Plant fibre product

Abstract

The invention relates in general to working or preserving a plant-fibre material, such as a wood-like material, and processing said material, such as in a plastic state in general, and may likewise be considered to be a technology of managing solid or solid-like waste materials, the waste materials comprising plant-fibre material. The present invention further relates to a structural product comprising the plant-fibre material, an insulation material, to a laminate product and a method of producing the laminate product.

Description

PLANT FIBRE PRODUCTField of the inventionThe invention relates in general to working or preserving a plant-fibre material, such as a wood-like material, and processing said material, such as in a plastic state in general, and may likewise be considered to be a technology of managing solid or solid-like waste materials, the waste materials comprising plant-fibre material. The present invention further relates to a structural product comprising the plant-fibre material, an insulation material, to a laminate product and a method of producing the laminate product.RELATED APPLICATIONSThe present application claims the benefit of priority from Dutch Patent Application NL2037215, filed on March 11, 2024, in the name of Beyond Wood Cobperatie U.A., The Netherlands.The entire contents of the above-referenced applications and of all priority documents referenced in the Application Data Sheet filed herewith are hereby incorporated by reference for all purposesBackground of the inventionWaste is considered to relate to unwanted or unusable materials. Waste is typically a substance which is discarded after a primary use, or otherwise considered worthless. In a circular economy such waste should be avoided, or at least minimized. An example thereof is waste recovery, in order to use the recovered waste in a further application. As such, waste is used as an input material to create valuable products. The amount of waste left for which no further use is (yet) available is therewith reduced. Such re-use has certain beneficial sideeffects, such as reducing an amount of otherwise used raw materials, saving land space as less waste is deposited, less pollution now and in the future, such as due to washing out, creating work, etc. Therewith waste recovery may be considered as part of a circular economy. A goal thereof is to minimize use of (scarcely available) natural resources, as well as to optimize use of resources in general.In modem agriculture, horticulture, greenhouse cultivation, forestry, cultural landscape, and so on, huge amounts of waste are produced, typically non-sellable plant materials, such as fibre-comprising materials. These materials are typically discarded, and often burned as biological fuel. Such contributes to carbon dioxide emission. Also methane may be produced from these materials by bacteria. So a re-use of such materials is wanted.Therefore it is highly desirable to re-use such materials or, when such materials are re-used already in certain amounts, to further increase the amount of re-used material applied in products comprising the said material. This however requires new innovative solutions and technologies to make this possible.Some plants may comprise fibre and in particular may be grown for such purposes. Some plants may produce fibres as a side product. Or waste material may be obtained from plants having fibres. So various sources of plant fibres exist. Plants with fibres are characterized by having a large concentration of cellulose, giving them their strength. These fibres may be used in composite materials. Fibre crops are generally harvestable after a single growing season, as distinct from trees, which are typically grown for many years before being harvested. In specific circumstances, fibre crops can provide advantages over wood pulp fibre in terms of technical performance, environmental impact or costA re-use that is typically considered is that of artificial boards wherein use is made of glues, typically [volatile organic] solvent based glues such as trialdehyde glue (ureaformaldehyde, formaldehyde, phenolic). During production this is already an issue. Further, when the plate is burned, amongst others hydrogen is produced, which is highly toxic and has potential huge hazards.Incidentally, US4339405 (A) recites a process for making cast vegetable / mineral structural products having flame retardant properties utilize a major volume portion of ligneous plant fragments such as soft and hardwoods, sugarcane, cereal and fibre plant stalks, and a minor volume proportion of a mineral binder deposit comprised of magnesium or calcium oxyphosphates and inert filler particles. Fragments having thicknesses ranging from 0.3 mm to 8 mm including chips, shavings, strips, strands, fibre bundles, slivers, fibres and peeled and sawn veneer sheets, have applied to their surfaces an aqueous solution of ammonium polyphosphate or soluble acid