US Patent 11364711 Multi-layer substrates comprising sandwich layers and polyethylene

Multi-layer substrates comprising a top surface layer of pulp fibers, a bottom surface layer of pulp fibers, and a melted thermoplastic material layer between the pulp fiber layers, where the thermoplastic material comprises polyethylene or has a tan delta value of 0.2 to 0.4 within the temperature range of 100° F. to 350° F. The multi-layer substrate can include a cleaning composition loaded onto the multi-layer substrate, where a fluid pathway through the melted thermoplastic material allows the cleaning composition to travel from the top surface layer to the bottom surface layer. The multi-layer substrate may be void of chemical adhesives, where adhesion between the top surface layer and the thermoplastic layer, and between the bottom surface layer and the thermoplastic layer is instead provided by the thermoplastic material itself, which bonds to groups of fibers in the pulp fibers top and bottom surface layers that are in contact with the thermoplastic material as it melts.