WO2007054322A1

WO2007054322A1 - Vacuum insulator and method for its production

Info

Publication number: WO2007054322A1
Application number: PCT/EP2006/010771
Authority: WO
Inventors: Hans-Frieder Eberhardt
Original assignee: Porextherm Dämmstoffe GmbH
Priority date: 2005-11-10
Filing date: 2006-11-10
Publication date: 2007-05-18
Also published as: EP1945871A1; DE102005054012A1

Abstract

For the simple production of an exactly fitting vacuum insulator (1) comprising upper and lower flat sides and narrower end sides, wherein an open-cell, open-pore, microporous and/or fibrous core (2) is completely enclosed by a gastight multilayer film (3), the end edges (e.g. 5 and 6) of which are sealed together, it is proposed that a sealing seam (4, 4') is provided on each of the flat sides (18, 18') of the vacuum insulator (1). It is preferred for the two sealing seams (4, 4') on the upper and lower flat sides (18, 18') to be arranged off-centre, in particular arranged offset oppositely in relation to each other, each by approximately 1/3 of the overall width of the vacuum insulator (1). Moreover, a corresponding production method is proposed.

Description

description

Vacuum insulation body and method for its production

The invention relates to a vacuum insulation body according to the preamble of claim 1 and a corresponding manufacturing method.

Vacuum insulation bodies are increasingly used in insulation and insulation in a variety of applications. A vacuum insulation body is understood to be an insulation element which has a core or supporting body made of an open-cell, open-pore, microporous and / or fibrous material, which is enveloped by a film and then evacuated. The attenuation values of such materials can be significantly improved by keeping them in an evacuated environment. Thus, up to 10 times higher insulation values can be achieved so that the layer thickness of the insulation panels can be reduced by the corresponding value.

As sheathings for the cores or supporting bodies so-called barrier materials are used, in particular multilayer films in which alternate metal layers, metallized layers and plastic layers. In such vacuum insulation bodies is also critical that in the areas in which a vacuum insulation body abuts the next, so-called bridges arise, for example cold bridges, which significantly reduce the insulation values of the total insulation compared to the insulating values of a single vacuum insulation body. The cause of these bridges is usually that in the conventional vacuum insulation bodies, a jointless juxtaposition of adjacent vacuum insulation body is practically impossible.

In the usual Vakuumisolationskörpem two foil blanks are welded together as wrapping in the narrow edge region of the core, since the welding of the foil blanks takes place at the narrow end faces of the plate. Thus arises circumferentially on these narrow sides of a weld, which protrudes from the edges of the insulation plate. If two such vacuum insulation panels are applied to each other, then the welding edges of both Vacuum insulation plates (also referred to as VIP) between the two cores, making a virtually seamless clashing impossible. Rather, there is pending wrapping material between the abutting vacuum insulation plates, whereby the heat / cold bridges arise, greatly reducing the total insulation value of the construction.

From DE 100 58 566 C2, a film-coated, evacuated thermal insulation molded article and a production method comprising a single film blank with a sealed seam in the longitudinal direction are already known. Here, the core blank is wrapped in a plastic film after wrapping with fleece. This film corresponds in its width to the sum of the core width, core height and the sealing seam width (in each case two times). Thus, a format change is in most cases associated with a change of the film web for the foil bag, which can cause considerable Umrüstkosten.

The core, which is moved further by a transport device, takes the film web with a leading edge. Then pivots a welding jaw up, while the film roll is braked to keep the film web taut. As a result, however, considerable forces are exerted on the fragile core blank, so that it can break out just in the edge area. This not only affects the fit. Rather, broken core material can also have a negative effect on the seal, in particular if the additional nonwoven covering is to be dispensed with for cost reasons.

Object of the present invention is therefore to provide a vacuum insulation body available, which can be connected almost seamlessly to a similar vacuum insulation body, and is inexpensive to produce by a corresponding manufacturing process.

