Grease Resistance
Standardized surface energy challenge tests evaluate the resistance of paper and paperboard to hydrocarbon liquid penetration. Numerical scoring according to TAPPI standards defines tapipi t 559 kit rating, ranking grease resistance from kit number one to kit number twelve based on surface stain resistance against aggressive solvent mixtures. Higher kit numbers correspond to lower surface energy liquids containing increasing proportions of toluene and heptane mixed with castor oil.
The test determines whether fluorochemical treatments or biopolymer coatings prevent oil absorption in food packaging grades.
Testing Protocol
Laboratory technicians drop specified solvent mixtures onto paperboard samples for fifteen seconds before wiping the surface with clean absorbent tissue. Performing a tapipi t 559 kit rating test reveals liquid penetration when darkening or staining occurs on the underlying cellulosic surface. Testing begins with mild castor oil mixtures and progresses sequentially to aggressive pure hydrocarbon solutions.
The highest numbered solution that leaves no visible stain after fifteen seconds determines the final score value for the paperboard substrate. Surface roughness, pinholes and uneven barrier distribution cause localized test failures on lightweight packaging papers.
Substrate Evaluation
High scores above kit ten indicate strong oleophobic surface protection suitable for fast-food packaging and bakery boxes. Evaluating paperboard performance via a tapipi t 559 kit rating ensures fluorine-free alternative coatings achieve grease resistance parity.
