阅读说明：本技术 硅脂影响冷缩电缆附件回缩仿真测试方法 (Silicone grease influence cold-contraction cable accessory retraction simulation test method ) 是由 孙晓维 葛旺泉 于 2021-08-24 设计创作，主要内容包括：本发明属于硅脂测试技术领域,具体涉及一种硅脂影响冷缩电缆附件回缩仿真测试方法。采用热老化实验方法对硅脂溶胀率进行测试,比较回缩率＝(硅脂区回缩后直径-无硅脂区回缩后直径)/无硅脂区回缩后直径*100％。本发明所述的硅脂影响冷缩电缆附件回缩仿真测试方法,选用最常用的硅橡胶冷缩制品冷缩管作为测试样品,不需要制作硅橡胶试片,试品选材简单普通,而且克服了硅橡胶试片制作时由于温度、硫化、环境等影响,导致硅橡胶试片与冷缩电缆附件制品本身存在差异的问题,提高了测试结果的准确性、真实性和适用性。(The invention belongs to the technical field of silicone grease testing, and particularly relates to a silicone grease influence shrinkage simulation testing method for a cold-shrinkage cable accessory. A thermal aging experiment method is adopted to test the silicone grease swelling rate, and the shrinkage rate is compared to be equal to (the diameter after silicone grease area shrinkage-the diameter after silicone grease-free area shrinkage)/the diameter after silicone grease-free area shrinkage *100%. According to the silicone grease influence shrinkage simulation testing method for the cold-shrinkage cable accessory, the most common silicone rubber cold-shrinkage product cold-shrinkage pipe is selected as a test sample, a silicone rubber test piece does not need to be manufactured, the test piece is simple and common in material selection, the problem that the silicone rubber test piece and the cold-shrinkage cable accessory product have difference due to the influence of temperature, vulcanization, environment and the like during manufacturing of the silicone rubber test piece is solved, and the accuracy, authenticity and applicability of the test result are improved.)

1. A silicone grease influence cold contraction cable accessory retraction simulation test method is characterized by comprising the following steps: the method comprises the following steps:

(1) sleeving a layer of plastic membrane on the surface of a No. 1 support tube for the cold-shrink tube, and then smoothing the surface of the plastic membrane without folds;

(2) coating the silicone grease sample on the surface of the non-woven fabric, and uniformly kneading to fully dissolve the silicone grease in the non-woven fabric;

(3) wrapping the non-woven fabric dissolved with silicone grease at 1/3-1/2 in the length direction of the No. 1 supporting tube, and fixing with a thin fiber rope;

(4) sleeving a No. 2 cold shrinkage pipe outside the whole body of the No. 1 supporting pipe, wherein the No. 2 cold shrinkage pipe comprises a non-woven fabric wrapping part dissolved with silicone grease, and extracting the No. 2 cold shrinkage pipe from the No. 2 supporting pipe to prepare a silicone grease test sample for testing;

(5) 3-6 parts of each silicone grease sample for testing are respectively prepared according to the steps (1) to (4) and are numbered and distinguished;

(6) placing the prepared silicone grease test samples for testing in an oven, keeping the temperature at 90 ℃, standing, and taking out each silicone grease test sample for testing in three test time periods;

(7) extracting the No. 1 supporting tube of the silicone grease sample for testing, and taking out the plastic diaphragm and the non-woven fabric to obtain a retracted No. 2 cold-shrinkable tube silicone rubber sleeve;

(8) and (3) carrying out data measurement on the retracted 2# cold-shrink tube silicone rubber sleeve by using a digital display vernier caliper, and calculating and comparing the retraction rate, wherein the calculation formula is as follows: the percent retraction is (diameter after retraction of silicone grease zone-diameter after retraction of silicone grease-free zone)/diameter after retraction of silicone grease-free zone 100%.

2. The silicone grease affected cold shrink cable accessory retraction simulation test method as recited in claim 1 wherein: the 1# support tube for the cold-shrink tube in the step (1) and the 2# support tube in the step (4) are made of the same material, and the length of the support tube is 200-400 mm.

