MULTI-LAYER INSULATION WITH USE OF POLYIMIDE AEROGEL FILMS

Abstract

An insulation material for thermal and/or acoustic insulation. The insulation material comprises a plurality of layered sheets, including one or more flexible polyimide aerogel film/s being at least partially covered with a reflective coating on one or both of its surfaces. A method is provided for thermally and/or acoustically insulating an entity. The method comprises at least partially shielding, covering and/or enveloping the entity with an insulation material comprising comprises a plurality of layered sheets, including one or more flexible polyimide aerogel film/s being at least partially covered with a reflective coating on one or both of its surfaces.

Claims

1. An insulation material for at least one of thermal or acoustic insulation, comprising: a plurality of layered sheets including one or more flexible polyimide aerogel films having a first and second surface with at least a partial cover of a reflective coating on one or both of the surfaces.

2. The insulation material according to claim 1, wherein at least one of the one or more flexible and at least partially coated polyimide aerogel films has a mean thickness of at most 1 mm.

3. The insulation material according to claim 1, wherein at least one of the one or more flexible and at least partially coated polyimide aerogel films has a mean thickness of at least 8 m.

4. The insulation material according to claim 1, wherein at least one of the one or more flexible and at least partially coated polyimide aerogel films has a mean thickness of at most 60 m.

5. The insulation material according to claim 1, wherein at least one of the one or more flexible and at least partially coated polyimide aerogel films has a mean thickness of at least 35 m.

6. The insulation material according to claim 1, wherein at least one of the one or more flexible and at least partially coated polyimide aerogel films has an essentially uniform thickness at least throughout a zone of the film.

7. The insulation material according to claim 1, wherein at least one of the one or more flexible and at least partially coated polyimide aerogel films includes at least two zones of different respective mean thicknesses.

8. The insulation material according to claim 1, wherein at least one of the one or more flexible and at least partially coated polyimide aerogel films has an essentially uniform porosity at least throughout a portion of the respective sheet.

9. The insulation material according to claim 1, wherein at least one of the one or more flexible and at least partially coated polyimide aerogel films includes at least two portions with different respective porosities.

10. The insulation material according to claim 1, wherein the insulation material includes two or more sheets comprising polyimide aerogel, wherein the two or more flexible at least partially coated polyimide aerogel films have different mean sheet thicknesses.

11. The insulation material according to claim 1, wherein the insulation material includes two or more sheets comprising polyimide aerogel, wherein the two or more flexible at least partially coated polyimide aerogel films have different mean porosities.

12. The insulation material according to claim 1, wherein the plurality of layered sheets includes one or more spacer sheets comprising polyimide aerogel.

13. The insulation material according to claim 12, wherein at least one of the one or more spacer sheets is at least partially covered with a reflective coating on one or both surfaces, wherein the reflective coating comprises at least one region having an uneven surface.

14. The insulation material according to claim 12, wherein the one or more spacer sheets include at least one sheet shaped as a grid including a plurality of cut-outs, wherein a total area of the cut-outs is at most of a total area extension of the sheet.

15. The insulation material according to claim 12, wherein the one or more spacer sheets include at least one sheet shaped as a grid including a plurality of cut-outs, wherein a total area of the cut-outs is at most of a total area extension of the sheet.

16. The insulation material according to claim 1, wherein the insulation material is configured as a flexible Mil material.

17. A method for at least one of thermally or acoustically insulating an entity, the method comprising: at least one of partially shielding, covering or enveloping the entity with an insulation material according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In the following, preferred embodiments of the present invention are explained with respect to the accompanying drawings. As is to be understood, the various elements and components are depicted as examples only, may be facultative and/or combined in a manner different than that depicted. Reference signs for related elements are used comprehensively and are not defined again for each figure.

