Method for sealing hollow fiber membranes
The present invention is directed to a method of sealing the free end of a hollow fiber membrane for use in a single header filtration module by dipping the end of the membrane into a low-viscosity light-curable adhesive and curing the adhesive. The invention further encompasses the resulting sealed hollow fiber membrane with a diameter that is only slightly larger than the diameter of the unsealed membrane.
1. A plurality of hollow fiber membranes for use in a single-header filtration module, comprising:
a plurality of hollow fiber membranes each having an interior wall defining a hollow internal bore, a first end and a second end, wherein
said first end is coated with a low-viscosity light-curable adhesive;
said internal bore near said first end is sealed with a low-viscosity light-curable adhesive plug;
the thickness of said adhesive coating on said first end is between 0.05 mm and 0.8 mm; and
said second end is open;
wherein when the second ends of the plurality of hollow fiber membranes are secured in said single-header filtration module, the first ends of said plurality of hollow fiber membranes achieve a density of greater than 64 membranes per square inch.
2. The hollow fiber membranes of claim 1 , wherein said first end has a diameter and the diameter of said first end coated with said adhesive is less than 4 mm.
3. The hollow fiber membranes of claim 1 , wherein said plug extends a length of between 2 and 10 mm.
4. The hollow fiber membranes of claim 3 , wherein said first end is coated with said adhesive to a length of between 2 and 10 mm from said first end.
5. The hollow fiber membranes of claim 3 , wherein said adhesive extends into said interior wall integrally to said plug.
6. A hollow fiber filtration module, comprising:
a plurality of hollow fiber membranes of claim 1 each having an interior wall defining a hollow internal bore, a first end and a second end, wherein said first end is coated with a low-viscosity light curable adhesive, said internal bore near said first end is sealed with a low-viscosity light curable adhesive plug, the thickness of said adhesive coating on said first end is between 0.05 mm and 0.8 mm, and said second end is open; and
one header,
wherein when said second end of each of said hollow fiber membranes is secured within said header in a potting compound, the first ends of said plurality of hollow fiber membranes achieve a density of greater than 64 membranes per square inch.
7. The hollow fiber membranes of claim 1 , wherein said hollow fiber membranes is braid-reinforced hollow fiber membrane.
8. The hollow fiber membranes of claim 7 , wherein said plug and said coating are formed with the same low-viscosity light-curable adhesive.
9. The module of claim 6 , wherein the plurality of hollow fiber membranes are secured in said header such that a density of greater than 81 membranes per square inch is achieved.