EP1247916A1 - Insulated element especially wood fibre insulated plate, process for its production and use - Google Patents

Abstract

The insulating board is formed on a base of fibers with ligno-cellulose content and adhered by a binder. The fibers (2) in the insulating board have a preferred orientation parallel to a plane (9) extending at right angles to the front (3) and rear (4) surfaces. The front and/or rear surface are open natural joints. At least one narrow face (6) of the insulating board which extends parallel to the plane of preferred orientation is constructed at least partially from a closed pressed surface of hard fiber board. Independent claims are included for a procedure of the manufacture of insulating components in the form of hard fiber boards, and for a use for the insulating components which can be fitted on a wall or on the underside of a ceiling.

Description

The invention relates to an insulating molded body, in particular an insulation board with the characteristics of the generic term of Claim 1. Furthermore, the invention relates to a Processes and uses of such molded inserts.

Different insulation materials are used in construction. A special category of these insulation materials are insulation boards Wood pulp. These include so-called soft wood fiber boards, traditionally manufactured mainly by so-called wet processes become. As a more general, from the manufacturing process independent designation is "factory-made wood fiber insulation materials" used, this term in addition to plates Roll goods include.

The present invention relates to insulating molded articles with essential fixed external dimensions, in particular Insulation panels count in which the front surface as well as the rear surface with which the insulation board in the insulation direction begins and ends, run parallel to each other. The molded inserts can also have a different spatial shape exhibit.

A special known application of insulation boards according to the generic term of claim 1 are so-called composite thermal insulation systems. These are based, for example, on a network between one Insulation layer made of the insulation boards and a weather protection layer, which is mostly a mineral plaster can. Such a thermal insulation composite requires high inherent strength the insulation layer, since only this is the weather protection layer wearing. In another known composite thermal insulation system on insulation boards according to the preamble of claim 1 a flexible Attachment shell applied. Specifically, a plasterboard or Gypsum fibreboard with a tie directly on the Glued insulation board. The insulation board can be used on both Wall mounted as well as hanging on the underside of a ceiling be, if possible, also by gluing with a tie he follows. In addition, it is also known that the insulation boards in thermal insulation composite systems on one or both sides with higher strength Planking materials that are decoratively designed and also can be kept very thin.

For all known uses described so far the front surface and the rear surface, with where the insulation boards start and end in the insulation direction, formed by the natural broad sides of the insulation boards, such as by gluing in the manufacture of wood fiber boards the lignocellulose-containing fibers originated originally.

Regarding the requirements for the inherent strength of the insulation boards is common to all applications described here that a sufficiently high tear resistance of the insulation board from the Wall or ceiling on the one hand and the one applied to the insulation board Visible material must be given on the other hand. The Requirements for this tear-off strength are in DIN 68755-1 "Wood fiber insulation materials for construction" from June 2000, in which so-called tear strength groups were introduced, which for the applicability of wood fiber insulation as a plaster base are decisive. The decisive factor is that perpendicular to Normal plane of the panel determined tear strength, which in eight Tear resistance groups is classified. The three highest in the tear strength groups listed in DIN 68755-1 are included Denoted T15, T20 and T30. These meet the requirements the mean tear strength of ≥ 15 kPa; ≥ 20 kPa and ≥ 30 kPa. The tensile strength of an insulation board made of wood fiber material to increase the compression of the fibers in the Insulation board can be increased. This in turn runs the thermal insulation contrary to the insulation board. The result is familiar with Insulation boards made of wood fiber material, on their thermal conductivity the requirement is that it does not exceed 0.060 W / m * K, and therefore only a certain concentration of Fibers allows a maximum tear strength of about 30 kPa reachable. This value is not significantly exceeded possible. Accordingly, there was no higher tear resistance group in the DIN T40 or the like.

Wood fiber insulation materials are in direct competition with insulation boards made of mineral or glass fibers. For the area of application there is a special insulation board made of mineral fibers as a plaster base with special tear-off strength, as a slat plate referred to as. A slat plate is made that first a starting plate made from mineral fibers whose thickness corresponds to the later width of the lamella plate. Strips are then sawn out of the starting plate, which correspond to the slat plates. That is, the breadth of the Stripes form the thickness of the lamella plates. The front one Surface as well as the rear surface with which the Slat plate begins and ends in the insulation direction sawn surfaces. In addition, the mineral fibers in the Slat plate a preferred orientation parallel to a cross from the front surface and across to the rear surface level at that of the original manufacture the starting plate comes from the mineral fibers. For the Tear resistance of lamellar panels is usually a value of ≥ 80 kPa. The typical plate format of lamella plates is 120 cm long, 20 cm wide and a selectable thickness typically in the range of a few centimeters.

