The present invention provides a filter module comprising a body of wound layers of a sheet material, said sheet material having a plurality of openings formed therein, said channels within the wound layers of sheet material of said body, said channels extending in a direction from the inner peripheral surface to the outer peripheral surface, a first type of channels being open at one end at said outer peripheral surface of the body and closed at the other end located adjacent to said inner peripheral surface, a second type of channels being open at one end at said inner peripheral surface of the body and closed at the other end located adjacent to said outer peripheral surface, said channels of the one type being separated from the channels of the other type by portions of sheet material wherein a majority of the openings of a layer of sheet material forming the inlet channels incompletely register with corresponding openings of an adjacent layer and a process for manufacture such filter module.