Browsing by Author "Oravala, Ilmari"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
- Suberin-based dispersion coatings for moisture barrier in packaging applications
Kemian tekniikan korkeakoulu | Master's thesis(2024-06-11) Oravala, IlmariA current trend in the packaging industry is to produce more easily recyclable packaging solutions. One of the main goals is to reduce plastic waste accumulation. Roughly 40 % of all plastic is used in packaging. Thus, having barrier materials which are more sustainable are highly desired. Along with having polymers with better end-of-life or recovery schemes, bio-based polymers are also in interest due to the limitations of petroleum resources. Various bio-based materials have gained interest as potential barrier materials, such as suberin, which is a lipophilic biopolyester found in the bark of certain trees. This master’s thesis explores preparation of suberin dispersions with varying pigment concentrations and investigates the barrier performance of paperboard and paper coated with the prepared suberin dispersions. The suberin used in this work was extracted from birch outer bark. Two types of pigments were used in the suberin-pigment dispersions: kaolin and talc. The pigment ratio varied from 0 to 60 wt%. The experimental work tries to find answers to how varying pigment ratios for both kaolin and talc affect the following properties: particle size, water vapor transmission rate (WVTR), water absorption (Cobb60), grease barrier (KIT) and water contact angles (WCA) of the coated paperboards and papers. One of the key observations is to find the critical pigment volume concentration (CPVC) of the coatings from the obtained WVTR results. As a side project for the experimental part, plain suberin dispersion was also coated in pilot scale on same substrates with an off-machine coater. WVTR and water absorption were measured from pilot scale coated substrates. Plain suberin and suberin-pigment dispersions were prepared and coated on paperboard and paper successfully. Overall, the barrier properties of the coated paperboards and papers were improved. The one property that was decreased, for all samples, in the terms of barrier performance was WCA. Furthermore, water absorbance (Cobb60) of all coated paper samples was increased compared to the uncoated paper. - Usage of Cardanol from Cashew Nutshell Liquid (CNSL) in Epoxy Resins
Kemiantekniikan korkeakoulu | Bachelor's thesis(2019-12-23) Oravala, Ilmari