Abstract: Methods of making membrane elements for fluid or gas filtration, comprising applying feed or reject spacers, or intermediate spacers, or fold line protection strips, or end support strips directly to a membrane sheet, or to a substrate material which are subsequently applied to a membrane sheet, which thereby avoids contamination from directly printed adhesives, inks, or polymers, or damage from heat or radiation damage to the membrane sheet during direct application of spacers or patterns to the surface of the membrane sheet, thereby avoiding utilization of conventional feed spacer mesh materials. Membrane sheets and spiral wound filtration elements having spacers applied to defined regions of the sheet, in some embodiments having spacers mounted on substrates with different material properties, e.g., stiffness, than the underlying membrane.

Abstract: Methods of making membrane elements for fluid or gas filtration, comprising applying feed or reject spacers, or intermediate spacers, or fold line protection strips, or end support strips directly to a membrane sheet, or to a substrate material which are subsequently applied to a membrane sheet, which thereby avoids contamination from directly printed adhesives, inks, or polymers, or damage from heat or radiation damage to the membrane sheet during direct application of spacers or patterns to the surface of the membrane sheet, thereby avoiding utilization of conventional feed spacer mesh materials. Membrane sheets and spiral wound filtration elements having spacers applied to defined regions of the sheet, in some embodiments having spacers mounted on substrates with different material properties, e.g., stiffness, than the underlying membrane.

Abstract: The present invention relates to a spiral wound membrane element designs that utilize entrance and exit points in the feed space channel and utilize barriers on the perimeter of the feed space as well as barriers in the feed space area to direct fluid flow in the membrane element.

Abstract: The present invention relates to a spiral wound membrane element designs wherein the membrane sheet is fabricated with selective flux and rejection characteristics that can then be modified using various intensities and wavelengths of energy such as UV or the visible spectrum to optimize characteristics of the membrane sheet such as flux or rejection, and that can be utilized to optimally bond photopolymer spacers either above the active surface of the membrane sheet, or below the active surface.

Abstract: Features applied to the inlet or exit edges of membrane sheets in spiral wound membrane elements may incorporate different heights or patterns than the feed space patterns in the middle of the membrane sheets in order to facilitate more open and more fluid dynamically favorable inlet spaces for the feed solution in spiral wound membrane elements. This configuration can reduce the fouling potential on the feed end of the membrane element, and provide less pressure drop on the inlet and exit ends of the membrane modules.