Burette with polytetrafluoroethylene tube head

Abstract

The burette with the polytetrafluoroethylene tube head comprises a tube body and the tube head, the tube body is a slender glass tube, and the tube head comprises an upper tube of the tube head, a cock part and a lower tube of the tube head. And the tube head upper tube is in threaded connection with the tube body. The cock part comprises a cock sleeve, a cock and a fastening nut, the inner wall of the cock sleeve is matched with the outer wall of the cock, and the cock is provided with a cock hole used for operating the solution to flow out. And the tail end of the lower tube of the tube head is narrowed to form a sharp mouth. The tube body is made of glass. The pipe head is made of polytetrafluoroethylene. The lubricity of the polytetrafluoroethylene material is good, so that the cock disclosed by the utility model has good rotation flexibility, and the problem that the burette is broken when the cock is rotated with force can be avoided. Polytetrafluoroethylene has elasticity, the cock sleeve and the cock are tightly combined, and the water tightness of the burette is high. Due to the two-section burette structure of the tube head and the tube head, after the tube body is damaged, a new tube body is replaced, the burette can be reused, and the cost for purchasing glass instruments can be saved.

Description

Technical Field

[0001] This utility model belongs to the field of laboratory instrument technology, specifically relating to a polytetrafluoroethylene (PTFE) burette. Background Technology

[0002] A burette is a measuring instrument used during titration to accurately measure the volume of the solution flowing out. Burettes are generally divided into two types: one is a stoppered burette, often called an acid burette; the other is a non-stoppered burette, often called an alkaline burette.

[0003] Acid burettes are used to hold acidic and oxidizing solutions, but are not suitable for alkaline solutions because alkaline solutions can corrode glass, and over time, the stopcock will become unable to turn. Before using an acid burette, petroleum jelly should be applied between the stopcock and the stopcock sleeve to ensure the stopcock is watertight and to allow it to turn freely.

[0004] One end of an alkaline burette is connected to a rubber or latex tube containing glass beads to control the flow of solution. A pointed glass tube is then connected to the bottom of the rubber or latex tube. Alkaline burettes are used to hold alkaline and non-oxidizing solutions; any solution that reacts with rubber should not be placed in an alkaline burette.

[0005] Currently, a new type of burette is finding some applications in laboratories. Its shape and structure are similar to an acid burette, except that the stopcock is made of polytetrafluoroethylene (PTFE). Because PTFE is resistant to acids, alkalis, and oxidation, this burette can be used as both an acid and an alkaline burette. In other words, the PTFE stopcock burette can be used for titrating acidic and oxidizing solutions, as well as alkaline solutions. Since the PTFE stopcock is elastic, the tightness between the stopcock and the stopcock sleeve can be adjusted by adjusting the tightening nut at the end of the stopcock; therefore, this new type of burette does not require the application of petroleum jelly.

[0006] As can be seen from the above, PTFE stopcock burettes have many advantages over traditional acid and alkali burettes, thus finding some application in laboratories. However, due to the poor lubricity of glass, the stopcock of this new type of burette is not very flexible in rotation, especially in newly used burettes. Because the PTFE stopcock and the glass stopcock sleeve have not undergone a break-in process, turning the stopcock is often difficult. Applying Vaseline between the PTFE stopcock and the glass stopcock sleeve does not improve the flexibility of rotation. When forcefully turning the stopcock, the burette may break due to excessive force, rendering it unusable. Sometimes, a broken burette can even injure the operator's hand, posing a laboratory safety hazard. Some researchers try to reduce friction between the stopcock and the stopcock sleeve by loosening the fastening nut, making the stopcock easier to turn, but this can cause leakage.

[0007] For titration analysis, controlling the titration endpoint is crucial, requiring the titrant to be added drop by drop to obtain an accurate endpoint. Because the stopcock of a PTFE stopcock burette is not flexible, it is difficult to add the titrant drop by drop near the titration endpoint, often resulting in over-titration and necessitating a repeat titration operation. Summary of the Invention

[0008] The technical problem to be solved by this utility model is to provide a PTFE-tipped burette, in which both the stopcock and the stopcock sleeve are made of PTFE material, which can increase the lubrication between the stopcock and the stopcock sleeve, making the stopcock rotate flexibly and facilitating the titration operation. It can avoid the problem of the burette breaking due to excessive force and the problem of difficulty in controlling the titration endpoint.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0010] A polytetrafluoroethylene (PTFE) burette includes a tube body and a burette head. The tube body is a slender glass tube, and the burette head includes an upper tube, a stopcock, and a lower tube. The burette head is connected to the tube body via the upper tube.

[0011] Furthermore, the lower part of the tube body is provided with internal threads.

[0012] Furthermore, the tube head is provided with an external thread.

[0013] Furthermore, the tube on the tube head and the tube body are connected by threads, and the internal thread of the tube head and the external thread of the tube head are compatible.

[0014] Furthermore, the stopcock includes a stopcock sleeve, a stopcock, and a fastening nut. The inner wall of the stopcock sleeve and the outer wall of the stopcock are adapted to each other, and the stopcock has a stopcock hole for operating the outflow of the solution.

[0015] Furthermore, the lower end of the tube tapers to form a cylinder.

[0016] Furthermore, the tube body is made of glass.

[0017] Furthermore, the tube head is made of polytetrafluoroethylene.