The object of the present invention is to provide insulating moldings according to the preamble of claim 1 and a method and To show uses of such molded inserts, in which one Tear resistance in the same order of magnitude as with lamellar panels made of mineral fibers with low thermal conductivity is achieved to wood fiber insulation for the To make construction competitive.

According to the invention, this object is achieved with an insulating molded body solved by the features of claim 1. Advantageous embodiments of the molded insulating body are in the subclaims 2 to 12 described.

With the new molded insulating body, which is in particular is an insulation board, so that these two terms in the Sequence also used synonymously, the lignocellulose-containing ones Fibers that make up an insulating molding essentially there is a preferred orientation parallel to one transverse to the front surface and across the rear surface level. The preferred orientation runs with it perpendicular to the typical preferred orientation of fibers in a well-known insulation board made of wood fiber material, which is parallel aligned with the front surface and the rear surface is. This special preferred orientation of the Fibers in the new molded insulating body, which is also available as a web-oriented Fiber structure can be called, the tensile strength of the new insulation molded body, which in its tear resistance in one Composite system results from known insulation boards Wood pulp increases dramatically and easily achieves that Values of known lamella plates made of mineral fibers. This is on a multiple overlap of the fibers with resulting mutual anchoring attributable only to the Gives directions of preferred orientation, one of which at the new molded insulating body with the direction of the tensile load coincides. The new molded insulation body points in this direction also good compressive strength if it is not to local, d. H. punctual compressive stresses. How with a slat plate made of mineral fiber can with the new Insulation molded body the front surface and the rear surface, with which the molded insulation body begins in the insulation direction and ends up not being closed surfaces. Rather acts it is open partitions, the local pressure loads not withstand particularly well in many places. closed Surfaces can only be found in the new molded insulating body Narrow surfaces. These closed surfaces run parallel to the preferred orientation level.

The closed surfaces of the molded insulating body are preferred closed press surfaces from the manufacture of a Fibreboard, which is the basis for the new molded insulation serves.

Such a wood fiber board as the basis for the new one Insulation molded body must normally have a thickness that the Corresponds to the width of the molded insulating body. Starting from one It can be the desired width of the insulating molded body of about 20 cm but make sense, the appropriate thickness of the wood fiber board to produce in two steps. So two wood fiber boards glued flat with a respective thickness of 10 cm to a starting plate with a thickness of 20 cm achieve. The new moldings can then be separated from this become. This results in at least one parallel to that Inner adhesive surface running at the preferred orientation level the molded insulating body on which the pressing surfaces of the two wood fiber boards are glued together. This principle can also can be implemented with three or more wood fiber boards. It is preferred, however, if only two wood fiber boards together are glued or the board thickness of each wood fiber board, from which the new molded insulating body is made, is at least 80 mm.

The density of the wood fiber boards for the production of the new insulating molded body should be in the range of 100 to 230 kg / m ³ . In this area, stable wood fiber boards with low thermal conductivity can be produced.

The thickness of the new insulation molding, d. H. the distance of the front Surface from the back surface is typically 50 to 400 mm. In principle, however, it can be freely selected. He can, but in particular need not be constant. Rather can between the front surface and the rear surface of the Insulating molded body, a wedge angle can be provided, for example has advantages when insulating roofs. A special one Insulating molded body for insulating flat roofs has a wedge angle <20 ° on.

It is understood that the level or preferred orientation at an insulating molded body with a wedge angle between the front Surface and the rear surface are not perpendicular to either the front surface as well as the rear surface can. In principle, this is not mandatory. It is enough a transverse orientation of the preferred orientation of the fibers to that front surface and the rear surface, the angle between the level of preferred orientation of the surfaces is only around 90 °, ie in the range from 60 to 120 °. So are also molded inserts with parallel front and rear Surfaces and narrow surfaces in the form of press surfaces with diamond-shaped instead of rectangular cross-section possible.

With such a diamond-shaped cross section can be joined together the molded insulation body is formed perpendicular to the insulation level running light columns are avoided. Another Avoidance of light gaps can be achieved by accidentally two opposite narrow surfaces of the new molded insulating body can be achieved with complementary step folds.

