Patent ID: 7094348

Claim:
A method for manufacturing a dialyzer comprising a substantially cylindrical case, a hollow fiber bundle made of a plurality of hollow fiber membranes provided in said case, a blood flow path formed by lumens of the hollow fiber membranes, a dialyzate flow path formed by gaps between the hollow fiber membranes and between the inner wall of the case and the hollow fiber membranes and a cylindrical heat-shrinkable tube provided on an outside of the hollow fiber bundle wherein at least a part of said heat-shrinkable tube can be shrunk by heating and wherein the heat-shrinkable tube is fixed to the inner wall of the case with rings inserted in the lumen of the heat-shrinkable tube, comprising the following steps (1) to (3), (1) inserting the cylindrical heat-shrinkable tube into the substantially cylindrical case, (2) subsequently, inserting the hollow fiber bundle into a lumen of the heat-shrinkable tube in the case, and (3) subsequent to step (2), heating at least a part of the heat-shrinkable tube in the case to shrink the tube.