METHOD FOR RECYCLING INSULATING WOOL, APPARATUS FOR PROCESSING INSULATING WOOL, FIBRE-REINFORCED FOAM, WOOD-BASED MATERIAL WITH COMBUSTION RESISTABILITY AND METHOD FOR PRODUCING A WOOD-BASED MATERIAL WITH COMBUSTION RESISTABILITY

Abstract

The present invention relates to a method for producing a recycled insulating material from insulating wool, said method comprising the steps of: comminuting insulating wool to give a first intermediate comprising fibre balls; adding binder to the first intermediate to give a second intermediate; hot-pressing the second intermediate into the desired shape, to give a third intermediate; and curing the third intermediate to give the recycled insulating material. The present invention further relates to a method for recycling insulating wool, an apparatus for processing insulating wool, and a fibre-reinforced foam. The invention additionally embraces a fire-resistant wood-based material and a method for producing it.

Claims

1. Method for producing a recycled insulating material from insulating wool, comprising the steps of: S1: comminuting insulating wool to give a first intermediate comprising fibre balls; S2: adding binder to the first intermediate to give a second intermediate; S3: hot-pressing the second intermediate into the desired shape to obtain a third intermediate; and S4: curing the third intermediate to obtain the recycled insulating material.

2. Method for producing a recycled insulating material from insulating wool according to claim 1, wherein the insulating wool to be comminuted is rock wool and the binder is inorganic and comprising water glass, or the insulating wool to be comminuted is glass wool and the binder is organic and comprising one or more of powder, urea, resins, starch, lignin and sugars.

3. Method for producing a recycled insulating material from insulating wool according to claim 1, wherein a foaming agent is also added in step S2.

4. Method for producing a recycled insulating material from insulating wool according to claim 1, wherein wood chips are also added in the step S2.

5. Method for producing a recycled insulating material from insulating wool according to claim 1, wherein in step S3 the second intermediate is hot-pressed at a temperature of 50° C. to 180° C. and a pressure of 0.05 bar to 5.0 bar.

6. Method for producing a recycled insulating material from insulating wool according to claim 1, wherein in step S4 the curing comprises a pyrolysis treatment of the third intermediate to form the recycled insulating material.

7. Method for producing a recycled insulating material from insulating wool according to claim 6, wherein the pyrolysis treatment takes place with the exclusion of oxygen at temperatures between 400° C. and 1450° C.

8. Method for producing a recycled insulating material from insulating wool according to claim 6, wherein the pyrolysis treatment is a sintering process which takes place at temperatures between 1200° C. and 1450° C.

9. Method for producing a recycled insulating material from insulating wool according to claim 6, wherein before the pyrolysis treatment the third intermediate is provided with channels which at least partially extend into an interior of the third intermediate, or is provided with depression profiles which extend on a surface.

10. Method for recycling insulating wool, comprising a method according to claim 1, wherein in step S1 fibres are also obtained and wherein the fibres are processed in a method for producing insulating wool.

11. Apparatus for processing insulating wool, comprising: a drum; a tool group which is arranged on a lower region of the drum; a drive which drives the drum and the tool group to rotate relative to one another; a housing enclosing the drum; a suction devices; and an actuating element, wherein: at least one outer wall of the drum has an opening, so that an intermediate space between an outer face of the drum and an inner face of the housing is connected via the opening to an interior of the drum; a position of the actuating element determines how much material can pass through the opening; and the suction device is set up to draw off material located in the intermediate space.

12. Apparatus for processing insulating wool according to claim 11, wherein the tool group comprises at least one tool selected from a rake, a rod, a cutting tool, a friction body, a trapezoid, a comb, a beater or a combination thereof.

13. Apparatus for processing insulating wool according to claim 11, wherein the apparatus also comprises an inner drum wall tool group which is arranged on or adjacent to an inner drum wall of the drum.

14. Apparatus for processing insulating wool according to claim 13, wherein the opening is arranged on a lateral surface of the drum, on the outer face or inner side of which the actuating element is arranged such that the opening area of the opening through which material can pass is determined by means of the positioning of the actuating element.