The new molded insulating body can be used as an insulation board with the usual Standard dimensions should be formed so that the front surface and the rear surface one in the plane of the preferred direction running length from 600 to 1500 mm and a perpendicular to it have a running width of 150 to 300 mm. In these Areas fall the standard dimensions of 1200 mm in length and 200 mm Width.

The easily attainable tear strength of the new Insulated body between the front surface and the rear Surface used in composite systems with support surfaces are easily glued, is at least 100 kPa, itself if a relatively low average bulk density of the molded insulating body given is.

A method according to the invention for the production of the new insulating molded body is characterized by the features of claim 13, advantageous embodiments of this method are in the subclaims 14 to 16.

Already in the description of the new molded insulation body was on Details of its manufacture noted. Basically from a wood fiber board that is perpendicular to after external pressing surfaces on which the lignocellulose-containing Fibers are densely compressed above average, is separated along dividing surfaces. At these dividing surfaces the front surfaces and the rear surfaces are created Surfaces of the molded inserts. Typically it will Cut the fibreboard with the new process Sawing reached.

The open structure of the front sawn Surfaces and rear surfaces are local Resistance to pressure. But it will be an excellent one Possibility of anchoring pasty adhesives. So is the instant adhesion of the new molded inserts when Stick to ceilings and walls so well that they are only pressed on will need and can then be released without them fall down again.

If the desired width of the molded inserts is not determined by the Thickness of a single wood fiber board can be provided can, several wood fiber boards over their pressing surfaces be glued to each other before separating the so formed multi-layer fibreboard into the individual Insulation molded body takes place.

The flat gluing of the fibreboard can be done with one Dispersion adhesive or with alkali silicate. The closed press surfaces of the fibreboard let in permanent gluing using very small amounts of adhesive to.

The uses of the new molded insulating articles according to the invention are defined in claims 17 and 18. Advantageous embodiments these uses can be found in subclaims 19 and 20.

In the first use according to the invention, the individual Insulation molded body arranged close to each other, whereby their front surfaces and their rear surfaces, respectively coincide. That is, it becomes a closed layer of the Insulated molded bodies that span the entire level of Layer an identical composition exclusively from the Fibers of the molded inserts and the binding agent that holds them together having.

In the second use according to the invention, the individual Insulated molded bodies arranged next to each other on the gap, their front surfaces and their rear surfaces again each coincide. There will be free space between the Insulation moldings but filled with other insulation materials, at which are wood fiber insulation materials as roll goods or others Insulation materials can act.

Preferably, the individual molded inserts with their rear surface glued to a wall or ceiling. in this connection presents itself through the open rear surface of the new Insulation molded a very stable connection because of the Adhesive can partially penetrate the surface.

On their front surface, the molded inserts can be used with a Plaster or a plate-shaped planking can be glued. Also this is due to the open structure of the surface a very stable connection. The stability is not just that mechanically, but also given weather conditions. The open structure of the surfaces of the new molded insulation body is noticeable positively, because once entered Moisture can easily escape again and not under a closed top layer.

Fig. 1

einen Querschnitt durch eine erste Ausführungsform des neuen Dämmformkörpers,

Fig. 2

einen Querschnitt durch eine zweite Ausführungsform des neuen Dämmformkörpers,

Fig. 3

einen Querschnitt durch eine dritte Ausführungsform des neuen Dämmformkörpers,

Fig. 4

einen Querschnitt durch eine vierte Ausführungsform des neuen Dämmformkörpers,

Fig. 5

eine Draufsicht auf den Dämmformkörper gemäß Fig. 2,

Fig. 6

die Herstellung des neuen Dämmformkörpers in der Ausführungsform einer der Fig. 1 und 2,

Fig. 7

eine erste Verwendung von neuen Dämmformkörpern,

Fig. 8

eine zweite Verwendung von neuen Dämmformkörpern und

Fig. 9

eine dritte Verwendung von neuen Dämmformkörpern.

The invention is explained and described in more detail below on the basis of concrete exemplary embodiments, and shows

Fig. 1

3 shows a cross section through a first embodiment of the new molded insulating body,

Fig. 2

a cross section through a second embodiment of the new molded insulating body,

Fig. 3

2 shows a cross section through a third embodiment of the new molded insulating body,

Fig. 4

a cross section through a fourth embodiment of the new molded insulating body,

Fig. 5

3 shows a plan view of the molded insulating body according to FIG. 2,

Fig. 6

the production of the new molded insulating body in the embodiment of one of FIGS. 1 and 2,

Fig. 7

a first use of new molded inserts,

Fig. 8

a second use of new insulation moldings and

Fig. 9

a third use of new insulation moldings.

