Patent ID: 8454829

Claim:
A spiral cross-flow filter, comprising: an outer cylindrical shell; a permeate cylindrical tube coaxially aligned within the shell and radially offset therefrom; and an annular pleated filter element disposed within an annulus between the outer shell and the permeate tube, the filter element comprising a composite filter material comprising: a first layer of a membrane material adjacent the outer shell, and a second layer of a permeate spacer material adjacent the permeate tube, wherein the membrane material and the permeate spacer material are bonded together at an inlet edge and an outlet edge of the filter element; the pleats of the filter element defining a plurality of circumferentially spaced radial leaves, wherein the plurality of leaves wrap around the permeate tube in a uniform direction, wherein each leaf comprises an attachment to the permeate tube at a proximal edge of the leaf, and wherein each attachment comprises a direct bond between the permeate tube, the membrane material, and the permeate spacer material.