The article is provided by Jinan Sanquan Zhongshi Experimental Instrument***.
I. Introduction. With the rapid development of the packaging industry, plastic packaging has been widely used because of its lightweight, durable, moisture-proof, shockproof and other characteristics. The sealing performance of plastic packaging, as an important indicator of its quality, directly affects the shelf life of the product and the consumer experience. Therefore, it is necessary to test the sealing performance of plastic packaging. As an effective test method, the negative pressure vacuum method has been widely used in the sealing test of plastic packaging.
2. Introduction to negative pressure vacuum pumping method.
Negative pressure vacuum method is a test method to judge the sealing performance of plastic packaging by reducing the pressure in the test chamber to deform or rupture under the action of the internal and external pressure difference. This method has the advantages of simple operation and accurate test results, and is widely used in the sealing performance test of various plastic packaging.
Third, the test principle.
The test principle of the negative pressure vacuum method is to use a vacuum pump to pump the test chamber into a vacuum state to reduce the pressure in the chamber. At this point, the pressure on the outside of the package is greater than the pressure on the inside, and if the package is poorly sealed, it will deform or crack in weak points. By observing and measuring the degree of deformation or breakage, the sealing performance of plastic packaging can be judged.
Fourth, the test steps.
Place the plastic packaging to be tested into the test chamber to ensure that the packaging is not damaged or deformed.
Close the test chamber door, start the vacuum pump, and pump the pressure in the chamber to a preset negative pressure value.
Observe and record the deformation or rupture of plastic packaging under negative pressure.
According to the test results, judge whether the sealing performance of the plastic packaging meets the requirements.
5. Advantages and applications.
The advantages of the negative pressure vacuum method in the sealing test of plastic packaging are mainly reflected in the following aspects:
High accuracy: By accurately controlling the pressure and vacuum in the cavity, the sealing performance of plastic packaging can be accurately judged, avoiding the limitations of traditional detection methods.
Easy to operate: only need to put the plastic package to be tested into the test chamber and start the vacuum pump to test, which is simple and convenient to operate.