Membrane laminate

1. An ultrafiltration device, comprising:

a plurality of porous ultrafiltration membranes, wherein the plurality of porous ultrafiltration membranes is made of a polymeric material selected from the group consisting of polysulfone, polyethersulfone, blends thereof and/or copolymers thereof;

a first support plate and a second support plate, each of the first support plate and the second support plate formed of polyvinylidene fluoride, the first and second support plates each having a first surface facing each other and a second surface opposite the first surface of each support plate;

wherein the plurality of porous ultrafiltration membranes are heat bonded to the first surface of said first support plate along a sealing line such that molten polyvinylidene fluoride infiltrates into pores of the porous ultrafiltration membranes and, optionally, wherein at least one second support plate comprises a porous ultrafiltration membrane;

a thermal bond between the first support plate and the second support plate, wherein the thermal bond forms a liquid tight seal outside the sealing line on each first support plate, wherein the number of porous ultrafiltration membranes is in a number equal to the number of the first support plates; and

at least one port, the at least one port formed from the first surface to the second surface of each the first support plate and the second support plate.

2. The ultrafiltration device of claim 1 , further comprising a composite membrane having at least one zone of asymmetry and at least one zone of symmetry.

3. The ultrafiltration device of claim 1 , having a first end and a second end, said device comprising a first outermost cassette on said first end of the ultrafiltration device, a second outermost cassette on said second end of the ultrafiltration device and two or more cassette frames disposed between.

4. The ultrafiltration device of claim 1 , wherein the first and second support plates are bonded to each other around the periphery of each.

5. The ultrafiltration device of claim 1 , wherein the first support plate has at least one additional port formed from the first surface through to the second surface of the first support plate.

6. The ultrafiltration device of claim 1 , wherein both the first support plate and the second support plate have at least one additional port formed from the first surface through to the second surface of each support plate.

7. The ultrafiltration device of claim 1 , wherein the first support plate has at least one additional port formed from the first surface through to the second surface of the first support plate and wherein that at least one additional port forms a vent.

8. The ultrafiltration device of claim 1 , further comprising a series of two or more additional first and second support plates with a membrane bonded to the first surface of each additional first support plate along a sealing line, each series of additional support plates being heat bonded to each other and adjacent second surfaces of the adjoining set of support plates outside of the sealing line.

9. The ultrafiltration device of claim 1 , further comprising a series of two or more additional first and second support plates with a membrane bonded to the first surface of each additional first support plate along a sealing line, each series of additional support plates being heat bonded to each other and adjacent second surfaces of the adjoining set of support plates outside of the sealing line and a first end plate bonded to the outermost second surface of the first support plate and a second end plate bonded to the outermost surface of the second support plate in the series to form the liquid tight outer seal between adjacent plates.