Fire-resistant and recyclable component

Abstract

The invention relates to a method for producing a fire-resistant and recyclable component from renewable raw materials, a binder and water, as well as to a component produced according to the method. The object of the invention is therefore to eliminate the disadvantages of the prior art and to provide a method for producing a fire-resistant component from renewable raw materials and a component resulting therefrom, wherein the component is waterproof, vapour-permeable, flame-retardant and free from environmentally harmful additives. Said object is achieved by means of the features specified in the claims.

Description

Fire-resistant and recyclable building element Description

[0001] The invention relates to a method for producing fire-resistant and recyclable building elements from renewable raw materials, a binder and water, as well as to a building element produced by the method.

[0002] Building elements within the meaning of this invention can have various shapes. The most likely shape will be that of a plate. For example, a plate-shaped building element can be used for a drywall for interior construction. A plate-shaped building element can also be used as an acoustic and / or thermal insulation wall. A plate-shaped building element can also serve as a furniture panel, for example a tabletop. However, such a plate-shaped building element can also be used to manufacture complex structures, for example furniture. The production of complex, functional structures from one or more building elements is also conceivable, for example fire-resistant cable trays. In addition, a building element according to this invention can also have a cuboid shape and be used like a stone. Other shapes are not excluded.In principle, further processing and / or design of a component, for example painting, coating, gluing, etc., is not excluded.

[0003] Due to the growing world population and the need to achieve ambitious climate targets to curb global warming, there is also a great demand in the construction sector for building elements based on rapidly renewable raw materials, especially since state-of-the-art building elements have no or only insufficient recycling capability.

[0004] Natural building materials offer numerous advantages, such as high thermal and acoustic insulation properties, renewable raw material sources, the possibility of recycling or easy disposal through composting at a reasonable price, even for small batches.

[0005] Nevertheless, they must meet the requirements for their mechanical properties, particularly in terms of strength and fire resistance, while remaining lightweight.

[0006] Such building elements are generally made from wood fibers or wood chips, fiberglass, or gypsum using a binder. These materials are preferably processed into panels. Another disadvantage is that fiberglass and gypsum, in particular, have high melting points, requiring complex solutions for both production and recycling.

[0007] Recent efforts in the context of a bio-based circular economy envisage the utilization of agricultural and industrial / civilization waste for the above-mentioned purposes, for example the use of grain, rapeseed or hemp straw.

[0008] In this regard, EP 3 325425 B1 discloses a construction product in the form of an interior cladding panel, as well as a method for producing the construction product. According to claim 6, the construction product contains up to 35% cement binder. A disadvantage of this is that cement-like binders impede the product's permeability. They therefore promote the formation of condensation and the associated problems, such as mold growth. Furthermore, the construction product contains only up to 30% hemp shives, so that a large part of the interior cladding panel consists of lime and cement binder, and the essential aspect of sustainability is only peripherally applied.

[0009] The same applies to the construction product according to the teaching of WO2022157466A1. This discloses a construction product based on bioaggregates, which consists of a lignocellulose-containing, plant-based granulate and a calcium carbonate-derived binder, as well as a method for producing the construction product. Furthermore, the construction product according to claims 18 and 23 at least optionally comprises a cementitious binder, which can be described as disadvantageous.

[0010] What is needed is a process that allows the production of a bio-based building element that meets the requirements of the construction industry, both in terms of mechanical properties and processability, as well as with regard to the ecological aspects of using renewable raw materials, preferably from waste streams from agricultural, forestry and fishery production, and environmentally friendly recyclability after their end of use. Description of the invention

[0011] The object of the invention is to eliminate the disadvantages of the prior art and to provide a method for producing fire-resistant and recyclable building elements from renewable raw materials as well as a resulting building element, wherein the building element is waterproof, permeable to diffusion, flame-retardant and free from environmentally harmful additives.

[0012] This problem is solved by the features listed in the claims.

