Synthetic insulation with microporous membrane

1. An insulation package comprising:

at least one functional fabric layer on an exterior side of the insulation package;

a breathable water repellant insulating layer on an interior side of the insulation package; and

a breathable, air permeable polytetrafluoroethylene microporous membrane layer having a network of pores, disposed between said at least one functional fabric layer and said breathable water repellant insulating layer, wherein the size of the pores is between about 1 and about 8 μm;

wherein the functional fabric, microporous membrane layer and the insulating layer, are laminated to one another throughout the entire insulation package to form a waterproof breathable insulated fabric; and

wherein the insulation package has a Water Vapor Transmission Rate (WVTR) of about 3521 g/m 2 /24 hrs.

2. The insulation package of claim 1 , wherein at least one of the at least one functional fabric layers is a water resistant fabric.

3. The insulation package of claim 2 , wherein the functional fabric layer is coated with a cire coating.

4. The insulating package of claim 1 , further comprising a second functional fabric layer.

5. The insulating package of claim 4 , wherein the second functional fabric is laminated to the insulating layer on the non-membrane side.

6. The insulation package of claim 1 , wherein the size of a pore in the network of pores is defined by stretching the microporous membrane.

7. The insulation package of claim 1 , wherein said insulation package permits vapor transfer and inhibits water transfer.

8. The insulation package of claim 1 , wherein the breathable water repellant insulating layer is nonwoven and comprises fibers selected from the group consisting of microfibers, macrofiber, natural fibers, and blends thereof.

9. The insulation package of claim 1 , wherein the breathable water repellant insulating layer is woven and comprises fibers selected from the group consisting of microfibers, macrofiber, natural fibers, and blends thereof.

10. The insulation package of claim 1 , wherein the breathable water repellant insulating layer has a cohesive fiber structure comprising an assemblage of:

(a) from 70 to 95 weight percent of spun and drawn, synthetic polymeric microfibers having a diameter of from 3 to 12 microns; and

(b) from 5 to 30 weight percent of synthetic polymeric macrofibers having a diameter of 12 to 50 microns.

11. The insulation package of claim 1 , wherein the breathable water repellant insulating layer formed as a batt having a smooth surface compatible for lamination techniques.

12. The insulation package of claim 11 , wherein the smooth surface is formed by at least one process selected from the group consisting of IR calendaring, hot plate calendaring, using heated rollers, resin coatings, and hot air oven processing.

13. The insulation package of claim 1 , wherein the functional fabric is selected from the group consisting of fleece, woven, and nonwoven fabrics.

14. A method of forming a waterproof insulation package according to claim 1 , the method comprising the steps of:

providing a first layer of functional fabric on an exterior side of the insulation package;

providing a second layer of polytetrafluoroethylene microporous membrane disposed between said at least one functional fabric layer and said breathable water repellant insulating layer;

providing a third layer of breathable water repellant insulating layer on an interior side of the insulation package;

bonding the first layer to said second layer; and

bonding the second layer to the third layer.

15. The method of claim 14 , further comprising the step of forming the third layer as a batt.

16. The method of claim 15 , further comprising the step of forming a smooth surface on said batt.

17. The method of claim 14 , wherein the bonding of the first and second layers is a lamination process.

18. The method of claim 14 , wherein the bonding of the second and third layers is a lamination process.

19. The method of claim 14 , further comprising the step of providing a second functional fabric layer.

20. The method of claim 19 , wherein the second functional fabric layer is laminated to the breathable water repellant insulating layer.

21. An insulation package comprising:

at least one functional fabric layer on an exterior side of the insulation package;

a breathable water repellant insulating layer on an interior side of the insulation package; and

a breathable, air permeable, non-waterproof polytetrafluoroethylene microporous membrane layer having a network of pores, disposed between said at least one functional fabric layer and said breathable water repellant insulating layer;

wherein the functional fabric, microporous membrane layer and the insulating layer, are laminated to one another throughout the entire insulation package to form a waterproof breathable insulated fabric; and

wherein the insulation package has a Water Vapor Transmission Rate (WVTR) of about 3521 g/m 2 /24 hrs.

22. An article comprising the insulation package according to claim 1 .