Multilayer separator and methods of manufacture and use
A multilayer deep cycle battery separator comprising at least two layers of an automotive-sized separator bonded or welded together. The automotive-sized separator layers include a backweb having a backweb thickness between 6 to 10 mils, an overall thickness of between 25 to 65 mils, and a rib base width of between 20 to 35 mils. The automotive-sized separator layers also have an extraction time of between 45 to 75 seconds, thereby providing an overall extraction time of less than a standard deep cycle battery separator.
1. A deep cycle battery comprising a multilayer separator which is characterized by: a first separator layer and a second separator layer connected together, the first separator layer being a polyethylene (PE) or polypropylene (PP) separator and the second separator layer being a polyethylene (PE) or polypropylene (PP) separator.
2. The deep cycle battery of claim 1 wherein each said separator layers comprises:
a backweb having a backweb thickness of between 5 and 10 mils,
an overall thickness of between 25 and 65 mils, and
a rib having a rib base width of between 12 and 50 mils.
3. The deep cycle battery of claim 1 wherein each said separator layer has an extraction time of between 45 to 75 seconds.
4. The deep cycle battery of claim 1 wherein at least one of said separator layers is a PE separator.
5. The deep cycle battery of claim 4 wherein each of said separator layers is an PE separator.
6. The deep cycle battery of claim 1 wherein said separator layers are welded together.
7. The deep cycle battery of claim 6 wherein said layers of automotive-sized separator are welded together by welding techniques selected from the group consisting of: heat; pressure; heat and pressure; sonic welding; vibration; crimping; laser; and combinations thereof.
8. The deep cycle battery of claim 1 wherein said layers of automotive-sized separator are connected together by a layer of adhesive.
9. The deep cycle battery of claim 8 wherein said adhesive is selected from the group consisting of: a standard adhesive; latex rubber; a coating with a basic solution of sodium silicate that is ultimately neutralized with acid; and combinations thereof.
10. The deep cycle battery of claim 1 further including one or more additives selected from the group consisting of: ground rubber; latex rubber; one or more lignins; sodium sulfate; and combinations thereof.
11. The deep cycle battery of claim 10 wherein said one or more additives are between the layers, and/or wherein said one or more additives are pocketed into a welded region.
12. The deep cycle battery of claim 1 wherein said layers of automotive-sized separator are without any welding or other means of attachment.
13. The deep cycle battery of claim 1 wherein said layers of automotive-sized separator are positioned together by being enveloped, wrapped, sleeved or stacked.
14. The deep cycle battery of claim 1 wherein said layers of automotive-sized separator are embossed together.
15. The deep cycle battery of claim 14 wherein said layers are embossed together by two or more layers being fed through a pair of mated rollers with a three dimensional pattern, whereby when the two or more layers are embossed, the original shape of ribs being modified in the pattern of the embossed roll.
16. The deep cycle battery of claim 15 wherein points of connectivity of said embossed layers are across an entire face of the separator.
17. The deep cycle battery of claim 1 , wherein said two layers of separator are connected in a back to back configuration by which backwebs of each layer are positioned adjacent to one another.
18. The deep cycle battery of claim 17 wherein at least one of the separator layers further includes negative ribs, which negative ribs are thereby positioned between the two backwebs of the two layers.
19. The deep cycle battery of claim 1 , wherein the two separator layers are stacked on top of one another.
20. The deep cycle battery of claim 1 comprising two layers of automotive-sized separator together in a rib to rib configuration with ribs stacked on top of each other or with ribs offset from one another, a ribbed separator and a flat sheet, wherein at least one of the layers comprises ribs.
21. The deep cycle battery of claim 20 wherein said ribs are selected from the group consisting of: straight vertical ribs; sinusoidal; diagonal; discontinuous; embattlement; cross rib patterns; and combinations thereof, or wherein said ribs are straight vertical ribs.
22. The deep cycle battery of claim 1 further comprising a composite structure.
23. The deep cycle battery of claim 22 wherein said composite structure includes a stiffening material between the separator layers.
24. The deep cycle battery of claim 23 wherein said stiffening material is selected from the group consisting of: a glass mat; glass fibers; a synthetic mat; synthetic fibers; and combinations thereof.