flow meter through the air tube, which facilitates the flow of gas from the shearing capillary into the gas flow meter. The gas flow meter measures the gas flow rate in the shearing capillary, thereby obtaining the equivalent orifice diameter of the shearing capillary.
[0022] 6) A metering structure for the equivalent pore size of a capillary tube as described in 5), wherein:
[0023] The inner sleeve has a second internal thread groove on its inner surface facing the quick-connect block, and the quick-connect block has a second external thread groove on its outer surface facing the inner sleeve. The quick-connect block is screwed into the second internal thread groove through the second external thread groove and is threadedly connected to the inner sleeve.
[0024] This utility model adopts a threaded connection with a second internal thread groove and a second external spiral groove, which allows the quick-connect block to be screwed into the inner sleeve body, maintaining the fixed connection between the quick-connect block and the inner sleeve body and improving the stability of the connection between the two.
[0025] Compared with the prior art, this utility model also has the following technical effects:
[0026] The metering structure provided by this utility model can fix a capillary tube with holes after shearing. When used with a gas flow meter, it can measure the equivalent pore size of the sheared capillary tube. It is applicable to capillary tubes of different diameters, including but not limited to fused silica capillary tubes, polyimide-coated capillary tubes, glass capillary tubes, or metal capillary tubes. It has a wide range of applications and is easy to operate. When using this metering structure to measure the equivalent pore size of the sheared capillary tube, the capillary tube remains intact after the measurement. It can be used as a positive sample for drug leak detection research and verification. It can accurately measure each capillary tube of different lengths to ensure the accuracy of the pore size of each positive sample. This is helpful for the use of capillary tubes in the research stage of positive defects in drug leak detection and in commercial production. Attached Figure Description
[0027] Figure 1 This is a schematic diagram of a metering structure for the equivalent pore size of a capillary tube according to the present invention.
[0028] Figure 2 for Figure 1 Sectional view of AA. Detailed Implementation
[0029] The following detailed description illustrates the specific implementation method:
[0030] The reference numerals in the accompanying drawings include: tube body 1, gas flow meter 2, vacuum pump 3, inlet 4, outlet 5, outer sleeve 6, inner sleeve 7, quick-connect block 8, sealing sleeve 9, inlet channel 10, inlet 11, shearing capillary 12, gas space 13, outlet channel 14, and exhaust port 15.
[0031] See the example. Figure 1As shown, this embodiment of a capillary equivalent aperture metering structure includes a gas flow meter 2, a vacuum pump 3, and an adapter. The adapter has a gas space 13 for positioning and shearing capillary 12. One end of the adapter has an inlet channel 10 communicating with the gas space 13, and the inlet channel 10 is connected to the shearing capillary 12 in the gas space 13. The other end of the adapter has an outlet channel 14 communicating with the gas space 13. The outlet channel 14 faces the gas flow meter 2 and is connected to the inlet 4 of the gas flow meter 2. The outlet 5 of the gas flow meter 2 is connected to the vacuum pump 3.
[0032] Before use, the shear capillary 12 is inserted into the sealing sleeve 9 using a tool, and placed into the gas space 13 of the adapter through the air inlet channel 10. The shear capillary 12 is positioned and fixed by the gas space 13. During use, the vacuum pump 3 is started, and the outlet 5 of the gas flow meter 2 connected to the vacuum pump 3 forms a negative pressure. Under the negative pressure of the outlet 5 of the gas flow meter 2, the external gas is allowed to enter the shear capillary 12 through the air inlet channel 10 of the adapter. The airflow in the shear capillary 12 flows to the outlet channel 14 of the adapter. The airflow flows into the gas flow meter 2 through the outlet channel 14 of the adapter. The gas flow rate of the airflow is obtained through the gas flow meter 2, thereby obtaining the gas flow rate in the capillary and accurately obtaining the equivalent aperture of the shear capillary 12.
