Plastic centrifuge tube sealing performance testing method

Summary:

The sealing performance of the centrifuge tube is an important factor affecting the accuracy of the experimental analysis results. In this paper, the process of testing the sealing performance of a brand of plastic centrifuge tube is taken as an example. A method for detecting the sealing performance of a centrifuge tube is introduced . The principle and equipment parameters of the test procedure and test equipment MFY-01 A seal tester are briefly described. Provide a reference for companies to verify the sealing performance of Centrifuge Tubes.

Key words:

Centrifuge tube, plastic centrifuge tube, sealing performance, leak, seal tester, negative pressure method

1 , meaning

Centrifugal Tube is a commonly used experimental instrument, mainly used for stratification and separation of liquid components in tubes. There are many classification methods for centrifuge tubes. For example, according to different capacities, they can be divided into large-capacity centrifuge tubes, small-capacity centrifuge tubes, and micro-centrifuge tubes. According to different materials, they can be divided into glass centrifuge tubes, plastic centrifuge tubes, steel centrifuge tubes, etc. . Most of the centrifuge tubes are equipped with a tube cover. If the compatibility between the tube cover and the centrifuge tube is poor, and the seal is not strict, it will easily lead to liquid spillage and leakage in the centrifuge tube, corrode the centrifuge and affect its service life. In the case of a liquid of a sexual component, it is also liable to cause a loss of volatility and dispersion, which affects the content of each component in the centrifuge tube, and causes a deviation in the experimental results. Therefore, there should be good sealing between the cap and the centrifuge tube.

Figure 1 different types of centrifuge tubes

2 , testing basis

At present, there is no test standard for the performance of centrifugal tube sealing in China. This paper tests the sealing performance of the centrifuge tube based on the negative pressure test principle.

3 , test samples

In this paper, a brand of plastic centrifuge tube is used as a test sample. Commonly used in the production of plastic centrifuge tubes are polyethylene, polycarbonate, polypropylene, etc., of which polypropylene plastic centrifuge tubes have better performance.

4 , test equipment

The commonly used testing equipment for soft plastic packaging and packaging container sealing performance testing is the sealing tester. The testing equipment used in this paper is MFY-01 A sealing tester, which is independently developed by Jinan Chenchi Testing Instrument Co., Ltd.

Figure 2 MFY-01 A seal tester

4.1

Test principle

The basic test principle of the device is the principle of negative pressure method, that is, the vacuum is used to make the external environment of the sample reach a certain degree of vacuum, so that a certain pressure difference is formed inside and outside the sample, and if the sample is poor in sealing, the inside is The gas will overflow from the inside of the sample along the poor seal under the pressure difference, and the sealing performance can be determined by observing whether there is continuous bubble on the surface of the sample in water or the shape recovery of the sample after releasing the vacuum.

4.2

Control of the parameters of the degree of vacuum equipment is 0 ~ -90 KPa, testing accuracy of level 1, the effective size of the vacuum chamber with a 270 mm (diameter) × 210 mm (height), 360 mm (diameter) × 585 mm (height) , 460 mm (diameter) × 330 mm (height) to choose three kinds, the test system uses digital preset degree of vacuum and vacuum retention time, ensure the accuracy of test data, automatic constant pressure qi further ensure that the test can be preset Under vacuum conditions, the professional software supports automatic backflush unloading and automatic end test functions to ensure the smooth progress of the test process.

4.3

Scope of application

The device is suitable for testing the overall sealing performance of bags, boxes, bottles, tubes, cans, boxes and other seals made of plastic composite materials, paper-plastic composite materials, metal materials, plastic materials, glass materials, etc., and conforms to GB/ T

15171 , American standard D3078 and other countries and standards.

5 , the test process

(1) Immerse the sample of the centrifuge tube to be tested in the water of the sealed tank of the equipment and cover the sealing cover.

(2) Set parameters such as vacuum degree and holding time, open the vacuum pump, press the start button on the device panel, and the test starts.

(3) Observe whether or not continuous bubbles are generated on the test surface during vacuuming or holding.

6 , test results

This paper is detected sealing performance of the centrifugal tube 3 samples, three samples were at -65.1 KPa, -63.9 KPa-70.3 KPa air leakage.

7 , conclusion

The sealing performance of the centrifuge tube is an important factor that affects whether the test can be carried out smoothly and the accuracy of the test results. In this paper, the MFY-01 A seal tester is used to test the sealing performance of plastic centrifuge tubes. The simple method of verifying the sealing performance of plastic centrifuge tubes is introduced. The test process is simple and the equipment is easy to operate.