Patent ID: 7462754
Filing Date: 2008-12-09
Classification: A61F,A61L,Y10T

Abstract:
1. Method for producing an absorbent structure, comprising the following steps: introducing a thermoplastic polymer, and a superabsorbent particulate polymer material into a closed system extrusion apparatus wherein the superabsorbent particulate polymer material has a moisture content of at least 0.5% by weight; melting the thermoplastic polymer material at temperatures below a melting or degradation temperature of the superabsorbent particulate polymer material at an elevated pressure to produce a mixture; extruding the mixture, whereby the moisture in the superabsorbent particulate polymer material evaporates as pressure is reduced and results in foaming of the melted thermoplastic polymer, which bonds the particulate superabsorbent polymer material together with the thermoplastic polymer to create a matrix composed of foamed thermoplastic polymer surrounding superabsorbent particulate polymer material; wherein the percentage by weight of the superabsorbent particulate polymer material is at least 70% by weight of the admixture introduced into the extrusion apparatus; wherein the method is integrated into a production process for hygiene articles and therein the absorbent structure is extruded directly inside machinery for the high-speed production of hygiene articles, wherein inside the high-speed production machinery a triple-layer absorbent core is formed by coextrusion of the layers, whereby the absorbent core comprises the absorbent structure as absorbent core layer and a fluid distribution and intermediate retention layer on the body-facing side of the core layer and wherein the third layer is a fluid-impervious film which is located on the side of the absorbent core layer facing away from the body.