3. The silicone grease affected cold shrink cable accessory retraction simulation test method as recited in claim 1 wherein: the plastic diaphragm in the step (1) is a polyethylene plastic bag, the length is 200-400mm, and the diameter is consistent with that of the No. 1 support tube.

4. The silicone grease affected cold shrink cable accessory retraction simulation test method as recited in claim 1 wherein: the non-woven fabric in the step (2) is a fused silicone grease base bed, belongs to medical non-woven fabrics, and has the length and width of 50-80 x 150-200 mm.

5. The silicone grease affected cold shrink cable accessory retraction simulation test method as recited in claim 1 wherein: the silicone grease in the step (2) is common silicone grease or fluorinated silicone grease.

6. The silicone grease affected cold shrink cable accessory retraction simulation test method as recited in claim 1 wherein: and (4) taking out each silicone grease sample for test in the step (6) in three test time periods, wherein the three test time periods are 168 hours, 336 hours and 504 hours respectively.

7. The silicone grease affected cold shrink cable accessory retraction simulation test method as recited in claim 1 wherein: and (4) the No. 2 cold-shrink tube silicone rubber sleeve in the step (8) consists of a silicone grease zone No. 2 cold-shrink tube silicone rubber sleeve and a silicone grease-free zone No. 2 cold-shrink tube silicone rubber sleeve.

Technical Field

The invention belongs to the technical field of silicone grease testing, and particularly relates to a silicone grease influence cold-shrink cable accessory retraction simulation testing method.

Background

The silicone grease is a substance which is coated on a main insulation composite insulation interface of the cold-shrinkable cable accessory and the cable in the installation process and plays roles of lubricating, sealing, improving the breakdown strength of the composite interface and the like. Therefore, silicone grease is a necessary accessory material for the installation of cold-shrink cable accessories.

The swelling ratio of the silicone grease is one of the important parameters of the performance of the silicone grease, and in principle, the lower the swelling ratio of the silicone grease, the better the silicone grease can absorb on the premise of meeting the requirements of products and cost. The silicone grease in the current market is of various types, and certain difficulty is caused for the selection of the silicone grease for daily cold-shrink cable accessories. Therefore, a simple, convenient and practical test method is needed to select the silicone grease with low absorption swelling rate and small influence on the shrinkage rate of the cold-shrink cable accessory. At present, the silicone grease is tested after a cold-shrink accessory silicone rubber is made into a test piece and the silicone grease is soaked in the test piece, but the test method has the defects that the manufacture of the silicone rubber test piece is influenced by temperature, vulcanization, environment and the like, has a certain difference with a silicone rubber cold-shrink accessory product, and the content of the soaked silicone grease in the test piece is different from the coating amount in the actual construction process, so that the reference significance of the swelling parameters of the silicone grease and the silicone rubber in the test piece obtained through testing on the application of the silicone grease of the cold-shrink cable accessory in the actual installation process is not high.

Disclosure of Invention

The purpose of the invention is: a silicone grease influence cold contraction cable accessory retraction simulation test method is provided. The testing method can simply, easily and visually test various silicone greases at the same time, and more truly reflect the swelling parameters between the silicone greases and the cold-shrinkage cable accessories.

The invention relates to a silicone grease influence cold-shrink cable accessory retraction simulation test method, which comprises the following steps:

(1) sleeving a layer of plastic membrane on the surface of a No. 1 support tube for the cold-shrink tube, and then smoothing the surface of the plastic membrane without folds;

(2) coating the silicone grease sample on the surface of the non-woven fabric, and uniformly kneading to fully dissolve the silicone grease in the non-woven fabric;

(3) wrapping the non-woven fabric dissolved with silicone grease at 1/3-1/2 in the length direction of the No. 1 supporting tube, and fixing with a thin fiber rope;

