Gurley Cobb Absorption Testers

Purpose of list

Water absorptiveness of paper board or other materials is a function of various characteristics such as sizing, porosity, etc. The Gurley-Cobb sizing test can be used to test absorption or resistance to absorption of water, oil and other liquids.

This procedure determines the quantity of water absorbed by a sample of paper or other sheet material in a specified time and under standardized conditions. Other liquids such as ink, beverages, oil and water based solutions may be used instead of water. The standard area is one hundred square centimeters (cm2), into which 100cc of liquid are poured to reach a specific height of 1 cm. For smaller samples, proportionately smaller areas (25 and 10 cm2) can be tested.

The Gurley-Cobb Sizing Tester consists of a hollow metal cylinder or ring (100, 25 or 10 cm2 inside area); a metal base plate with a clamping device to hold the ring against the sample and a Neoprene mat. Neoprene gaskets also are supplied to seal off the cylinder when testing uneven materials where an ungasketed seal is difficult to maintain. A critical component of this test is a solid stainless steel roller having a smooth face 20cm wide and weighing 10.0+ 0.5kg.

Also required for the test are a 100ml graduated cylinder, a balance with sensitivity of 0.01g or better, blotting paper and a timer or stopwatch.