The cross-section in FIG. 1 transverse to its main direction of extension Shown insulating body 1 consists of lignocellulose-containing Fibers 2 that are not separate with one here reproduced binders are bound. The molded insulation body 1 has a front surface 3 and a rear surface 4 on, the assignment front and back initially arbitrary is. It is crucial that the molded insulating body 1 with the front Surface 3 and the rear surface 4 in an insulation direction 5, which runs perpendicular to the surfaces 3, 4, begins or ends. The front surface 3 and the rear surface 4 are sawn partitions with an irelatively open surface structure. In contrast, the molded body 1 on its two Narrow surfaces 6 visible in FIG. 1, closed pressing surfaces 7 on which the fibers 2 have a compression above the middle Have bulk density of the molded body 1 also. The typical one Width of the molded insulating body 1, which is also used here as an insulation board can be referred to because the surfaces 3 and 4 are parallel run to each other, is 20 cm, the thickness in the direction of Insulation direction 5 a few centimeters, here it is 8 cm. The fibers 2 in the insulating molded body 1 have a preferred orientation parallel to a plane 9 which is transverse to the surfaces 3 and 4 is aligned. Specifically, the alignment is vertical here to the surfaces 3 and 4. So that the plane 9 runs parallel to the insulation direction 5. Furthermore, it runs perpendicular to Drawing plane, d. H. parallel to the narrow surfaces 6. This is based insist that the preferred orientation of the fibers 2 ultimately of a pressing process, via which the pressing surfaces 7 are formed were. The preferred orientation of the fibers 2 parallel to level 9 gives the molded body 1 a special tensile strength in the insulation direction 5 between the surfaces 3 and 4. There is also good compressive strength here, although this not due to the open structures of surfaces 3 and 4 is available locally.

The molded body 1 according to FIG. 2 differs from that 1 in that in the middle between the narrow surfaces 6 an inner adhesive surface 10 is provided, on which two additional pressing surfaces 7 are glued together. During the Shaped body 1 according to FIG. 1 from a one-piece wood fiber board is separated out, the molded body 1 according to FIG. 2 a two-layer fibreboard, which from two individual wood fiber panels glued along the adhesive surface 10 consists. In addition, the thickness of the 2 with about 6 cm smaller than that of the molded insulating body 1 according to FIG. 1.

The insulating molded body 1 according to FIG. 3 differs from the two previous embodiments in that he has two Has adhesive surfaces 10, on which pressing surfaces 7 with each other are glued. That is, it is based on three together single glued wood fiber panels. The 3 in the insulation direction 5 here is 10 cm. As a further difference to the previous ones Embodiments are the opposite narrow surfaces 6 provided with step folds 11 by milling 12 are formed. The step folds 11 allow one juxtaposing several molded insulating bodies 1 under partial Overlap to avoid light gaps.

The embodiment of the molded insulating body 1 according to FIG. 4 differs differs from all previous embodiments in that that the surfaces 3 and 4 are not parallel to each other, but at a wedge angle 13. That is, the thickness of the Insulating molded body 1 varies perpendicular to the surface 3 between 6 and 9 cm. The insulation direction 5, d. H. the shortest The connection of surfaces 3 and 4 is no longer precise parallel to the narrow sides 6 and through those there Press surfaces defined level 9 of the preferred orientation Fibers 2. The preferred orientation runs exactly here perpendicular to the surface 3, but only across the surface 4, their deviation from the perpendicular to the wedge angle 13 equivalent. The molded body 1 according to FIG. 4 is for the insulation of a Badger with a small angle of inclination of the size of the wedge angle 13 provided. On the downward facing front surface 3, a horizontal ceiling area is formed under the roof.

FIG. 5 shows a top view of the insulating body 1 according to FIG. 2 its front surface 3. The now visible length 14 of the Shaped body 1 is 120 cm. You can also see the adhesive surface 10 with the press surfaces glued to one another there Surface 3 has a typically sawn separating surface 15 in Compared to the narrow surfaces 6 an open structure.

