EP3323576B1 - Method for the preparation of fire-retardant insulating panels/mats on the basis of renewable resources - Google Patents

Description

The present invention relates to a method for producing a fire-retardant insulating panel or mat and a corresponding blow-in insulating material made from fibers based on renewable raw materials.

DIN 4102 with the designation "Fire behavior of building materials and components" represents a standard for the fire behavior of building materials and components. The building materials and components are assigned to building material classes or fire resistance classes. A national classification according to DIN 4102-1 of building materials and components is divided into classes A1 and A2, which are classified as "non-flammable", in class B1, which is classified as "hardly inflammable", in class B2, which is classified as "normally flammable" and in class B3, which is classified as "easily flammable". Insulating materials based on renewable raw materials in general and insulating materials containing lignocellulose in particular are now classified in Class B2 according to DIN 4102 and in Class E for "normally flammable" according to DIN EN 13501-1, the standard for the classification of building products and building types in terms of their fire behavior " classified. The afterglow, which decisively prevents the classification in the "hardly flammable" area, is to be evaluated particularly critically. Fire loads in the magnitude of the fire test prescribed by the standard ensure such a high energy input into the product that afterglow and continued glowing cannot be prevented.

The aim is to expand the use of bio-based insulating materials to applications that are not possible or permitted due to their "normally flammable" properties. This applies in particular to the use of such insulating materials in higher building classes. This lays another cornerstone for the industrial and sustainable production of insulation materials from renewable raw materials. The consumption of fossil resources (minerals, hard coal, oil and natural gas) can thus be further reduced.

A generic method for producing a fire-retardant wood-based panel from a mixture of lignocellulose-containing chips and expandable graphite is from DE 10 2009 005 155 B4 or the EP 2 208 594 B1 known. Wood-based panels are becoming more widespread due to their technical properties and are among the fastest growing wood-based products worldwide. Thicknesses of 2 mm to 60 mm with a density of 600 kg/m ³ to 1000 kg/m ³ are usually commercially available. A method for the production of fire-retardant wood-based panels is also from U.S. 2004/258898 A1 known.

According to the "Plastic Additives" handbook (ISBN-13: 978-3-446-43291-8), intumescent flame retardants are chemical fire retardants. Intumescent systems inflate into foams, which are used to protect combustible materials from the effects of heat and fire. Basically, the flame retardant effect is due to the use of synergistic mechanisms. With their help, the combustion process of the wood fibers is prevented both chemically and physically. Phosphate compounds are the main components of the chemically active substances. Their water solubility is a prerequisite for the use of wood fibers. Phosphate compounds can also serve as a reactive flame retardant solution, chemically binding the flame retardant to the wood fiber. In addition, the physical effect of acid intercalated types of graphite is used. In this case, the expandable graphite is present as a separate particle in the wood fiber matrix.

In contrast, insulating boards or mats made from fibers based on renewable raw materials have significantly lower densities of up to 300 kg/m ³ . Due to the different densities, insulation fiber boards differ significantly from wood-based panels in terms of fire behavior. Insulation boards made of fibers based on renewable raw materials have significantly larger internal spaces and significantly lower thermal conductivity than wood-based panels. On the one hand, these circumstances produce the desired insulating effect, but on the other hand - particularly in the event of a fire - lead to the disadvantageous effect that heat present in the insulating board is dissipated extremely poorly. So can the residual heat stored in the insulation board can lead to the insulation material smoldering and smoldering even after a fire has supposedly been over.

The object of the present invention is to provide fire-retardant insulating materials based on renewable raw materials that achieve class B1 according to DIN EN 4102 and, in the case of flame exposure, reduce the critical heat input in order to effectively prevent afterglow.

The object of the invention is achieved by the subject matter of claim 1, relating to a method for producing fire-retardant insulation boards/mats from a mixture containing fibers based on renewable raw materials and a physical and/or chemical fire protection agent.

According to the method of the invention, the insulation panels / mats are made from a mixture which fibers based on renewable raw materials such. B. lignocellulose fibers or shredded lignocellulosic material, and physical and / or chemical fire retardants such. B. contains an intumescent fire retardant. Accordingly, the fire retardant is mixed directly with the broken down fibers, so that better mixing and bonding between the fibers on the one hand and the fire retardant on the other is achieved, with the result that the fire protection of the insulating material is significantly improved. In addition, a chemically active fire retardant can be applied to the surface of the wood fiber in such a way that it partially penetrates into the molecular structure of the wood fiber and is fixed or chemically modified (thereby binding the flame retardant to the fibre). In order to increase the diffusion of the fire retardant into the amorphous structures of the wood fibers, the surface of the wood fibers can be modified using various chemical additives and the surface tension of the fire retardant can also be reduced.

The achievement of class B1 according to DIN EN 4102 is ensured by the equipment of the bio-based insulating materials according to the invention. The physical flame retardant forms an insulating layer in the event of flaming and thus reduces the critical heat input so that afterglow - triggered by a pyrolysis effect - is prevented. Alternatively or additionally, a chemically active fire retardant such. B. a chemical compound based on phosphorus can be used. Through various, e.g. B. physically and chemically acting fire retardant types synergistic effects can be achieved.

terms and definitions

In the context of the invention, intumescence refers to expansion or swelling, ie an increase in volume of the fire protection agent, preferably when exposed to heat above the so-called activation temperature. An intumescent fire retardant preferably forms an insulating layer with low thermal conductivity when it expands. This effect is used within the scope of the invention in order to prevent the fibers or other components of the insulating board from igniting.

• Aufschäumen, d. h. das Formen einer leichten Isolierungsschicht als Hitzebremse. Eingebrachte Stoffe (z. B. expandierbares Graphit / Blähgraphit) setzen bei Wärmeeinwirkung Gase frei. Zusammen mit dem veraschenden Isolierungsmaterial entsteht eine "geschäumte" Ascheschicht, welche die Sauerstoffzufuhr - und somit die Flammenausbreitung - behindert.
• Endotherme Wirkung durch Hydrate, die durch Wasserdampffreisetzung kühlen.
• Expansionsdruck aufbringen, z. B. um Hohlräume, durch welche Luftzufuhr möglich ist, im Brandfall zu versiegeln.

The intumescence forms an insulating layer that increases the distance to the fire and prevents self-ignition on the side facing away from the fire. In the context of the invention, the term intumescence accordingly designates the expedient "swelling" or foaming of the fire protection agent in connection with the chemical reaction of an additional fire protection agent. An intumescent or intumescent fire retardant increases in volume under the effect of heat and correspondingly decreases in density and preferably achieves the following effects:

• Foaming, ie forming a light insulation layer as a heat barrier. Substances introduced (e.g. expandable graphite / expandable graphite) release gases when exposed to heat. Together with the ashing insulation material, a "foamed" layer of ash is created, which impedes the supply of oxygen - and thus the spread of the flame.
• Endothermic effect due to hydrates that cool by releasing water vapor.
• Apply expansion pressure, e.g. B. cavities through which air supply is possible to seal in case of fire.

insulation panel/mat

Insulation boards or mats made from fibers based on renewable raw materials, in particular insulation boards containing lignocellulose fibers or wood fiber insulation boards, sometimes also called soft wood fiber boards or softwood fiber boards, are a type of fiber boards, namely panel insulation materials made from fibers based on renewable raw materials, which are mostly used for thermal insulation of the outer shell surfaces of a building . They counteract the passage of heat. Sometimes they are also used in dry construction for the construction of internal building parts (wall, floor). They are among the oldest industrially produced ones Natural insulating materials and were already being produced in this way in the first half of the 20th century.

