Time the contact before the pull
Packaging sample showroom of SamBound New Material Technology Company Ltd. (sambound.com).
The dwell starts when the loaded sled is in contact with the specimen and ends when the pull starts. During that interval some film surfaces can settle or develop more contact, which may change the force recorded at the onset of motion. The effect depends on the surface pair, load and conditions. A peak by itself does not show whether the change came from the contact or the fixture.
Use fresh specimens to isolate dwell
Imagine a laboratory sets the sled down and starts pulling immediately, while another waits while entering sample details. To compare the two approaches, run both dwell intervals on fresh, equivalently conditioned specimens from the same lot. Match the contacting faces, alignment, normal load and pull speed. Use the same way of lowering the sled and record the interval for each run.
If a difference repeats, specify the dwell in the agreed procedure and use it for future comparisons. If the difference varies across runs, inspect how the sled is placed and how the force peak is captured before assigning it to the film.
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