Cleaning pads that are pulled across a surface by the hand require a minimum level of friction with the hand under use conditions in order to exhibit grippability, that is, to keep the hand from slipping off.
Such cleaning pads may have multiple layers for scrubbing, absorbency, and other functions such as a barrier to keep moisture or cleaning solution from the hand. The layer of the cleaning pad that is in contact with the hand should contain at least 40% by weight of pulp fibers to meet the requirement of grippability in the presence of cleaning agents/surfactants.
In order to demonstrate the influence of the substrate composition on grippability, the friction coefficient between the hand and the hand-facing layer of the cleaning pad was measured. The cleaning pad was affixed with hand-facing side up to a platform mounted on vertical and horizontal load cells, and then the hand was moved across it in a standardized procedure (distance, speed, pressure). Values of friction coefficient thus collected were consistent across people (after accounting for hand size) and showed statistical differentiation.