[0018] The burette proposed in this invention consists of a body and a head. The body is made of glass, and the head is made of polytetrafluoroethylene (PTFE). The transparency of glass allows for clear observation of the meniscus of the solution, facilitating the reading of the titration volume. PTFE's elasticity and lubricity allow for a tight contact between the stopcock and its sleeve, providing excellent watertightness. It also ensures flexible stopcock rotation, preventing breakage when forcefully turning the stopcock and making the titration endpoint easier to determine, thus improving the accuracy of the titration operation.

[0019] Polytetrafluoroethylene (PTFE) material has excellent machinability, and with the widespread use of CNC lathes in the machining industry, it is possible to manufacture PTFE parts with high precision at decreasing costs. High-precision cocks and cock sleeves enhance their adaptability, improve the watertightness of the pipe head, and increase the flexibility of cock rotation.

[0020] The burette proposed in this invention adopts a two-section structure in which the tube body and the tube head can be separated, and the tube body and the tube head are connected by threads. Due to the elasticity of polytetrafluoroethylene (PTFE), the external threads of PTFE and the internal threads of glass can be tightly combined, making the connection between the tube body and the tube head firm and providing good water tightness between them.

[0021] When using a conventional glass burette for titration, the top of the burette or the burette tip can be damaged due to improper handling, rendering the entire burette unusable. The burette proposed in this invention features a two-section structure. When the top of the burette is damaged, a new burette body is provided, allowing the original burette to be used again, saving experimental costs and reducing laboratory waste. Because the burette tip is made of polytetrafluoroethylene (PTFE), which has excellent toughness, the tip is less prone to damage from impacts. Therefore, the two-section burette structure extends the burette's lifespan.

[0022] The advantages of this utility model compared with the prior art are:

[0023] (1) The good lubricity of polytetrafluoroethylene material gives the stopcock good rotation flexibility, which can avoid the problem of the burette breaking due to forceful rotation of the stopcock.

[0024] (2) Polytetrafluoroethylene is elastic, and both the stopcock sleeve and the stopcock are made of polytetrafluoroethylene. The two are tightly bonded, and the burette has strong water tightness.

[0025] (3) The two-section burette structure allows for replacement of the burette body after it is damaged, avoiding the scrapping of the entire burette, saving the cost of purchasing glassware, and reducing the generation of laboratory waste. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the polytetrafluoroethylene burette of this utility model.

[0027] In the figure: pipe body (1), pipe head tube (2), pipe head lower tube (3), pipe head tube external thread (4), plug sleeve (5), plug (6), fastening nut (7), plug hole (8). Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and by way of embodiments.

[0029] Although the present invention has been disclosed with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims. Example 1

[0030] A polytetrafluoroethylene (PTFE) burette includes a tube body 1 and a burette head. The tube body 1 is a slender glass tube, and the burette head includes an upper tube 2, a stopcock, and a lower tube 3. The burette head is connected to the tube body 1 via the upper tube 2.

[0031] Furthermore, the lower part of the tube body 1 is provided with internal threads.

[0032] Furthermore, the tube head 2 is provided with an external thread 4.

[0033] Furthermore, the tube 2 on the tube head and the tube body 1 are connected by threads, and the internal thread of the tube body and the external thread 4 on the tube head are compatible.

[0034] Furthermore, the stopcock includes a stopcock sleeve 5, a stopcock 6, and a fastening nut 7. The inner wall of the stopcock sleeve 5 and the outer wall of the stopcock 6 are adapted to each other. The stopcock has a stopcock hole 8 for operating the outflow of the solution.

[0035] Furthermore, the lower end of the tube 3 narrows to form a pointed tip.

[0036] Furthermore, the tube body 1 is made of glass.

[0037] Furthermore, the tube head is made of polytetrafluoroethylene.

[0038] The method of using the PTFE tube-head burette proposed in this invention is the same as that of a general PTFE stopcock burette. The PTFE tube-head burette has better stopcock rotation flexibility and watertightness than a general PTFE stopcock burette.

Claims

1. A burette with a polytetrafluoroethylene (PTFE) tube head, characterized in that, It includes a tube body (1) and a tube head. The tube body (1) is a slender glass tube. The tube head includes a tube head tube (2), a stopcock, and a tube head lower tube (3). The tube head is connected to the tube body (1) through the tube head tube (2).

2. The polytetrafluoroethylene burette head according to claim 1, characterized in that, The lower part of the tube body (1) is provided with internal threads.

3. A PTFE burette according to claim 1, characterized in that, The pipe head (2) is provided with an external thread (4).

4. A polytetrafluoroethylene burette with a tube head according to claim 1, 2, or 3, characterized in that, The tube on the pipe head (2) and the tube body (1) are connected by threads, and the internal thread of the tube body and the external thread (4) of the tube on the pipe head are compatible.

5. A PTFE burette according to claim 1, characterized in that, The stopcock includes a stopcock sleeve (5), a stopcock (6) and a fastening nut (7). The inner wall of the stopcock sleeve (5) and the outer wall of the stopcock (6) are adapted to each other. The stopcock has a stopcock hole (8) for operating the flow of solution.

6. A polytetrafluoroethylene burette with a tube head according to claim 1, characterized in that, The lower tube (3) of the tube head narrows at the end to form a pointed tip.

7. A polytetrafluoroethylene burette with a tube head according to claim 1 or 2, characterized in that, The tube (1) is made of glass.

8. A polytetrafluoroethylene burette with a tube head according to claim 1, 3, 5, or 6, characterized in that, The tube head is made of polytetrafluoroethylene.

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