85 ml200 mmhg tmp 120 mldialysate volume 730 mlmaximum tmp 500 mmhg______________________________________ performance subject to variations in cuprophan membrane the invention has other uses beside that in hemodialysis for example it can be used in laboratory dialysis regarding variations i note that the curing time can be reduced or virtually eliminated by increasing the viscosity of the potting material when it is first pumped in so that it will be viscous enough for the evacuation step much sooner using an initially more viscous potting material will require greater pumping pressures and consequently higher initial positive pressures on the dialysate side to keep the fold entrances closed or larger flow channels in the casing a second variation is to paint an adhesive primer on the membrane tips and allow the primer to cure in order to bond adjacent tips to each other and thereby close the fold entrances this can replace or supplement the use of positive pressure to close these entrances with this variation no curing of the potting is necessary prior to the evacuation step because the entrances will not reopen as a result of evacuation and thus there will advantageously be no seepage of potting into the spaces between the membrane folds during evacuation rather the membrane stack as a whole will be forced against the support netting and receive support therefrom one chooses for the primer one that will improve the bond between the potting and the membrane a third.