Wood fiber insulation boards usually consist of approx. 90 to 95% dry weight of wood fibers. Softwoods are preferred as the starting material because of their higher fiber quality.

Wood fiber insulation boards are particularly suitable for roof insulation and exterior wall insulation outdoors, indoors as floor insulation, insulation of ceilings and interior walls and in cavities (intermediate rafters, partition walls, beam layers). In addition, wood fiber insulation boards are also suitable for soundproofing indoors and outdoors and for footfall soundproofing even of apartment dividing ceilings with increased requirements.

Advantageous developments are the subject matter of the dependent claims.

• Schritt A1: Bereitstellen eines faserhaltigen, nachwachsenden Rohstoffs, vorzugsweise Sägereste, bevorzugt Schwarte, Spreißel, und/oder Hackschnitzel, bevorzugt aus Nadelholz.
• Schritt A2: Vorwärmen des faserhaltigen, nachwachsenden Rohstoffs, vorzugsweise in einem Vorwärmer.
• Schritt A3: Fördern und/oder Pressen und/oder Kochen des faserhaltigen, nachwachsenden Rohstoffs, vorzugsweise mit einer Stopfschnecke und/oder in einem Kocher.
• Schritt A4: Zerfaserung des faserhaltigen, nachwachsenden Rohstoffs, vorzugsweise in einem Refiner, zur Gewinnung der Fasern auf Basis des nachwachsenden Rohstoffs.

It can prove helpful if fibers based on renewable raw materials are provided in step A of the method, preferably by carrying out at least one of the following sub-steps:

• Step A1: Provision of a fibrous, renewable raw material, preferably sawdust, preferably rind, splinters, and/or wood chips, preferably made of softwood.
• Step A2: preheating of the fibrous, renewable raw material, preferably in a preheater.
• Step A3: Conveying and/or pressing and/or cooking of the fibrous, renewable raw material, preferably with a stuffing screw and/or in a cooker.
• Step A4: defibration of the fibrous, renewable raw material, preferably in a refiner, to obtain the fibers based on the renewable raw material.

Round wood (trunks), wood chips, slabs, possibly waste wood, residual rolls from rotary cut veneer production, veneer residues and sawdust are preferably used as the fibrous, renewable raw material for the production of the insulating fiber boards according to the invention.

The raw material is preferably debarked and mechanically crushed, sorted or sieved and cleaned. Foreign matter is preferably removed from the raw material by machine, preferably in a so-called "dry cleaning" or a so-called "wet cleaning". In dry cleaning, the raw material is cleaned with the help of a gaseous medium, e.g. B. air, from heavy bodies freed. In wet cleaning, stones, sand and metals are separated from the raw material in a liquid medium, e.g. e.g. water.

Before defibration, the raw material usually goes into a pre-steaming tank for hydrothermal pre-treatment, where it is pre-steamed at up to 100°C. This treatment softens the central lamella, favoring both the compressibility of the raw material and subsequent defibration. The partially plasticized raw material reaches z. B. via a vibratory discharge floor or via a stuffing screw in a cooker. However, the hydrothermal pre-treatment is not absolutely necessary, so that the raw material can also be fed directly into the digester. The stuffing screw has an increasing gradient towards the downstream end and compresses the raw material into a relatively pressure-tight plug, whereby the so-called squeeze water is squeezed out. The plug forms a seal with the digester. In the cooker, the raw material is boiled at a steam pressure of preferably between 6 and 16 bar, with the steam pressure varying depending on the type of wood and the requirements placed on the fibers. After a residence time in the digester of preferably one to eight minutes, the raw material preferably passes through a conveyor screw and via the feed screw into the refiner (defiberer). In the refiner, the raw material is defibrated between grinding discs and blown out of the refiner via a controllable valve through a "blow line" (or blow line). The steam pressure in the refiner is preferably in the range from 6 to 16 bar, with the steam forming the means of transport for the fibers on their way through the blow line into the dryer.

After defibration, the fibers obtained are preferably dried in a stream dryer with simultaneous conveyance by hot air in the drying tunnel, so that the fibers with about 8 to 12% moisture (based on the dry mass of the fibers) are separated from the air stream in cyclones. In the case of dry sizing, the fibers can optionally be dried down to approx. 2% (based on the dry mass of the lignocellulose fibres), provided the fibers are not further processed with the existing wood moisture.

• Schritt B1: Verrühren der Fasern mit Wasser zu einem Brei, vorzugsweise mit einem Anteil von bis zu 98 % Wasser.
• Schritt B2: Beigabe von Zusatzstoffen zu dem Brei, vorzugsweise harz- oder bitumenhaltige Stoffe, bevorzugt zur Erhöhung der Festigkeit und/oder zur Vermittlung von wasserabweisenden Eigenschaften.
• Schritt B3: Zwischenlagerung des Breis, vorzugsweise in Bütten auf einer Formmaschine.
• Schritt B4: Formen des Breis zu einem Faserkuchen.
• Schritt B5: Entwässern des Faserkuchens, vorzugsweise durch mechanisches Auspressen des im Faserkuchen enthaltenen Wassers.
• Schritt B6: Zuschneiden des Faserkuchens.
• Schritt B7: Trocknen des Faserkuchenzuschnitts, vorzugsweise in einem Trockenkanal, bevorzugt bei Temperaturen zwischen 110 und 220 °C.
• Schritt B8: Verkleben mehrerer Faserkuchenzuschnitte zu einer mehrschichtigen Dämmplatte/-matte.
• Schritt B9: Zuschneiden der Dämmplatte/-matte.

It can be useful if, in step B, the insulation boards/mats are produced using the wet process, preferably using at least one of the following sub-steps:

• Step B1: Mixing the fibers with water to form a paste, preferably with a proportion of up to 98% water.
• Step B2: Addition of additives to the pulp, preferably substances containing resin or bitumen, preferably to increase the strength and/or to impart water-repellent properties.
• Step B3: intermediate storage of the pulp, preferably in vats on a molding machine.
• Step B4: Forming the pulp into a fiber cake.
• Step B5: Dewatering of the fiber cake, preferably by mechanically squeezing out the water contained in the fiber cake.
• Step B6: Cutting the fiber cake.
• Step B7: Drying of the fiber cake blank, preferably in a drying tunnel, preferably at temperatures between 110 and 220°C.
• Step B8: Gluing several fiber cake cuts to form a multi-layer insulation panel/mat.
• Step B9: Cutting the insulation board/mat.

