EP0951389B1 - Heat-insulating moulded bodies with envelope, and method for producing same - Google Patents

Abstract

The invention relates to a compressed heat-insulating moulded body, in particular a heat-insulating panel, comprised of at least three layers, namely a central layer (B) based on a microporous ceramic material consisting of fine particles, and outer layers (A, A'/A''). To obtain greater homogeneity and improved heat insulation on all sides, the outer layers (A, A'/A'') are made of a fine-grain or macroporous ceramic material. The central layer (B), which is smaller by circumference, is inserted into the outer layers (A) in such a way as to be embedded in a relatively thick border thereof.

Description

The invention relates a process for Manufacture of molded thermal insulation moldings.

Because molded thermal insulation bodies are based on pressed microporous Insulation material have a low strength and at mechanical stresses or the usually one-sided. Bend the heat and also crumble it slightly, they will at least have a protective layer on one side Mistake. Such thermal insulation bodies are particularly sensitive on the edges.

From EP-A-00 59 860 or DE-A-195 06 411 it is known to provide such thermal insulation bodies made of microporous or highly dispersed ceramic thermal insulation materials on one or both sides with a covering Mistake. With such enclosures, the cavities between the casing and the thermal insulation material in the sense of a optimal thermal insulation cannot be minimized.

An insulating composite molded part is known from DE-C-43 31 590 Made of powdered ceramic material with a middle layer from a first ceramic material from two sides with one Top layer of second in its structure different ceramic material is pressed. The cover layers are through webs penetrating the middle layer are interconnected. Depending on the type of webs, one can also be provided at the same time Obtain edging. As with the inner ones Web, first a layer of the second material with a layer of the first material spread over it The action of pressure is pre-compressed, with projecting web and Edge punches penetrate the upper layer and in the lower one create a depression. The padded second material for the top layer also fills the holes and depressions in the compacted plate. However, there is the edge here just like the webs made of both material components.

The enclosure has an even greater homogeneity and surround One of the tasks of the Invention. This continues to be an inexpensive one Molded thermal insulation body based on finely divided, microporous to create compressed thermal insulation with all-round covering, which ensures optimal protection and thermal insulation and a process for their simple manufacture allows.

The object is solved by the features of claim 1.

• die gerüstbildende Umhüllung der hochdispersen Dämmschicht und der verhältnismäßig breite und stabile wärmedämmende Rand den Wärmedämmformkörpern eine hohe mechanische und die Handhabung erleichternde Festigkeit verleihen;
• durch die Körnigkeit der Hüllschichten beim Verdichten die Luft besser austreten kann, was den bei Wärmedämmformkörpern oft zur Zerstörung führenden Partialdruck der Luftfüllung senkt; und
• außerdem durch den isolierenden Rand der Hüllschichten eine beträchtliche Einsparung an den teuren Kieselsäureprodukten der Mittelschicht erzielt wird.

The molded thermal insulation articles produced by the process according to the invention have the following advantageous properties, where:

• the scaffolding covering of the highly dispersed insulation layer and the relatively wide and stable heat-insulating edge give the heat insulation molded articles a high mechanical strength and ease of handling;
• due to the granularity of the cladding layers, the air can escape better during compression, which lowers the partial pressure of the air filling which often leads to destruction in the case of thermal insulation molded articles; and
• in addition, the insulating edge of the cladding layers results in a considerable saving in the expensive silica products of the middle layer.

The method according to the invention is also minimal machine effort feasible and enables in easier Way an adaptation of the devices to the respective Dimensions of the thermal insulation molded parts.

Fig. 1

eine Draufsicht auf eine Wärmedämmplatte mit Ausbruch;

Fig. 2

eine Preßmatrize eines Unterwerkzeugs einer Preßvorrichtung und einen ersten Preßstempel;

Fig. 3-6

eine zweite Vorrichtung mit einem Förderband und Preßtisch und einem zweiten Preßstempel;

Fig. 7

die Preßmatrize gemäß Figur 2 mit dem zweiten Preßstempel;

Fig. 8

die Preßmatrize gemäß Figur 2 mit den drei zu verpreßenden Schichten mit dem ersten Preßstempel; und

Fig. 9

die verpreßte Wärmedämmplatte vor dem Ausstoß.

In the drawing, the invention is described using the example of a thermal insulation board and a process diagram using a device. Here show:

Fig. 1

a plan view of a thermal insulation panel with a breakout;

Fig. 2

a press die of a lower tool of a press device and a first press die;

Fig. 3-6

a second device with a conveyor belt and press table and a second press ram;

Fig. 7

the press die according to Figure 2 with the second press die;

Fig. 8

the press die according to Figure 2 with the three layers to be pressed with the first press die; and

Fig. 9

the pressed thermal insulation board before ejection.