15. Fibre-reinforced foam comprising a foam and fibres which are embedded in the foam.

16. Fire-resistant wood-based material, comprising: a wood strip, insulating wool fibres; and binder with which the wood strip is impregnated, wherein the binder is selected from one or more of inorganic water glass, inorganic water glass specifications, organic resins such as urea, melamine or phenol, and fire-retardant additives such as precipitants or acid or acid hardeners.

17. Fire-resistant wood-based material according to claim 16, wherein a plurality of wood strips with the fibres and the binder are pressed or/and glued together to form a profile.

18. Method for producing a fire-resistant wood-based material, comprising the steps of providing a wood strip; adding insulating wool fibres; and impregnating the wood strip with liquid binder which is selected from one or more of inorganic water glass, inorganic water glass specifications, organic resins such as urea, melamine or phenol, and fire-retardant additives such as precipitants or acid or acid hardener.

19. Method for producing a fire-resistant wood-based material according to claim 18, wherein the method further comprises: providing a plurality of wood strips produced according to claim 18; applying adhesive to the plurality of wood strips; and pressing the plurality of wood strips and the insulating wool fibres together.

20. Fire-resistant wood-based material according to claim 16, wherein the wood strips are made of waste wood, spruce wood, preferably spruce wood damaged by bark beetles, or/and poplar-like wood or/and birch wood or/and willow wood.

Description

[0083] FIG. 1 is a flowchart of a method for producing a recycled insulating material;

[0084] FIG. 2 is a top view of a collection of fibre balls made of comminuted glass wool

[0085] (FIG. 2a) and comminuted rock wool (FIG. 2b);

[0086] FIG. 3 is a schematic representation of an apparatus for processing insulating materials;

[0087] FIG. 4 shows a tool group which can be used in the apparatus shown in FIG. 3,

[0088] FIG. 5 shows a tool group comprising a beater, which can be used in the apparatus shown in FIG. 3,

[0089] FIG. 6 is a cross-section through a fibre-reinforced foam.

[0090] FIG. 1 is a flow chart of a method for producing a recycled insulating material from insulating wool, which comprises steps S1 to S4 according to the invention. The method steps and products outlined in FIG. 1 with solid lines are those which are required for the method for producing a recycled insulating material from insulating wool, whereas the products outlined with dashed lines are optional.

[0091] According to the invention, the insulating wool is comminuted in step S1 in order to obtain a first intermediate which comprises fibre balls 20.

[0092] Examples of fibre balls 20 made of rock wool or glass wool can be seen in FIGS. 2a and 2b. The fibre balls shown have a maximum extent of 0.1 cm to 1 cm. A fibre ball made of glass wool with a maximum extent of 2 mm is shown by way of example with the reference numeral 21, and a fibre ball made of rock wool with a maximum length of 5 mm is shown by way of example with the reference numeral 23.

[0093] A binder is added to the first intermediate in step S2 to give a second intermediate. Furthermore, in step S2 additives can be added, such as a foaming agent, wood chips, natural fibres and/or synthetic fibres, water, carbon-containing additives, lime, preferably slaked lime, or foam glass granulate. On the one hand, the binder and optionally one or more additives can be added by heaping up the first intermediate in a desired form and then pouring the binder and optionally one or more additives onto it/wetting it. On the other hand, the first intermediate, the binder and optionally one or more additives can be mixed and then formed into the desired shape.

[0094] In the subsequent step S3, the second intermediate is hot-pressed into the desired shape in order to obtain a third intermediate, which is then cured in step S4 to form the recycled insulating material. In the simplest case, the curing can be cooling and/or drying. After cooling and/or drying, the recycled insulating material can already be marketed.

[0095] However, in order to obtain a recycled insulating material with high fire resistance, a curing step can be chosen which additionally or alternatively comprises a pyrolysis treatment. Furthermore, the moisture and the mould/fungus resistance of the refined recycled insulating material is increased, and it can thus be ensured that the organic material necessary for the fungus or mould infestation is no longer present in the refined recycled insulating material.