In the manufacture of the insulating boards/mats according to the invention in the wet process, the inherent binding forces of the fibers based on renewable raw materials are used by the fibrous raw material being defibrated and bonded in the form of a fiber cake under the action of heat. In the case of wood containing lignocellulose, lignin is released, which takes on the function of an otherwise necessary binding agent when the fiber cake sets. The use of a separate binder can therefore be omitted. In order to avoid unwanted dilution of the fire retardant by the water used to form the slurry, the fire retardant is preferably only added in step B3.

• Schritt C1: Trocknen der Fasern, vorzugsweise unmittelbar nach Schritt A4, wobei das Material bevorzugt mittels einer Blowline in einen Stromtrockner eingebracht wird, vorzugsweise auf einen Feuchtegehalt im Bereich von 2 bis 12 %, bevorzugt auf einen Feuchtegehalt im Bereich von 3 bis 10 %, besonders bevorzugt auf einen Feuchtegehalt im Bereich von 4 bis 9 %, ganz besonders bevorzugt auf einen Feuchtegehalt im Bereich von 7 bis 9 %, jeweils bezogen auf die Trockenmasse der Fasern.
• Schritt C2: Vermischen der Fasern mit Bindemittel, vorzugsweise durch Mischerbeleimung, Blowline-Beleimung und/oder Trockenbeleimung, bevorzugt in einem Beleimturm, in einer Blowline oder in einer Trockenbeleimungsvorrichtung.
• Schritt C3: Zugabe von synthetischen Textilfasern oder Fasern auf Basis nachwachsender Rohstoffe zur Erhöhung der Faserflexibilität sowie diversen Zusätzen zur Verbesserung weiterer Eigenschaften.
• Schritt C4: Herstellen einer Streuung aus Fasern, ggf. Bindemittel und/oder weiteren Zugaben, vorzugsweise in einer Streumaschine.
• Schritt C5: Verpressen der Streuung zu Dämmplatten/-matten, vorzugsweise durch eine Kalibrier- und Aushärteeinheit.
• Schritt C6: Härten der Dämmplatten/-matten, vorzugsweise durch ein Gemisch aus Dampf und Luft.
• Schritt C7: Zuschneiden der Dämmplatten/-matten.

It can be useful if, in step C, the insulation boards/mats are produced using a dry process, preferably using at least one of the following sub-steps:

• Step C1: Drying of the fibers, preferably immediately after step A4, with the material preferably being introduced into a flow dryer by means of a blowline, preferably to a moisture content in the range from 2 to 12%, preferably to a moisture content in the range from 3 to 10%, particularly preferably to a moisture content in the range from 4 to 9%, very particularly preferably to a moisture content in the range from 7 to 9%, in each case based on the dry matter of the fibers.
• Step C2: Mixing of the fibers with binder, preferably by mixer sizing, blowline sizing and/or dry sizing, preferably in a sizing tower, in a blowline or in a dry sizing device.
• Step C3: Addition of synthetic textile fibers or fibers based on renewable raw materials to increase fiber flexibility and various additives to improve other properties.
• Step C4: Production of a scattering of fibers, optionally binders and/or other additions, preferably in a scattering machine.
• Step C5: Pressing the scattering into insulation panels/mats, preferably using a calibration and curing unit.
• Step C6: Hardening of the insulation boards/mats, preferably by a mixture of steam and air.
• Step C7: Cutting the insulation panels/mats.

To produce the insulating boards/mats according to the invention in a dry process, the fibers based on renewable raw materials are preferably dried directly after defibration in step A to the residual moisture required for gluing (approx. 8% based on the dry mass of the fibers) and then preferably in one Glue channel or tower or mixer glued with the binder. Steps C1 and/or C2 and/or C4 (drying, gluing and spreading of the fibers) are particularly suitable for treating the fibers with the fire retardant in order to form the mixture from which the insulating boards/mats according to the invention are produced. The fire retardant can be distributed very evenly over the fibers in order to achieve an advantageous fire protection effect over the entire cross section of the insulation board/mat. For example, a chemically active fire retardant can partially penetrate into the molecular structure of the wood fiber and be fixed or chemically modified thereon, as a result of which the fire retardant is bonded to the fiber. To increase the diffusion of the fire retardant into the amorphous structures of the wood fibers, the surface of the wood fibers can be modified by various chemical additives and the surface tension of the fire retardant can also be reduced.

• Das Brandschutzmittel ist ein intumeszierendes Brandschutzmittel oder umfasst eine intumeszierende Brandschutzmittel-Komponente.
• Das Brandschutzmittel ist ein chemisches oder chemisch wirkendes Brandschutzmittel oder umfasst eine chemische oder chemisch wirkende Brandschutzmittel-Komponente, bevorzugt eine chemische Verbindung auf Phosphorbasis.
• Die Aktivierungstemperatur des Brandschutzmittels (d. h. die Temperatur, bei der das Brandschutzmittel zu blähen beginnt), vorzugsweise des intumeszierenden Brandschutzmittels oder der intumeszierenden Brandschutzmittel-Komponente, liegt im Bereich von 100°C bis 1000°C, vorzugsweise im Bereich von 100°C bis 300°C.
• Das Brandschutzmittel umfasst verschiedene Komponenten, vorzugsweise wenigstens zwei intumeszierende Komponenten mit unterschiedlichen Blähvolumina, wobei bevorzugt das Blähvolumen einer ersten intumeszierenden Komponente bei 1000°C 0,01 bis 0,5 mal, vorzugsweise 0,1 bis 0,5 mal das Blähvolumen der zweiten intumeszierenden Komponente bei 1000°C ist, wobei das Blähvolumen der ersten intumeszierenden Komponente bei 1000°C beispielsweise im Bereich von 60 cm³/g bis 200 cm³/g und das Blähvolumen der zweiten intumeszierenden Komponente bei 1000°C beispielsweise im Bereich von 400 bis 700 cm³/g liegt, wobei besonders bevorzugt das Mischverhältnis der ersten zur zweiten intumeszierenden Komponente im Bereich von 1:1 bis 1:2 liegt, insbesondere bei 1:1,5.
• Das Brandschutzmittel umfasst überwiegend Partikel mit Partikelgrößen im Bereich von 1 µm bis 1000 µm, vorzugsweise im Bereich von 40 µm bis 700 µm, bevorzugt im Bereich von 150 µm bis 400 µm
• Das Brandschutzmittel weist einen pH-Wert im Bereich von 3 (sauer) bis 10 (leicht alkalisch/basisch), vorzugsweise im Bereich von 7 bis 9 auf.
• Das Brandschutzmittel enthält ein Treibmittel, vorzugsweise eingelagert in die Molekülstruktur.
• Das Brandschutzmittel umfasst wenigstens eines der folgenden Additive, vorzugsweise in einer Zudosierung von bis zu 20 %, bevorzugt im Bereich von 2 bis 8 %:
  • ∘ Anorganische Brandhemmer, vorzugsweise in Form einer chemischen Verbindung auf Phosphorbasis.
  • ∘ Stärkebasierende, organische Substanzen mit Funktion zum Einschluss der Faser (Kapseleffekt), vorzugsweise auf pflanzlicher Basis.
  • ∘ Synergetische Additive.
• Das Brandschutzmittel ist oder enthält Graphit, vorzugsweise Blähgraphit, bevorzugt säureinterkalierte Blähgraphite.
• Das Brandschutzmittel ist modifiziert und/oder interkaliert und/oder kohlenstoffhaltig.
• Das Brandschutzmittel ist durch chemische Behandlung mit starken Säuren und/oder Oxidationsmittel wie Wasserstoffperoxid oder Kaliumpermanganat hergestellt.
• Das Brandschutzmittel ist vorhanden in einer Dosierung von 3 bis 30 Gewichtsprozent, vorzugsweise 5 bis 20 Gewichtsprozent, bevorzugt 10 bis 18 Gewichtsprozent bezogen auf eine Trockenmasse der Fasern.