Fig. 6 outlines how a single or multi-layer Fibreboard 16 a plurality of moldings 1 along the parting surfaces 15 are separated out, the broad surface 17 of the fiberboard 16 is the pressing surface 7, which in the manufacture of Fibreboard 16 has been created. The width of each Strips which are separated from the fibreboard 16 is the thickness of the insulation molded body 1 in the insulation direction 5. Die The length of the strips 14 corresponds to the length of the insulating molded body. The thickness of the wood fiber board 16 that is not visible here is Width 8 of the molded inserts. The wood fiber board 16 can as in the case of the molded insulating body 1 according to FIG. 1, one layer or as in the case of the molded inserts of FIGS. 2 and 3 be multilayered. That is, individual glued together Have wood fiber boards.

7 is a horizontal cross section through a composite thermal insulation system reproduced in front of a wall 18. The Composite insulation system consists of parallel to gap juxtaposed insulating moldings 1, with their rear surface 4 are glued to the wall 18. In the between the insulating moldings 1 remaining gaps 19 Insulation material 20 in the form of non-dimensionally stable wood fiber insulation arranged, which is available as roll goods. On the front Surfaces 3 of the molded insulating body 1 is a dense fibreboard 26 glued on, for example to form a Room wall surface can be overtape.

8, which is also in a horizontal cross section is shown in front of a Outer wall 21 insulating molded body 1 arranged close to each other. The Insulation molded body 1 are with their rear surface 4 to the Glued outer wall 21. On their front surface 3 are the Insulated molded body 1 plastered, with a plaster holding net in the plaster 22 23 is arranged. The plaster 22 forms a weather protection layer for the insulating molded body 1.

In the case of the composite thermal insulation system according to FIG. 9, the molded insulating bodies are 1 arranged close together under a blanket 24 to which they are glued with their rear surfaces 4. Under the Shaped body 1 is a plasterboard on the front surface 3 25 glued. In the formation of this composite thermal insulation system can the insulating molded body 1 with a plaster gypsum binder can be pressed directly onto the ceiling 24 and are held there immediately. The same applies to the plasterboard 25.

In the following examples, test trials become the Use of the new molded insulating body 1 reports:

Example 1:

A tensile strength test according to DIN EN 1607 (200 mm * 200 mm edge length) of an insulating molded body according to the invention showed a tensile strength of 380 kPa. The wood fiber board from which the molded insulating body had been removed had an average bulk density of 210 kg / m ³ .

Example 2:

A tensile strength test according to DIN EN 1607 (200 mm * 200 mm edge length) of an insulating molded body according to the invention showed a tensile strength of 180 kPa. The wood fiber board from which this molded insulating body had been removed had a density of 145 kg / m ³ .

Example 3:

One molded insulating body according to the invention was made using a commercially available Gypsum girder on a vertical concrete wall and on a concrete ceiling (from below). The liability took place at full-surface binder application immediately. A support for the molded insulating body until the binder cured was not necessary. After the bond between the insulation body has hardened and the wall became four times larger, 12.5 mm in area strong plasterboard as flexible plasterboard with the same gypsum tie directly onto the molded insulating body applied. Here, too, liability was immediate, although the Planking due to its own weight, great forces in the tear-off direction exerted on the molded insulating body. This construction was on an uncovered outer wall attached. A three month natural weathering over the winter season through rain, ice and snow could even when the plasterboard was completely damp and the underlying insulation molding of liability do nothing. Rather, it quickly dried out dry weather observed.

Appendix: Process for the production of wood fiber boards as Starting material for the production of the molded inserts

The wood fiber boards from which the new invention Insulation moldings can be produced, should be characterized by a low average bulk density with stable binding of the fibers distinguished. In the following an exemplary method for Production of such wood fiber boards described in more detail.

It is a process for the production of lightweight wood fiber boards with an average bulk density of less than 250 kg / m ³ based on lignocellulose-containing fibers and binders, in which the binder is applied to the fibers and the fibers are then formed into a fiber mat which are calibrated and subjected to a heat treatment to harden the binder. In contrast to so-called wet processes, a fiber moisture content of the fibers is set so that it is less than 20% when calibrating the fiber mat and during heat treatment. Furthermore, in contrast to so-called hot air processes, the fiber mat is contacted on both sides with smoothly closed heating surfaces for heat transfer. The opposing heating surfaces are distance-controlled to maintain a predetermined distance from one another, and a bulk density profile of the wood fiber boards is set so that there is an edge increase in the bulk density compared to the average bulk density of the wood fiber boards of at least 20%.

