DE3626382A1 - Mineral fibre felt in the form of rolls or slabs for insulating hot surfaces on heating devices and process for the production thereof and heating device equipped therewith - Google Patents

Abstract

A mineral fibre felt (5) containing an organic binder is used for insulating a hot surface (3) of a heating device (1), the temperature of the hot surface (3) being so high that the organic binder in the mineral fibre felt (5) would decompose with odour pollution under the effect of this temperature. To avoid this, in a surface region (6) adjacent to the hot surface (3), the binder content is reduced to zero, for which purpose, in particular a heat application to the corresponding surface (7) of the mineral fibre felt (5) during the production of the mineral fibre felt (5) is suitable, which heat application leads to a corresponding decomposition of the binder. When the heating device (1) is first put into operation, odour pollution need no longer be feared. With the exception of the additional heat application, no change of any kind to the industrial production process for the mineral fibre felt (5) is necessary. The surface (7) freed of the binder can be post-treated with a temperature above the softening temperature of the mineral fibres to obtain a mechanical consolidation of the superficial mineral fibres at that location. <IMAGE>

Description

The invention relates to a roll or plate form Mineral fiber felt for the insulation of hot Surfaces on thermal devices such as ovens or the like, according to the preamble of claim 1, and a process for its manufacture according to the generic term of claim 3 and a thermal technology equipped with it cal device according to the preamble of claim 6.

Such mineral fiber felts are known to be produced by defibrating mineral melt in defibration units and depositing it on a production belt, the fibers falling onto the production belt being sprayed with a binder, usually phenolic resin. A fiber layer forms on the production belt, which is compressed by rolling, the binder being cured in a tunnel oven. Depending on the degree of compression and binder content, this results in loose, rollable felts with a low bulk density of, for example, 15 to 30 kg / m ³ or denser, harder boards with higher bulk densities up to 200 kg / m ³ and more.

Mineral fiber felts or sheets produced in this way become Solving a wide variety of insulation problems set and to the respective application by corresponding appropriate choice of bulk density, binder content, Equipment etc. adjusted as best as possible. As far as such  Mineral fiber felts for insulating thermal devices their exact properties are to be used coordinated in detail with the device manufacturer and he follows its delivery with specially for this gefer mineral fiber felts, which are then available from the device manufacturer be installed in the devices.

If now such a product, as generic in advance is used for the insulation of hot surfaces to heat serves technical devices, so takes place in the operation of the Ge considerable heat incidence on the hot surface facing side of the mineral fiber felt. If that Mineral fiber felt well insulated according to its purpose and thus a sharp drop in temperature across its thickness generated so that those adjacent to the hot surface Surface areas temperatures of several 100 ° C be exposed. The exact temperature load in the on occasion is determined by the properties of the device, for which the device manufacturer the mineral fiber product relates. Commonly used binders such as phenol Resins are only resistant to temperatures from 100 to 200 ° C resistant, therefore decompose at higher temperatures. Harmless gases are released in the process, but they are ei sometimes produce an unpleasant smell, so that when commissioning new thermal devices with such insulation in the initial phase Odors are inevitable until the binder in the areas subject to temperature degradation and at he no longer releases gases under a new temperature.

To avoid such an unpleasant smell, one has already working with binder-free mineral fiber felts tet, so in the chute below the defibrillation aggregates no binder is added. Instead the felt is mechanically solidified by Na deln, steppes or the like.  

In this way, the odor nuisance can be avoided avoid, however, such needle felts, quilting mats or the like under industrial manufacturing conditions only at low production speeds of 10 m / min, for example, since the mechanical Has a corresponding time requirement on the felt. The usual production speeds at bindemit mineral fiber felts are of the order of magnitude of 40 m / min and more, so that a much more rational industrial manufacturing is possible.

In contrast, the invention is based on the object a mineral fiber felt for thermal insulation To create devices according to the preamble of claim 1 the when the previously unused thermal technology is put into operation odor nuisance occurring on the device che way avoided or drastically reduced without for this from the usual type of industrial Manufactured with high production speed must be chen.

This problem is solved by the label the features of claim 1.

By reducing the amount of it in undecomposed form present binder where the mineral fiber felt as intended on the hot surface of the thermal Device is present, there is a correspondingly reduced Possibility of further decomposition of the binder. In any case, there is a reduction to zero the hot side of the felt to completely bind it there medium-free layer or extremely low-binder zone to create sufficient depth, under "binders" always undecomposed in this context, i.e. still broken settable binder is to be understood, which is used for heat action of gases releases gases.  

Due to the practically complete absence of decomposable Binder in the temperature resistance of the Binder also exposed to the hot area Odors are avoided. But because of this no mechanical impact on the felt on the Pro production such as needles, steppes or the like derlich, can with undiminished high production speed are manufactured so that a rational Industrial mass production possible at an affordable price is what comes out of such mass products has significant importance.

The measures of claim 2 is in the usual or ganic binders such as phenolic resin despite where appropriate high decomposition with any decomposition in the device Certainty excluded, so that absolute odorlessness is achieved.

