ADVANCED GEL SHEET PRODUCTION

• US 20080093016A1
• Filed: 06/13/2007
• Published: 04/24/2008
• Est. Priority Date: 06/24/2003
• Status: Active Grant

• Current Assignee: Aspen Aerogels, Incorporated
• Original Assignee: Aspen Aerogels, Incorporated
• Inventors: Lee, Kang, Stepanian, Christopher, Gould, George, Gronemeyer, William
• Granted Patent: US 7,780,890 B2
• Time in Patent Office: Days
• US Class Current: 156/242
• CPC Class Codes: B01J 13/0091 Preparation of aerogels, e.g. xerogels
• CPC Class Codes: B29B 15/122 with a matrix in liquid form, e.g. as melt, solution or latex
• CPC Class Codes: B29C 39/14 for making articles of indefinite length by depositing material on a substrate and stripping off the shaped article B29C41/24
• CPC Class Codes: B29C 39/16 between endless belts
• CPC Class Codes: B29C 39/18 incorporating preformed parts or layers, e.g. casting around inserts or for coating articles B29C39/206 takes precedence
• CPC Class Codes: F16L 59/026 Mattresses, mats, blankets or the like

Abstract

The present invention provides various methods for producing gel sheets in a continuous fashion. The embodiments of the present invention help reduce the time of producing gel sheets that is suitable for industrial manufacturing. Such gel sheets are used in manufacturing aerogel blankets used in a variety of applications including thermal and acoustic insulation.

Claims

1. A method for casting gel sheets comprising the steps of:

providing a reinforcing layer;

providing a separator layer;

combining reinforcement layer and separator layer to make a pre-form roll;

infusing a sol into the pre-form roll; and

gelling the sol in the pre-form roll to produce gel sheets.

2. The method of claim 1 further comprising the step of drying said gel sheets using supercritical fluids.

3. The method of claim 2 wherein drying is performed on the gelled pre-form roll.

4. The method of claim 3 further comprising the step of unrolling the dried gel sheets.

5. The method of claim 1, wherein the sol comprises a material selected from the group consisting of zirconia, yttria, hafnia, alumina, titania, ceria, and silica, magnesium oxide, calcium oxide, magnesium fluoride, calcium fluoride, and combinations thereof.

6. The method of claim 1, wherein the sol comprises a material selected from the group consisting of polyacrylates, polyolefins, polystyrenes, polyacrylonitriles, polyurethanes, polyimides, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehydes, resorcinol formaldehydes, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, and agarose, and combinations thereof.

7. The method of claim 1 wherein the gelling of the sol is enhanced by a process selected from the group consisting of (a) a chemical process, and (b) dissipating a predetermined quantity of energy from an energy source into a cross-sectional area of the sol.

8. The method of claim 1 wherein the separator layer is impermeable.

9. The method of claim 1 wherein the separator layer is a flexible sheet.

10. The method of claim 1 wherein infusion of sol is performed using vacuum infiltration techniques.

11. A method for preparing gel sheets, comprising the steps of:

dispensing a sol onto a moving element as a continuous sheet;

rolling the dispensed sheet into a plurality of layers; and

drying the layers.

12. The method of claim 11 wherein drying is accomplished using supercritical fluids.

13. The method of claim 11 further comprising the step of providing a fibrous batting material in the gel sheet.

14. The method of claim 11 further comprising the step of providing crimped fibers in the gel sheet.

15. The method of claim 11, wherein the sol comprises a material selected from the group consisting of zirconia, yttria, hafnia, alumina, titania, ceria, and silica, magnesium oxide, calcium oxide, magnesium fluoride, calcium fluoride, and combinations thereof.

16. The method of claim 11, wherein the sol comprises a material selected from the group consisting of polyacrylates, polyolefins, polystyrenes, polyacrylonitriles, polyurethanes, polyimides, polyfurfural alcohol, phenol furfuryl alcohol, melamine formaldehydes, resorcinol formaldehydes, cresol formaldehyde, phenol formaldehyde, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, and agarose, and combinations thereof.

17. The method of claim 11 wherein dispensed sol is gelled before rolling.

18. The method of claim 11 further comprising the step of introducing a spacer layer between any two gel sheet layers.

19. The method of claim 18 wherein the spacer layer is permeable.

20. The method of claim 18 wherein the spacer layer is impermeable.

21. The method of claim 17 wherein the gelling of the sol is enhanced by a process selected from the group consisting of (a) a chemical process, and (b) dissipating a predetermined quantity of energy from an energy source into a cross-sectional area of the sol.

22. The method of claim 13 wherein fibers in the fibrous batting have a diameter within a range of about 0.1 μ

m to about 10000 μ

m.

23. The method of claim 13 wherein fibers in the fibrous batting have a diameter within a range of about 0.001 μ

m to about 10 μ

m.

24. A process for casting gel sheets, comprising the steps of:

providing a quantity of fibrous batting material;

introducing a impermeable layer to the fibrous batting material and rolling into a fiber-roll preform having a plurality of fibrous layers;

infusing a quantity of sol into the fiber-roll preform;

gelling the sol precursor in the fiber-roll preform;

removing the impermeable material to leave remaining a gel material; and

introducing a quantity of a permeable material to separate the gel material into a plurality of layers wherein the permeable material has a form selected from the group consisting of a mesh, a sheet, a perforated sheet, a foil, and a perforated foil.

25. A process for casting gel sheets, comprising the steps of:

providing a quantity of fibrous batting material;

rolling the fibrous batting material into a fiber-roll preform having a plurality of fibrous layers;

infusing a quantity of sol into the fiber-roll preform;

gelling the sol in the fiber-roll preform; and

drying the gelled fiber-roll perform.