Surface tension detection method

There are three commonly used detection methods.

1. Peel inspection with BOPP single-sided tape

Attach the BOPP single-sided tape to the surface of the film to be tested, press it tightly, and then tear it open. If the surface tension of the film meets the requirements for use, then the peeling is very hard and the sound is small; on the contrary, it is easy to peel off and is accompanied by a "rustle" sound.

2. Test with dyne test pens

When the surface tension value of the film meets the requirements (BOPP: 3.8x10-2N/m, PET: 5.010-2N/m, nylon: 5.2x10-2N/m), the liquid marks in the places where the strokes are tested are uniform, no break marks, no shrinkage Otherwise the test solution will shrink. If one part shrinks and one part does not shrink, it means that the treatment is not enough.

It is worth mentioning that when testing PET and nylon, a large-scale test pen is needed. Typical specifications for surface tension test pens are: 3.8×10-2N/m, 4.0×10-2N/m, 4.2×10-2N/m, 4.4×10-2N/m, and 4.8×10-2N/m. (For measuring aluminum foil).

3 self-made surface tension test solution

Part of the surface tension test solution formulations see the attached table. The test method is to apply a few test liquids to the treated surface with a cotton ball, and the judgment method is approximately the same as the second point.

The treated film should not be placed for a long time, up to 7 days. The longer the time, the more obvious the surface tension decreases. If it needs to be placed for a long time, the initial value of the surface tension will increase (2~4)*10~2N/m when the film is processed.

Source: admin