To produce such a mineral fiber felt conceivable, the binder additive in the chute below to influence the defibration unit in such a way that there is a binder-free surface layer, or with fibers from a plurality of cascaded Fibering units to work, the fibers of the in Production direction last defibration unit without Binder are stored. Except that here by intervening in the actual production process becomes what is difficult with such, manufacturing technology Products is always problematic, can be practice that the system is completely free of binders not provided on the hot surface always reach reliably, so that odor nuisance conditions, albeit somewhat reduced or shorter, occur can.

The mineral fiber felt is therefore preferred according to claim 3 in the usual way with the addition of binders  and then in the course of production the surface of the Mi exposing the fiber web to heat, which preferably one on the surface of the mineral fiber web Surface temperature of at least 500 ° C generated. By such a heat effect will bind the binder up to decomposed or burned out to a desired depth. Especially Such a burnout and decomposition expediently takes place of the binder in addition to a surface area a bandage reduced for this surface area addition of funds, in view of the lower bandage appropriation of funds is correspondingly cheaper. In the way but no need to look at the subsequent burnout special effort to be driven to already at the The fibers are deposited in an almost binder-free zone aim, but can reduce the amount of binder on the surface-side fibers to the extent in which there are no disruptions to production operations are expected.

The one for the complete burnout of the surface side necessary heat exposure takes place expediently below a temperature, which corresponds to the sintering temperature of the mineral fibers speaks. In this way, the exposure to heat without Influencing the mineral fibers in the way and via egg NEN such a period of time that everything reliably Desired binder is burned out without a Anyone feared changing the consistency of the mineral fibers that must.

Particularly expediently takes place in one second step is only a brief heat kung, which is above the softening temperature of the fibers generated lying temperature. This will make the upper surface fibers at their contact points welded and the surface is smoothed and stabilized. Even after removing the binder in  this area results in any case sufficient surface consolidation of the mineral fiber felt, so that this is full compared to the handling through-hardened plate or the like no disadvantages as shows greater susceptibility to damage etc.

The present invention also manifests itself in one thermal technology insulated with such a mineral fiber felt device that is odor-free when used for the first time remains. Such a thermal device is in the Claims 6 and 7 indicated.

From DE-OS 35 04 873 it is already known bindemite tel from a binding mineral fiber web selek tivively to remove by heat. This is what it is about However, the manufacture of insulating plates for Basement walls made hydrophobic by impregnation are equipped. To create drainage channels in the Mi The impregnation becomes mineral fiber material for a water drain locally removed by heat and the binder also decomposes. It is here thus a similar treatment of a mine Ralf felt, however, is the intended use this mineral fiber felt not with the invention Use in thermal devices comparable and who who achieved and strived for completely different effects, the only for a different application, but not in the frame men of the invention have meaning.

Similarly, it is known from DE-OS 31 47 316, on one mineral fiber felt containing binder is a binder-free Generate surface layer, but then with a Lamination is provided and a fire shaft test must be subjected to DIN 4102, Part 1. Here goes it is the problem that when applying the lamination with an organic binder the binder content of the the lamination of the adjacent mineral fiber layer into one  local excessive exposure to organic materials leads to a classification in class in the fire shaft test A 1 (non-flammable). Instead of a blind woman local organic pollution through use of an inorganic adhesive for lamination beaten, the binder from the neighboring surface remove the area of the mineral fiber web. Such Considerations in connection with the fire behavior of im Building construction materials to be used are however Field of application of mineral fiber felts for thermal insulation in thermal devices completely foreign, as it is here is not about building materials whose behavior in the Fire is of safety-relevant importance. Consequently can, according to the invention, to known techniques returned for local disposal of the binder content are gripped, but in a completely different way Use case and for completely different purposes.

Finally, it is known from US Pat. No. 4,381,330 which Surface of a mineral fiber felt from a heat treatment up to the softening temperature of the mineral fibers to suspend out there without using a liner to achieve a mechanically stabilized surface. A such a procedure can be within the scope of the present invention can also be used, however, according to the teaching of US-PS 43 81 330 the mineral fiber felt binder-free posed, then needled, which a corresponding min changes in production speed, and then exposed to heat, after which only an impregnation of the finished felt with binder he follows. If ent within the scope of the present invention speaking claim 5 a heating of the mineral fibers their softening point takes place, so lies Mineral fiber felt containing binder and without mechanical Processing like needling, but already with surfaces side burned out binder, and is in one last step of such additional heat  subjected to solidification of the surface.

Further details, features and advantages of the invention result from the following description of a Embodiment based on the drawing.

It shows

Fig. 1 is a perspective view of an oven with a partially cut out peripheral wall and

Fig. 2 shows the cut-out wall area of Fig. 1 in section and in an enlarged view.

In the drawing, 1 denotes a thermal device such as an oven or the like, of which only a wall 2 is shown, which has an outer hot surface 3 . This is to be insulated, for example, in relation to a housing outer wall, designated 4 , of the thermal device 1 in a confined space such that the outer side of the outer housing wall 4 has no temperature that is too high for the use of the thermal device 1 .

