Endprodukteigenschaften von PET-Verpackungsbändern in Abhängigkeit von thermischen Einflussfaktoren im Produktionsprozess

Translated title of the contribution: Final product properties of PET-packaging tapes depending on thermal processing parameters

Pamela Kremser

Research output: ThesisMaster's Thesis

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Abstract

High strength packaging tapes of Polyethyleneterephthalate (PET), which are produced of recycled PET beverage bottles, are applied to bundle packaging goods and/or reduce volume. Due to quality variations of the recycled material it is important to know the interactions of separate processing parameters and their influences on the performance of the packaging tapes. In a initial step of the present work, important processing parameters such as drying temperature, annealing conditions and stretch ratio were changed systematically to characterize their influences on the resulting tape properties. In order to get information about morphology of recycled PET packaging tapes differential scanning calorimetry (DSC) and thermomechanical analysis (TMA) were used. The mechanical properties were determined by tensile tests, tear strength tests and relaxation tests. Additionally, the melt volume index (MVI) of each material state was determined. As a main result it could be shown that the conditioning steps before extrusion dont have a significant influence on the tape properties. Nevertheless, to avoid a change in molecular weight during the extrusion process a maximum moisture content of the predried material must not be exceeded. On the other hand, the mechanical properties and especially the splice and shrinkage behaviour strongly depend on the annealing conditions after extrusion. Generally, the annealing process improves the shrinkage behaviour of the tape but the crystallization on the elevated temperatures increases the splice tendency. As a result of the present work, optimized annealing parameters were found out which lead to a distinct decrease of shrinkage and improved splice behaviour at application relevant temperatures up to 80°C. This optimization can be realized with reduced annealing times (minute range) and an increase of annealing temperature up to 20°C in comparison to the standard annealing parameters. Together with a reduction of conditioning temperatures prior to extrusion these optimization steps also have the potential to save processing energy.
Translated title of the contributionFinal product properties of PET-packaging tapes depending on thermal processing parameters
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
  • Pinter, Gerald, Supervisor (internal)
  • Krziwanek, Thomas, Supervisor (external), External person
  • Pilz, Gerald, Co-Supervisor (internal)
Award date26 Mar 2010
Publication statusPublished - 2010

Bibliographical note

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Keywords

  • PET packaging tapes mechanical properties recycling

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