phosphate salt supplying from 0.15 to 0.40 parts of P2O5 as phosphate ion per part of fragments by weight, and particulate cement solids comprised of MgO or CaO or Mg(OH)2 or Ca(OH)2 or MgCCh or CaCCh ranging from 0.25 to 1.0 part per part of fragment, and from 0.01 to 0.80 parts of inert filler particles and the mixture is moulded and held under predetermined compaction pressure until the product has rigidified, in about 10 minutes' time. The process, however, provides an adhered mineral cladding layer of a surface area of a ligneous body (see e.g. figures), so a main body with ligneous material, and a thin layer [cladding] of mineral origin. Further ammonia is released during production of the material. EP 0 004 372 Al recites flame-retardant moulded articlescomprising mineral-clad ligneous particles, from lightweight and low-cost concreted products utilizing as filler material lignocellulosic fragments, and employing as bonding agent some form of mineral cement, to produce building materials. Typical cements have comprised Portland and other hydraulic cements and pozzolans, and magnesia cements such as Sorel cement. The problems of forming products of adequate strength and with densities less than unity arise because of inferior junction bond strength, that is, the adherence of the mineral mass to the woody filler. An understanding of the composition of wood fragments, and the chemistry of the reactants producing the mineral bond mass, may be gained by considering the following discussion. CN 107 130 894 B recites a fireproof door middle seam provided with flame-retardant straw fire prevention boards. The fireproof door middle seam comprises a door frame, door leaves and hinges, wherein the door leaves are connected with the door frame by the hinges; a face exposed to fire and a face unexposed to fire are respectively formed at the two sides of each door leaf; a middle seam is formed by the contact surfaces of the left door leaf and the right door leaf; the left door leaf and the right door leaf are respectively formed by two parts, wherein the four flame-retardant straw fire prevention boards are arranged in the parts at the sides close to the middle seam, and the other parts connected with the flame-retardant straw fire prevention boards are made from steel section; a seam cover plate is also arranged in the fireproof door middle seam and is formed by cutting the flame-retardant straw fire prevention board. The fireproof door middle seam creatively overcomes the defect that a middle seam of the traditional steel or wooden fireproof door is easily deformed in the event of high temperature of a fire; the flame-retardant straw fire prevention boards are set as the parts, close to the middle seam, of the door leaves and the seam cover plate, so that the effects of fire prevention, flame retardance and smoke suppression are effectively achieved; the fireproof door middle seam guarantees the stability of a framework structure of the fireproof door when the fireproof door is in a fire; the middle seam is non-deformable and fireproof. CN 108 101 418 A recites an environment-friendly building material including, by weight, 14-21 parts of calcium silicate powder, 25-29 parts of ethylene-vinyl acetate copolymer, 25-28 parts of polymerized rosin, 17-25 parts of aluminum silicate powder, 5-11 parts of magnesium oxide, 15-27 parts of bamboo carbon powder, 13-17 parts of nano ZnO, 5-7 parts of nano silver, 13-17 parts of zirconium hydrogen phosphate, 5-7 parts of tannin, 5-9 parts of green silicon carbide, and 70-88 parts of plant fibres. In the invention, plant fibres are matched with the ethylene-vinyl acetate copolymer and the polymerized rosin to press the building material, wherein the plant fibres areeffectively utilized to turn the wastes into resources. By adding the bamboo carbon powder which has strong adsorption capability, can purify air and eliminate odors, absorb moisture and prevent mildew, and has anti-bacterial effects and using the nano silver, zirconium hydrogen phosphate and tannin, excellent anti-bacterial effect is achieved. CN 108 247 805 A recites a flame-retardant straw-based panel and a method for making the same. The flameretardant straw-based panel comprises a bare panel, and a facing layer which is arranged on at least one surface of the bare panel, wherein the bare panel comprises the following components in parts by weight: 5-80 parts of straw particles, 2-25 parts of adhering agent, and 5-65 parts of flame retardant. The flame-retardant straw-based panel has outstanding comprehensive performances such as high efficiency performance, flame retarding performance, smokeless performance and nontoxic performance. The method is characterized in that the bare panel is manufactured by a hot compression and fixation technology; the step of forming is avoided, so that the production efficiency is greatly improved, and the production cost is decreased. CN 108 165 039 A recites a flame-retardant wood-plastic