(4) sleeving a No. 2 cold shrinkage pipe outside the whole body of the No. 1 supporting pipe, wherein the No. 2 cold shrinkage pipe comprises a non-woven fabric wrapping part dissolved with silicone grease, and extracting the No. 2 cold shrinkage pipe from the No. 2 supporting pipe to prepare a silicone grease test sample for testing;

(5) 3-6 parts of each silicone grease sample for testing are respectively prepared according to the steps (1) to (4) and are numbered and distinguished;

(6) placing the prepared silicone grease test samples for testing in an oven, keeping the temperature at 90 ℃, standing, and taking out each silicone grease test sample for testing in three test time periods;

(7) extracting the No. 1 supporting tube of the silicone grease sample for testing, and taking out the plastic diaphragm and the non-woven fabric to obtain a retracted No. 2 cold-shrinkable tube silicone rubber sleeve;

(8) and (3) carrying out data measurement on the retracted 2# cold-shrink tube silicone rubber sleeve by using a digital display vernier caliper, and calculating and comparing the retraction rate, wherein the calculation formula is as follows: the percent retraction is (diameter after retraction of silicone grease zone-diameter after retraction of silicone grease-free zone)/diameter after retraction of silicone grease-free zone 100%.

Wherein:

the 1# support tube for the cold-shrink tube in the step (1) and the 2# support tube in the step (4) are made of the same material, and the length of the support tube is 200-400 mm.

The plastic diaphragm in the step (1) is a polyethylene plastic bag, the length is 200-400mm, and the diameter is consistent with that of the No. 1 support tube.

The non-woven fabric in the step (2) is a fused silicone grease base bed, belongs to medical non-woven fabrics, and has the length and width of 50-80 x 150-200 mm.

The silicone grease in the step (2) is Common Silicone Grease (CSG) or Fluorinated Silicone Grease (FSG).

And (4) taking out each silicone grease sample for test in the step (6) in three test time periods, wherein the three test time periods are 168 hours, 336 hours and 504 hours respectively.

And (4) the No. 2 cold-shrink tube silicone rubber sleeve in the step (8) consists of a silicone grease zone No. 2 cold-shrink tube silicone rubber sleeve and a silicone grease-free zone No. 2 cold-shrink tube silicone rubber sleeve.

The silicone rubber insulating material for the cold shrink sleeve of the cold shrink tube meets the following indexes:

the application of the silicone grease influence retraction simulation test method for the cold-shrink cable accessory can intuitively reflect the influence of the silicone grease on the retraction of the cold-shrink cable accessory, and a silicone grease product with a lower retraction rate can be selected in practical application.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the silicone grease-influenced retraction simulation test method for the cold-shrink cable accessory, the most common silicone rubber cold-shrink tube is selected as a test sample, a silicone rubber test piece does not need to be manufactured, the material selection of the test sample is simple and common, the problem that the silicone rubber test piece and the cold-shrink cable accessory product are different due to the influences of temperature, vulcanization, environment and the like during the manufacturing of the silicone rubber test piece is solved, and the accuracy, the authenticity and the applicability of a test result are improved.

(2) According to the simulation test method for influencing retraction of the cold-shrink cable accessory by silicone grease, a silicone grease sample is dissolved in non-woven fabric, the silicone grease content is coated when the cold-shrink cable accessory is installed, and the problem that the silicone grease content of a silicone rubber test piece immersed in the silicone grease is different from the actual silicone grease content is solved.

(3) The silicone grease influence cold-contraction cable accessory retraction simulation test method can simply realize the simulation of a thermal aging environment; simulating a thermal aging operation environment: the silicone rubber sample coated with silicone grease was placed in an oven at 90 c to simulate the maximum temperature of long-term operation of the cable accessory.

(4) According to the silicone grease influence cold-shrink cable accessory retraction simulation test method, the silicone grease area and the silicone grease-free area are compared on one cold-shrink tube test piece, the quantification of the test result is realized, and the test result is more visual and accurate.

