Low emissivity, high reflectivity insulation
A multi-layer flexible insulation (I) comprises a series of layers which include a pair of closed-cell insulation sheets ( 10,12 ) made of multicellular plastic film (i.e. closed cell air bubbles or bubble-pack) and laminated on both sides of a thin white polyethylene film ( 14 ), a pair of aluminum foil layers or films ( 16,18 ) adhesively mounted on the outer surfaces of the bubble-pack insulation sheets ( 10,12 ), and a pair of thin clear polyester layers ( 20,22 ) provided on the outer surfaces of the aluminum layers. The aluminum layers ( 16,18 ) are vapor deposited on the polyester layers ( 20,22 ) and are assembled to the hot bubble-pack insulation sheets ( 10,12 ) while the latter are cooled. The bubble-pack sheets ( 10,12 ) are then adhered to the central polyethylene film ( 14 ) with a hot melt glue. If the polyester ( 20,22 ) is highly smooth, the aluminum ( 16,18 ) can be deposited thereon in a uniform state thereby providing a high reflectivity, low emissivity, laminate. The outer polyester coatings ( 20,22 ) also protect the aluminum layers ( 16,18 ) such as to prevent any aluminum from rubbing off the insulation (I) and also prevent the aluminum layers ( 16,18 ) from oxidizing. Furthermore, the polyester coatings ( 20,22 ) provide an hygiene barrier for the insulation (I).
1. A high reflectivity insulative material comprising an outer polyester sheet, a plastic backing, and an aluminum film between the polyester sheet and the plastic backing, wherein the polyester sheet has a high smoothness such that the aluminum film is substantially uniformly coated thereon, whereby the insulative material has a high reflectivity with said polyester sheet facing outwardly thereof, and wherein the polyester sheet, the aluminum film and the plastic backing form a laminate, a pair of said laminates being assembled symmetrically on each side of an assembly of at least two insulation layers with a plastic sheet between successive insulation layers.
2. An insulative material as defined in claim 1 , wherein the polyester sheet has a melt point of at least approximately 400° F.
3. An insulative material as defined in claim 1 , wherein the polyester sheet has an optical density of at least 3.10 at 75° F.
4. An insulative material as defined in claim 1 , wherein the polyester sheet has a 48 gauge thickness.
5. An insulative material as defined in claim 1 , wherein each of the insulation layers comprises a closed-cell type insulation.
6. An insulation material as defined in claim 5 , wherein the closed cells of at least two of the insulation layers are of different dimensions.
7. An insulative material as defined in claim 1 , wherein each of the plastic sheet is made of white polyethylene.
8. An insulative material as defined in claim 1 , wherein the plastic backing has a reflective color.
9. An insulative material as defined in claim 8 , wherein the plastic backing is made of polyethylene.
10. A high reflectivity insulative material comprising an outer polyester sheet, a plastic backing, and an aluminum film between the polyester sheet and the plastic backing, wherein the polyester sheet has a high smoothness such that the aluminum film is substantially uniformly coated thereon, whereby the insulative material has a high reflectivity with said polyester sheet facing outwardly thereof, and wherein the polyester sheet, the aluminum film and the plastic backing form a laminate, a pair of said laminates being assembled symmetrically on each side of an insulation layer.
11. An insulative material as defined in claim 10 , wherein the insulation layer comprises a closed-cell type insulation.
12. A method for producing a high reflectivity insulative material, comprising the steps of:
a) providing and beating a polyester film having a melt point of at least approximately 400° F.;
b) depositing a coating of aluminum on the heated polyester film; and
c) providing a reflective plastic backing on the aluminum coating opposite the polyester film.
13. A method as defined in claim 12 , further comprising the step of:
d) providing a thermally insulative layer on the reflective plastic backing opposite the aluminum coating; and
e) providing a plastic sheet on the thermally insulative layer opposite the reflective plastic backing.
14. A method as defined in claim 12 , wherein in step (b), the aluminum is vapor deposited on said polyester film.
15. A method as defined in claim 12 , wherein the reflective plastic backing is made of polyethylene.