Fixing support for polyethylene chemical resistance test

Abstract

The utility model belongs to the technical field of testing tools, and particularly relates to a fixing support for a polyethylene chemical resistance test. The fixing support for the polyethylene chemical resistance test comprises two fixing plates which are oppositely arranged, and a plurality of pairs of test piece holes are formed in the two fixing plates; the two ends of each connecting rod are fixedly installed on the two fixing plates respectively. Based on the device disclosed by the utility model, two end parts of a polyethylene test piece are respectively put into the paired test piece holes of the two fixing plates, and then the fixing bracket is put into a soaking container, so that a soaking solution can be slowly injected to carry out detection work. In the soaking process, the polyethylene test piece is limited in the test piece hole and cannot float upwards, and the accumulation of the test piece can be avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of testing tools, and in particular relates to a fixing bracket for testing the chemical resistance of polyethylene. Background Art

[0002] At present, the external anti-corrosion layer of oil and gas pipelines at home and abroad generally adopts the anti-corrosion form of three-layer polyethylene (3PE), which is composed of a fused epoxy powder (FBE) bottom layer, a polyethylene binder middle layer and a polyethylene (PE) outer layer. As the first line of defense for pipeline protection, the polyethylene outer layer must not only have certain mechanical strength and durability, but also have good chemical corrosion resistance. Current polyethylene product standards such as GB / T23257-2017 "Polyethylene Anti-corrosion Layer for Buried Steel Pipelines" stipulate the requirements for polyethylene chemical medium corrosion resistance testing, which is of great significance for evaluating the chemical stability and durability of polyethylene in service environments.

[0003] However, the polyethylene chemical medium immersion test standard, such as Appendix I of GB / T 23257-2017, stipulates that the immersion specimens should not be exposed to the liquid surface during immersion, and the specimens and the container wall should not contact each other. At present, the immersion containers such as wide-mouth bottles with lids and glass beakers commonly used by various laboratories are difficult to meet the technical requirements of the immersion standard: first, the density of polyethylene specimens is less than the immersion medium specified in the standard, and they will float on the liquid surface, resulting in the specimens being unable to be completely immersed in the chemical medium; second, the number of polyethylene immersion specimens specified for each chemical medium is not less than 5. When multiple specimens in the same group are immersed, the specimens are usually piled together, and there is a phenomenon of contact between the specimens and between the specimens and the container wall. These will affect the effect of the specimen chemical resistance immersion and the accuracy of the test results. How to make polyethylene specimens fully meet the immersion requirements specified in the standard has become a difficulty in the current polyethylene chemical medium resistance immersion test.

[0004] In view of the above factors, it is necessary to develop a fixing bracket for polyethylene chemical resistance testing. Utility Model Content

[0005] In order to overcome the shortcomings of the existing polyethylene immersion device, the utility model provides a polyethylene chemical resistance test fixing bracket, which is suitable for polyethylene chemical resistance test. The fixing bracket is convenient and efficient to operate, stable and durable, with low maintenance rate, and can achieve no contact between the test pieces and between the test pieces and the container wall, and can completely immerse the test pieces in the chemical medium.

[0006] The technical solution provided by the utility model is as follows:

[0007] A fixing bracket for polyethylene chemical resistance testing, comprising:

[0008] Two fixed plates are arranged opposite to each other, and a plurality of pairs of test piece holes are arranged on the two fixed plates;

[0009] And a plurality of connecting rods, two ends of each connecting rod are respectively fixedly installed with the two fixing plates.

[0010] Based on the above technical solution, the two ends of the polyethylene specimen are respectively placed into the paired specimen holes of the two fixing plates, and then the fixing bracket is placed in the immersion container, and the immersion solution can be slowly injected to carry out the detection work.

[0011] Specifically, each of the test piece holes is in the shape of an elongated strip.

[0012] Based on the above technical solution, the shape of the specimen hole matches the shape and structure of the end of the polyethylene specimen. The size of the end of the polyethylene specimen can be matched by adjusting the size of the specimen hole. The number of specimen holes meets the number of specimen immersion requirements for chemical resistance testing.

[0013] Specifically, each of the test piece holes is arranged horizontally, vertically or obliquely.

[0014] Based on the above technical solution, the polyethylene specimens can be placed in multiple ways as needed. At the same time, different observation angles can also be provided.

[0015] Specifically, a plurality of rows of evenly distributed test piece holes are arranged on the fixing plate.

[0016] Based on the above technical solution, multiple polyethylene test pieces can be tested simultaneously.

[0017] Specific:

[0018] Two adjacent rows of test specimen holes are arranged side by side or staggered;

[0019] The test specimen holes in each row are arranged at equal intervals.

[0020] Based on the above technical solution, a neat arrangement of polyethylene specimens can be provided, wherein the staggered arrangement can further increase the density of polyethylene specimens, thereby reducing the height requirement of the fixing plate.

[0021] Preferred:

[0022] Each of the fixing plates is rectangular;

[0023] The number of the connecting rods is at least three, and they are respectively located at the left and right ends and the upper end of the fixing plate.

