Using synthetic urine, gushes of the liquid are dosed into the centre of the nappy using a pump. For newborn nappies each gush is 30mL, for infant nappies it's 40mL, for crawler nappies it's 50mL, for toddler nappies it's 55mL, for walker nappies it's 60mL and for junior nappies it's 65mL. This simulates a child wearing the nappy overnight. We measure the amount of time it takes for the liquid to disappear. This is repeated four times with a five-minute gap between each gush. The total time taken for all four gushes to be absorbed is the absorption speed.
Five minutes after the last gush from the absorption test, six pre-weighed dry filter papers are placed on the wet nappy and held down for 30 seconds. The filter paper is then removed and weighed. Ideally, the filter paper should remain relatively dry.