For this purpose, between the wall 2 and the Gehäu seaußenwand 4 is a mineral-fiber 5 is inserted, over its illustrated cross-section, a correspondingly steep temperature drop to his at the housing outer wall 4 adjacent the surface 8 towards occurs as be known and is conventional.

The mineral fiber felt 5 is produced in the usual manner with phenolic resin as an organic binder, which is arranged in a substantially homogeneous distribution in conventional mineral fiber felts. If the temperature of the hot surface 3 , the maximum value of which is determined by the intended use of the thermal device 1 , reaches a value of approximately 200 ° C., the heat incidence is in the surface area designated by 6 and the hot surface 3 of the mineral fiber felt 5 so strong that the binder present there would decompose. This releases gases which are harmless per se, but which are perceived as odors.

In order to avoid this, the mineral fiber felt 5 has been put out in the course of its production by the mineral fiber manufacturer in the event of a heat effect on its surface 7 of the surface area 6 , which leads there to a corresponding decomposition of the binder present there. Alternatively or in support, a surface layer of reduced binder content can also be produced as part of the laying down of the fibers. In any case, this has the consequence that the surface area 6 up to the dash-dotted line 9 is practically free of organic binder when the mineral fiber felt 5 is installed in the thermotechnical device 1 . Taking into account the known maximum heat from the hot surface 3 ago and the temperature drop in mineral fiber 5 , the depth of the surface area 6 denoted by t is chosen up to the illustrated dash-dotted line 9 so that only one line 9 is left Temperature of 150 ° C or less is present, so that the areas of the mineral fiber felt 5 lying in the drawing below the line 9 are not exposed to any Temperaturein effect, which would decompose the binder there with unpleasant odors.

This way, the odor nuisance is the first Commissioning of the thermal device on simple and safely avoided.

Of course, the removal of the binder in the surface area 6 leads to a corresponding reduction of the binding forces there. Where this interferes with the handling or during the assembly as by susceptibility to damage of the surface region 6, following the removal of the binder a further heat treatment may be carried out the surface of the surface portion 6 temperature with a Tempe, which is above the softening temperature of the mineral fibers. As a result, the surface-side mineral fibers are melted, combine with each other and form a relatively firm, abriebfe ste and stable surface without the use of an organic binder.

Since the technique of removing the surface of Binder made of mineral fiber felt, albeit too much their purposes and for completely different applications, per se is known, as is the surface-side hardening by softening the mineral fibers, for example by flame can shine on a more detailed explanation and representation of these techniques can be dispensed with.

Claims (7)

1. In the form of rolls or sheets of mineral fiber ( 5 ) for the insulation of hot surfaces ( 3 ) on thermal devices ( 1 ), such as ovens or the like, which has an organic binder, the temperature resistance of which is determined by the temperature of the hot surface ( 3 is exceeded), characterized in that the present in undecomposed form binder of the Mineralfaserfilzes (5) from the side opposite with respect to the hot surface (3) surface (8) to the provided for the abutment against the hot surface (3) surface ( 7 ) is reduced to zero. 2. Mineral fiber felt ( 5 ) according to claim 1, characterized in that the binder present in undecomposed form on the provided for contacting the hot surface ( 3 ), preferably unclad surface ( 7 ) of the mineral fiber felt ( 5 ) at least up to one such depth ( t ) is reduced to zero, in which a temperature of approximately 150 ° C. or less is present when used as intended. 3. A method for producing a mineral fiber felt ( 5 ) according to claim 1 or 2, in which the mineral fibers are deposited and sealed with a uniform or stepwise addition of the organic binder on a production belt to a mat with a uniform or thickness-wise decreasing binder content and the binder is cured, characterized in that the surface ( 7 ) of the mineral fiber web is exposed after the binding has cured by means of a heat effect which produces a surface temperature on the mineral fiber web of preferably at least 500 ° C. 4. The method according to claim 3, characterized in that the heat creates a temperature that below the sintering temperature of the mineral fibers lies. 5. The method according to claim 3 or 4, characterized records that in a second step a heat action occurs during which a brief over the softening temperature of the fibers rature is generated. 6. Thermal machine (1), in particular oven or the like, characterized by a voltage applied to hot surfaces (3) insulation of an organic binder-containing mineral fiber (5), terized in that the present in undecomposed form binder of the Mineralfaserfilzes (5) of the Oberflä facing away with respect to the hot surface (3) surface (8) to the hot at the surface (3) at their null redu to exposed surface (7) to the value. 7. Apparatus ( 1 ) according to claim 6, characterized in that the binder present in undecomposed form on the hot surface ( 3 ) adjacent to the preferably non-laminated surface ( 7 ) of the mineral fiber felt ( 5 ) at least up to such a tie fe ( t ) is reduced to zero, in which there is a temperature of approximately 150 ° C. or less when the device ( 1 ) is used as intended.