Test Principle
Oil permeability refers to the weight of standard transformer oil permeated into a paper or cardboard sample of a certain area within a certain period of time under a certain temperature and pressure, and the unit is mg/(m2·h).
The oil permeability Tester is composed of oil cup cover, oil cup, oil cup reversing handle, pressure ball, pressure gauge, etc. It is suitable for measuring the oil permeability of oil-proof paper for packaging oily food. The inner diameter of the oil cup is (90±0.1) mm, and the diameter of the qualitative filter paper is 105mm. Before using the oil permeability Tester, you should calibrate the pressure gauge, check the tightness and calibrate the time relay. The principle of the test is: under a certain pressure, make a specific oil (such as 25# transformer oil) penetrate the paper. The greater the amount of oil permeated in a certain time and a certain area, the greater the oil permeability of the paper; otherwise, the smaller the oil permeability of the paper.
Test Methods
Refer to the national standard GB 16929 "Test methods for packaging materials, oil permeability" for the test, and the test instrument is an oil permeability Tester. The specific test steps include the following points.
①Sample collection and processing. Sampling according to GB450, cut 6 pieces of 120mm × 120mm samples along the transverse direction of the paper web, and mark the front and back sides. According to the requirements of GB10739, carry out temperature and humidity pretreatment on the samples.
②Pour 20mL of standard transformer oil with a temperature of (20±1)℃ into the oil cup.
③ Put the sample on the oil cup lined with 3 layers of filter paper, then cover the cup and press it tightly.
④Turn the oil cup over 180°, so that the standard transformer oil covers the paper, start timing, and quickly pressurize to 49kPa with a pressurized ball, and the operation time of inflation and pressurization shall not exceed 10s.
⑤ After the timing reaches 5 minutes, exhaust and depressurize immediately, then turn over the oil cup, take out the backing paper within 15 seconds, and weigh to an accuracy of 0.0001g. The weight difference of the backing paper before and after the test is the oil permeability.
⑥Test the rest of the samples in turn. For every 6 samples, pour out the used oil in the oil cup, replace with new oil, and proceed to the next test.
⑦ Calculate the oil permeability of the sample.
The test results are reported as the arithmetic mean of all test values (including front and back sides). If the pressure used during the test is not 49kPa and the time used is not 5min, it should be indicated in the report.