[0048] Shown is schematically in

[0049] FIG. 1 is a portion of a first exemplary embodiment of an insulation material according to the present invention;

[0050] FIG. 2 is a portion of a second exemplary embodiment of an insulation material according to the present invention;

[0051] FIG. 3 is a portion of a third exemplary embodiment of an insulation material according to the present invention;

[0052] FIG. 4 is a portion of a fourth exemplary embodiment of an insulation material according to the present invention; and

[0053] FIG. 5 is a possible configuration of a spacer sheet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0054] In FIG. 1, an insulation material 10 according to a first exemplary embodiment of the present invention is depicted in a sectional view. The insulation material 10 (as well as, analogously, insulation materials 10, 10, 10 shown in FIGS. 2, 3 and 4 and described below) serves to thermally and/or acoustically insulate a respective entity it may envelop, shield and/or cover. It is configured as an MLI material composed of a plurality of layered sheets.

[0055] An outmost one of the sheets is a protective cover 1. The protective cover 1 may be a film comprising PET, PEEK and/or polyimide, or it may be a fabric made of ceramic fibers and/or fiberglass, aramid fibers or any other fabric or coating appropriate for the application. It may serve to protect the insulation material, as well as to provide favorable thermo-optical properties for some applications. Preferably, the protective cover is configured to face, in application, an exterior environment of an enveloped, shielded and/or covered entity; according to a preferred embodiment of the inventive method, the insulation material 10 is arranged accordingly, with the cover fabric 1 facing outwards.

[0056] The insulation material 10 further comprises a plurality of layered sheets 2 and 3 of two types arranged alternately stacked. Three sheets 2 and 3 are respectively depicted, further ones may be included, as indicated, in the figure, by vertically arranged dots.

[0057] Sheets 2 are flexible polyimide aerogel films. In the shown example, at least in the portion depicted, each sheet 2 has a uniform thickness, and all sheets 2 have the same thickness. Such thickness may preferably be at least 8 m, at least 15 m or at least 35 m, and/or at most 1 mm, at most 0.7 mm, at most 0.3 mm, at most 75 m or at most 60 m.

[0058] On both of their respective opposite surfaces, the sheets 2 have a coating 2a, 2b reflective to thermal radiation, such as metal, in particular aluminum, silver and/or gold. The coating may, for instance, be applied by means of a physical vapor deposition method.

[0059] Sheets 3 further included in the insulation material 10 are conventional spacers configured to inhibit thermal contact of adjacent sheets 2, in particular to inhibit physical contact of the coatings 2a, 2b of respective corresponding sheets 2 facing the respective sheet 3.

[0060] In comparison to a conventional MLI material, the sheets 2 comprising a polyimide aerogel film replace conventional PET, PEEK, polyimide or other films. As a consequence, the insulation material 10 can be constructed with less weight and a lower heat transfer coefficient than a conventional MLI material with the same number of layers.

[0061] At the surface opposite to the protective cover 1, the insulation material 10 might comprise a further protective cover (not shown), which may be a protective film (e.g. comprising PET, PEEK or polyimide). Such protective cover may be at least partially coated with reflective coatings on one or both of its surfaces.

[0062] In FIG. 2, an insulation material 10 according to an alternative embodiment of the present invention is shown, which is likewise configured as an MLI material composed of a plurality of layered sheets. It includes a protective cover 1 which may have the properties and which may be used as described above with respect to FIG. 1.

[0063] Moreover, the insulation material 10 comprises conventional sheets being polyimide films 4, which are at least partially coated, preferably metalized, e.g., with aluminum, silver and/or gold and/or by application of a physical vapor deposition method.

[0064] Additionally, the insulation material 10 comprises at least one sheet 2 being a flexible, at least partially coated polyimide aerogel film as described with respect to FIG. 1.

[0065] In the exemplary embodiment shown in FIG. 2, sheets 5 comprise (or even consist of) polyimide aerogel, and they act as spacers inhibiting thermal contact of adjacent sheets 4, in particular to inhibit physical contact of the coatings 4a, 4b, 2b of respective sheets 4, 2 facing the respective sheet 5.

[0066] In the present case, the spacer sheets 5 each have a uniform thickness (in the shown portion), and all sheets 5 have the same thickness. Such thickness may preferably be at least 8 m, at least 15 m or at least 35 m, and/or at most 1 mm, at most 0.7 mm, at most 0.3 mm, at most 75 m or at most 60 m.

