Sealing the ends of hollow fibre dialyzers

Claim 1

A hollow fibre diffusion device which comprises a bundle of hollow fibres disposed in a substantially rigid, tubular housing, said bundle and housing having relatively diametricAly enlarged manifold members adjacent opposite housing ends, and being sealed at said opposite ends, and a relatively resilient plastics sleeve member carried at each end of the housing and sealed thereto, each sleeve member having a sleeve of smaller inner diameter than the inner diameters of the manifold members, said sleeve being coaxially positioned relative to said housing to receive, hold, and centre the ends of said bundle, said sleeve containing a mass of potting compound which is interspersed throughout the exterior surfaces of the fibre of said bundle, said sleeve being made of a material which sealingly adheres to said potting compound. 2. The diffusion device of Claim 1 in which said sleeve member including the inner sleeve is made of 4 GB 2 053 725 A a polyvinyl chloride plastics material, and the potting compound is a polyurethane. 3. The diffusion device of Claim 1 or2in which each end of the housing is sealed by means of an attached end closure member, said closure member having a central port, and an inwardly pointing annular sealing ring positioned to sealingly press against the end of the inner sleeve. 4. The diffusion device of Claim 3 in which each closure member has a plurality of eccentrically positioned projections which communicate with the exterior space about the sealing ring, and an extruded 0-ring filling said exterior space. 5. The diffusion device of Claim 4 in which the inner diameter of said sleeve is substantially the same as the inner diameter of the central portion of said tubular housing. 6. The diffusion device of Claim 3 in which said sleeve is radial ly spaced inwardly from the end of said housing, and defining an open space about the radially outer surface of said inner sleeve which is surrounded by said housing end. 7. A hollow fibre diffusion device constructed substantially as herein described with reference to Figures 1 to 3 of the accompanying drawings. 8. A hollow fibre diffusion device constructed substantially as herein described with reference to Figures 4 and 5 of the accompanying drawings. 9. A method of sealing the ends of a hollow fibre diffusion device which comprises a bundle of hollow fibres disposed in a substantially rigid, tubular housing, the method comprising:- 4 engaging a sleeve member in each end of the housing so as to close said end, each member having a sleeve spaced radially inwardly of the remainder of the member, inserting each end of said bundle into a respective sleeve, whereby the ends of said bundle are held and centred coaxially in the housing; applying potting compound to the ends of said bundle within the sleeves to permeate and enclose the bundle ends within the sleeves; allowing said potting compound to cure; slicing away the outer, closed ends of said sleeves and the outermost portions of said bundle ends to expose the open bores of the individual fibres of the bundle; and attaching to each end of said housing a closure member which has a central port and an inwardly pointing, annular sealing ring, and positioning said sealing ring to sealingly press against the cut end of said sleeve to define a manifold chamber within said annular sealing ring for communication between the central port and the bores of the fibres. 10. The method of Claim 9 including the step of go applying sealant material through ports in the diffusion device to form a sealant ring about the exterior of said sealing ring which is substantially not under compression. 11. A method according to Claim 1, substantially as herein described with reference to Figures 1 to 3 or Figures 4 and 5 of the accompanying drawings. Printed for Her Majesty's Stationery Office. by Croydon Printing Company Limited, Croydon. Surrey, 1981. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained. 1.1 -1