[0024] Based on the above technical solution, the fixing plate has a compact structure and a reduced height, which can reduce the requirement on the height of the cover of the soaking container.

[0025] Preferred:

[0026] Each of the fixing plates comprises a lower rectangular portion and an upper trapezoidal portion;

[0027] The number of the connecting rods is at least three, and they are respectively located at the left and right ends of the rectangular portion and the upper end of the trapezoidal portion.

[0028] Based on the above technical solution, the uppermost connecting rod is away from the surface of the immersion liquid, and the removal and placement of the fixed bracket is safer.

[0029] In the above technical solution, the connecting rod not only plays a connecting role but also facilitates taking.

[0030] Specific:

[0031] Each of the connecting rods comprises an internal threaded rod and screw rods at both ends;

[0032] The fixing plate is provided with a mounting through hole corresponding to the screw rod, and the screw rod passes through the mounting through hole and is threadedly connected with the internal thread rod.

[0033] Specific:

[0034] The two fixing plates are arranged in parallel;

[0035] The connecting rods are arranged in parallel.

[0036] Specific: two pairs of test piece holes are set at the same height.

[0037] The components of the fixed bracket can be made of PVC, nylon, etc. with a density greater than 1.0g / cm 3 The material is inert to chemical media such as acids and alkalis.

[0038] The utility model is suitable for chemical medium immersion test of polyethylene, has the advantages of easy use, convenient placement, safety and stability, and greatly improves the effect of chemical medium immersion resistance and the accuracy of test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The utility model provides a fixing bracket for testing chemical resistance of polyethylene.

[0040] Figure 2 The utility model provides another fixing bracket for testing chemical resistance of polyethylene.

[0041] Figure 3 The utility model provides another fixing bracket for testing chemical resistance of polyethylene.

[0042] Figure 4 It is a schematic diagram of the structure of the polyethylene specimen.

[0043] Attached Figure 1 , 2, 3, and 4, the structures represented by each number are listed as follows:

[0044] 1. Fixing plate; 2. Connecting rod; 3. Specimen hole; 4. Polyethylene specimen. DETAILED DESCRIPTION

[0045] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0046] It should be noted that when a part or component is considered to be "connected", "located", or "assembled" on another part or component, it may be directly disposed on the other part or component or there may be a central part or component at the same time. The terms "left", "right", "upper", "lower" and similar expressions used herein are for illustrative purposes only.

[0047] Example 1

[0048] like Figure 1 , 2 As shown in , 3, the fixed bracket for polyethylene chemical resistance test comprises: two fixed plates 1 arranged opposite to each other, and a plurality of pairs of test piece holes 3 are arranged on the two fixed plates 1; and a plurality of connecting rods 2, and the two ends of each connecting rod 2 are fixedly installed on the two fixed plates 1. Based on this technical solution, Figure 4 The two ends of the polyethylene test piece 4 shown are respectively placed in the paired test piece holes of the two fixing plates. During immersion, the fixing bracket can prevent the polyethylene test piece from floating.

[0049] Example 2

[0050] On the basis of Example 1, Figure 1 As shown, the fixing bracket for polyethylene chemical resistance test comprises two fixing plates 1 arranged in parallel and opposite to each other, and three connecting rods 2 arranged in parallel.

[0051] Each fixing plate 1 comprises a lower rectangular portion and an upper trapezoidal portion. Three connecting rods 2 are respectively located at the left and right ends of the rectangular portion and the upper end of the trapezoidal portion. The connecting rod located at the upper end is convenient for taking and placing.

[0052] The test holes 3 are arranged in multiple rows, and are evenly distributed in each row, and the number can be 4 to 6. Each test hole 3 is long and arranged vertically. The test holes 3 in two adjacent rows are staggered, and the test holes 3 in each row are arranged at equal intervals.

[0053] Optionally, each specimen hole may be arranged horizontally or inclined.

[0054] Optionally, two adjacent rows of test piece holes 3 are arranged in parallel.

[0055] Example 3

[0056] On the basis of Example 1, Figure 2 As shown, the fixing bracket for polyethylene chemical resistance test comprises two fixing plates 1 arranged in parallel and opposite to each other, and three connecting rods 2 arranged in parallel.

[0057] Each fixing plate 1 is rectangular. Three connecting rods 2 are respectively located at the left and right ends and the upper end of the fixing plate 1. This layout can reduce the height of the entire device.

[0058] The test holes 3 are arranged in multiple rows, and are evenly distributed in each row, and the number can be 4 to 6. Each test hole 3 is long and arranged horizontally. The test holes 3 in two adjacent rows are staggered, and the test holes 3 in each row are arranged at equal intervals.

[0059] Optionally, each specimen hole may be arranged vertically or inclined.

[0060] Optionally, two adjacent rows of test piece holes 3 are arranged in parallel.

[0061] Example 4

[0062] On the basis of Example 1, Figure 3 As shown, the fixing bracket for polyethylene chemical resistance test comprises two fixing plates 1 arranged in parallel and opposite to each other, and three connecting rods 2 arranged in parallel.

[0063] Each fixing plate 1 is rectangular. Three connecting rods 2 are respectively located at the left and right ends and the upper end of the fixing plate 1. This layout can reduce the height of the entire device.

