CN104515697B - The detection preparation method of sample and vacuum degasser of normal temperature cure Silicone Rubber Based Coatings - Google Patents

Abstract

The invention discloses a test sample preparation method and a vacuum degassing device for a normal temperature curing silicone rubber coating, comprising the following steps: 1) taking the finished product of the normal temperature curing silicone rubber coating and shaking and shaking; 2) shaking and shaking the normal temperature curing silicone rubber The finished paint is poured into the paint cup, and vacuum degassing treatment is carried out. The processing time is 2-3min, and the vacuum degree is < ^10-1 Pa to obtain the degassed paint; 3) Remove the condensation film on the surface of the degassed paint, Then pour it into the mold, let it stand until the surface of the paint condenses, put the mold under the conditions of temperature: 20-25°C, humidity: 30%-35%, and then let it stand for 96-102h, take it out, and it will be at room temperature Cured silicone rubber coating samples. This scheme effectively eliminates the influence of environmental factors, such as dissolved gas in the paint and dust in the air, on the test results, and improves the accuracy of the random test.

Description

Test sample preparation method and vacuum degassing device for normal temperature curing silicone rubber coating

technical field

The invention belongs to the field of paint testing, in particular to a test sample preparation method and a vacuum degassing device for normal temperature curing silicone rubber paint.

Background technique

With the development of the national economy, pollution sources in various places are increasing, and the pollution on the surface of insulators is becoming more and more serious. Under severe weather conditions, pollution flashover accidents are prone to occur, threatening the safe and stable operation of the power system. The room temperature curing silicone rubber coating has excellent hydrophobicity And hydrophobic migration, can significantly improve the pollution flashover voltage of insulators, practice has proved that spraying room temperature curing silicone rubber coating on the surface of insulators can effectively reduce the probability of pollution flashover, which is of great significance to ensure the safe and stable operation of the power system. However, there are many manufacturers of room temperature curing silicone rubber coatings in China, and the product quality is uneven. Therefore, the network inspection of room temperature curing silicone rubber coatings is very necessary. In the sampling test project, the volume resistivity, relative permittivity, dielectric loss angle, dielectric strength and other parameters of the normal temperature curing silicone rubber coating determine the insulation performance of the coating. The determination of these parameters needs to be prepared in advance. Like this, the quality of the sample directly determines the final test result, but there is no unified method or standard to standardize the preparation process of the room temperature curing silicone rubber coating sample, which can easily cause problems such as inaccurate test results.

Contents of the invention

In view of the above problems, the present invention proposes a method for preparing test samples of normal temperature curing silicone rubber coatings, which can effectively eliminate the influence of environmental factors, such as dissolved gas in the coating, dust in the air, etc. on the detection results, and improve the accuracy of the sampling test .

In order to achieve the above object, the present invention adopts the following technical solutions:

A method for preparing a detection sample of a normal temperature curing silicone rubber coating, comprising the steps of:

1) Take the finished product of normal temperature curing silicone rubber coating and shake it well;

2) Pour the finished room-temperature-cured silicone rubber coating into the coating cup after shaking and shaking, and carry out vacuum degassing treatment. The treatment time is 2-3 minutes, and the vacuum degree is <10 ^-1 Pa to obtain the degassed coating;

3) Remove the condensation film on the surface of the degassed paint, then pour it into the mold, let it stand under vacuum until the surface of the paint condenses, and put the mold at a temperature: 20°C-25°C, humidity: 30%- Under the condition of 35%, let it stand still for 96-102h, take it out, and obtain the test sample of the silicone rubber coating cured at room temperature.

Preferably, in step 1), the shaking time is 2-3min.

Further, in step 2), the paint cup is an open cup.

Further, in step 3), the mold is an open grooved flat mold.

Further, in step 3), the specific steps of pouring into the mold are: placing the mold on a horizontal table, and after adjusting the level of the groove surface, pour the degassed and film-removed coating from the center of the mold to the volume of the coating in the mold. Stop when it is more than 2/3 of the total mold volume.

Further, in step 3), the mold is always in a horizontal state.

The present invention also provides a vacuum degassing device for testing samples of silicone rubber coatings cured at room temperature. The upper part of the vacuum tank is equipped with a pressure gauge, the lower part of the side wall of the vacuum tank is equipped with a vent valve, and the bottom of the vacuum tank is equipped with a vibration table.

Preferably, the connecting pipe is connected with the vacuum tank through an exhaust hole. The pressure in the vacuum tank can be precisely conditioned by adjusting the size of the vent hole opening.