This object is achieved by a vacuum insulation body according to claim 1 and a method according to claim 8. Advantageous embodiments are the subject of the dependent claims. The vacuum insulation body according to the invention has a core made of a microporous material, which is surrounded on its flat top and bottom by a sheath with two sealing seams in the longitudinal direction. The core is thus completely surrounded by two blank sheets of a gas-tight multilayer film. A gas-tight multilayer film is understood as meaning a film in which at least two plastic layers alternate with at least one barrier layer. By this arrangement, a particularly high density of the material is achieved because several plastic and metal layers alternate. An example of such a multilayer film is: polyamide / nylon - metal layer - polypropylene - polyester - metal layer - polyethylene. The individual layers are interconnected, for example by lamination. The end edges of the film are thus gas-tightly sealed together after welding.

By using two blank sheets of the film and thus two longitudinal seams, a vacuum insulation body is achieved in which the sealing seams or the welds closely fit tightly against the core and practically do not apply. When juxtaposing adjacent vacuum insulation body of the same kind thus a jointless juxtaposition is possible. The evacuation of the envelope of the vacuum insulation body is usually carried out prior to sealing, whereby also methods are known in which a first "partial" sealing takes place, which is then completed after evacuation. As can be seen, the vacuum insulation body according to the invention essentially has the dimensions of the core plus the thickness of the multilayer film used. The seal seams are extremely flat and closely conform to the microporous core.

Preferably, the sealing seams to the center each offset by a few centimeters against each other on the top and bottom of the vacuum insulation body. For example, in such a plate-shaped vacuum insulation body, the respective sealing seam offset from each other by about one third of the total width of the vacuum insulation body to the central axis. Since the staggered sealing seams are relatively flat by the above configuration, the transverse seals on the narrow side can be sealed particularly well. This also causes the transverse Sealing seams kept relatively flat, which further prevents bridging between adjacent vacuum insulation bodies. Furthermore, it is achieved by attaching the sealing seams adjacent to the core as close as possible to ensure that the excess film material can be placed in the corner region around the edges of the core, which in turn results in a compact construction.

The invention will be explained in more detail with reference to the drawings and described. Show it:

1 shows a section through a vacuum insulation body according to the invention.

Fig. 2 is a perspective view of FIG. 1;

3 is a schematic view of the manufacturing method of the invention; and

4 is a perspective view of a completed vacuum insulation body.

The vacuum insulation body 1 according to the invention has a core 2 of a microporous material which is completely enveloped by a multilayer film 3. The vacuum insulation body 1 of the embodiment of FIGS. 1 and 2 is a plate-shaped vacuum insulation body 1 or flat cuboid. As can be seen in particular from FIG. 1, a first sealing seam 4 runs on the upper side 18 approximately in the middle region of the vacuum insulation body 1 and displaces a second sealing seam 4 'on the lower side for this purpose. These two sealing seams 4 and 4 'on the two main surfaces (here, the upper and lower flat sides 18 and 18' in comparison to the narrower end faces 12, 13 and 14, 17, see Fig .. 4) can also in the opposite direction of the Center offset, as shown in Fig. 2.

These sealing seams 4 and 4 'are formed by respectively sealing the end edges 5 and 6 of the multilayer film 3 in the area where they abut and overlap. In this case, the outer surface of the end edge 5 with the inner surface of the end edge 6 collide (so-called. AB seal). This results in a particularly flat sealing seam 4. However, it is also possible to use an AA seal, as shown for the sealing seam 4 'on the underside 18', likewise in FIG. 2, since with this type of sealing two layers of the film 3 can generally be sealed to one another without difficulty.