It may be helpful if a fire retardant having at least one of the following characteristics is used to form the mixture:

• The fire retardant is an intumescent fire retardant or includes an intumescent fire retardant component.
• The fire retardant is a chemical or chemically acting fire retardant or includes a chemical or chemically acting fire retardant component, preferably a chemical compound based on phosphorus.
• The activation temperature of the fire retardant (ie the temperature at which the fire retardant starts to expand), preferably the intumescent fire retardant or the intumescent fire retardant component, is in the range from 100°C to 1000°C, preferably in the range from 100°C to 300 °C
• The fire retardant comprises various components, preferably at least two intumescent components with different expansion volumes, the expansion volume of a first intumescent component at 1000° C. preferably being 0.01 to 0.5 times, preferably 0.1 to 0.5 times the expansion volume of the second intumescent component component at 1000°C, the expansion volume of the first intumescent component at 1000°C, for example, in the range from 60 cm ³ /g to 200 cm ³ /g and the expansion volume of the second intumescent component at 1000°C, for example in the range from 400 to 700 cm ³ /g, with the mixing ratio of the first to the second intumescent component particularly preferably being in the range from 1:1 to 1:2, in particular 1:1.5.
• The fire retardant predominantly comprises particles with particle sizes in the range from 1 μm to 1000 μm, preferably in the range from 40 μm to 700 μm, preferably in the range from 150 μm to 400 μm
• The fire retardant has a pH in the range from 3 (acidic) to 10 (slightly alkaline/basic), preferably in the range from 7 to 9.
• The fire retardant contains a propellant, preferably embedded in the molecular structure.
• The fire retardant comprises at least one of the following additives, preferably in a dosage of up to 20%, preferably in the range from 2 to 8%:
  • ∘ Inorganic fire retardants, preferably in the form of a phosphorus-based chemical compound.
  • ∘ Starch-based, organic substances with the function of enclosing the fibers (encapsulation effect), preferably based on plants.
  • ∘ Synergic additives.
• The flame retardant is or contains graphite, preferably expandable graphite, preferably acid-intercalated expandable graphite.
• The flame retardant is modified and/or intercalated and/or contains carbon.
• The fire retardant is produced by chemical treatment with strong acids and/or oxidizing agents such as hydrogen peroxide or potassium permanganate.
• The flame retardant is present in a dosage of 3 to 30 percent by weight, preferably 5 to 20 percent by weight, preferably 10 to 18 percent by weight, based on a dry weight of the fibers.

• Das Brandschutzmittel weist einen Zustand noch nicht begonnener oder teilweiser erfolgter Intumeszenz auf.
• Das Brandschutzmittel ist pulverförmig oder kugelförmig, bevorzugt schuppig oder flockig, granular und/oder partikelförmig.
• Das Brandschutzmittel ist ein Gemisch, vorzugsweise eine Emulsion, ein Gel, ein Schaum, ein Aerosol, eine Suspension oder ein Gemenge.
• Das Brandschutzmittel ist in einer Emulsion als Trägermaterial eingebunden, wobei die Emulsion vorzugsweise gebildet wird aus Wasser und einem Emulgator, bevorzugt bifunktionale bzw. bifunktionelle Silane oder auf Ether basierende synthetische Öle.
• Das Brandschutzmittel ist in Schaum als Trägermaterial eingebunden, vorzugsweise unter Ausführung wenigstens eines der folgenden Teilschritte:
  • ∘ Bildung eines Schaums, vorzugsweise aus Wasser und anionischen/kationischen Additiven und/oder einer schäumenden Chemikalie als Schaumbildner.
  • ∘ Stabilisierung der Schaumstruktur, vorzugsweise unter Einsatz eines auf Ether basierenden oberflächenaktiven Additivs und/oder eines carboxymetylcellulosehaltigen Additivs als Schaumstabilisator.
  • ∘ Oberflächenmodifizierung des Brandschutzmittels zur Herabsetzung der Oberflächenspannung, um eine bessere Bindekraft zu den Fasern zu erzielen.
  • o Einbinden des Brandschutzmittels in den Schaum.
• Das Brandschutzmittel ist in Gel als Trägermaterial eingebunden, vorzugsweise unter Ausführung wenigstens eines der folgenden Teilschritte:
  • ∘ Bildung des Gels, vorzugsweise durch Vermischen von Wasserglas und einer Silziumdioxiddispersion (als sogenanntes Nanosol).
  • ∘ Modifizieren der Rheologie der Gelstruktur, vorzugsweise durch Zugabe eines stärkebasierenden Celluloseethers, wobei das Gel bevorzugt als Haftvermittler zwischen dem Blähgraphit und den Fasern dient.
  • ∘ Einbinden des Brandschutzmittels in das Gel.
• Das Brandschutzmittel bildet ein Gemisch mit Bindemittel, vorzugsweise mit einem Bindemittel, das wenigstens einen der folgenden Bestandteile aufweist:
  • ∘ Einen Klebstoff, vorzugsweise einen Klebstoff auf Basis von Isocyanaten, Kunstharzen, PVAC, Proteinen (z.B. Kaseine, enzymatische Proteine) und Stärke, bevorzugt in Kombination mit Klebstoffsystemen auf wässriger nanostrukturierter silikatischer Basis.
  • ∘ Einen Leim, vorzugsweise einen natürlichen Leim, bevorzugt auf Basis von Kasein und/oder Stärke.
• Das Brandschutzmittel bildet ein Gemisch, wobei das Brandschutzmittel vorzugsweise in Partikelform vorliegt und mittels einer organischen Verbindung modifiziert wird (z.B. chemische Verbindung auf Phosphorbasis), welche auch die Funktion als Flammschutzmittel erfüllt), sodass die Oberflächenspannung der Partikel herabgesetzt und deren Fließ- bzw. Rieselfähigkeit erhöht wird, um ein heterogenes Gemisch (Dispersion) aus festen Schwebeteilchen in einem Gas zu bilden.