Preferably, a heating wire is arranged on the vibrating table.

Preferably, the side wall of the vacuum tank is made of transparent material and provided with inwardly protruding rubber gloves.

Preferably, the outer surface of the cuff of the rubber glove is in sealing connection with the side wall of the vacuum tank.

Beneficial effects of the present invention:

1. The present invention provides a simple and effective test sample preparation method for room temperature curing silicone rubber coatings, effectively eliminating environmental factors such as dissolved gas in the coating, dust in the air, etc. The impact of the test results and improve the accuracy of the random test.

2. The preparation process of the present invention is simple, the cost is low, and the prepared coating sample has high stability, high reproducibility and detection precision.

Description of drawings

Fig. 1 is the operation flowchart of the present invention

Figure 2 is a structural diagram of the vacuum degassing device, wherein, 1-vacuum tank 2-pressure gauge 3-vent hole 4-vibration table 5-connecting pipe 6-deflation valve 7-vacuum pump 8-sealing cover 9-paint cup 10-vacuum tank side wall 11-rubber gloves.

Figure 3 is a side view of the vacuum degassing device

Detailed ways

The present invention is further illustrated by way of examples below, but the present invention is not limited to the scope of the examples. For the experimental methods not indicating specific conditions in the following examples, select according to conventional methods and conditions.

Example 1

Before opening the barrel, shake and shake the finished silicone rubber coating at room temperature. For the paint that has been left standing for a long time, shake it for 2 minutes. After shaking well, open the barrel and quickly pour the sample into the paint cup for 3 /4 place, try to avoid the air from dissolving into the paint, vacuumize the vacuum device, the vacuum time is 3min, and the vacuum degree is <10 ^-1 pa. During the vacuuming process, in order to test the vacuuming effect, obvious air bubbles can be seen on the surface of the coating. After the gas in the sample is precipitated, use tweezers to remove the surface condensation film, and quickly pour the paint into an open groove-shaped flat mold. The mold should be placed on a horizontal table under vacuum conditions, and the groove surface must be kept level. After the surface of the paint is condensed, place the mold in a constant temperature and humidity box, keep the level when moving the mold, and at the same time ensure that the mold is in a horizontal state in the constant temperature and humidity box. The temperature was set at 20°C, the humidity was 30%, and it was taken out after 96 hours.

The results show that: compared with the original detection method, the method provided by the invention can improve the detection accuracy of volume resistivity, relative permittivity, dielectric strength, dielectric loss tangent and other indicators by 5%-7%, At the same time, the inventive method eliminates the interference of environmental factors and human factors on the detection results, and the detection results have high repeatability.

A vacuum degassing device for testing samples of silicone rubber coatings cured at room temperature, the vacuum tank 1 is connected to the vacuum pump 7 through the connecting pipe 5, the top of the vacuum tank 1 is provided with an openable sealing cover 8, and the upper part of the side wall of the vacuum tank 1 is provided with The pressure gauge 2 is provided with a vent valve 6 at the bottom of the side wall of the vacuum tank, and the vibration table 4 is provided at the bottom of the vacuum tank 1 .

Preferably, the connecting pipe 5 is connected with the vacuum tank 1 through the exhaust hole 3 .

Open the sealing cover 8 of the vacuum tank 1, place the coating cup 9 with the coating on the vibrating table 4 in the vacuum tank, close the sealing cover 8, close the valve switch of the air release valve 6, open the vibrating table 4, and the vibration intensity is as high as It is advisable that the paint cup 9 does not move. Turn on the vacuum pump 7. With the reduction of the gas in the vacuum chamber, the sealing cover 8 is tightly adsorbed on the vacuum tank 1. Observe the pressure gauge 2. When the vacuum degree reaches 10 ^-1 Pa, maintain 3min, at this time, the gas in the paint is completely discharged, turn off the vacuum pump 7 and the vibration table 4, open the switch of the air release valve 6, after the air pressure is balanced, open the sealing cover 8, and take out the paint cup 9. (Refer to Figure 2 for the specific device)

Preferably, a heating wire is arranged on the vibrating table. The temperature in the vacuum tank can be controlled by heating to meet the testing requirements of different materials.

Preferably, the side wall 10 of the vacuum tank is made of transparent material and provided with a rubber glove 11 protruding inward. The user can operate the sample in the vacuum tank through gloves, realizing the test of the sample under absolute vacuum conditions and avoiding the interference of the external environment.

