Hollow fiber membrane layer laminate and method of manufacturing hollow fiber membrane layer laminate

A hollow fiber membrane layer laminate for an oxygenator, comprising:

• a plurality of hollow fiber membranes wound into a cylinder:
• wherein the plurality of hollow fiber membranes form a laminate having a plurality of layers in a radial direction of the cylinder;
• wherein the plurality of hollow fiber membranes within each respective layer are separated from each other by a predetermined separation distance;
• and
• wherein a pitch of the hollow fiber membranes is successively reduced from an innermost layer of the cylinder to an outermost layer of the cylinder so that the predetermined separation distance is maintained throughout the layers;
• wherein the layers include an innermost first layer with a first separation distance d1 and a plurality of radially overlying layers each with a respective separation distance d;
• and
• wherein a respective ratio of d1 to each respective overlying separation distance d is within a range from 0.8 to 1.2.

A hollow fiber membrane layer laminate for an oxygenator, comprising:

• a plurality of hollow fiber membranes wound into a cylinder;
• wherein the plurality of hollow fiber membranes form a laminate having a plurality of layers in a radial direction of the cylinder;
• wherein the plurality of hollow fiber membranes within each respective layer are separated from each other by a separation distance;
• and
• wherein a variation in the separation distance between successive layers is 20% or less in comparison with an innermost layer.