It can be useful if the fire retardant is mixed with the fibers to form a mixture in at least one of the following states:

• The fire retardant is in a state where intumescence has not yet started or has partially taken place.
• The flame retardant is in the form of a powder or spheres, preferably flaky or flaky, granular and/or particulate.
• The fire retardant is a mixture, preferably an emulsion, a gel, a foam, an aerosol, a suspension or a mixture.
• The flame retardant is bound in an emulsion as a carrier material, the emulsion preferably being formed from water and an emulsifier, preferably bifunctional or bifunctional silanes or ether-based synthetic oils.
• The fire retardant is integrated into foam as a carrier material, preferably with at least one of the following sub-steps being carried out:
  • ∘ Formation of a foam, preferably from water and anionic/cationic additives and/or a foaming chemical as a foaming agent.
  • ∘ Stabilization of the foam structure, preferably using an ether-based surface-active additive and/or a carboxymethylcellulose-containing additive as foam stabilizer.
  • ∘ Surface modification of the fire retardant to reduce the surface tension in order to achieve better binding power to the fibers.
  • o Incorporation of the fire retardant into the foam.
• The fire retardant is incorporated in gel as a carrier material, preferably with at least one of the following sub-steps being carried out:
  • ∘ Formation of the gel, preferably by mixing water glass and a silicon dioxide dispersion (as a so-called nanosol).
  • ∘ Modifying the rheology of the gel structure, preferably by adding a starch-based cellulose ether, with the gel preferably serving as an adhesion promoter between the expandable graphite and the fibers.
  • ∘ Binding of the fire retardant in the gel.
• The fire retardant forms a mixture with a binder, preferably with a binder, which has at least one of the following components:
  • ∘ An adhesive, preferably an adhesive based on isocyanates, synthetic resins, PVAC, proteins (eg caseins, enzymatic proteins) and starch, preferably in combination with adhesive systems based on aqueous nanostructured silicates.
  • ∘ A glue, preferably a natural glue, preferably based on casein and/or starch.
• The fire retardant forms a mixture, with the fire retardant preferably being in particle form and modified by means of an organic compound (e.g. chemical compound based on phosphorus), which also fulfills the function as a flame retardant), so that the surface tension of the particles is reduced and their flowability or pourability reduced is increased to form a heterogeneous mixture (dispersion) of suspended solid particles in a gas.

• In Schritt A, vorzugsweise in wenigstens einem der Teilschritte A1, A2, A3, A4 und/oder zwischen zweien dieser Teilschritte, bevorzugt ausschließlich in Teilschritt A4.
• In Schritt B, vorzugsweise in wenigstens einem der Teilschritte B1, B2, B3, B4, B5, B6, B7, B8, B9, insbesondere B1 und/oder B2 und/oder B3, und/oder zwischen zweien dieser Teilschritte, bevorzugt ausschließlich in Teilschritt B3.
• In Schritt C, vorzugsweise in wenigstens einem der Teilschritte C1, C2, C3, C4, C5, C6, C7, insbesondere C1 und/oder C2 und/oder C4, und/oder zwischen zweien dieser Teilschritte, bevorzugt ausschließlich in Teilschritt C2.
• Zwischen den Schritten A und B und/oder zwischen den Schritten A und C.

It may prove useful if the fire retardant is mixed with the fibers into a mixture in at least one of the following process steps:

• In step A, preferably in at least one of the sub-steps A1, A2, A3, A4 and/or between two of these sub-steps, preferably exclusively in sub-step A4.
• In step B, preferably in at least one of the sub-steps B1, B2, B3, B4, B5, B6, B7, B8, B9, in particular B1 and/or B2 and/or B3, and/or between two of these sub-steps, preferably exclusively in Substep B3.
• In step C, preferably in at least one of the sub-steps C1, C2, C3, C4, C5, C6, C7, in particular C1 and/or C2 and/or C4, and/or between two of these sub-steps, preferably exclusively in sub-step C2.
• Between steps A and B and/or between steps A and C.

Another aspect of the invention relates to an insulating board/mat made from a mixture containing fibers based on renewable raw materials and a physical and/or chemical fire protection agent, preferably using the method according to one of the preceding statements.

• Als Holzfaserdämmplatte, hergestellt im Nassverfahren, vorzugsweise nach Schritt B, wobei die Holzfaserdämmplatte bevorzugt wenigstens eines der folgenden Merkmale aufweist:
  • ∘ Die Dicke der Holzfaserdämmplatte liegt im Bereich von 4 bis 250 mm, vorzugsweise im Bereich von 40 bis 200 mm, bevorzugt im Bereich von 50 bis 200 mm.
  • ∘ Die Dichte der Holzfaserdämmplatte liegt im Bereich von 80 bis 300 kg/m³, vorzugsweise im Bereich von 110 bis 250 kg/m³, bevorzugt im Bereich von 160 bis 220 kg/m³.
• Als Holzfaserdämmplatte, hergestellt im Trockenverfahren, vorzugsweise nach Schritt C, wobei die Holzfaserdämmplatte bevorzugt wenigstens eines der folgenden Merkmale aufweist:
  • ∘ Die Dicke der Holzfaserdämmplatte liegt im Bereich von 10 bis 300 mm, vorzugsweise im Bereich von 60 bis 240 mm,
  • ∘ Die Dichte der Holzfaserdämmplatte liegt im Bereich von 80 bis 300 kg/m³, vorzugsweise im Bereich von 100 bis 250 kg/m³, bevorzugt im Bereich von 140 bis 180 kg/m³.
• Als flexible Holzfaserdämmmatte, wobei die Holzfaserdämmmatte vorzugsweise wenigstens eines der folgenden Merkmale aufweist:
  • ∘ Die Dicke der Holzfaserdämmmatte liegt im Bereich von 10 bis 400 mm, vorzugsweise im Bereich von 50 bis 300 mm, bevorzugt im Bereich von 100 bis 200 mm.
  • ∘ Die Dichte der Holzfaserdämmmatte liegt im Bereich von 35 bis 80 kg/m³, vorzugsweise im Bereich von 40 bis 75 kg/m³, bevorzugt im Bereich von 40 bis 55 kg/m³.

It can be an advantage if the insulation board/mat is designed in one of the following ways:

• As a wood fiber insulation board, produced in a wet process, preferably after step B, the wood fiber insulation board preferably having at least one of the following features:
  • ∘ The thickness of the wood fiber insulation board is in the range from 4 to 250 mm, preferably in the range from 40 to 200 mm, preferably in the range from 50 to 200 mm.
  • ∘ The density of the wood fiber insulation panel is in the range from 80 to 300 kg/m ³ , preferably in the range from 110 to 250 kg/m ³ , preferably in the range from 160 to 220 kg/m ³ .
• As a wood fiber insulation board, produced in a dry process, preferably after step C, the wood fiber insulation board preferably having at least one of the following features:
  • ∘ The thickness of the wood fiber insulation board is in the range of 10 to 300 mm, preferably in the range of 60 to 240 mm,
  • ∘ The density of the wood fiber insulation board is in the range from 80 to 300 kg/m ³ , preferably in the range from 100 to 250 kg/m ³ , preferably in the range from 140 to 180 kg/m ³ .
• As a flexible wood fiber insulation mat, the wood fiber insulation mat preferably having at least one of the following features:
  • ∘ The thickness of the wood fiber insulating mat is in the range from 10 to 400 mm, preferably in the range from 50 to 300 mm, preferably in the range from 100 to 200 mm.
  • ∘ The density of the wood fiber insulation mat is in the range from 35 to 80 kg/m ³ , preferably in the range from 40 to 75 kg/m ³ , preferably in the range from 40 to 55 kg/m ³ .

