Membrane module

1. A membrane module comprising:

at least one hollow fibre membrane;

a first resin layer formed around an end of the at least one hollow fibre membrane;

a second resin layer chemically bound to the first resin layer, wherein the second resin layer is of greater flexibility than the first resin layer; and

a potting sleeve constructed and arranged to receive the first and second resin layers, the potting sleeve including a first groove formed on a surface of the potting sleeve in contact with and adhered to the first resin layer and a second groove formed on a surface of the potting sleeve in contact with and adhered to the second resin layer, a portion of the first resin layer extending into the first groove and a portion of the second resin layer extending into the second groove.

2. The module of claim 1 , wherein the first resin layer comprises an epoxy resin material.

3. The module of claim 2 , wherein the second resin layer comprises a polyurethane resin material.

4. The module of claim 3 , wherein an isocyanate group of the polyurethane resin material is chemically reacted with an epoxy group of the epoxy resin material.

5. The module of claim 1 , wherein the second resin layer comprises a flexibilizing agent.

6. The module of claim 5 , wherein the first and second resin layers comprise the same resin material.

7. The module of claim 1 , wherein the end of the at least one hollow fibre membrane is sealed.

8. The module of claim 1 , wherein the potting sleeve comprises adhesion means, wherein the adhesion means assist in adhesion of at least one of the first and second resin layers to the potting sleeve.

9. The module of claim 8 , wherein a surface of the potting sleeve in contact with at least one of the first and second resin layers is roughened.

10. The module of claim 8 , wherein the potting sleeve comprises at least one protrusion formed on a surface of the potting sleeve in contact with at least one of the first and second resin layers.