floor and a preparation method thereof, and relates to the technical field of wood-plastic floors. The flame-retardant wood-plastic floor comprises the following raw materials in parts by weight: 20-35 parts of cotton straw powder, 20-35 parts of corn stalk powder, 10-25 parts of wood powder, 15-28 parts of bamboo powder, 20-35 parts of plastic particles, 1-5 parts of a compatilizer, 0.8-5.2 parts of a modified flame retardant, 1.2-3.6 parts of a lubricant, 1.1-3.2 parts of an antioxidant and 1-2 parts of an antibacterial agent. The wood-plastic floor provided by the invention has stable structure, high folding and pressing resistance, and good flame retardancy; and the preparation method is simple, and has low production cost and goodmarket application prospect. WO2024 / 058659 Al recites working or preserving a plant-fibre material, such as a wood-like material, and processing said material, such as in a plastic state in general, and may likewise be considered to be a technology of managing solid or solid-like waste materials, the waste materials comprising plant-fibre material.The present invention relates to an improved method of producing a plant-fibre product and various aspects thereof and such a product, which overcomes one or more of the above disadvantages, without jeopardizing functionality and advantages.SUMMARY OF THE INVENTIONThe present invention relates in a first aspect to a plant fibre product, in particular a structural product. In summary, the present invention provides a sustainable solution of producing and obtaining plant-fibre based materials.Thereby the present invention provides a solution to one or more of the above mentioned problems. The present inventors developed a method of producing a plant-fibre product and various aspects thereof and such a product, which highly increased the amount of plant-fibre in the plant-fibre product of the present invention. Without jeopardizing functionality and advantages, the amount of plant-fibre applied in the plant-fibre product of the invention was possible to be increased significantly.Advantages of the present description are detailed throughout the description. References to the figures are not limiting, and are only intended to guide the person skilled in the art through details of the present invention.The present invention relates in a first aspect to a plant fibre product, in a second aspect to a structural product, in a third aspect to a laminate product, in a fourth aspect to a method of producing the plant fibre product, in a fifth aspect to a product obtainable by said method, and in a sixth aspect to a method of producing a laminate product.In a first aspect, the invention relates to a plant fibre product, in particular a wood fragment product, comprising (a) 51-95 wt.% plant fibre, in particular 70-95 wt.%, more in particular 80-94 wt.% plant fibre, more in particular 90-93 wt.% plant fibre, most preferably 51-70 wt% plant fibre, and 90-99 vol.% plant fibre, in particular 95-98 vol.% plant fibre, or in particular 52-70 wt.%, more in particular 53-68 wt.% plant fibre, more in particular 55-65 wt.% plant fibre, and 60-80 vol.% plant fibre, in particular 65-75 vol.% plant fibre, wherein the plant fibre comprises 2-32 wt.% lignocellulosic biomass, in particular 5-30 wt.%, wherein the plant fibre comprises 5-40 wt.% water, in particular 10- 35 wt.% water, more in particular 20- 30 wt.% water, wherein plant fibre wt.%’s are based on the total weight of the plant fibre, wherein the fibres have a cross section of 0.2-8 mm (as measured using the SYMPATEC Image Analysis system (IA) QICPIC in combination with the dry disperser GRADIS / L. The symbols and indices employed in the tabular printouts and graphical representation, as well as the type and form of the plotted results were in accordance with the ISO 13320-1 standard “Particle size analysis - Laser Diffraction methods - Part 1”. In this standard a normative reference is made to ISO 9276 - 1 : 1990. “Representation of results of particle size analysis), in particular 0.3-7 mm, such as 0.5-5mm, (b) and a remainder plant fibre product part of 5-49 wt.%, in particular 5-40 wt.%, more in particular 6-20 wt.%, more in particular 7-10 wt.%, the remainder plant fibre product part comprising (bl) 25-75 wt.% magnesium oxide particles, in particular 29-72 wt.%, more in particular 35-55 wt.%, and (b2a) 7-30 wt.% phosphate selected from polyphosphate and phosphate, in particular 9-25 wt.%, with the proviso that at least 6 wt.% of the phosphate is polyphosphate, in particular wherein 40-95 wt.% of the phosphate is polyphosphate, wherein phosphate wt.% are based on the polyphosphate / phosphate content, more in particular 55-90 wt.% polyphosphate, and (b2b) 18-45 wt.% water, in particular 16-50 wt.% water, and wherein the remainder plant fibre product part wt.%’s are based on a total weight of the remainder plant fibre product part. In particular, the plant fibre product comprises less than 15 wt.