Another aspect of the invention relates to a blow-in insulation material, produced from a mixture containing fibers based on renewable raw materials and a physical and/or a chemical fire protection agent, preferably according to the method according to one of the preceding statements, the blow-in insulation material preferably having a density in the range of 20 to 60 kg/m ³ , particularly preferably a density in the range from 28 to 40 kg/m ³ .

Further preferred developments result from any combination of the features disclosed herein.

Detailed description of the preferred embodiments

According to the process of the invention, fire-retardant insulating boards/mats are made from a mixture which contains fibers based on renewable raw materials, such as e.g. B. lignocellulose fibers, and a physical and / or chemical fire retardant, such as. B. contains an intumescent fire retardant.

The lignocellulose fibers are obtained according to the process steps described above from lignocellulose-containing raw material, in particular wood, mixed with the intumescent fire retardant and processed into the fire-retardant, lignocellulose-fiber-containing insulation boards/mats, for example in a wet process or dry process. Of course, instead of the lignocellulose fibers, fibers based on other renewable raw materials such. B. hemp and / or other fire retardants can be used instead of the intumescent fire retardant.

The exemplary embodiments disclosed within the scope of the invention differ primarily in the form in which the fire retardant is administered and the point in time or the method step in which the fire retardant is mixed with the fibers. Depending on the selected processing of the fibers (in the wet process or dry process), the preferred dosage forms can vary of the fire retardant and the selection of the preferred point in time for mixing the fire retardant with the fibers.

The flame retardant used in the process according to the invention is, for example, an effective and environmentally friendly intumescent flame retardant based on a modified and intercalated mineral made from pure carbon as a halogen-free intumescent agent.

As modified intercalated, carbonaceous flame retardants such. B. modified graphites in question, which expand when heated to temperatures above 150 ° C. Such graphites are known and commercially available. They can contain stored acids as blowing agents. Acid-intercalated expandable graphites are preferred.

Expandable graphite, which is produced by chemical treatment of graphite, contains particularly effective intumescent components. Here, graphite is treated with substances, mostly strong acids and/or oxidizing agents such as hydrogen peroxide or potassium permanganate. The acids and/or oxidizing agents are incorporated into the lattice structure of the graphite. This incorporation into the graphite structure widens the interlayer spacing of the graphite layers. Under the effect of heat, a graphite pretreated in this way will expand with a large increase in volume in the event of a fire.

Expandable graphite is suitable as a flame retardant additive because a protective intumescent layer forms on the surface when exposed to heat, slowing down the spread of fire and counteracting the spread of toxic gases and smoke.

The expandable graphite z. B. as a flaky or flaky powder, as granules or in the form of preformed particles. Mixtures of expandable graphites of different shapes and/or types are also possible. The expandable graphite can also be partially expanded before it is used.

The intumescence preferably starts at the lowest possible temperatures in order to ensure faster response behavior of the equipped building components in the event of a fire. The intumescent fireproofing agent preferably has an activation temperature between 100°C and 1000°C. A mixing ratio between small and large inflation volumes has proven particularly advantageous. The particle sizes of the graphite are to be selected according to the expansion volumes to be achieved and can range predominantly between 1 and 1000 μm, preferably between 150 and 700 μm. The surface of the fire retardant is pH-neutral, with a pH value of up to 10 (alkaline/basic). The effectiveness of the fire retardant can be significantly improved by admixing specially tailored additives, preferably inorganic fire retardants, preferably a chemical compound based on phosphorus, and/or starch-based organic substances with the function of enclosing the wood fibers (encapsulation effect), preferably based on plants. The invention envisages special application methods or forms of administration in connection with application locations that make sense in terms of production technology. These are described in more detail below, including the necessary chemical adjustments to the fire retardant.

application methods Dosage forms of the fire retardant

The fire retardant can be introduced into the process in pure form as a powder or as a mixture, incorporated in an emulsion, a foam, a gel or a binder.

Possible application locations for the fire retardant are in the refiner, in the preheater, in the stuffing screw between the preheater and grinding disks), in the blowline (between the refiner and flash dryer), in the glue tower (area of dry gluing of the fibers), during the spreading process, in the mixing chest (for the wet process production).

The possible dosage forms and application methods or times of introduction can be implemented in the following exemplary embodiments, among others:
First Embodiment - Powder

Variant 1 - wet process

The first embodiment of the invention relates in the first variant to a process for the production of fire-retardant, lignocellulose fiber-containing insulation panels/mats in the wet process according to steps A and B from a mixture containing lignocellulose fibers and intumescent fire retardant, the intumescent fire retardant in the form of expandable graphite being dry and is added in pure form as a powder in step B1 and/or B2 and/or B3 (in the mixing chest), for example exclusively in step B3.

Variant 2 - dry process

The second variant of the first exemplary embodiment of the invention relates to a method for producing fire-retardant insulating panels/mats containing lignocellulose fibers using a dry method after steps A and C of a mixture containing lignocellulose fibers and intumescent fire retardant, the intumescent fire retardant in the form of expandable graphite being dry and in pure form as a powder in step C2 (in the glue tower) or in step C4 (directly in the spreading process), for example exclusively in Step C2, is brought into the process.

The advantages of supplying the intumescent fire retardant in powder form lie in the low cost of preparing the material, since the fire retardant does not have to be additionally modified.

Second embodiment - feeding the fire retardant integrated in emulsion

In order to make the fire retardant, which is usually in powder form, pumpable and sprayable, it can be bound in an emulsion as a carrier material. An emulsifier (bifunctional or bifunctional silanes or ether-based synthetic oils) is added to the water to form the emulsion.

Variant 1 - wet process

According to the first variant, the second exemplary embodiment of the invention relates to a method for producing fire-retardant, lignocellulose-fiber-containing insulating boards/mats in the wet process according to steps A and B from a mixture containing lignocellulose fibers and intumescent fire retardant, the intumescent fire retardant in the form of expandable graphite being incorporated in an emulsion is added as carrier material in at least one of steps A1, A2, A3 or A4 (preheating until defibration) and/or in step B1 and/or B2 and/or B3 (in the mixing chest).

Variant 2 - dry process

The second variant of the second exemplary embodiment of the invention relates to a method for producing fire-retardant insulation boards/mats containing lignocellulose fibers in a dry process according to steps A and C from a mixture containing lignocellulose fibers and intumescent fire retardant, the intumescent fire retardant in the form of expandable graphite being incorporated in a Emulsion is introduced into the process as a carrier material in at least one of steps A1, A2, A3 or A4 (preheating until defibration) and/or in step C2 (in the gluing tower) and/or in step C4 (directly in the spreading process).