[0096] A possible method for producing a fibre-based recycled insulating material according to an embodiment of the invention is to be described in more detail below. As a starting material, insulating wool in the form of rock wool can be comminuted in order to obtain 65% to 90% fibre balls and 10% to 35% dust and particles as the first intermediate in step S1. In step S2, water glass, for example low-sodium water glass, and possibly water glass hardener can then be added as a binder to the first intermediate in order to obtain a second intermediate, wherein the binder can be added according to one of the two options mentioned above. On the one hand, the binder and optionally one or more additives can be added by heaping up the first intermediate in a desired form and then pouring the binder and optionally one or more additives onto it/wetting it; on the other hand, the first intermediate, the binder and optionally one or more additives can be mixed and then formed into the desired shape.

[0097] As mentioned, an additive can be added in addition to the binder in step S2. The addition can take place together with the binder according to the two previously mentioned options. A conceivable additive is an inorganic additive, such as foam glass granulate, by means of which the thermal insulation and the pressure stability of the recycled insulating material can be increased.

[0098] The second intermediate can then be hot-pressed in step S3 at a temperature of 50° C. to 180° C. and a pressure of 0.05 bar to 5 bar (0.05 kg/cm.sup.2 to 5 kg/cm.sup.2) in order to obtain the third intermediate. Preferably, the temperature in step S3 is between 80° C. and 180° C. in order to increase the water resistance of the material and to reduce the cycle time of the process. In this way, for example, a recycled insulating material in the form of a panel having a thickness ranging from 2 mm to 15 mm or more can be obtained.

[0099] After step S4, in which the third intermediate can be cured by means of cooling, a weather-resistant recycled insulating material can be produced which is suitable for external use.

[0100] Instead of cooling and/or drying, the curing can additionally take place by means of a pyrolysis treatment, wherein the recycled insulating material cured by means of pyrolysis treatment is also designated as refined recycled insulating material. The refinement can lead to a very high-quality mineral fibre-based recycled insulating material, which has very good fire resistance, F30, F60 (fire resistance classes according to DIN 4102-2), and can be used, for example, to insulate windows, doors or walls. In this way, a recycled insulating material in the form of a panel having a thickness ranging from 2 mm to 15 mm or more can be obtained.

[0101] An alternative method for producing a fibre-based recycled insulating material according to a further embodiment of the invention is to be described in more detail below. For this, glass wool can be used as the starting material for the insulating wool to be comminuted in step S1. The first intermediate may comprise 65% to 90% fibre balls and 10% to 35% dust and particles obtained from the comminution of insulating wool. The binder to be added in step S2 can be an organic one, such as an organic powder, an organic resin, or a renewable resource such as starch, lignin, or sugars such as dextrose, maltose, glucose, etc.

[0102] Possible binders can be in the form of powdered substances and can be mixed with the first intermediate, causing them to adhere to the fibres. Alternatively, the binders can also be used as liquid solutions. As described above, the binder can be added to the first intermediate in two different ways. On the one hand, the binder and optionally one or more additives can be added by heaping up the first intermediate in a desired form and then pouring the binder and optionally one or more additives onto it/wetting it. On the other hand, the first intermediate, the binder and optionally one or more additives can be mixed and then formed into the desired shape.

[0103] Furthermore, this first intermediate can be mixed with additional additives, such as a carbon-containing additive, a renewable raw material such as starch, lignin, sugar, if these are not already present in the binder. Additives containing carbon can also be fillers and extenders, such as sawdust, straw or other inexpensive, renewable or synthetic raw materials.

[0104] The second intermediate comprising the binder and optionally the one or more additives can then be hot-pressed to form a third intermediate in step S3 and then cooled in step S4 to form the recycled insulating material. The recycled insulating material obtained in this way can already be used as insulation if no increased fire resistance is required.

[0105] In addition, it is possible to further refine the recycled insulating material by coking it with the exclusion of oxygen. This can take place in a furnace at temperatures between 600° C. and 900° C. The carbon can fuse with the fibres and form a fibre-reinforced carbon foam. If a foaming agent, for example aluminium powder, was also added in step S2 so that it is included in the second intermediate, the gas bubbles filled with hydrogen gas that are formed as a result promote a foam structure, resulting in a closed-cell carbon foam, wherein the hydrogen gas diffuses out of the interior of the carbon foam within a very short time.