(5) The silicone grease influence cold-shrink cable accessory retraction simulation test method does not need a special test instrument, professional data analysis is carried out, the test method is simpler and more universal, no special professional requirements are required on test personnel, and universality is strong.

Drawings

FIG. 1 is a schematic structural view of a test silicone grease sample prepared before testing;

FIG. 2 is a schematic structural diagram of a silicone grease sample measured by a digital vernier caliper;

wherein:

1. a No. 1 supporting tube; 2. a plastic diaphragm; 3. a non-woven silicone layer; 4. 2# cold-shrinkable tube; 5. after retraction, no silicone grease zone No. 2 cold-shrink tube silicone rubber sleeve; 6. and the retracted silicone grease zone No. 2 cold-shrink tube silicone rubber sleeve.

Detailed Description

The invention relates to a silicone grease influence cold-shrink cable accessory retraction simulation test method, which comprises the following steps:

(1) sleeving a layer of plastic membrane on the surface of the No. 1 support tube, and then smoothing the surface of the plastic membrane without folds;

(2) coating the silicone grease sample on the surface of the non-woven fabric, and uniformly kneading to fully dissolve the silicone grease in the non-woven fabric;

(3) wrapping the non-woven fabric dissolved with the silicone grease at 1/3 positions in the length direction of the No. 1 supporting tube, and fixing by using a thin fiber rope;

(4) sleeving a No. 2 cold shrink tube outside the whole No. 1 support tube, wherein the No. 2 cold shrink tube comprises a non-woven fabric wrapping part dissolved with silicone grease, and drawing out the No. 2 cold shrink tube from the No. 2 support tube to prepare a silicone grease sample for testing, the structural schematic diagram of the silicone grease sample is shown in the attached drawing 1, wherein 1 is the No. 1 support tube, a plastic membrane 2 is sleeved outside the No. 1 support tube, then a non-woven fabric silicone grease layer 3 is arranged at 1/3 in the length direction, and the outermost layer is 4 and is the No. 2 cold shrink tube;

(5) 3 parts of each silicone grease sample for testing are respectively manufactured according to the steps (1) to (4) and are numbered and distinguished;

(6) placing the prepared silicone grease test samples for testing in an oven, keeping the temperature at 90 ℃, standing, and taking out each silicone grease test sample for testing in three time periods;

(7) and (3) extracting the No. 1 supporting tube of the silicone grease sample for testing, and taking out the plastic diaphragm and the non-woven fabric to obtain the retracted No. 2 cold-shrinkable tube silicone rubber sleeve. The structure is shown in figure 2, wherein 5 is a retracted silicone rubber sleeve of a No. 2 cold-shrink tube without a silicone grease zone, and 6 is a retracted silicone rubber sleeve of a No. 2 cold-shrink tube with a silicone grease zone;

(8) and (3) carrying out data measurement on the retracted 2# cold-shrink tube silicone rubber sleeve by using a digital display vernier caliper, and calculating and comparing the retraction rate, wherein the calculation formula is as follows: the percent retraction is (diameter after retraction of silicone grease zone-diameter after retraction of silicone grease-free zone)/diameter after retraction of silicone grease-free zone 100%.

(9) And analyzing the test statistical data, and comparing the comparative retraction rate to obtain a silicone grease test sample with relatively low comparative retraction rate.

Wherein:

the 1# support tube for the cold shrink tube in the step (1) and the 2# support tube in the step (4) are made of the same material, and the length of each support tube is 200 mm.

The plastic diaphragm in the step (1) is a polyethylene plastic bag, the length of the plastic diaphragm is 200mm, and the diameter of the plastic diaphragm is consistent with that of the No. 1 support tube.

The non-woven fabric in the step (2) is a fused silicone grease base bed, belongs to medical non-woven fabrics, and has the length and width of 50 x 150 mm.

And (4) taking out each silicone grease sample for test in the step (6) in three test time periods, wherein the three test time periods are 168 hours, 336 hours and 504 hours respectively.

