Atomikerroskasvatuksen hyödyntäminen pakkausrakenteissa

Nowadays, a lot of attention is focused on the possibilities for using Atomic Layer Deposition (ALD) process in packaging solutions. The greatest benefit of an ALD layer is the loss of weight to the packaging. This leads to cost savings during the packaging life cycle. The main target concerning packaging solutions is to create a profitable way to manufacture an ALD layer to packages. At the moment, the most applicable solution seems to be the development of Roll-to-Roll ALD (RRALD) process being faster and cheaper than the batch ALD process. In this thesis the ALD process is first explained briefly. Then the materials in the process are presented followed by comparison between different ALD processes. Finally, the benefits of using ALD in packaging technology and new ideas about possible solutions based on ALD are discussed. Results indicate, that a few nanometers thick aluminum oxide layer produced by ALD can improve water vapour and oxygen barrier significantly, when this layer is deposited onto a polymer substrate. On polyethylene terephthalate (PET) surface and in the best scenario, an Al2O3 ALD layer decreased moisture and oxygen permeation through the structure to one percentage of the original value. On top of polyolefins, such as low density polyethylene and polypropylene (LDPE and PP, respectively), and polylactic acid (PLA) the Al2O3 ALD layer decreased the measured moisture and oxygen permeation through the structure tens of times lower level compared to the value of polymer only. An Al2O3 ALD layer no thicker than 40 – 50 nm is enough to improve the water vapor permeation of LDPE, PP and PET films less than 1 g/m2/24h in normal conditions. A film with a top Al2O3 ALD layer can be further extrusion coated with an extra LDPE layer to create a structure with excellent sealing properties. Currently RRALD process might be a slightly more expensive way to produce packaging than the conventional laminating process, but there will be savings in terms of material and transportation costs (empty packages, packaging with the product and packaging eventually as litter). Packaging in which aluminum foil is replaced by an ALD layer can also be recycled and thus avoid ending up in a landfill