[0067] As compared to conventional MLI materials, the insulation material 10 may be constructed with an even lower areal density, and, due to the buffer effect of the spacer sheets 5, so as to provide a better protection against micrometeorites and orbital debris. Moreover, due to the low heat conductivity of the spacer sheets 5, it may exhibit a lower heat transfer coefficient than a traditional MLI material having the same number of layered sheets.

[0068] Again, at the surface opposite to the protective cover 1, the insulation material 10 might comprise a further protective cover (not shown), as mentioned above with respect to FIG. 1.

[0069] In FIG. 3, a portion of a third embodiment of an inventive insulation material 10 is shown. Further to a protective cover 1 (which may have the properties and which may be used as described above with regard to FIG. 1), the insulation material 10 comprises sheets 2, 5 as described above, wherein the sheets are stacked alternatingly. Three sheets of each type are depicted, further ones may be included, as indicated, in the figure, by vertically arranged dots.

[0070] FIG. 4 shows a further insulation material 10 being an exemplary embodiment of the present invention. The insulation material 10 comprises a protective cover 1 and a plurality of at last partially coated flexible polyimide aerogel films 2 as described above with respect to FIG. 1.

[0071] At the surface opposite to the protective cover 1, the insulation material 10 comprises a further protective cover 7, which in the case depicted is a protective film (e.g., of PET, PEEK or polyimide). The protective cover 7 is at least partially coated with reflective coatings 7a, 7b on both of its surfaces.

[0072] The insulation material 10 further comprises at least one spacer sheet 6 comprising polyimide aerogel and reflective coatings 6a, 6b. Therein, the coatings 6a, 6b have an uneven surface, resulting from the coatings at least partially maintaining elevations and suppressions in the surface of the polyimide aerogel they cover. The unevenness provides for interspaces between the spacer sheet 6 and the respective neighboring sheets 2, which inhibit or at least reduce thermal contact.

[0073] The coatings 6a, 6b, 7a, 7b each may comprise a metal such as aluminum, silver and/or gold. Preferably, they may have been applied by physical vapor deposition.

[0074] FIG. 5 shows a plan view of a possible spacer sheet 8 comprising polyimide aerogel. The spacer sheet 8 comprises a plurality of cut-outs, three of which are exemplarily identified by reference sign C. In the exemplary embodiment depicted, the cut-outs are shaped as squares. As is to be understood, a spacer sheet may additionally or alternatively comprise cut-outs with one or more other geometric shape(s), such as disc(s). Preferably, a total area of the cut-outs is at most or at most of the total area extension of the sheet 8 (including the cut-outs). The cut-outs provide for interspaces between neighboring sheets and, therewith, for an improved reduction of thermal contact.

[0075] The spacer sheet 8 may be configured as each of spacer sheets 5 and 6 described above. In particular, it may be uncoated or at least partially covered with a reflective coating as described above.

[0076] Disclosed is an insulation material for thermal and/or acoustic insulation. The insulation material comprises a plurality of layered sheets including one or more flexible polyimide aerogel film/s being at least partially covered with a reflective coating on one or both of its surfaces.

[0077] Further disclosed is a method for thermally and/or acoustically insulating an entity. The method comprises at least partially shielding, covering and/or enveloping the entity with an insulation material according to an embodiment of the present invention.

[0078] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

REFERENCE SIGNS

[0079] 1 protective cover [0080] 2 at least partially coated flexible polyimide aerogel film [0081] 2a, 2b coating of sheet 2 [0082] 3 conventional spacer [0083] 4 conventional polyimide film [0084] 4a, 4b coating of sheet 4 [0085] 5 spacer sheet comprising polyimide aerogel [0086] 6 spacer sheet comprising polyimide aerogel [0087] 6a, 6b coating of sheet 4 [0088] 7 protective cover [0089] 7a, 7b coating of sheet 7 [0090] 8 spacer sheet [0091] 10, 10, 10, 10 insulation material [0092] C cut-outs in spacer sheet 8