Abstract: A method of measuring indices in superabsorbents, by initially charging excess aqueous solution or dispersion, swelling the superabsorbent in the initially charged aqueous solution or dispersion while stirring, dissolving or dispersing a component A in the aqueous solution or dispersion, measuring the enrichment of component A in the aqueous solution or dispersion during the swelling of the superabsorbent, using the enrichment of component A in the aqueous solution or dispersion to measure the time-dependent swelling characteristics and using these to determine the swelling constant k or the characteristic swell time T, the index being dependent on the permeability of the superabsorbent, and ascertaining the index by means of a correlation measured beforehand between swelling constant k and index or characteristic swell time T and index.

Abstract: The present invention relates to a fluid-absorbent article, comprising a fluid-absorbent core, comprising from 0 to 90% by weight fibrous material and from 10 to 100% by weight water-absorbent polymer particles having a mean sphericity (SPHT) from 0.8 to 0.95, based on the sum of water-absorbent polymer particles and fibrous material; and an acquisition-distribution layer between having a three dimensional apertured structure having a femal side (5) and a male side (6), wherein the femal side presents a multiplicity of openings extending in the form of through holes in the direction of a lower surface of the same structure being the male side, wherein the quantity of the water absorbent polymer particles within the fluid absorbent core is at least 3 g.