1

Preßmatrize, 1a Ausstoßöffnung

2

Ausstoßplatte

3

Erster Preßstempel

4

Förderband

5

Abstreifer

6

Randblech (Schütte)

7

Preßtisch

8

Mantelmatrize, 8a zugeschärfter unterer Rand

9

Zweiter Preßstempel

10

Schlauchleitung

In the figures:

1

Press die, 1a discharge opening

2

ejector plate

3

First press stamp

4

conveyor belt

5

scraper

6

Edge plate (chute)

7

press table

8th

Sheath die, 8a sharpened lower edge

9

Second stamp

10

hose

The device shown in the drawing consists of two separate, but also interlinkable parts. On the one hand it consists of a press with a fixed, through a Press mold or die 1 illustrated lower part and one movable, illustrated by a first press ram 3 Top. To change it consists of a press table 7 below the upper run of a conveyor belt 4 together with a chute 5, 6 and one with a sharpened edge 8a at the bottom Sheath die 8 and one fitted into the sheath die 8 Press ram 9 with a not shown switchable Exhaustor leading hose 10.

For the cladding layer A, consisting of the layers A ' 1 and A ″ according to FIG. 1 are in particular inflatable and / or layered minerals like mica, pearlite, vermiculite or Volcanic rock or a mixture thereof for use.

Come for the intermediate or middle layer B according to FIG. 1 Aerogels, especially metal oxides such as pyrogenic ones Silica including arcing silica, low alkali Precipitated silicas, similarly produced aluminum oxide, Titanium oxide and zirconium dioxide or a mixture of at least two of these highly dispersed, microporous materials in question. The preferred binder is water glass because it is has relatively short curing times. As a fiber additive come to the outer layer A or to the middle layer B. Rock wool and glass fibers into consideration.

Example 1:

Für die Hüllschichten A' und A" bestand ein erstes Gemisch aus:

70 Gew.-% Vermiculit

30 Gew.-% Wasserglas

und für die Mittelschicht B bestand ein zweites Gemisch aus:

63 Gew.-% hochdisperser Kieselsäure

34 Gew.-% Ilmenit

3 Gew.-% Perlit.

A 15 mm thick plate according to FIG. 1 with an area of 250 × 300 mm was produced by pressing the following mixtures at 1.0 MPa:

For the cladding layers A 'and A ", a first mixture consisted of:

70 wt% vermiculite

30% by weight water glass

and for middle layer B a second mixture consisted of:

63% by weight of highly disperse silica

34% by weight ilmenite

3% by weight pearlite.

• in eine Preßmatrize 1 des Pressenunterteils einer Preßvorrichtung eine entsprechend der vorbestimmten Dicke der unteren Hüllschicht A' vorgegebene Menge des ersten Gemischs gemäß Fig. 2 eingegeben und mit einem ersten Preßkolben 3 leicht (ca 60% der vorgesehenen Dicke) vorgepreßt,
• das zweite Gemisch für die Mittelschicht B wurde auf einen Preßtisch 7 oder einem darüber geführten Förderband 4 in einer vorgegebenen Dicke gemäß Fig. 3 aufgetragen,
• aus dem aufgetragenen Gemisch wurde mit der Mantelmatrize 8 gemäß Fig. 4 ein dem Umfang der jeweiligen Mittelschicht B entsprechendes Gemischteil abgetrennt,
• das abgetrennte Gemischteil wurde in der Mantelmatrize 8 durch einen zweiten, flächenkleineren Preßstempel 9 ebenfalls gemäß Fig.5 vorgepreßt,
• danach wurde der Preßstempel 9 gemäß Fig. 6 nach oben etwas zurückgesetzt und in dem Preßraum mit dem Exhaustor über die Schlauchleitung 10 ein den Transport des Gemischs für die Mittelschicht B ermöglichendes Vacuum erzeugt,
• die Mantelmatrize 8 mit dem zweiten Preßstempel 9 wurde sodann gemäß Fig. 7 mit der vorgeformten Mittelschicht B zentrisch in die Preßmatrize 1 eingeführt und durch Einlaß von Luft in den Raum unterhalb der Preßfläche des Preßstempels 9 das vorgeformte Gemischteil B auf die untere Hüllschicht A' abgesetzt,
• nach Entfernen der Mantelmatrize 8 wurde sodann eine der vorgegebenen Dicke der oberen Hüllschicht A'' entsprechende Gemischmenge des ersten Gemisches in die Preßform 1 eingefüllt und nun gemäß Fig. 8 alle drei Schichten A'-B-A'' miteinander auf eine vorgegebene Dichte des Wärmedämmformkörpers bei einem Druck von 1,2 MPa verpresst, wie in Fig. 9 zu sehen.

