GB/T 31726-2015Test method for anti-fogging property of plastic film (English PDF)

3.1 Anti-foggingproperty

The plastic film has the property of improving or preventing the formation of water droplets or water mist in the enclosed space.

5.1 Sampling

The sample should be evenly sampled along the entire width to avoid appearance defects such as wrinkles and impurities on the surface that affect the test results.

5.2 Dimensions and sample preparation

5.2.1 Flat sheet. The size is (120 ± 3) mm × (120 ± 3) mm, enough to cover the beaker mouth.

5.2.2 Square bag. Take a film with a size of (300 ± 2) mm × (160 ± 2) mm as shown in Figure 1, with the test surface facing inward along the center The line is folded in half, and the two sealed sides are combined into a square bag with a sealing width of 5mm ~ 15mm. Make a positioning mark at (70 ± 2) mm from the opening edge of the sample Remember to put on the beaker mouth so that the positioning mark coincides with the beaker mouth, as shown in Figure 2.

5.2.3 A group of tests should use samples of the same shape and size. Explanation.

L1 --- opening edge, the size is (160 ± 2) mm;

L2 --- sealing edge, the size is (300 ± 2) mm;

L3 --- The distance between the positioning mark and the opening edge is (70 ± 2) mm.

Figure 1 Preparation of the sample before sealing the square bag The unit is mm Explanation.

1 --- Square bag sample;

2 --- Locating mark;

3 --- Double-sided tape or rubber band;

4 --- Water level line;

5 --- Beaker.

5.3 Number of samples

Each group of tests was conducted 3 times. If the results of 3 tests were inconsistent, 2 additional tests were conducted. If a group of trials appears 3 and so on Grade, need to retest.

5.4 Standard environment for sample condition adjustment and test

Unless otherwise specified, the sample should be in accordance with the provisions of GB/T 2918-1998, in an environment of temperature (23 ± 2) °C and relative humidity (50 ± 10)% Under the state, the state adjustment time is not less than 4h, and the test is carried out in this environment.

6.1 Cold fog method

6.1.1 Inject (200 ± 10) mL, (23 ± 2) °C tertiary water that meets the requirements of GB/T 6682-2008 into a flat-mouth beaker.

6.1.2 Fix the sample with double-sided tape or rubber band so that the anti-fog test face is buckled on the mouth of the beaker, and the test site should be flat.

6.1.3 Place the flat beaker with the fixed sample in a low temperature incubator or refrigerator with a temperature of (3 ± 2) ° C and start timing.

6.1.4 At 5 minutes, take out the beaker with the sample and place it on the standard logarithmic near vision chart in Appendix B of GB 11533-2011 to burn The bottom center of the cup is aligned with the 0.1 center line of the eye chart. Under natural light or a 40W fluorescent lamp, observe the film from top to bottom perpendicular to the bottom of the beaker Observe the surface of the sample within 5s.

6.2 Rapid Hot Mist Method

6.2.1 Place the flat beaker on the standard logarithmic near vision chart in Appendix B of GB 11533-2011, align the bottom center of the beaker In the 0.1 center line of the eye chart, inject (200 ± 10) mL, (85 ± 2) °C in line with GB/T 6682-2008 requirements of tertiary water.

6.2.2 Quickly fix the sample with double-sided tape or rubber band so that the anti-fog performance test face is buckled on the mouth of the beaker, and the test site should be flat. this The time is started and the test time is 60s.

6.2.3 Complete the fixation of the samples in 6.2.1 and 6.2.2, the total time shall not exceed 20s.

6.2.4 At 60s, under natural light or 40W fluorescent lamp, observe the surface of the film sample from top to bottom perpendicular to the bottom of the beaker, observe within 5s Finished.

6.3 Water bath hot mist method

6.3.1 Add tap water to the sink and fix the standard logarithmic near vision chart in GB 11533-2011 Appendix B after waterproofing and fix the water bath On the bottom plate of the trough, the clarity of the visual acuity chart visible in the water is consistent with the natural state.

6.3.2 Pour (200 ± 10) mL, (23 ± 2) °C into the flat mouth beaker to meet the requirements of GB/T 6682-2008 tertiary water.

6.3.3 Fix the sample with double-sided tape or rubber band so that the anti-fog performance test surface is buckled on the beaker mouth, and the test site should be flat.

6.3.4 Place the flat beaker with the sample in a constant temperature water tank at (60 ± 2) ° C, so that the bottom of the cup is submerged in the water bath (50 ± 5) mm, start Timing.

6.3.5 At 15min, under natural light or 40W fluorescent lamp, observe the film sample surface from top to bottom perpendicular to the bottom of the beaker, observe within 5s Finished.