The fiber moisture of the fibers when calibrating the fiber mat and during the heat treatment for curing the binder can, as in the case of conventional so-called drying processes, be in the range of below 10%. Just as with a classic dry process, the heat treatment of the fiber mat takes place via smoothly closed heating surfaces, via which the heat is transferred to the fiber mat to harden the binder. It is important that the heating surfaces are distance-controlled and not pressure-controlled, as is the case when conventional drying processes are carried out. The very low bulk density of the wood fiber boards produced by the present method does not allow controlled pressure control of the heating surfaces. However, by controlling the distance between the heating surfaces, a raw density profile is imprinted on the wood fiber boards produced, which has an edge increase in the raw density compared to the average bulk density of the wood fiber boards of at least 20%. The edge areas of the wood fiber boards are thus compressed in relation to their average bulk density. In conjunction with the smoothly closed heating surfaces that cause this compression, this results in a smoothly closed surface of the wood fiber boards produced. This smoothly closed surface is unusual for wood fiber boards in the density range below 250 kg / m ³ . It enables simple and precise flat bonding of individual wood fiber boards during the production of the new molded inserts.

It can not be overlooked that a low density, too already with the fiber mat, a heat transfer up to the center of the fiber mat is not during the heat treatment just relieved. That is why it is in the present procedure preferred to use the fiber mat before the heat treatment Spray water or an aqueous solution. In this way can be a burst of steam due to water evaporating on the heating surfaces be directed into the interior of the fiber mat, which is where the Promotes curing of the binder. In addition, the water gives way Fibers on the surface of the fiber mat, so that by the Effect of the smooth heating surfaces particularly smooth surfaces can be achieved in the finished wood fiber boards can.

Except for the determination of the area-related mass occupancy the fiber mat through the heating surfaces controlled at a distance can also be calibrated.

The specified distance between the heating surfaces and the thickness of the manufactured ones Corresponding to wood fiber boards is typically 20 to 300 mm. It is just in the larger area Thicknesses in this area are astonishing that the fiberboard can still be produced using a dry process.

In the method described here, it is particularly preferred if the bulk density profile of the wood fiber boards like this is set that there is an edge increase in the bulk density compared to the average bulk density of the wood fiber boards from results in at least 60%. A stronger edge increase of the bulk density is the basis for the training of a particularly firm closed surface of the finished fiberboard, the for example, a considerable pressure stability compared with the average bulk density of the wood fiber boards can.

If the average bulk density of the wood fiber boards is set to 150 to 250 kg / m ³ , a conventional synthetic resin of the wood-based panel industry can be used as a binder. The usual synthetic resins of the wood-based panel industry include urea-formaldehyde, melamine-urea-formaldehyde, melamine-urea-phenol-formaldehyde, phenol-urea-formaldehyde, phenol-formaldehyde and PMDI resins.

If the average bulk density of the wood fiber boards is set to 60 to 250 kg / m ³ , a foam-forming polyurethane binder can be used as the binder. In this area of bulk density, the advantage of filling the cavities in the wood fiber board between the individual fibers by the polyurethane foam has a positive effect. The particularly light wood fiber boards in the range below 150 kg / m ³ cannot be produced in a usable quality without the use of a foam-forming binder.

As a foam-forming polyurethane binder, a so-called One-component system are used, which for example was developed by Bayer and basically is available. Preferably, however, it is easier to control Two-component system used, the foam-forming Polyurethane binder a first, NCO group-containing Binder component and a second at least one polyol having binder component.

It is in a particularly preferred embodiment of the The method described here provided the fibers before Apply the binder in at least two batches and on a first of these lots only the first, the NCO groups having binder component and a second of these lots only the second binder component containing the polyol apply and the parts of the fibers first immediately before forming the fiber mat together mix. Until the parts of the fibers are mixed they are two binder components so completely apart Cut. Even while mixing the lots of fibers there is still no significant contact between the two binder components. It is only when the fiber mat is formed this contact at the contact points of the fibers. This However, contact is still not enough for a polyurethane reaction alone trigger to a significant extent. Only over very long periods of time or through the heat treatment the relevant major part of the polyurethane reaction is triggered, the then to the desired binding of the fibers in the wood fiber boards leads. It is surprising that the polyurethane reaction ultimately despite the microscopic inhomogeneous Distribution of the binder components during heat treatment completely done. That means there is no noticeable loss of reaction by determining that both binder components not on all fibers. Because at the same time the reactivity of the binder fully to the polyurethane reaction within the fiber mat is concentrated, the binder can relatively small proportions based on the fibers and the desired Strengths of the wood fiber boards used become.