It was:

• in a press die 1 of the lower press part of a press device, a quantity of the first mixture according to FIG. 2 predetermined according to the predetermined thickness of the lower cladding layer A 'and lightly pre-pressed with a first press piston 3 (approx. 60% of the intended thickness),
• the second mixture for the middle layer B was applied to a press table 7 or a conveyor belt 4 guided over it in a predetermined thickness according to FIG. 3,
• a mixture part corresponding to the circumference of the respective middle layer B was separated from the applied mixture with the jacket matrix 8 according to FIG. 4,
• the separated mixture part was also pre-pressed in the jacket die 8 by means of a second, smaller die 9 as shown in FIG. 5,
• 6 the press ram 9 was then set back somewhat upwards and a vacuum which made it possible to transport the mixture for the middle layer B was generated in the press space with the exhaust gate via the hose line 10,
• 7 with the preformed middle layer B was then inserted centrally into the pressing die 1 and the preformed mixture part B was placed on the lower cladding layer A 'by admission of air into the space below the pressing surface of the pressing die 9 .
• after removal of the jacket die 8, a mixture amount of the first mixture corresponding to the predetermined thickness of the upper cladding layer A '' was then poured into the mold 1 and now, according to FIG. 8, all three layers A'-B-A '' together to a predetermined density of Heat insulating molded body pressed at a pressure of 1.2 MPa, as can be seen in Fig. 9.

An alternative process step is provided in the annulus between the mold shell and the shell die 8 a predetermined amount of the first mixture as an additional Fill in edge material for the covering layer A (cf. FIG. 7).

Example 2:

Für die Hüllschicht A' und A'' bestand ein erstes Gemisch aus:

60 Gew.-% Vermiculit, und

40 Gew.-% Kieselsol;

und für die Mittelschicht B bestand ein zweites Gemisch aus:

50 Gew.-% hochdisperser Kieselsäure,

25 Gew.-% Zirkonsilikat,

15 Gew.-% Vermiculit, und

10 Gew.-% Perlit.

Furthermore, a 20 mm thick plate with an area of 250 x 300 mm was pressed by pressing the following mixtures at 1.0 MPa:

For the cladding layer A 'and A'', a first mixture consisted of:

60 wt% vermiculite, and

40 wt% silica sol;

and for middle layer B a second mixture consisted of:

50% by weight of highly disperse silica,

25% by weight of zirconium silicate,

15% by weight vermiculite, and

10% by weight pearlite.

The thermal conductivity of the manufactured thermal insulation boards with a relatively thin middle layer B, the on all sides of the cladding layer A with a relatively strong, peripheral edge (see FIG. 1) was at 1000 ° C. each less than 0.04 W / mK.

Due to the homogeneous structure of the cladding layers A and A '/ A' ' draw with a compact border to embed the middle layer B. the insulation boards produced by a special high strength.

Claims (3)

1. Method for the production of a compressed heat-insulating moulded body, in particular a heat-insulating panel comprised of at least three layers, namely a central layer based on a microporous ceramic material consisting of fine particles, and a covering layer consisting of fine-grain or macroporous ceramic material, wherein the circumference of the central layer (B) is smaller than that of the covering layer (A, A'/A"), so that the central layer (B) is embedded in a strong edge, and wherein the method is characterized by the following steps:

   a) a predetermined amount of mixture corresponding to a predetermined thickness of a lower covering layer (A') is entered into a press matrix (1) and is pre-pressed by application of pressure,

   b) a mixture for a middle layer (B) is placed on a separate press table (7) in a predetermined thickness,

   c) a form is cut out of the mixture for the middle layer (b) spread on the press table (7) with a smaller jacket matrix (8) corresponding to the circumference of the respective middle layer (B) and is also pre-pressed under application of pressure with a pressure ram (9),

   d) then the pressure ram (9) is set back to some extent and a vacuum is generated in the press space allowing the transport of the middle layer (B),

   e) the jacket matrix (8) with the pre-pressed mixture of the middle layer (B) is placed centredly into the press matrix (1) on the first covering layer (A'),

   f) then the jacket matrix (8) is removed, and

   g) a mixture amount corresponding to the thickness for the upper covering layer (A") is filled into the press matrix (1), and then

   h) all layers (A'-B-A") are pressed together to a preset thickness of the heat-insulating moulded body.
2. Method according to claim 1, characterized by the further step that prior to the removal of the jacket matrix (8), after partial step e), a mixture amount of the first mixture (A) corresponding approximately to the thickness of the middle layer (B) is filled into the annular space between the press matrix (1) and the jacket matrix (8) for edge reinforcement.
3. Method according to claim 1 or 2, characterized in that a partially or complete envelope of a shrinkable plastic foil is shrunk onto the pressed heat-insulating moulded body.

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