Characterisation of stretch hood and stretch wrapping films by hysteresis tensile test (only in stretching direction, e. g. generally in TD)
During processing, stretch hood tubular film is cut to length, sealed and stretched in the transverse direction of the film to such an extent that it can be slipped over a pre-packed pallet without contact. The film is then relieved of pressure and, due to the viscoelastic restoring forces of the materials used, clings tightly to the packed goods, building up a slight tension.
Since the standard tensile test is not suitable for determining the properties of these special products, we have developed this laboratory test that maps the most important key points of the stretch hood process under reproducible conditions. This hysteresis tensile test may be used for material comparisons and for specifying suitable film types. It is also suitable for stretch wrapping films, but these are usually tested in the longitudinal direction.
In short — AI-generated
The hysteresis tensile test simulates the application process of stretch hood and stretch wrapping films by repeatedly stretching and relaxing the material in a defined direction. This method measures the film's mechanical response under conditions that mimic the actual stretching over a pallet and the subsequent recovery phase.
The resulting values characterize the film's elastic recovery and holding force, which are critical for ensuring the load is secured tightly. These data points allow for objective material comparisons and help developers select the appropriate film type for specific palletizing requirements.
Text is AI-generated; based on test method data curated and verified by Innoform.