What are the factors that affect the water vapor transmissivity during the test of the moisture permeameter

As a professional instrument for testing the barrier performance of product packaging materials, the existence of moisture permeameter (also known as water vapor transmittance) is essential However, in the test process, some details are likely to be caused by human operation errors, which makes the data insufficient and provides the manufacturer with wrong data information So, what factors may affect the test results? Now, let's invite the engineers of R & D Department of Jinan Saicheng to explain in detail The factors affecting the water vapor transmission are: 1 Temperature According to the national standard GB / T 21529-2008, different materials are tested at different temperatures For example, for materials such as plastic film or sheet, the required temperature is about 23 ℃, and the error range is allowed to be 2 ℃ Therefore, in the test process, whether it is larger or smaller than this range, it will have a great impact on the data 2 Humidity According to the engineers of Jinan Saicheng R & D department, humidity has a more direct impact on the test data, which is because the test environment required in the national standard is 100% humid environment At present, this condition is only widely used in foreign countries, and limited by the development of technology in China At present, few enterprises can realize this condition 3 Test time According to the national standard, the test sample shall be tested in the specified temperature and humidity test environment for at least 4H If the time is too short, it is likely to lead to little significance of data referentiality, which will not help production; and if the time is too long, it may lead to the increase of error due to the change of the product itself In addition, before the test, whether the samples selected by the staff meet the requirements, such as uniform thickness, no crease, fold, pinhole, more importantly, the area of the sample should be larger than the penetration area of the penetration cavity, otherwise these factors will also bring deviation to the test results Therefore, it must be paid special attention to by the manufacturer For the test of this project, the "W \ 031 water vapor transmittance tester" independently developed by Jinan Saicheng strictly complies with the provisions of the national standard to minimize the system error caused by human error The instrument can measure three to six samples at a time in a single test It can also ensure that there is no interference with each other and independent test It is very convenient for users to test multiple samples at a time Therefore, it is an ideal testing instrument for manufacturers