% filler, in particular less than 5 wt.% filler, such as less than 0.6 wt.% filler. In the ISO 13320-1 standard a normative reference is made to ISO 9276. The DIN equivalent to ISO 9276 is DIN 66141 to 66145. These particular DINs are: 66141 : Representation of particle size distributions, basic standard, 66142: Part 1 : Representation and characterisation of separations of dispersive materials: fundamentals; Part 2: Representation and characterisation of separations of dispersive materials: application on analytical separations, 66143: Graphical representation of particle size distributions: Power function grid, 66144: Graphical representation of particle size distributions: Log-normal grid, 66145: Graphical representation of particle size distributions: RRSB grid. It is noted that particle size distributions can be described with an inverse-Gaussian approach; typically particle sizes of <0 do not exist; however, in vie of statistics, it has been found that statistical procedures, such as averages, mean, and standard deviation, apply more or less equally well to the inverse Gaussian-distributed particles. In general, when using relatively low amounts of fibre more stone-like material is obtained, whereas when using relatively high amounts of fibre a more wood-like material is obtained. So relatively small, but long fibres are used, in particular fresh fibres, that is fibres obtained from plants that have been cut or provided less than a few days ago, such as less than 24 hours ago. The plant fibres contain a relatively large fraction of lignocellulosic biomass, and water, hence the fresh cut aspect. The term “plant fibre” is intended to include all plant-based fibre-like materials, such as single fibres, composite fibres, multiple fibres, bundles of fibres, and so on. Further, typically intimately mixed, MgO provided in the form of particles, and phosphate, are present. A typical thickness is 1-50 mm, in particular 2-20 mm, whereas length and width may be in a range of 10 cm-600 cm, for plates or the like. In principle thepresent product can be provided in any suitable form, typically using a mould thereto. As water is present in various forms, such as in the plant fibre, and / or as the phosphate is provided in the form of a solution in the present process (e.g. 56 wt.% water), a final product may have an amount of water, typically incorporated in the product, of 2-40 wt.% water, typically 4-25 wt.%, more typically 6-22 wt.%, such as 15-18 wt.%. In this aspect water typically relates to the free available water, however, incorporated in the product.In a second aspect the present invention relates to a structural product, in particular selected from a panel, a board, and a composition material, comprising the plant fibre product as taught herein, in particular comprising 90-100 wt.% of said plant fibre product, more in particular wherein said structural product has a Modulus of Rupture (MOR) of 2-35 N / mm2, in particular 3-30 N / mm2. The resulting product composition was found to have a Modulus of Rupture (MOR) of 2-35 N / mm2, wherein it was even found to manufacture a composition with 95 wt.% of plant fibre, having a MOR value of up to 10. The resulting product further demonstrates characteristics such as being 90-100% recyclable, having a thermal extension coefficient of < 0.005 mm / (m*°C), being fire safe according to NEN class B or class A2, at least 10 years durable, a density of 0.5-1.8 kg / dm3, preferably of 0.7- 1,5 kg / dm3, in particular wherein the density is given by the formula density=wt.% fibre*- 0.014 + 2.04 ±10%, processable as an alternative to wood, a stability of > 200 cycles, in particular >100 cycles (measured using ASTM method Cl 186), a moisture uptake of < 10 wt.%, preferably < 5 wt.%, in particular < 2 wt.%, a modulus of elasticity of >1.5 kN / mm2, in particular 5 kN / mm2, more in particular 10 kN / mm2, and biodegradability.In a third aspect the present invention relates to a laminate product comprising a first structural product (1) as taught herein, a second structural product (2) as taught herein, in particular wherein the first and second structural products have a A between 0.13 W / m2K - 0.35 W / m2K, and in between said first and second structural products a layer of thermal insulation (3), in particular wherein the thermal insulation has a A between 0.03 W / m2K - 0.08 W / m2K.In a fourth aspect the present invention relates to a method of producing a plant fibre product according the invention, comprising providing 51-95 wt.% plant fibre, in particular 60-95 wt.%, more in particular 80-94 wt.% plant fibre, more in particular 90-93 wt.% plant fibre, wherein the plant fibre comprises 2-32 wt.% lignocellulosic biomass, wherein the plant fibre comprises 5-40 wt.% water, wherein the fibres have a cross section of 0.2-8 mm (as measured using SYMPATEC Image Analysis system (IA) QICPIC (ISO 13320)),typically with a mean of 0.2-8 mm, and a standard deviation of 0.6-24 mm, and a remainder plant fibre product part of 5-49 wt.