The schematic view of Fig. 3 shows in addition to the preparation of the two sealing seams 4 and 4 'after inserting a core 2 in a longitudinal welding device and a transverse sealing seam 15. As can be seen, the sealing of the Quemaht 15 between welding jaws, by the two inner sides of the film together to be sealed. This sealing seam 15 is carried out closely to the core 2 in order to achieve the closest possible envelope. As can also be seen from FIG. 4, the film material remaining from the covering is folded in the corner regions 10 and 11 of the vacuum insulation body 1 into a triangle which fits snugly against the core 2 or the end faces of the vacuum insulation body 1. As a result, Kältebzw. Thermal bridges are avoided.

Finally, FIG. 4 shows a perspective view of the finished vacuum insulation body 1. It can be seen that the vacuum insulation body 1 offset from the central region of the upper side 18 has the sealing seam 4, which is about one third of the opposite sealing seam 4 'at the bottom 18' Overall width is offset. Furthermore, the vacuum insulation body 1 has transverse seams 15, which are formed on the respective end faces 12 and 13 of the vacuum insulation body 1. By the offset of the longitudinal seams 4 and 4 'thus a film accumulation on the respective transverse seam 15 is advantageously avoided. The excess foil or the corner regions 10 and 11 are respectively folded over to the front sides 12 and 13, but can also be folded down to the narrow sides 14 and 17.

This proposed method allows by format change readily adaptation of the film wrapping to strongly varying dimensions of the shaped body (width, length and height) in the automated manufacturing process, which is shown schematically in Fig. 3. In particular, this can be for smaller format changes usually on a change of the film rolls (in Fig. 3 below the Welding device shown omitted), since the overlap region of the sealing seams 4 and 4 'are chosen wider, which can be carried out in a considerably shorter time, so means a time savings.

In summary, the following advantages of the solution according to the invention result:

Flexibility in VIP production (many different formats); It can be made larger area VIPs than with a foil sheet; the close-fitting foil allows virtually no thermal bridging of different VIPs to each other; more accurate VIPs can be produced, as the film order remains minimal; automated manufacturing allows economic benefits for the manufacturer and ultimately for the customer; an automatic laminating or foaming system can be connected directly to the

Device are connected in accordance with Figure 3; As a result, the VlP can be protected against mechanical damage immediately after production.

Claims

claims

1. Vacuum insulation body having an upper and lower flat side and narrower end faces, wherein an open-cell, open-pored, microporous and / or fibrous core (2) is completely enveloped by a gas-tight multilayer film whose end edges are sealed together, characterized in that on the flat sides ( 18, 18 ') of the vacuum insulation body (1) each have a sealing seam (4, 4') is provided.

2. Vacuum insulation body according to claim 1, characterized in that the respective sealing seam (4, 4 ') on the upper and lower flat side (18, 18') are arranged off-center, in particular the two sealing seams (4, 4 'by about 1 / 3 of the total width of the vacuum insulation body (1) are oppositely aligned aligned.

3. Vacuum insulation body according to claim 1 or 2, characterized in that after sealing projecting film areas (10, 11) to the narrower end faces (12, 13 or 14, 17) are folded.

4. Vacuum insulation body according to one of the preceding claims, characterized in that the multilayer film (3) has at least one two plastic layers and a barrier layer of metal, metallized plastic, metallic oxides such as SiO _x or Al ₂ O _x or Ormoceren®.

5. Vacuum insulation body according to claim 4, characterized in that the multilayer film (3) consists of a sequence of layers of plastics and barrier materials.

6. Vacuum insulation body according to one of claims 1 to 5, characterized in that the core (2) is cuboidal.

7. Vacuum insulation body according to one of claims 1 to 6, characterized in that the core (2) of compressed microporous material such as precipitated silica, fumed silica and / or aerogels, open-cell polystyrene foam, open-cell polyisocyanurate, fiber materials or combinations of such materials with each other or with separate Scaffolds such as Honeycomb structures exists.

8. A method for producing a vacuum insulation body according to one of claims 1 to 7, characterized in that the two sealing seams (4, 4 ') after insertion of the core (2) are welded in the transport direction, in particular at the same time at the upper and lower flat side (18th , 18 ').