Method development for measuring oil and grease resistance of coated paper- and board materials

Abstract

Dispersion coating is an application technology that provides barrier properties for paper and board materials. The function of barriers in food packaging is to block or reduce water, gas or oil flow throughout the package. Within the pulp and paper industry, there are several methods for measuring the effectiveness of barriers against oil and grease. Often, these methods use test reagents that do not correspond to oils used in food. A common method is KIT-test which is adequate for papers treated with fluorochemicals (FC). Due to their adverse health effect, these paper products are being replaced by FC-free products. This leads to increasing demand for replacing the KIT-test with methods suitable for grease-resistant coating without fluorochemicals. The purpose of this thesis is to implement ASTM- F119 for measuring the effectiveness of dispersion coated barriers against penetration of cooking oils. Another objective was to optimize ASTM- F119 by investigating the effect of different parameters such as temperature, amount of oil reagent and pressure. The result was compared with the reference methods, KIT-test and oleic acid test. The oil reagents were vegetable oils, such as olive oil, coconut oil, rapeseed oil, and animal fat such as butter. The penetration time was based on a subjective visual evaluation. The result shows that KIT-test can still be used to compare barriers, but there is a lack of information about how long it takes for a cooking oil reagent to go through the barriers. Therefore, ASTM F- 119 is more adequate for comparing barriers and estimating oil penetration times. The modified ASTM- F119 method shows good potential for evaluating grease resistance of different barriers using oils that correspond closely to the true food package contents and, are hence, realistic test oils.