Preferably, the outer surface of the cuff of the rubber glove is in sealing connection with the side wall of the vacuum tank. When the vacuum tank is in a vacuum condition, under the action of atmospheric pressure, the rubber glove expands inward, which is convenient for the user to put his hand into the glove.

Example 2

Before opening the barrel, shake and shake the finished silicone rubber coating at room temperature. For the paint that has been left standing for a long time, shake it for 3 minutes. After shaking well, open the barrel and quickly pour the sample into the paint cup for 3 minutes. /4 place, try to avoid the air from dissolving into the paint, vacuumize the vacuum device, the vacuum time is 3min, and the vacuum degree is <10 ^-1 pa. During the vacuuming process, in order to test the vacuuming effect, obvious air bubbles can be seen on the surface of the coating. After the gas in the sample is precipitated, use tweezers to remove the surface condensation film, and quickly pour the paint into an open groove-shaped flat mold. The mold should be placed on a horizontal table under vacuum conditions, and the groove surface must be kept level. After the surface of the paint is condensed, place the mold in a constant temperature and humidity box, keep the level when moving the mold, and at the same time ensure that the mold is in a horizontal state in the constant temperature and humidity box. The temperature was set at 25°C, the humidity was 60%, and it was taken out after 102 hours. The mold is always under vacuum condition, the degree of vacuum is less than 10 ^-1 Pa.

Example 3

Before opening the barrel, shake and shake the finished silicone rubber coating at room temperature. For the paint that has been left standing for a long time, the shaking time is 2.5 minutes. After shaking well, open the barrel and quickly pour the sample into the paint cup for 3 /4 place, try to avoid the air from dissolving into the paint, vacuumize the vacuum device, the vacuum time is 3min, and the vacuum degree is <10 ^-1 pa. During the vacuuming process, in order to test the vacuuming effect, obvious air bubbles can be seen on the surface of the coating. After the gas in the sample is precipitated, use tweezers to remove the surface condensation film, and quickly pour the paint into an open groove-shaped flat mold. The mold should be placed on a horizontal table under vacuum conditions, and the groove surface must be kept level. After the surface of the paint is condensed, place the mold in a constant temperature and humidity box, keep the level when moving the mold, and at the same time ensure that the mold is in a horizontal state in the constant temperature and humidity box. The temperature was set at 22.5°C, the humidity was 45%, and it was taken out after 98 hours.

Although the specific implementation of the present invention has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solution of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims (1)

1. a kind of detection preparation method of sample of normal temperature cure Silicone Rubber Based Coatings, it is characterised in that include the following steps：

1) concussion of normal temperature cure Silicone Rubber Based Coatings finished product is taken to shake up；

2）The normal temperature cure Silicone Rubber Based Coatings finished product shaken after shaking up is poured into paint cup, carries out Fruit storage, during processing Between be 2-3min, vacuum ＜ 10^-1Pa, the coating after must deaerating；

3）The surface for removing the coating after above-mentioned degassing condenses film, then is poured into mould, is stood under vacuum condition to painting After expecting that surface condenses, mould is placed in temperature：20 DEG C -25 DEG C, humidity：Under conditions of 30%-35%, then 96-102 h are stood, taken Go out, up to normal temperature cure Silicone Rubber Based Coatings sample；

Step 1）In, the concussion time is 2-3min；

Step 3）In, the mould is open type channel-shaped flat plate mold；

Step 3）In, pour into concretely comprising the following steps for mould：Mould is placed in horizontal table top, after adjusting groove face level, will be deaerated Coating after membrane removal is poured into from mold center position, is stopped when into mould, coatings volume is more than the 2/3 of mould cumulative volume；

Step 3）In, the mould is in horizontality all the time

Above-mentioned preparation method is completed using following vacuum degasser, which includes：Vacuum tank, vacuum pump, bumper； Vacuum tank is connected by connecting tube with vacuum pump, and vacuum upper end is provided with openable sealing cover, the top of vacuum pot sidewall Pressure gauge is provided with, the lower part of vacuum pot sidewall is provided with vent valve, and the bottom of vacuum tank is provided with bumper；

The connecting tube is connected by exhausting-gas hole with vacuum tank；

Heater strip is provided with the bumper；

The side wall of the vacuum tank is made of clear material, and is provided with inwardly protruded rubber gloves；

The lateral surface of the rubber gloves wrist mouth and the side wall of vacuum tank are tightly connected；

The sample is used to detect volume resistivity, relative dielectric constant, dielectric loss angle, dielectric strength.