A method is provided for producing a green paper for producing a gas diffusion layer (GDL) for a fuel cell. A first paper web is formed, and a second paper web is formed, which are brought together with and rigidly connected to the first paper web while still wet. The first paper web and the second paper web are mixed with metal powder and/or metal fibers and together form the green paper, optionally together with additional components and/or coatings. The final GDL is provided after a binding-removal process, a sintering process, a coating process, a (thermal) deposition process (atomic layer deposition process, ALD), and optionally additional process steps.

A method is provided for producing a green paper for producing a gas diffusion layer (GDL) for a fuel cell. A first paper web is formed, and a second paper web is formed, which are brought together with and rigidly connected to the first paper web while still wet. The first paper web and the second paper web are mixed with metal powder and/or metal fibers and together form the green paper, optionally together with additional components and/or coatings. The final GDL is provided after a binding-removal process, a sintering process, a coating process, a (thermal) deposition process (atomic layer deposition process, ALD), and optionally additional process steps.

A green paper is provided for producing a gas diffusion layer (GDL) for a fuel cell. A process is for producing a green paper for producing a gas diffusion layer (GDL) for a fuel cell. The green paper includes at least one first, watermarked paper web. The watermark forms the patterning for the flow field or gas distribution structure of the gas diffusion layer (GDL) produced from the green paper. The first paper web is admixed with metal powder and/or metal fibres. The eventual GDL is formed after debindering, sintering, coating, deposition of atomic layers (ALD—atomic layer deposition) and further operating steps.

A green paper is provided for producing a gas diffusion layer (GDL) for a fuel cell. A process is for producing a green paper for producing a gas diffusion layer (GDL) for a fuel cell. The green paper includes at least one first, watermarked paper web. The watermark forms the patterning for the flow field or gas distribution structure of the gas diffusion layer (GDL) produced from the green paper. The first paper web is admixed with metal powder and/or metal fibres. The eventual GDL is formed after debindering, sintering, coating, deposition of atomic layers (ALD—atomic layer deposition) and further operating steps.

A sheet manufacturing method includes a web forming step of forming a web by accumulating a defibrated product in a dry manner, a moisture imparting step of imparting the web with moisture, a pressurizing step of pressurizing the web to which the moisture is imparted, and a heating step of heating the web to which the moisture is imparted, in which a water content of the web to which the moisture is imparted in the moisture imparting step is 12% by mass or more, a pressure applied to the web in the pressurizing step is 0.2 MPa or more, and a temperature of the web in the heating step is 100° C. or lower.

A sheet manufacturing method includes a web forming step of forming a web by accumulating a defibrated product in a dry manner, a moisture imparting step of imparting the web with moisture, a pressurizing step of pressurizing the web to which the moisture is imparted, and a heating step of heating the web to which the moisture is imparted, in which a water content of the web to which the moisture is imparted in the moisture imparting step is 12% by mass or more, a pressure applied to the web in the pressurizing step is 0.2 MPa or more, and a temperature of the web in the heating step is 100° C. or lower.

A roll for molding a fibrous sheet. The roll includes a rotatably driven cylindrical shell. The cylindrical shell includes an interior surface, an exterior surface, and a permeable patterned surface on the exterior surface of the shell. The permeable patterned surface has at least one of a plurality of recesses and projections, a plurality of holes extending from the exterior surface to the interior to allow air to be moved through the shell. Each hole has an exterior end and an interior end, and a plurality of grooves. Each groove is fluidly connected to the exterior end of each hole and extends outward from the corresponding hole. The roll also includes a vacuum box on the inside of the cylindrical shell to draw air from the exterior surface of the shell to the interior surface. The vacuum box is stationary with respect to the rotation of the shell.

A roll for molding a fibrous sheet. The roll includes a rotatably driven cylindrical shell. The cylindrical shell includes an interior surface, an exterior surface, and a permeable patterned surface on the exterior surface of the shell. The permeable patterned surface has at least one of a plurality of recesses and projections, a plurality of holes extending from the exterior surface to the interior to allow air to be moved through the shell. Each hole has an exterior end and an interior end, and a plurality of grooves. Each groove is fluidly connected to the exterior end of each hole and extends outward from the corresponding hole. The roll also includes a vacuum box on the inside of the cylindrical shell to draw air from the exterior surface of the shell to the interior surface. The vacuum box is stationary with respect to the rotation of the shell.

A sheet manufacturing method includes a web forming step of forming a web by accumulating a defibrated product in a dry manner, a moisture imparting step of imparting the web with moisture, a pressurizing step of pressurizing the web to which the moisture is imparted, and a heating step of heating the web to which the moisture is imparted, in which a water content of the web to which the moisture is imparted in the moisture imparting step is 12% by mass or more, a pressure applied to the web in the pressurizing step is 0.2 MPa or more, and a temperature of the web in the heating step is 100° C. or lower.

A sheet manufacturing method includes a web forming step of forming a web by accumulating a defibrated product in a dry manner, a moisture imparting step of imparting the web with moisture, a pressurizing step of pressurizing the web to which the moisture is imparted, and a heating step of heating the web to which the moisture is imparted, in which a water content of the web to which the moisture is imparted in the moisture imparting step is 12% by mass or more, a pressure applied to the web in the pressurizing step is 0.2 MPa or more, and a temperature of the web in the heating step is 100° C. or lower.