A method of producing a contact filter block comprising the steps of supplying a granulate material to a heating and pressurising unit from a reservoir conveying the granulate material along a path of travel, heating the granulate material and pressurising the granulate material to an elevated pressure while conveying the granulate material along the path in a heating and pressurising unit, the heating and pressurising being performed according to a specific heating and pressurising profile, transferring the heated and pressurised granulate material to the extruder unit, heating the granulate material within the extruder to a temperature, extruding the mesh-type structural structure from the granulate material, the heating of the granulate material causing an expansion of a foaming additive causing the mesh- type structural structure to obtain a porous structure, cooling the extruded mesh- type structural structure by means of a cooling unit according to a specific cooling profile thereby stopping or halting expansion of the granulate material and/or the foaming additive and locking or fixating the porous structure of the mesh-type structural structure, and cutting the mesh-type structural elements using a measuring and cutting unit.