Abstract
A combination of elevated temperature, tension and
dimensional changes are common in converting and
packaging processes. Paperboard and polymer films, either
alone or as a combined material, can undergo either
desired or unwanted deformations. Here, two examples of
testing the deformation behaviour are presented and two
novel test methods for packaging materials are
introduced.
The development of new paper-based packaging requires
improvement in the thermoformability and extensibility of
paper. However, the extensibility of paper can be highly
dependent on the forming conditions, which may be either
an advantage or a hindrance for the forming performance.
VTT's novel, laboratory scale, 2-dimensional
thermoforming tester was improved in order to better
simulate the process conditions of thermoforming. The
results clearly show the softening effect of the forming
temperature on strength and stiffness, which are
temporarily reduced, and the improving effect on the
extensibility of polymer covered paperboard. The
influence of mechanical and novel chemical treatments of
the bleached softwood kraft pulp on the improved
extensibility of paperboard are presented.
The quality of printing on polymer film can be adjusted
by web tension, drying process conditions and by taking
account of the thermoplastic properties of the material.
A special electric heating device was mounted on to a
high strain-rate tensile tester in order simulate the
heat-induced changes in the tensile behaviour of the
polymer film. The heating device formed a small
non-contacting climate chamber, which was able to heat
the test samples to a target temperature of 30-110 °C
within a couple of seconds. Thermoplastic elongation of
polymer film was measured by utilizing constant tension
under cyclic temperature variation in order to simulate
web tension and elongation during printing and drying.
The studied polymer film showed extensive increases in
strain due to heating and contraction during the
subsequent cooling periods and permanent deformation
after the heating and cooling cycles.
| Original language | English |
|---|---|
| Title of host publication | Proceedings of the 28th IAPRI Symposium on Packaging 2017 |
| Publication status | Published - 2017 |
| MoE publication type | Not Eligible |
| Event | 28th IAPRI Symposium on Packaging 2017: Unlocking the full potential of packaging across the value-chain - Lausanne, Switzerland Duration: 9 May 2017 → 12 May 2017 |
Conference
| Conference | 28th IAPRI Symposium on Packaging 2017 |
|---|---|
| Country | Switzerland |
| City | Lausanne |
| Period | 9/05/17 → 12/05/17 |
Keywords
- creep
- shrinkage
- thermoformability
- thermoplastic
- polymer film
- paperboard