The coat weight values, measured in an air-conditioned room, were compared to values measured after drying the samples in an oven at 105C in order to determine the moisture absorbency.
The curlof the samples was measured as an average from four parallel round samples with an area of 100 cm2.
Curl is reported in millimetres representing the highest rise of sample edges (coated-side curl) or centre(back-side curl) from a horizontal level.
The grease resistance of the dispersion barrier–coated paperboard samples before converting was measured according to TAPPI 559 cm-02 (KIT test).
The KIT test uses a series of mixtures of castoroil, toluene and heptane.
As the ratio of oil to solvent is decreased, the viscosity and surface tension ofthe liquid also decrease, making successive mixtures more difficult for the barrier to resist.
The performance is rated by the highest numbered solution that does not darken the paper after 15 s.Thereby, a completely greaseproof substrate is expressed as KIT 12.