[0013] The problem is solved by a process for the production of fire-resistant building elements from rapidly renewable raw materials and / or recovered residues and / or biopolymers suitable for recycling, a binder and water, wherein the rapidly renewable raw materials are at least one of the group of cereal, rapeseed, linseed, hemp or rice straw or algae, hops, corn or paludicultures. Comparable renewable raw materials include hops, corn, and paludicultures such as reeds, Typha, sedges, or reed canary grass. The use of other renewable raw materials is conceivable. The raw materials can be processed whole, but are preferably crushed, for example, chopped. The binding agent is a mixture of magnesium carbonate, magnesium oxide, and magnesium chloride.The method comprises ten method steps: (i) adding binder and water to a temperature-controlled container; (ii) controlling the temperature of the binder-water mixture within a first defined temperature range; (iii) blending the binder-water mixture while maintaining the temperature of the first defined temperature range; (iv) maintaining the first defined temperature range for a first defined period of time; (v) controlling the temperature of the binder-water mixture within a second defined temperature range; (vi) adding the renewable raw materials while maintaining the temperature of the second defined temperature range; (vii) blending the binder-water-raw material mixture while maintaining the temperature of the second defined temperature range. (viii) maintaining the second defined temperature range for a second defined period of time; (ix) dispensing the binder-water-raw material mixture into a dimensionally stable casting mold; and (x) cooling and curing the binder-water-raw material mixture.

[0014] The composition of the mixtures, with regard to the proportions of raw material, magnesium carbonate, magnesium oxide, magnesium chloride, and water, can vary depending on the desired properties of the target product for their respective application. For example, a higher raw material content can increase acoustic insulation for soundproofing and noise reduction. A higher binder content can increase fire resistance.

[0015] The setting of the process parameters temperature and holding time can also vary. In general, the setting of the process parameters to create the conditions for optimal mixing of binder and raw material. Tempering increases the viscosity of the binder and enables a homogeneous coating of the raw material, which is a prerequisite for even curing during cooling. It also ensures latent decomposition of the raw material, increases its porosity, and thus enlarges its surface area for the adhesion of the binder. In addition to the desired properties of the target product, the setting of the process parameters depends, among other things, on the type of raw material used. For example, the process parameters for using cereal straw can be different from those for using algae, but can also be the same. The simultaneous use of two or more raw materials is conceivable.Furthermore, the process parameters can vary depending on the raw materials' original habitat, as this significantly determines their material composition. For example, plants of the same species but from different origins can have different proportions of lignocellulose. Furthermore, the process parameters can vary depending on the age of the raw materials, as this also determines their material composition. Furthermore, the storage duration and conditions of the raw materials used can influence the process parameters. For example, it may be necessary to temper a raw material stored at 6°C for longer than one stored at room temperature. Using a high proportion of raw material may require an increase in mixing time to ensure adequate blending with the binder.

[0016] The cooling and curing of the binder-water-raw material mixture takes place in air, but can be accelerated by applying heat. The use of waste heat is conceivable for this purpose.

[0017] According to various embodiments, the method is carried out continuously. A continuous implementation of the method can This can be achieved, for example, by carrying out process steps (i) to (viii) in at least one appropriately dimensioned storage container, which feeds a downstream process line. This can, for example, comprise a state-of-the-art continuous pressing system, such as that used for the continuous production of particleboard, OSB, MDF, and LVL, under the simultaneous influence of precise pressure and temperature.

[0018] According to various embodiments, the rapidly renewable agricultural raw materials are replaced completely or in part by components that are crushed and / or separated into suitable fractions and that were produced according to claim 1.

[0019] For example, a building element, such as a furniture board after a usage cycle or a building material board after a construction cycle, can be shredded and separated into corresponding fractions, which are then available either in their entirety or as a mixture for new products.

[0020] Furthermore, biopolymers, which also offer circular economy potential, can be used to produce the components. This applies, for example, to polyhydroxyalkanoates.

[0021] It is also conceivable to use residual materials obtained for this purpose, preferably from natural materials such as glass or materials suitable for recycling, for example civilised waste in the form of old packaging.

[0022] The aim here is the complete reuse of the components and / or objects produced with them after they have reached the end of their life cycle.

[0023] According to various embodiments, process steps (i) to (x) are repeated using different mixture compositions and / or process parameters such that carried out so that the resulting component has two or more different layers.

[0024] Accordingly, a different type of binder, water, and raw material mixture is applied to a first binder-water-raw material mixture and cured together. It is also conceivable to cure the mixtures sequentially. For example, this could produce a building element with a fire-resistant first side and an insulating second side. In this way, building elements with three or more layers can also be manufactured.