The first batch mentioned can generally be 10 to 90% and the second lot corresponding to 90 to 10% of the total fibers contain. But it makes perfect sense if the first and the second lot of fibers are approximately the same size, d. H. for example each contain 40 to 60% of the total fibers.

But this does not stand in the way of a third game subject the fibers to another treatment before mixing becomes. In particular, a third batch of fibers be left without binder component until they are with the other batches is mixed. This approach is special interesting in the area of very low binder proportions.

The process described here can be carried out batchwise as well as continuously, which is preferred. With continuous process control, the heating surfaces are typically on rear heated metal endless belts intended.

When using the manufacture of wood fiber boards of a PUR binder with two binder components continuously is carried out, the lots of fibers can after the application of the binder components and before their mixing are stored separately from each other. The reactivity of the binder components decreases with separate intermediate storage the parts of the fibers do not fall off even over longer periods of time.

The heat treatment for curing the wood fiber boards can be made so that in the middle of the molded body a temperature of only 50 to 100 ° C is reached. The means that compared to known methods very low Temperatures in the middle of the molded body are sufficient. Conversely, this results in a high degree of efficiency energy used in heat treatment and in short periods of time, which are required for the heat treatment. The minor In the new process, temperature is at least for that Harden the binder portion in the middle of the molded body sufficient if highly reactive polyurethane binders are used the reaction of which is not chemically impaired to a Suppress pre-reaction.

Preferably, the fibers used in the manufacture of the wood fiber boards processed, wood fibers in the form of usual defibrator fiber. The use of Recycled wood without any significant loss of quality in the end manufactured molded inserts possible.

The proportion of binder can be used in the manufacture of wood fiber boards be chosen within wide limits by the necessary strength of the wood fiber boards on the one hand and the economy of the process in view of high binder costs on the other hand are set. The following information refer to the use of a PUR binder.

Typically, the binder content of the wood fiber boards to a total of 2.5 to 5% by weight based on atro Wood fibers set. This results in molded inserts, some of them as pure thermal insulation bodies and at higher bulk densities also as wall elements with high rigidity and high insulation potential can be used.

The process described here for the production of wood fiber boards can also be carried out so that when molding the preform from the fibers a layer structure with different Compositions and / or proportions of the binder in the individual layers is set. For example the binder content in the top layers of the wood fiber boards be larger than in the middle class by one to achieve particularly high stability of the cover layers. It but are also other layer structures to adapt to certain requirement profiles with the new procedure realizable. It goes without saying that lots of fibers, provided for different layers of the layer structure are not together before forming the fiber mat are mixed, but only those fibers for each a layer with a uniform composition is provided.

In the process variants with the PUR binder from two Binder components can in particular by varying Composition and relative proportion of those containing the polyol Binder component the well-known wide range of properties be exploited by polyurethane bonds. It is also use of accelerators or decelerators Additions to one or both of the binder components possible. Likewise, fungicidal and / or herbicidal additives for the molded body to be used.

In the density range from 60 to 150 kg / m ³ , mechanically stable wood fiber boards are obtained using the process described here only using a foam-forming binder, ie a polyurethane binder which has at least two binder components, PMDI and polyol, or which is a one-component system , Such wood fiber boards can also be viewed as polyurethane foam stabilized by fibers. The binder content of atro fibers is at least 5%, which in absolute terms is not much.

From an average bulk density of about 150 kg / m ³ , fewer voids are present between the fibers, so that the proportion of binder can be reduced to below 5% atro fibers when using a foam-forming polyurethane binder. If the stabilities are not in the foreground, binder proportions down to above 1% can be sufficient. All percentages are understood as usual as percentages by weight.

From average bulk densities of around 150 to 200 kg / m ³ , non-foam-forming binders, ie conventional synthetic resins in the wood-based panel industry, can also be used. At lower bulk densities in this area, however, the proportion of binder should also be selected for lower strengths above 5%, and for higher strengths 7 to 15% of binder should be used. Mixing systems with the addition of melamine and phenols are preferred instead of the relatively fragile curing urea-formaldehyde resins. The usual trade-offs must be made between the price of the binder, possible formaldehyde elimination and possible harmful residual phenols.