And (4) the No. 2 cold-shrink tube silicone rubber sleeve in the step (8) consists of a silicone grease zone No. 2 cold-shrink tube silicone rubber sleeve and a silicone grease-free zone No. 2 cold-shrink tube silicone rubber sleeve.

Examples 1 to 4

The embodiments 1 to 4 all adopt the test method as described above, wherein the selected cold shrink tube is a No. 1 cold shrink tube produced by Shandong seven-star Electrical technology development Limited, and the cold shrink tube meets the requirements for cold shrink cable accessories in T/CEC 118-; 3 samples were taken from each example, and example 1 used FushundaL55/2 grease; example 2 used an OFX-0203 alkylphenyl silicone oil; example 3 employs DR-905 insulating grease (manufacturer shenzhen, shendengrun science and technology ltd); example 4 employs DR-49F fluorosilicone grease (manufacturer shenzhen shendengrun science and technology ltd); the silicone greases used in examples 1-4 all meet the national standards for insulating greases for installation of cold-shrink cable accessories, as shown in table 1 below:

TABLE 1 Main Performance index of insulating grease for installation

Comparative example 1

Wangxiao et al, vol 46, high Voltage technology, phase 9: 3177 and 3186, the experimental method recorded in the insulating swelling mechanism and influence factor of the coated silicone grease on the cable accessories is used for preparing samples (including preparation of silicone rubber test pieces and crosslinked polyethylene test pieces) and carrying out a heat aging experiment: the silicone rubber sample coated with the silicone grease is placed in a 90 ℃ oven to simulate the highest temperature of long-term operation of a cable accessory, the silicone grease in the embodiment 3 is selected as the silicone grease, after aging is finished, the sample is observed by adopting a method recorded in an article, the method comprises sample surface observation, sample side surface observation and infrared spectrum analysis, observation through a polarizing microscope shows that scratches appear on the surface of the silicone rubber after the silicone grease is subjected to thermal aging treatment, and the side surface observation of the sample shows that bulges appear on the silicone rubber part coated with the silicone grease due to swelling of the silicone rubber. The swelling of the silicone grease in the silicone rubber was confirmed by analysis of the infrared spectrum. This is consistent with the results of example 3 of the present invention, but the test method of the present invention is more intuitive, and knowing the swelling size, the swelling size of silicone grease in silicone rubber can be obtained more accurately, and no complicated analysis equipment or professional analysis is needed, which greatly saves time and improves the accuracy of the test.

The silicone grease samples of examples 1-4 were subjected to the swelling test and the test data are shown in Table 2 below.

TABLE 2 summary table of silicone grease test data

And (4) test conclusion: as can be seen from the measurement data in table 2: in the first week (168 hours), the silicone grease and the silicone rubber cold-shrink tube are not fully dissolved and absorbed, and the influence on the relative retraction rate of the cold-shrink tube sleeve is small; the silicone grease and the silicone rubber cold-shrink tube dissolve and absorb to reach a saturated state in the second week (336 hours), the influence on the comparative shrinkage rate of the cold-shrink tube sleeve is large, the comparative shrinkage rate data reaches the maximum value, and the silicone grease and the cold-shrink tube are in a stable state and can be used as silicone grease selection reference data; the experimental data of the third week (504 hours) almost leveled with the experimental data of the second week, and the effect of the silicone grease on the comparative shrinkage rate of the cold-shrink tube sleeve at the third week leveled with or slightly decreased from the second week (mainly due to the volatilization of the silicone grease), so that the comparative shrinkage rate of the silicone grease on the cold-shrink tube sleeve reached the maximum value at the second week; according to the test results, the silicone grease test sample in the embodiment 1 has low shrinkage and small influence on the cold-shrink cable accessories, the silicone grease test sample in the embodiment 2 has moderate shrinkage and has inferior influence on the cold-shrink cable accessories, and the silicone grease test samples in the embodiments 3 and 4 have high shrinkage and large influence on the cold-shrink cable accessories.