[0064] The test holes 3 are arranged in multiple rows, and are evenly distributed in each row, and the number can be 4 to 6. Each test hole 3 is long and obliquely arranged. The test holes 3 in two adjacent rows are staggered, and the test holes 3 in each row are arranged at equal intervals.

[0065] Optionally, each specimen hole may be arranged vertically or horizontally.

[0066] Optionally, two adjacent rows of test piece holes 3 are arranged in parallel.

[0067] Example 5

[0068] Based on the above embodiments, Figure 1 As shown, each connecting rod 2 includes an internal threaded rod and screw rods at both ends. The fixing plate 1 is provided with a mounting through hole corresponding to the screw rod, and the screw rod passes through the mounting through hole and is threadedly connected with the internal threaded rod. Optionally, the connecting rod may also adopt other existing technologies, such as providing pin holes at both ends, providing a through hole on the fixing plate 1, and fastening the fixing plate 1 to the connecting rod by a pin.

[0069] Steps:

[0070] According to Appendix I of GB / T 23257-2017 "Test Method for Chemical Corrosion Resistance of Polyethylene", the polyethylene specimens were immersed in 10% hydrochloric acid solution, 10% sodium hydroxide solution and 10% sodium chloride solution. The number of parallel specimens in each group was 5. The immersion device was made of PVC with a density greater than 1.0g / cm 3 . During the test, the inspector places the end of the polyethylene specimen from the outside of the fixed bracket for polyethylene chemical resistance test into the specimen hole of the fixed plate, and pushes it in parallel until the two ends of the specimen are respectively embedded in the specimen holes of the two fixed plates. After all the polyethylene specimens are placed, pick up the connecting rod, slowly place the fixed bracket for polyethylene chemical resistance test in the immersion device, and slowly inject a sufficient amount of chemical medium preheated to the experimental temperature into the test container so that the specimen is completely immersed in the medium, and record the start time of the test. Among them, the container cover of the test container can be covered according to environmental needs. When the test cycle is over, pick up the connecting rod, slowly remove the fixed bracket for polyethylene chemical resistance test from the immersion medium, and then remove the specimens from the specimen holes of the fixed bracket one by one, rinse and dry, and finally evaluate the chemical resistance according to the test standard requirements. During the immersion process, the polyethylene specimen is restricted in the specimen hole and will not float up. In addition, the fixed bracket can be taken in and out by the connecting rod.

[0071] On the one hand, this test process can ensure that the polyethylene specimen is completely immersed in the medium; on the other hand, when multiple specimens in the same group are immersed, it can avoid the specimens from piling up, ensuring that there is no contact between the specimens and between the specimens and the container wall, thus meeting the requirements of the test standards.

[0072] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A fixing bracket for polyethylene chemical resistance testing, characterized in that: include: Two fixing plates (1) arranged opposite to each other, with a plurality of pairs of test piece holes (3) being arranged on the two fixing plates (1); and a plurality of connecting rods (2), wherein two ends of each connecting rod (2) are respectively fixedly mounted on the two fixing plates (1).

2. The fixing bracket for polyethylene chemical resistance testing according to claim 1, characterized in that: Each of the test piece holes (3) is in the shape of an elongated strip.

3. The fixing bracket for polyethylene chemical resistance testing according to claim 1, characterized in that: Each of the test piece holes (3) is arranged horizontally, vertically or obliquely.

4. The fixing bracket for polyethylene chemical resistance testing according to claim 1, characterized in that: A plurality of rows of evenly distributed test piece holes (3) are arranged on the fixing plate (1).

5. The fixing bracket for polyethylene chemical resistance testing according to claim 4, characterized in that: Two adjacent rows of test piece holes (3) are arranged in parallel or staggered; Each row of test piece holes (3) is arranged at equal intervals.

6. The fixing bracket for polyethylene chemical resistance testing according to claim 1, characterized in that: Each of the fixing plates (1) is rectangular; The number of the connecting rods (2) is at least three, and they are respectively located at the left and right ends and the upper end of the fixing plate (1).

7. The fixing bracket for polyethylene chemical resistance testing according to claim 1, characterized in that: Each of the fixing plates (1) comprises a lower rectangular portion and an upper trapezoidal portion; The number of the connecting rods (2) is at least three, and they are respectively located at the left and right ends of the rectangular portion and the upper end of the trapezoidal portion.

8. The fixing bracket for polyethylene chemical resistance testing according to claim 1, characterized in that: Each of the connecting rods (2) comprises an internal threaded rod and screw rods at both ends; The fixing plate (1) is provided with a mounting through hole corresponding to the screw rod, and the screw rod passes through the mounting through hole and is threadedly connected with the internal thread rod.

9. The fixing bracket for testing polyethylene chemical resistance according to any one of claims 1 to 8, characterized in that: The two fixing plates (1) are arranged in parallel; The connecting rods (2) are arranged in parallel.

10. The fixing bracket for polyethylene chemical resistance testing according to any one of claims 1 to 8, characterized in that: The two paired test piece holes (3) are arranged at the same height.

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