ASTM D3285 – Standard Test Method for Water Absorptiveness of Nonbibulous Paper and Paperboard (Cobb Test) (Withdrawn 2010)
Significance and Use
Water absorptiveness is a function of various characteristics of paper or board, including sizing, porosity, and fiber composition.
This test method is useful in comparing various sheets or nonbibulous (not highly absorbent) paper or paperboard as to the relative rate of penetration of aqueous solutions, such as adhesives or coatings. It will indicate to some degree the surface and internal sizing. This test method is not intended as a water-resistance test, nor to measure the resistance to minute quantities of a liquid, such as from a writing pen.
1.1 This test method covers the determination of the quantity of water absorbed in a specified time by nonbibulous paper and paperboard with a minimum thickness of 0.1 mm. This test method is generally applicable to sized paper and paperboard, but is not recommended as a sizing test for writing papers. The test method is based upon studies by Cobb and Loew, Cobb, and other investigators (1, 2, 3, 4).
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.