The advantages of supplying the intumescent fire retardant integrated in an emulsion as a carrier material lie in the good distribution when mixed with lignocellulose fibers. This dosage form works particularly well in the shredder or refiner because the flame retardant is very finely distributed by the mechanical work of the shredder or refiner and, when bound in the emulsion, can adhere very well to the lignocellulose fibers.

Third exemplary embodiment - supply of the fire protection agent integrated in foam

In particular, to ensure optimal distribution, the fire retardant, which is usually in powder form, is embedded in a stable foam and applied. To produce the foam, water and anionic/cationic additives (foaming agents) are mixed in a special unit and a foam is formed. Alternatively, the foam can also be formed using water with the addition of a foaming siliceous binder. In order to prevent the foam from collapsing after a certain time, the foam structure must be additionally stabilized. For this purpose, an ether-based surface-active additive or a carboxymethylcellulose-containing additive is used as a foam stabilizer. In addition, a surface modifier is used that reduces the surface tension. This results in better binding power between the fire retardant and lignocellulose fibers.

The third exemplary embodiment of the invention accordingly relates to a method for producing fire-retardant, lignocellulose fiber-containing insulating panels/mats in a dry process according to steps A and C from a mixture containing lignocellulose fibers and intumescent fire retardant, the intumescent fire retardant in the form of expandable graphite incorporated in foam as the carrier material introduced into the process in step C2 (in the blow line or in the gluing tower) and/or in step C4 (directly in the forming process).

The advantages of supplying the intumescent fire retardant integrated in foam as a carrier material lie in the very small amount of water added, good distribution when mixed with lignocellulose fibers, and protection of the structure of the fire retardant.

Fourth exemplary embodiment—supply of the fire retardant bound in gel In particular to ensure optimal distribution, the fire retardant, which is usually in powder form, is bound in a gel and fed to the lignocellulose fibers embedded in this carrier material. To produce the gel, water glass and a Silica dispersion (as a so-called nanosol) mixed in a special unit and the gel formed. A starch-based cellulose ether is added to modify the rheology of the gel structure. Furthermore, the gel serves as an adhesion promoter between the fire retardant and lignocellulose fibers.

The fourth exemplary embodiment of the invention accordingly relates to a method for producing fire-retardant insulating boards/mats containing lignocellulose fibers in a dry process according to steps A and C from a mixture containing lignocellulose fibers and intumescent fire retardant, the intumescent fire retardant in the form of expandable graphite incorporated in gel as the carrier material introduced into the process in step C2 (in the blow line or in the gluing tower) and/or in step C4 (directly in the forming process).

Advantages of the fourth embodiment

The advantages of supplying the intumescent fire retardant bound in gel as a carrier material are the very small amount of water added, the good distribution when mixed with lignocellulose fibers and the protection of the structure of the fire retardant.

FIFTH EMBODIMENT—Supplying the fire retardant integrated in the binder According to the fifth embodiment of the invention, the fire retardant is premixed or admixed directly into the binder system. For this purpose, the binder system can be diluted in order to ensure better mixing and later distribution to the lignocellulose fibers. Adhesive systems based on isocyanates, synthetic resins, PVAC, proteins (e.g. caseins, enzymatic proteins) and starch are preferably used as binder systems. In addition, the combination with adhesive systems on an aqueous, nanostructured, silicate basis is conceivable.

The fifth exemplary embodiment of the invention consequently relates to a method for producing fire-retardant, lignocellulose-fiber-containing insulating boards/mats in a dry process according to steps A and C from a mixture containing lignocellulose fibers and intumescent fire retardant, the intumescent fire retardant in the form of expandable graphite incorporated in a binder as the carrier material introduced into the process in step C2 (in the blow line or in the gluing tower) and/or in step C4 (directly in the forming process).

The advantages of supplying the intumescent fire retardant integrated in a binder as a carrier material lie in the relatively low intervention in the previous application process and the good distribution when mixed with lignocellulose fibers.

It is also within the scope of the invention for the fire retardant to form a mixture such as an aerosol. The (expandable) graphite is modified by means of an organic compound, e.g. based on phosphorus, which also fulfills the function of a flame retardant. This reduces the surface tension of the graphite particles. The lower surface tension of the particles increases their ability to flow or pour. This is the prerequisite for forming a heterogeneous mixture (dispersion) of solid suspended particles in a gas, with the result that the modified graphite is present as aerosol particles or aerosol particles.

• Optimale Gleichverteilung der Partikel
• Optimale Rieselfähigkeit
• Verstopfungs- und störungsfreie Zudosierung des Partikelgemischs

The placement of the fire retardant in the dosage form as an aerosol is preferably carried out in the blow line or in the dry gluing. The powder components, for example expandable graphite and aluminum trihydroxide or alternatively pyrogenic silicon dioxide (Aerosil), are mixed in a high-performance mixer, preferably in an optimally uniform distribution. The evenly distributed mixture can be conveyed into a special container by means of negative or positive pressure. The container preferably has air inlets all around, into which air is blown via built-in valves. A resilient lip is preferably placed over each valve to create air vibration. The combination of all-round air injection and generated air vibrations keeps all particles moving and prevents adhesions between individual particles. This can achieve the following result:

• Optimum even distribution of the particles
• Optimum pourability
• Blockage and trouble-free dosing of the particle mixture

The particle mixture is then applied to the fiber flow in the channel by means of negative or positive pressure.

In the blowline, the dry mixture can be applied to the fibers together with a liquid flame retardant.

Other dosage form

It is also within the scope of the invention for the fire retardant to form a mixture of expandable graphite and a nanosol, consisting and premixed of water glass (sodium or potassium silicate) and preferably 10% silicic acid sols. This mixture is preferably added in the refiner or in the blowline.

• Holzfaserdämmplatte im Trockenverfahren:
  • ∘ Dicke: 10 bis 300 mm
  • ∘ Dichte: 80 bis 300 kg/m³
• Holzfaserdämmplatte im Nassverfahren:
  • ∘ Dicke: 4 bis 250 mm
  • ∘ Dichte: 80 bis 300 kg/m³
• Flexible Holzfaserdämmmatte:
  • ∘ Dicke: 10 bis 400 mm vorzugsweise bis 300 mm
  • ∘ Dichte: 35 bis 80 kg/m³
• Einblasdämmung:
  • ∘ Dicke: je nach Bauteildicke
  • ∘ Dichte: Einblasrohdichten 20 bis 60 kg/m³

Four different wood fiber insulation product types can be used in accordance with the invention from the mixture containing fibers based on renewable raw materials such. B. lignocellulose fibers, and a physical and / or chemical fire retardant are produced, namely:

• Wood fiber insulation board in the dry process:
  • ∘ Thickness: 10 to 300 mm
  • ∘ density: 80 to 300 kg / m ³
• Wood fiber insulation board in the wet process:
  • ∘ Thickness: 4 to 250 mm
  • ∘ density: 80 to 300 kg / m ³
• Flexible wood fiber insulation mat:
  • ∘ Thickness: 10 to 400 mm, preferably up to 300 mm
  • ∘ density: 35 to 80 kg / m ³
• blow-in insulation:
  • ∘ Thickness: depending on component thickness
  • ∘ Density: Blow-in raw densities 20 to 60 kg/m ³

The invention is not limited to the exemplary embodiments described. Meaningful further developments of the invention result for the person skilled in the art through combinations of the features disclosed in the description, the claims and the drawings.

