Reinforced, three zone microporous membrane
AssigneeCuno Incorporated
InventorsMark T. Meyering, Jack H. Vining JR., C. Thomas Badenhop
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Abstract
A three zone, reinforced, continuous, geometrically symmetrical microporous membrane including a porous support material encapsulated within a middle zone disposed between an upper zone and a lower zone wherein at least one of the three zones has a pore size at least about twenty (20%) percent greater than the pore size of the other two zones is disclosed. Apparatus and methods for fabricating three zone reinforced, continuous, geometrically symmetrical, microporous membrane are also disclosed.
Claims41
A three zone microporous membrane comprising:
- a porous support material substantially impregnated by a first dope to form a middle zone having two sides;
- and
- a second zone and a third zone formed from at least one additional dope, each zone having inner and outer surfaces, each of the second and third zones being operatively, continuously, connected to opposite sides of the middle zone, wherein at least one of the three zones has a pore size at least about twenty (20%) percent greater than the pore size of at least one of the other zones.
A three zone reinforced, continuous, geometrically symmetrical microporous membrane comprising:
- a porous support material;
- and
- a continuous microporous membrane having a middle zone disposed between an upper zone and a lower zone, each having an outer surface, wherein the support material is substantially embedded within the middle zone and at least one of the zones has a pore size at least about twenty (20%) percent greater than the pore size of at least one of the other zones.
A three zone microporous membrane prepared by a process comprising:
- the steps of:
- providing a continuous support material;
- at least substantially pressure impregnating the support material with a first dope utilizing a first die means;
- passing the dope impregnated continuous support material between substantially opposed second and third die means;
- and
- substantially, simultaneously coating both sides of the dope impregnated continuous support material with at least one additional dope on each side of the substantially impregnated support material.
Dependencies are inferred from the claim text.