Recycling of plastics from liquid carton packaging
Mäki-Tulokas, Sandra (2021)
2021
Materiaalitekniikan DI-ohjelma - Master's Programme in Materials Engineering
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2021-11-23
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202111188532
https://urn.fi/URN:NBN:fi:tuni-202111188532
Tiivistelmä
Liquid carton packages are a multilayer packaging type typically consisting of cardboard and plastics and in some applications aluminium. The recycling targets and directives for packaging has changed which demands on researching the potential to utilize packaging waste as raw material in consumer products.
The main objective of thesis was to evaluate the usability of plastics from liquid carton packages in consumer products. To evaluate the usability samples were processed from liquid carton packaging and cardboard recycling reject and the composition and properties of those were studied. For two samples repulping was done to reduce the fiber content and research the properties with different fiber contents. The rejects were compounded and extruded into granulates which were injection moulded into test specimen. The compositions of the sample rejects were determined using differential scanning calorimetry and thermogravimetric analysis. Energy dispersive spectroscopy was used to evaluate the aluminium content in the samples. To evaluate the processability and usability the viscosity of the samples was evaluated with melt mass-flow rate measurements and mechanical properties were determined with tensile testing. Also, thermal conductivity was measured using laser flash method and rotational moulding was tested as a feasible product processing method. To evaluate the usability the samples were compared to similar commercial wood plastic composites and biocomposites and methods to modify the reject properties were introduced.
All the researched samples were extrudable and injection mouldable. All the samples contained cellulose and LDPE. Some of the samples also contained LLDPE/HDPE, PP/EVOH, PET and aluminium. The repulping was successful and a suitable method to decrease the cellulose content and modify properties of the samples. The biggest differences between all the samples were on compositions and melt mass-flow rates, and they were also the biggest differences between the repulped and un-repulped samples. The mechanical properties and thermal conductivities of the samples were approximately on the same level. The sample from consumer liquid carton packaging recycling which was repulped is most suitable for consumer products because processing it was easiest. Because the mechanical properties of all the samples were relatively low, the rejects are not suitable for products with high demands for mechanical properties.
The main objective of thesis was to evaluate the usability of plastics from liquid carton packages in consumer products. To evaluate the usability samples were processed from liquid carton packaging and cardboard recycling reject and the composition and properties of those were studied. For two samples repulping was done to reduce the fiber content and research the properties with different fiber contents. The rejects were compounded and extruded into granulates which were injection moulded into test specimen. The compositions of the sample rejects were determined using differential scanning calorimetry and thermogravimetric analysis. Energy dispersive spectroscopy was used to evaluate the aluminium content in the samples. To evaluate the processability and usability the viscosity of the samples was evaluated with melt mass-flow rate measurements and mechanical properties were determined with tensile testing. Also, thermal conductivity was measured using laser flash method and rotational moulding was tested as a feasible product processing method. To evaluate the usability the samples were compared to similar commercial wood plastic composites and biocomposites and methods to modify the reject properties were introduced.
All the researched samples were extrudable and injection mouldable. All the samples contained cellulose and LDPE. Some of the samples also contained LLDPE/HDPE, PP/EVOH, PET and aluminium. The repulping was successful and a suitable method to decrease the cellulose content and modify properties of the samples. The biggest differences between all the samples were on compositions and melt mass-flow rates, and they were also the biggest differences between the repulped and un-repulped samples. The mechanical properties and thermal conductivities of the samples were approximately on the same level. The sample from consumer liquid carton packaging recycling which was repulped is most suitable for consumer products because processing it was easiest. Because the mechanical properties of all the samples were relatively low, the rejects are not suitable for products with high demands for mechanical properties.