Claims (7)

1. A method for manufacturing fire-retardant insulating boards/mats, wherein the insulating boards/mats are produced from a mixture containing fibres based on renewable raw materials and a physical and/or a chemical flame retardant,

   characterized in that

   as an insulating board/mat, a wood fibre insulating board is produced from the mixture by a wet process with a thickness in the range from 4 to 250 mm and a density in the range from 80 to 250 kg/m³ or a wood fibre insulating board is produced from the mixture by a dry process with a thickness in the range from 10 to 300 mm and a density in the range from 80 to 300 kg/m³ or a flexible wood fibre insulating mat is produced from the mixture by a dry process with a thickness in the range from 10 to 400 mm and a density in the range from 35 to 80 kg/m³, wherein

   the wet process is carried out by stirring the fibres with water to form a slurry, adding additives and the flame retardant to the slurry, forming the slurry into a pressed fibre mat, dewatering the pressed fibre mat, cutting the pressed fibre mat to size and drying the pressed fibre mat blank,

   the drying process is carried out by producing a dispersion from the fibres, the flame retardant and a binder and/or further additives, pressing the dispersion to form insulating boards/mats and curing the insulating boards/mats, and

   the flame retardant is an intumescent flame retardant or comprises an intumescent flame retardant component.
2. The method according to claim 1, characterized in that, in a step A of the method, fibers based on renewable raw materials are provided by carrying out at least one of the following substeps:

   a. Step A1: providing a fibrous, renewable raw material.

   b. Step A2: preheating the fibrous, renewable raw material.

   c. Step A3: conveying and/or pressing and/or cooking the fibrous, renewable raw material.

   d. Step A4: defibering the fibrous, renewable raw material to obtain the fibres.
3. The method according to claim 1 or 2, characterized in that, in a step B of the method the manufacture of the insulating boards/mats is carried out by means of a wet process, by executing at least one of the following substeps:

   a. Step B1: stirring the fibres with water to form a slurry with a water content of up to 98 %.

   b. Step B2: adding resinous or bituminous additives to the slurry.

   c. Step B3: temporarily storing the slurry.

   d. Step B5: dewatering the pressed fibre mat by mechanically squeezing out the water contained in the pressed fibre mat.

   e. Step B7: drying the pressed fibre mat blank at temperatures between 110 and 220 °C.

   f. Step B8: bonding a plurality of pressed fibre mat blanks to form a multi-layer insulating board/mat.

   g. Step B9: cutting the insulating board/mat to size.
4. The method according to claim 1 or 2, characterized in that, in a step C of the method the manufacture of the insulating boards/mats is carried out by means of a dry process, by executing at least one of the following substeps:

   a. Step C1: drying the fibres.

   b. Step C2: mixing the fibers with the binder by mixer gluing, blowline gluing and/or dry gluing.

   c. Step C3: adding synthetic textile fibres or fibres based on renewable raw materials to increase fibre flexibility as well as various additives for enhancing other properties.

   d. Step C4: preparing the dispersion in a dispersing machine.

   e. Step C5: pressing the dispersion to insulating boards/mats by a calibration and curing unit.

   f. Step C6: curing the insulating boards/mats using a mixture of steam and air.

   g. Step C7: cutting the insulating boards/mats to size.
5. The method according to any one of the preceding claims, characterized in that a flame retardant having at least one of the following characteristics is used to form the mixture:

   a. The flame retardant is a chemical or chemically acting flame retardant or comprises a chemical or chemically acting flame retardant component.

   b. The activation temperature of the flame retardant is in the range of 100 °C to 1000 °C.

   c. The flame retardant comprises various components.

   d. The flame retardant comprises particles with particle sizes ranging from 1 µm to 1.000 µm.

   e. The flame retardant has a pH value in the range of 3 (acidic) to 10 (alkaline/basic).

   f. The flame retardant contains a blowing agent.

   g. The flame retardant comprises at least one of the following additives, in an addition of up to 20 %:

   i. inorganic fire retardants.

   ii. starch-based, organic substances for enclosing the fibre

   iii. synergistic additives.

   h. The flame retardant consists of or contains graphite.

   i. The flame retardant is modified and/or intercalated and/or carbonaceous.

   j. The flame retardant is produced by means of chemical treatment with strong acids and/or oxidizing agents such as hydrogen peroxide or potassium permanganate.

   k. The flame retardant is present in a ratio of 3 to 30 percent by weight based on dry weight of the fibres.
6. The method according to any one of the preceding claims, characterized in that the flame retardant is mixed with the fibers in at least one of the following states for forming a mixture:

   a. The flame retardant is in a state of intumescence that has not yet started or has been partially completed.

   b. The flame retardant is in pulverulent or spherical form.

   c. The flame retardant is a mixture.

   d. The flame retardant is incorporated into an emulsion as a carrier medium, the emulsion being formed from water and an emulsifier.

   e. The flame retardant is incorporated into foam as a carrier medium by means of at least one of the following substeps:

   i. preparation of a foam from water and anionic/cationic additives and/or a foaming silicate binder as a foaming agent.

   ii. stabilization of the foam structure using an ether-based surfactant additive and/or a carboxymetyl cellulose-containing additive as a foam stabilizer.

   iii. surface modification of the flame retardant to reduce the surface tension in order to achieve better binding power to the fibres.

   iv. incorporation of the flame retardant into the foam.

   f. The flame retardant is incorporated into gel as a carrier medium by means of at least one of the following substeps:

   i. preparation of the gel by mixing water glass and a silicon dioxide dispersion (as a so-called nanosol).

   ii. modification of the rheology of the gel structure by adding a starch-based cellulose ether.

   iii. incorporation of the flame retardant into the gel.

   g. The flame retardant forms a mixture with a binder containing at least one of the following ingredients:

   i. An adhesive based on isocyanates, synthetic resins, PVAC, proteins (e.g. caseins, enzymatic proteins) and/or starch in combination with adhesive systems based on aqueous nanostructured silicates.

   ii. a glue based on casein and/or starch.

   h. The flame retardant forms an aerosol wherein the flame retardant is present in particulate form and is modified by means of an organic compound so that the surface tension of the particles is reduced and their flowability is increased to form a heterogeneous mixture of solid suspended particles in a gas.
7. The method according to any one of the preceding claims, characterized in that the flame retardant is mixed with the fibers in at least one of the following method steps for forming a mixture:

   a. In step A, in at least one of the substeps A1, A2, A3, A4 and/or between two of these substeps.

   b. In step B, in at least one of the substeps B1, B2 or B3 and/or between two of these substeps.

   c. In step C, in at least one of the substeps C1, C2, or C4 and/or between two of these substeps.

   d. Between steps A and B and/or between steps A and C.