Patent ID: 9321237
Filing Date: 2016-04-26
CPC Classification: B32B,E04B,F16L,Y02A,Y02B,Y10T

Claim Text:
1. An evacuated sheet material for thermal insulation, the sheet material comprising a) at least one flat core of an open-pored material having a first main surface and a second main surface which extend approximately parallel to each other, and a fully circumferential perimeter region connecting the first and second main surfaces to each other, b) a first barrier film in flat, areal contact with the first main surface of said core and comprising at least one sealing layer facing said core, as well as a fully circumferential protrusion of said first barrier film with respect to said first main surface of said core, c) a flat filter material that is in flat, areal contact with the second main surface of said core facing away from said first barrier film and presents a fully circumferential protrusion with respect to a second main surface of said core, d) a second barrier film in flat, areal contact with an outer face of said flat filter material and comprising a sealing layer facing said flat filter material, as well as a fully circumferential protrusion of said second barrier film with respect to the second main surface of said core, e) a sealing seam that extends fully circumferentially along the protrusions of said first and second barrier films and fixes said first and second barrier films to each other, f) wherein said filter material is welded fully circumferentially into said sealing seam between said first and second barrier films in such way, that the region of said sealing seam has a three-layer structure having three directly adjacent layers, namely i) the first barrier film as a first envelope film, ii) the flat filter material, and iii) the second barrier film as a second envelope film, wherein the filter material, as a middle component of this three-layer structure, passes all the way through the sealing seam, from an evacuated interior of the evacuated sheet material to the surrounding external space, which is under atmospheric pressure, and, in the region of the sealing seam, completely separates the first and second barrier films from each other, in such way that, precisely in the sealing seam, the first and second barrier films are not in any direct contact with each other, but are always separated from each other, g) and wherein a volume between said first and second films and said fully circumferential sealing seam, consisting of said core and an inner portion of said filter material, is sealed vacuum-tightly and evacuated.