TAPPI T 432 cm-21 PDF

This procedure determines the time required for an unsized and absorbent paper, such as a blotter, tissue, or towel, to completely absorb a specified quantity of water, suited to the kind of paper to be tested (1-4). 

It is not intended for sized papers nor those having an absorption time of over 120 s. Such papers should be tested in accordance with TAPPI T 441 "Water Absorptiveness of Sized (Non-Bibulous) Paper and Paperboard (Cobb Test)". For corrugating medium use TAPPI T 819 "Water Absorbency of Corrugating Medium." 
The water absorption results of this method can be used to judge the acceptability of tissue, toweling and blotter papers in sorptive tasks. For accurate comparisons of comparable materials this method has been superseded by more modern methods.