[0033] See Figure 2 As shown, the adapter in this embodiment includes a tube body 1, one end of which is snapped with an outer sleeve 6. The outer sleeve 6 has an air inlet channel 10 for inserting a shearing capillary tube 12. The end of the outer sleeve 6 away from the tube body 1 has an air inlet 11 communicating with the air inlet channel 10. The other end of the tube body 1 is snapped with a quick-connect block 8. The quick-connect block 8 has an air outlet channel 14 for gas flow. The position of the air outlet channel 14 corresponds to the position of the shearing capillary tube 12. The end of the quick-connect block 8 away from the tube body 1 has an exhaust port 15 communicating with the air outlet channel 14. There is an inner sleeve 7 forming a gas space 13 between the outer sleeve 6 and the quick-connect block 8.
[0034] The tube body 1 is formed by adjacent connection of an outer sleeve 6, a quick-insertion block 8, and an inner sleeve 7. The outer sleeve 6 is connected to the outside atmosphere through an air inlet 11, which allows air from the outside atmosphere to be introduced into the air intake channel 10. The air intake channel 10 also has a shear capillary tube 12 for insertion, so that after the shear capillary tube 12 is inserted, its position corresponds to the position of the air outlet channel 14, ensuring that the airflow in the shear capillary tube 12 flows towards the air outlet channel 14. The airflow in the shear capillary tube 12 can be measured by a gas flow meter 2, thereby obtaining the gas flow rate of the shear capillary tube 12. The equivalent aperture of the shear capillary tube 12 is obtained from the gas flow rate.
[0035] Meanwhile, the inner sleeve 7 is provided with a sealing sleeve 9 at the end facing the outer sleeve 6. In this embodiment, the sealing sleeve 9 can also be a plastic gasket, butyl rubber stopper, rubber stopper, etc., but is not limited to these. The sealing sleeve 9 has a limiting hole for clamping the shearing capillary 12. The limiting hole is connected to the air inlet channel 10 and the gas space 13 respectively. The end of the sealing sleeve 9 facing the gas space 13 is conical.
[0036] The shearing capillary 12 is fixed by the limiting hole of the sealing sleeve 9 and is located in the gas space 13 of the inner sleeve 7. At the same time, the end of the sealing sleeve 9 facing the gas space 13 is designed as a cone to clamp, fix and lock the shearing capillary 12, and maintain the stability of the position of the shearing capillary 12.
[0037] More specifically, the outer surface of the inner sleeve 7 has a first external thread groove, the inner surface of the outer sleeve 6 has a first internal thread groove, and the sealing sleeve 9 is embedded in the end of the inner sleeve 7 facing the outer sleeve 6. The thickness of the sealing sleeve 9 is less than the length of the shear capillary 12.
[0038] The sealing sleeve 9 connects the inner sleeve 7 and the outer sleeve 6. Through the thread rotation between the first internal thread groove of the outer sleeve 6 and the first external spiral groove of the inner sleeve 7, a tightening pressure is applied to the sealing sleeve 9 located between the outer sleeve 6 and the inner sleeve 7, forming a sealed state for the shear capillary 12. At the same time, the thickness of the sealing sleeve 9 is less than the length of the shear capillary 12, thereby clamping and fixing part of the shear capillary 12, so that other parts of the shear capillary 12 can transmit their own gas flow without being subjected to any compressive force, ensuring the accuracy of the detected gas flow data of the shear capillary 12.
[0039] Meanwhile, the end of the quick-connect block 8 furthest from the inner sleeve 7 has a tapered connector. An air tube is provided between the connector and the gas flow meter 2. One end of the air tube is for inserting the connector, and the other end is connected to the air inlet 4 of the gas flow meter 2. The tapered connector is designed to facilitate the insertion of the quick-connect block 8 into the end of the air tube, making operation simple and convenient. At the same time, by connecting the quick-connect block 8 to the gas flow meter 2 through the air tube, it is convenient to allow the gas flow of the shear capillary 12 to flow through the air tube into the gas flow meter 2. The gas flow meter 2 measures the gas flow rate in the shear capillary 12, thereby obtaining the equivalent orifice diameter of the shear capillary 12.