[0106] An overview of a combination of insulating wool, which is comminuted in step S1, according to its type, the selected binder, the consistency of the second intermediate and possible parameters of the method, is set out in the following table. Furthermore, the table shows a possible use of the recycled insulating material in which the curing in step S4 can only take place by means of cooling, i.e. without pyrolysis treatment, and also shows an achievable refinement by means of the pyrolysis treatment. The types of insulating wool to be comminuted that are shown in the table are type 1: production waste from the manufacture of insulating wool and/or construction site offcuts from new insulating wool; type 2: waste wool with RAL quality mark; and type 3: waste wool, harmful to health, without RAL quality mark before 1998. The abbreviation “o/a” used stands for “or/and”.

TABLE-US-00001 Use as insulating material Insulating Type of Consistency Pressing without with wool in insulating Type of of second Pressing times in Pressures pyrolysis pyrolysis step 1 wool binder intermediate temperatures minutes in bar treatment treatment glass wool type 1 o/a organic, e.g. wet 80° C.-160° C.  5-120 0.05-2  predominantly partially 2 starch refined 20% glass wool type 1 o/a organic, e.g. dry or wet 50° C.-120° C.  5-120 0.05-2  predominantly partially 2 lignin refined 20% glass wool type 1 o/a inorganic dry or wet 80° C.-180° C. 20-180 0.1-3 predominantly partially 2 e.g. water refined glass 20% hardener glass wool type 3 inorganic, wet 80° C.-180° C. 20-180 0.1-3 partially refined by e.g. water pyrolysis glass hardener glass wool type 3 organic, e.g. dry or wet 60° C.-130° C. 10-150 0.1-2 predominantly partially lignin refined 20% mineral type 1 o/a organic, e.g. wet 80° C.-160° C.  5-120 0.05-2  predominantly partially wool 2 starch refined 20% mineral type 1 o/a organic, e.g. dry or wet 50° C.-120° C.  5-120 0.05-2  predominantly partially wool 2 lignin refined 20% mineral type 1 o/a inorganic, wet 80° C.-180° C. 20-180 0.1-3 predominantly partially wool 2 e.g. water refined glass 20% hardener mineral type 3 inorganic, wet 80° C.-180° C. 20-180 0.1-3 partially refined by wool e.g. water pyrolysis glass hardener mineral type 3 organic, e.g. dry or wet 60° C.-130° C. 10-150 0.1-2 predominantly partially wool lignin refined 20% rock wool type 1 o/a inorganic, wet 80° C.-180° C. 20-240 0.1-5 predominantly partially 2 e.g. water refined glass 20% hardener rock wool type 3 inorganic, wet 80° C.-180° C. 20-240 0.1-5 poss. health refined by e.g. water risk pyrolysis glass hardener

[0107] A fire-resistant wood-based material, which is described below and is regarded as capable of independent protection, can also be added in step S2. The fire-resistant wood-based material comprises a wood strip which, for example, has a thickness of 1 mm to 10 mm, a width of 1 mm to 50 mm and a length of 500 mm to 4,000 mm and is optionally pricked, insulating wool fibres and a binder, which has optionally penetrated into the wood strips by means of the pricked configuration and with which the wood strips are impregnated, wherein the binder is selected from one or more of inorganic water glass, inorganic water glass specifications, organic resins such as urea, melamine or phenol, fire-retardant additives such as precipitants or acid or acid hardener. The wood strips are preferably splintered or/and preferably have an uneven surface.

[0108] The fire-resistant wood-based material is preferably made from waste wood, damaged spruce wood or poplar-like wood, with any wood being possible in principle, as well as willow or birch, for example also as damaged wood and windblown wood. Processing into wood strips can take place by means of splintering. The wood strips present as splinters can be dried and impregnated with the preferably fire-retardant binder. After the binder has dried, the wood strips can be used. Fire retardants are, for example, precipitants, acids or acid hardeners.

