Recycling of Absorbent Hygiene Products (AHP): An Engineering Case Study of a Sequential Pilot-Scale Processing Line

Used Absorbent Hygiene Products (AHP), especially disposable diapers, form a highly heterogeneous waste stream composed of polyolefin films and nonwovens, cellulose pulp, superabsorbent polymer (SAP), biological contamination, and strongly variable moisture content. This study evaluates the operational performance of a sequential pilot-scale recycling line developed by TAMAX Ltd. in cooperation with the Silesian University of Technology, Poland. The analysis focuses on the mechanical and process conditions required to open, separate, and recover useful fractions from AHP waste, rather than on a single unit operation. The process includes source-separated collection, hygienization, low-speed mechanical preprocessing, screening, and fraction separation aimed at recovering polyolefin (PE/PP), cellulose-rich, and SAP-containing fractions. The main mechanical modification is the triangular cuttingand-splitting blade system made of Hardox 450/500 steel. Its task is to cut and open the polymer cover layers without excessive shredding of the PE/PP foil fraction. Thermal measurements showed that the cutting-zone temperature remained below 326 K, which limited thermal microlamination and local polymer degradation. At the reported pilot stage, moisture and drive-load observations were used to define operating windows and to support operator-based adjustment of feed and shredding parameters. The line should therefore be treated as a mechanically reconfigurable pilot system, not as a fully sensor-integrated adaptive control system. Operational data from pilot-line validation indicate that stable processing depends mainly on feedstock moisture, shredding speed, screen selection, and the thermal regime of the cutting tools. The reported nominal capacity of 5 Mg·h^-1 refers to input waste throughput, not to the mass flow of a single recovered product. Recovered sodium polyacrylate (R-SAP) is discussed as a downstream valorization target for halloysite-based soil-modifier composites. The material-performance result for the R-SAP/halloysite system was previously reported by Sakiewicz et al. [1] and is used here only as an external reference for the potential use of the recovered R-SAP fraction. The direct contribution of this paper is the engineering assessment of the TAMAX sequential line as a pilot-scale process for producing recoverable AHP fractions. The results show that further development should focus on moisture control, cutting intensity, separation stability, and later implementation of sensor-based monitoring, which was not yet fully realized in the reported pilot configuration.