LIST OF REFERENCE NUMBERS

1 -

Insulating shaped body

2 -

fiber

3 -

front surface

4 -

rear surface

5 -

Dämmrichtung

6 -

narrow surface

7 -

pressing surface

8th -

width

9 -

Preferred orientation level

10 -

adhesive surface

11 -

shiplap

12 -

countersink

13 -

wedge angle

14 -

length

15 -

interface

16 -

Wood pulp board

17 -

wide area

18 -

wall

19 -

gap

20 -

insulating material

21 -

outer wall

22 -

plaster

23 -

retaining net

24 -

blanket

25 -

Plasterboard

26 -

Fiberboard

Claims (20)

Molded insulating body, in particular insulating board, on the basis of lignocellulose-containing fibers bonded with a binder, with an insulating direction and with a front surface and a rear surface with which the insulating molded body begins and ends in the insulating direction, characterized in that the fibers (2 ) have a preferred orientation in the insulating molded body (1) parallel to a plane (9) running transversely to the front surface (3) and transversely to the rear surface (4). Shaped insulating body according to claim 1, characterized in that the front surface (3) and / or the rear surface (4) are open partitions (15). Insulating molded body according to claim 1 or 2, characterized in that at least one narrow surface (6) of the insulating molded body (1), which runs parallel to the plane (9) of the preferred orientation, is at least partially formed by a closed pressing surface (7) of a wood fiber board (16) is. Insulated molded body according to one of claims 1 to 3, characterized in that at least one inner adhesive surface (10) running parallel to the plane (9) of the preferred orientation is provided, on which the pressing surfaces (7) of two wood fiber boards (16) are glued together. Insulated molded body according to claim 3 or 4, characterized in that the panel thickness of each wood fiber board (16) is greater than or equal to 80 mm. Insulating molded body according to one of claims 3 to 5, characterized in that the wood fiber boards (16) have a bulk density of 100 to 230 kg / m3. Molded insulating body according to one of claims 1 to 6, characterized in that the distance between the front surface (3) and the rear surface (4) is 50 to 400 mm. Insulated molded body according to one of claims 1 to 7, characterized in that the distance between the front surface (3) and the rear surface (4) is constant. Insulated molded body according to one of claims 1 to 7, characterized in that a wedge angle (13) of less than 20 ° is formed between the front surface (3) and the rear surface (4). Insulated molded body according to one of claims 1 to 9, characterized in that two narrow surfaces (6) lying opposite one another are provided with complementary step folds (11). Insulating molded body according to one of claims 1 to 10, characterized in that the front surface (3) and the rear surface (4) have a length (14) in the plane (9) of the preferred direction of 600 to 1500 mm and a length perpendicular to this Have width (8) from 150 to 300 mm. Molded insulating body according to one of claims 1 to 11, characterized in that a tear-off strength between the front surface (3) and the rear surface (4) is at least 100 kPa. A process for the production of molded insulating bodies according to one of claims 1 to 12, characterized in that a wood fiber board (16) is cut perpendicular to the pressing surfaces (7) directed outwards along separating surfaces (15), the front surfaces on the separating surfaces (15) (3) and the rear surfaces (4) of the molded insulating body (1). A method according to claim 13, characterized in that the wood fiber board (16) is sawn for cutting along the separating surfaces (15). A method according to claim 14 or 15, characterized in that, prior to the separation, a plurality of wood fiber boards (16) are glued to one another over their pressing surfaces (7). A method according to claim 15, characterized in that the wood fiber boards (16) are glued flat with a dispersion adhesive or with alkali silicate. Use of molded insulating bodies according to one of claims 1 to 12, characterized in that the individual molded insulating bodies (1) are arranged close to one another, their front surfaces (3) and their rear surfaces (4) each coinciding. Use of molded insulating bodies according to one of claims 1 to 12, characterized in that the individual molded insulating bodies (1) are arranged next to one another on a gap, their front surfaces (3) and their rear surface (4) each coinciding and gaps (19) free spaces be filled with other insulating materials (20) between the molded insulating bodies (1). Use according to claim 17 or 18, characterized in that the individual shaped insulating bodies (1) are glued with their rear surface to a wall (18, 21) or ceiling (24). Use according to claim 19, characterized in that the insulating molded body (1) is glued to its front surface (3) with a plaster (22) or a plate-shaped planking (25, 26).

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