[0109] The addition of the fire-resistant wood-based material to a fibre pulp in step S2 is to be described below, wherein rock wool as insulating wool and an inorganic binder are preferably considered. In this way, a homogeneous and full-volume composite fibre body can be produced, without flaws or gaps or/and interstices, which comprises the fibre pulp and the fire-resistant wood-based material.

[0110] The fire-resistant wood-based material can be placed in shaped forms, for example arranged systematically in the longitudinal direction, wherein an arrangement in different orientations of the fire-resistant wood-based material is likewise possible, for example in order to increase transverse and longitudinal tensile strengths. Diagonal insertion for improved static properties is also possible.

[0111] The fire-resistant wood-based material can be laid in layers, wherein each layer can have the fibre pulp poured over it. A layer thickness can be 0.1 mm to 2 mm. A certain excess can be used here in order to close all the gaps in the wood-based material, i.e. between the wood strips. Another special feature is the shape of the press templates or press models (e.g. approx. 20 cm-60 cm wide, approx. 20 cm-60 cm high and 300 cm −1200 cm long) these are provided with outlet openings (e.g. bores (6 mm to 15 mm) so that the excess fibre-binder pulp can escape.

[0112] For example, all required layers, each with an intermediate layer of fibre pulp, can be filled into a press template of gross dimensions with a width of about 20 cm to about 60 cm, a height of about 20 cm to about 60 cm and a length of at least 300 cm to about 1200 cm. The templates can be closed and pressed under high pressure, for example 2 bar to 8 bar, i.e. 2 kg/cm.sup.2 to 8 kg/cm.sup.2, at a temperature of 80° to 180°. The templates may be formed such that one side and an upper ram are formed so as to be slidable. As a result, the material to be pressed can undergo a relatively linear pressure from above and from one side, which leads to an optimised and homogeneous compression in the finished material, i.e. the recycled insulating material. Hardening can take place by cooling.

[0113] With a combination of high pressure, which partially compensates for unevenness in the wood splinters, a temperature that hardens the binder, and the very stable fibre-reinforced glue joint, a recycled wood-based insulating material which can be classified in fire resistance class of at least B1, possibly A2, (according to EN 13501-1 and DIN 4102-1) can be achieved.

[0114] The fibre pulp may be advantageous for the process of making the recycled insulating material. All gaps and cavities can be filled, so that a capillary action in the material can be avoided. The fibre pulp can cure completely and can fill all cavities. Excesses can escape through the pressure valves built into the press template. The hardened fibre pulp can replace a conventional glue joint. However, because of its internal stability due to fibres, it can be significantly thicker than traditional glue joints without losing cohesion or load-bearing capacity. In the finished surface design, a new and visually very attractive image of a recycled wood-based insulating wool material can be created. This can be classified in the fire resistance class B1, if applicable A2, (according to EN 13501-1 and DIN 4102-1).

[0115] FIG. 3 is a schematic representation of an apparatus for processing insulating materials, such as mineral insulating wool. The apparatus, generally designated by 30, comprises a drum 32, a tool group 34 which is arranged on a lower region of the drum 32, a drive (not shown) which drives the drum 32 and the tool group 34 in rotation relative to one another, a housing 36 enclosing the drum 32, a suction device, not shown, and an actuating element 38. In the illustrated embodiment, the tool group 34 is mounted on a disc 40 and the disc 40 rotates relative to the drum as indicated by the arrow 41. Alternatively, it is possible for the drum 32 to be driven by the drive and for the tool group 34 to be stationary.

[0116] Due to a relative movement of the drum 32 and the tool group 34, material such as insulating wool located in the drum 32 can follow a defined material flow 39 which can run centrally in the drum 32. In this way, the material located in the drum is guided to an inner drum wall of the drum 32 and the tool group 34. This can be achieved even more advantageously if the material flow 39 is an elliptical material flow 39.