[0040] More specifically, the inner sleeve 7 has a second internal threaded groove on its inner surface facing the quick-connect block 8, and the quick-connect block 8 has a second external threaded groove on its outer surface facing the inner sleeve 7. The quick-connect block 8 is screwed into the second internal threaded groove through the second external threaded groove and is threadedly connected to the inner sleeve 7. The threaded connection of the second internal threaded groove and the second external threaded groove allows the quick-connect block 8 to be screwed into the inner sleeve 7, maintaining a fixed connection between the quick-connect block 8 and the inner sleeve 7 and improving the stability of the connection between the two.
[0041] The provided metering structure can fix a capillary tube with holes after shearing. Combined with a gas flow meter 2, it can measure the equivalent pore size of the sheared capillary tube 12. It is suitable for capillary tubes of different diameters, including but not limited to fused silica capillary tubes, polyimide-coated capillary tubes, glass capillary tubes, or metal capillary tubes, but not limited to these. It can also be applied to various types of droppers such as glass microdroppers. It has a wide range of applications and is easy to operate. When using this metering structure to measure the equivalent pore size of the sheared capillary tube, the capillary tube remains intact after the measurement. It can be used as a positive sample for drug leak detection research and verification. It can accurately measure each capillary tube of different lengths, ensuring the accurate pore size of each positive sample. This is helpful for the use of capillary tubes in the research stage of positive defects in drug leak detection and in commercial production.
[0042] The above are merely embodiments of this utility model. Commonly known technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. These modifications and improvements should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.
Claims
1. A metering structure for the equivalent pore size of a capillary tube, characterized in that, The device includes a gas flow meter, a vacuum pump, and an adapter. The adapter has a gas space for positioning a shearing capillary. One end of the adapter has an inlet channel communicating with the gas space and the inlet channel is connected to the shearing capillary within the gas space. The other end of the adapter has an outlet channel communicating with the gas space. The outlet channel faces the gas flow meter and is connected to the inlet of the gas flow meter. The outlet of the gas flow meter is connected to the vacuum pump.
2. The metering structure for the equivalent pore size of a capillary tube according to claim 1, characterized in that: The adapter includes a tube body, one end of which is snapped with an outer sleeve. The outer sleeve has an air inlet channel for inserting a shearing capillary tube. An air inlet communicating with the air inlet channel is opened at the end of the outer sleeve away from the tube body. The other end of the tube body is snapped with a quick-connect block. The quick-connect block has an air outlet channel for gas flow. The position of the air outlet channel corresponds to the position of the shearing capillary tube. An exhaust port communicating with the air outlet channel is opened at the end of the quick-connect block away from the tube body. An inner sleeve forming a gas space is provided between the outer sleeve and the quick-connect block.
3. The metering structure for capillary equivalent pore size according to claim 2, characterized in that: The inner sleeve is provided with a sealing sleeve at the end facing the outer sleeve. The sealing sleeve has a limiting hole for clamping the shearing capillary. The limiting hole is connected to the air inlet channel and the gas space respectively. The end of the sealing sleeve facing the gas space is conical.
4. The metering structure for capillary equivalent pore size according to claim 3, characterized in that: The outer surface of the inner sleeve has a first external thread groove, the inner surface of the outer sleeve has a first internal thread groove, the sealing sleeve is embedded in the end of the inner sleeve facing the outer sleeve, and the thickness of the sealing sleeve is less than the length of the shear capillary.
5. The metering structure for the equivalent pore size of a capillary tube according to claim 2, characterized in that: The end of the quick-connect block away from the inner sleeve has a tapered connector. An air pipe is provided between the connector and the gas flow meter. One end of the air pipe is for the connector to be inserted, and the other end is connected to the air inlet of the gas flow meter.
6. The metering structure for the equivalent pore size of a capillary tube according to claim 5, characterized in that: The inner sleeve has a second internal thread groove on its inner surface facing the quick-connect block, and the quick-connect block has a second external thread groove on its outer surface facing the inner sleeve. The quick-connect block is screwed into the second internal thread groove through the second external thread groove and is threadedly connected to the inner sleeve.