The sealing performance of the centrifuge tube is an important factor that affects the accuracy of the experimental analysis results. This article takes the process of testing the sealing performance of plastic centrifuge tubes as an example, introduces a method for testing the sealing performance of centrifuge tubes, and briefly describes the principles and equipment parameters of the test process and the test equipment sealing tester to verify the centrifuge tubes for enterprises. Provide reference for sealing performance.

The centrifuge tube is a commonly used experimental instrument, mainly used for layering and separation of liquid components in the tube. There are many types of centrifuge tubes, such as large-capacity centrifuge tubes, small-capacity centrifuge tubes, and micro-centrifuge tubes according to different capacities, and glass centrifuge tubes, plastic centrifuge tubes, steel centrifuge tubes, etc. according to different materials. . Most 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 cause the liquid in the centrifuge tube to overflow and leak, corrode the centrifuge, affect its service life, and contain volatile As far as the liquid of the sexual component is concerned, it is also easy to cause volatility into dispersion loss, which affects the content of each component in the centrifuge tube, which in turn causes deviations in the experimental results. Therefore, there should be a good seal between the tube cover and the centrifuge tube.

Test method and test equipment

At present, there is no domestic standard for testing the sealing performance of centrifuge tubes. This article tests the sealing performance of centrifuge tubes based on the principle of negative pressure test. The commonly used testing equipment for the sealing performance testing of flexible plastic packages and packaging containers is the sealing tester

Test samples and Experimental procedure

Test principle: The basic test principle of this device is the principle of negative pressure method, that is, the external environment where the sample is located is reached a certain degree of vacuum by vacuuming, so that a certain pressure difference is formed between the inside and outside of the sample, if the sample is poorly sealed , The gas inside will overflow from the inside of the sample along the poor seal under the action of the pressure difference. Determine whether the seal is sealed by observing whether there are continuous bubbles on the surface of the sample in water or the shape of the sample recovers after the vacuum is released performance.Test samples and test process

Testing sample:

This article uses a brand of plastic centrifuge tubes as test samples. The materials commonly used in the production of plastic centrifuge tubes are polyethylene, polycarbonate, polypropylene, etc., among which polypropylene plastic centrifuge tubes have better performance.

Experimental procedure:

(1) Immerse the sample of the centrifuge tube to be tested in the water in the sealed jar of the device and close the sealing cap.

(2) Set parameters such as vacuum degree and pressure holding time, turn on the vacuum pump, and press the start key on the equipment panel to start the test.

(3) Observe whether there are continuous bubbles on the test surface during the process of vacuuming or holding pressure.

Test results and analysis

In this paper, a total of three centrifuge tube samples were tested for sealing performance, and the three samples were leaked at -65.1 KPa, -63.9 KPa, and -70.3 KPa. The sealing performance of the centrifuge tube is an important factor affecting the smoothness of the test and the accuracy of the test results. This paper introduces a simple method for verifying the sealing performance of plastic centrifuge tubes by using a sealing tester to test the sealing performance of plastic centrifuge tubes. The test process is simple and the equipment is easy to operate.