[0025] According to various embodiments, the process steps of tempering, mixing, and holding are computer-aided and automated. This allows dedicated processes for defined scenarios to run automatically without the need for manual intervention.

[0026] According to various embodiments, the first defined temperature range is between 25 and 60°C. The second defined temperature range may be identical, but may also differ.

[0027] According to various embodiments, the defined time periods are only a few seconds.

[0028] The object is further achieved by a component manufactured according to the method described here, wherein the component comprises at least one renewable raw material from the group of cereal, rapeseed, linseed, hemp or rice straw or algae, hops, corn or paludicultures and a binder made of magnesium carbonate, magnesium oxide and magnesium chloride as well as water, wherein the component is waterproof, permeable to diffusion, flame-retardant and free from environmentally harmful additives.

[0029] According to various embodiments, the raw material content of the component is between 55 and 80%.

[0030] According to various embodiments, the structural element is preferably a panel. Examples of fire-resistant panels include ceiling, floor, or wall panels for sound or thermal insulation, decorative wall panels for table coverings, roofing materials, insulating panels or ducts for utility lines, sound-absorbing linings, veneer backings, door materials, underlays in construction, and also elements in furniture construction, aircraft construction, vehicle construction, or shipbuilding. Other uses are conceivable.

[0031] Furthermore, common further processing and design options with regard to the component can be applied without restriction, for example painting, coating, gluing and much more.

[0032] The structural element manufactured using the described process is highly rigid, both bending and tear-resistant, permeable to vapor diffusion, flame-retardant according to fire protection standards Class A2 or B1, free of toxic additives, and universally applicable. At the end of its service life, it can be recycled or composted.

Claims

Claims 1. A method for producing fire-resistant building elements from renewable raw materials and / or recovered residues and / or biopolymers suitable for recycling, a binder, and water, wherein the renewable raw materials are at least one from the group of cereal, rapeseed, linseed, hemp, or rice straw, or algae, hops, corn, or paludicultures, and wherein the binder is a mixture of magnesium carbonate, magnesium oxide, and magnesium chloride, comprising the method steps of a) introducing binder and water into a temperature-controlled container, b) controlling the temperature of the binder-water mixture within a first defined temperature range, c) blending the binder-water mixture while maintaining the temperature of the first defined temperature range, d) maintaining the first defined temperature range for a first defined period, e) controlling the temperature of the binder-water mixture within a second defined temperature range,f) feeding the shredded renewable raw materials while maintaining the temperature within the second defined temperature range, g) mixing the binder-water-raw material mixture while maintaining the temperature within the second defined temperature range, h) maintaining the second defined temperature range for a second defined period, i) discharging the binder-water-raw material mixture into a dimensionally stable casting mold, j) cooling and curing the binder-water-raw material mixture.

2. Method according to claim 1, characterized in that the binder-water-raw material mixture is discharged continuously onto a conveyor line.

3. A method according to claim 1 or 2, characterized in that the rapidly renewable agricultural raw materials are replaced completely or in part by crushed and / or separated into suitable fractions building elements which were produced according to claim 1.

4. Method according to one of the preceding claims, characterized in that the method steps a) to j) are carried out repeatedly using different mixture compositions and / or process parameters such that the components have two or more different layers.

5. Method according to one of the preceding claims, characterized in that the method steps of tempering, mixing and holding are carried out automatically with computer support.

6. Method according to one of the preceding claims, characterized in that the first defined temperature range is between 25 and 60°C.

7. Method according to one of the preceding claims, characterized in that the first and second temperature ranges are identical.

8. Method according to one of the preceding claims, characterized in that the defined time periods are only a few seconds.

9. Construction element produced according to the method of claims 1 to 8, characterized in that the construction element comprises at least one renewable raw material from the group of cereal, rapeseed, flax, hemp or rice straw or algae, hops, corn or paludicultures and / or crushed and / or separated into suitable fractions construction elements which were produced according to claims 1 to 7, and / or recovered residues and / or biopolymers suitable for recycling and a binder from Magnesium carbonate, magnesium oxide and magnesium chloride as well as water, whereby the component is waterproof, permeable to diffusion, flame-retardant and free from environmentally harmful additives.

10. Component according to claim 9, characterized in that the raw material content of the component is between 55 and 80%.

11. Component according to claim 9 or 10, characterized in that the component is a plate.

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