[0117] An outer wall of the drum 32 can have an opening 42 which in the present case is indicated only schematically in the lateral surface of the drum 32. The opening 42 is designed so that material located in the drum 32 can move through it in order to be able to enter an intermediate space 44 between an outer face of the drum 32 and an inner face of the housing 36. For example, three opening states of the opening 42 can be present, which can correspond to the three fractions that arise during comminution of insulating wool. For example, a first opening area can be in the form of a screen through which only dust and particles can pass, a second opening area can have first apertures that are larger than the perforations of the screen in order to allow individual fibres and small fibre bundles to pass through, and a third opening area can have second apertures which are larger than the first apertures, so that fibre balls can pass through. In addition, there can be an opening area that is so large that uncomminuted insulating wool can be introduced.

[0118] For example, the actuating element 38 can be used to vary the opening area of the opening 42 so that there are at least two different opening areas depending on the position of the actuating element. In the embodiment shown in FIG. 3, the actuating element 38 is a cylinder 38 that fits closely against the outer face of the drum 32 and has various perforations, such as slots, grids, oblong holes, which can be used as screens and first and second apertures. Depending on the positioning of the close-fitting cylinder 38 relative to the opening 42 of the drum 32, the opening 42 may correspond to one of the perforations in the close-fitting cylinder 38.

[0119] It will be understood that the drum 32 has a plurality of openings 42 and the close-fitting cylinder 38 has a corresponding number of perforations. A sheet metal material is, for example, a possible material for the production of the close-fitting cylinder 38 since it can be easily adapted to the shape of the drum 32.

[0120] Conversely, the drum 32 can also have openings with various perforations, such as slots, grids, oblong holes, which can serve as a screen and first and second apertures, and these can be opened or closed by the actuating element 38 as required.

[0121] Material exiting the drum through the openings 42 can enter the intermediate space 44. For example, a distance between the outer face of the drum and the inner face of the housing is between 50 mm and 100 mm. Thus, sufficient material can accumulate in the intermediate space 44 and can be removed from there by means of the suction device, not shown. A filter, a screen and/or an air classifier can be connected to the suction device in order to be able to better fractionate the material into the appropriate fractions for further processing.

[0122] A possible tool group 34, such as can be used in the apparatus 30 shown in FIG. 3, is shown in FIG. 4. This preferably comprises two cutting tools 46, the cutting edges of which are aligned in the direction of rotation. In FIG. 4 the tool group 34 is arranged, for example, on a disc 40 which can rotate relative to the drum 32, as indicated by the arrow 41.

[0123] Another possible tool group 34, such as can be used in the apparatus 30 shown in FIG. 3, is shown in FIGS. 5a, 5b and 5c in a front view, side view and top view, respectively. This can comprise at least one spherical beater 50, a base 52 and a shaft 54 connecting the spherical beater 50 and the base 52. The spherical beater 50 may have apertures 56 which may be formed in a hemispherical shape as shown in FIGS. 5a and 5b or in another shape such as a pyramid shape. The spherical beater 50 can have a diameter of about 30 mm, for example from 25 mm to 35 mm, in order to ensure effective processing of insulating wool. The shaft 54 can have a length of 50 mm to 150 mm, wherein the length is determined in such a way that, on the one hand, material accumulation is avoided and, on the other hand, a stable attachment can be achieved. In order to increase the stability of the shaft 50, a reinforcement 58 which is, for example, welded on can also be provided, as can be seen in FIG. 5b. It goes without saying that this group of tools can be arranged on the disk 40 of the apparatus 30.

[0124] An example of a fibre-reinforced foam is shown in FIG. 6. The fibre balls 20, which are covered by the fibre-reinforced foam, are visible in this figure. The illustrated fibre-reinforced foam has an approximately circular shape in cross section, but may have any other shape in cross section, such as rectangular or triangular. It can also be seen in FIG. 6 that between the fibre balls 20 the fibre-reinforced foam has intermediate regions 48 which are cavities 48, for example.

[0125] The apparatus can also have nozzles which are set up to spray a liquid, for example a binder or an additive, onto a material located in the drum, for example onto insulating wool which has been comminuted or is to be comminuted.

[0126] The system can be encapsulated when the apparatus is used for insulating wool of type 3, i.e. with waste wool that is hazardous to health without the RAL quality mark.