%, in particular 5-40 wt.%, more in particular 6-20 wt.%, more in particular 7-10 wt.%, the remainder plant fibre product part comprising 25- 75 wt.% magnesium oxide particles, 7-30 wt.% phosphate selected from polyphosphate and phosphate, with the proviso that at least 6 wt.% of the phosphate is polyphosphate, wherein the phosphate wt.% is based on the polyphosphate / phosphate content, and 18-45 wt.% water, and wherein the remainder plant fibre product part wt.%’s are based on the total weight of the remainder plant fibre product part, mixing the plant fibre, the magnesium oxide, phosphate, and water during a mixing time and at a mixing temperature, therewith forming a homogeneous mixture, pressing the homogeneous mixture during a pressing time and pressing temperature under a pressure of 10-10.000 kPa, and drying the product at an elevated temperature of 20-80° C during a drying time to remove volatile compounds, such as ammonia.In a fifth aspect the present invention relates to a product obtained by the method of producing a plant fibre product as taught herein, wherein the product comprises at least one characteristic selected from 90-100% recyclable, a thermal extension coefficient of < 0.005 mm / (m*°C), fire safe according to NEN class B or class A2, at least 10 years durable, a density of 0.5-1.8 kg / dm3, preferably of 0.7-1, 5 kg / dm3, in particular wherein the density is given by the formula density=wt.% fibre*-0.014 + 2.04 ±10%, processable as an alternative to wood, a stability of > 200 cycles, in particular >100 cycles (measured using ASTM method Cl 186), a moisture uptake of < 5 wt.%, (at 20 °C under 90% RH, during 48 hours), in particular < 2 wt.%, more in particular < 0.1 wt.%, a modulus of elasticity of >10 kN / mm2, a modulus of rupture of at least 2 N / mm2, in particular at least 3 N / mm2, in particular at least 5 N / mm2, more in particular at least 10 N / mm2, more in particular at least 15 N / mm2, in particular according to NEN-EN 14080 / NEN EN 338, and biodegradability.In a sixth aspect the present invention relates to a method of producing a laminate product comprising a first structural product (1) as taught herein, a second structural product (2) as taught herein, and in between said first and second structural products a layer of thermal insulation (3), comprising providing said first and second structural products, placing the structural products at a distance of 5-30 cm from each other, in particular by providing spacers at the sides of the first and second structural products therewith forming an enclosed space, filling the space in between said first and second structural product with thermal insulation material, providing a pressure to the first andsecond structural products and the thermal insulation material of 2-10 MPa, in particular 4- 5 MPa, in particular wherein the insulation material comprises the plant fibre product as taught herein, in particular wherein the thermal insulation material has a density of 100-400 g / dm3.The present invention provides a solution to one or more of the above mentioned problems and overcomes drawbacks of the prior art.DETAILED DESCRIPTION OF THE INVENTIONIn an exemplary embodiment the present plant fibre product comprises 1-30 wt.% of an aqueous dispersion, in particular 2-25 wt.%, more in particular 2-5 wt.%, the dispersion comprising polymer microparticles, the polymer being selected from natural and synthetic rubbers. The microparticles typically have a size of 10-300 pm, such as 20-200 pm; a standard deviation G is in the order of 10-30 pm. Most (>90%) particles tend to be smaller than the higher value mentioned.In an exemplary embodiment of the present plant fibre product the polymer is selected from natural rubbers, in particular from latex.In an exemplary embodiment of the present plant fibre product magnesium oxide particles comprise < 1 wt.% Mg(OH)2In an exemplary embodiment of the present plant fibre product the magnesium oxide particles are obtained by heating to a temperature of > 973 K, in particular > 1050K, during a heating period of > 60 minutes [dead-burned MgO or DBM],In an exemplary embodiment of the present plant fibre product magnesium oxide particles comprise < 2 wt.% Si, in particular < 0.3 wt.% Si. Typically < 5.5 wt.% CaO, and / or < 8.5 wt.% Fe2O3, and even smaller quantities of Q12O, TiCE, &2O3, and CO2O3 may be present, each individually typically < 2 wt.%, such as < 1 wt.%.In an exemplary embodiment of the present plant fibre product magnesium oxide particles comprise >60 wt.% Mg on a metal :metal basis, in particular > 85 wt.% Mg, more in particular > 90 wt.% Mg, such as > 95 wt.% Mg. The exemplary MgO comprise 98.5 wt.%.In an exemplary embodiment of the present plant fibre product the magnesium oxide particles have a mesh size of <200 Mesh (<0.077 mm Sieve size ISO 565: 1990 and ISO 3310-1 :2000), preferably of <325 Mesh (<0.044 mm), more preferably of <500 Mesh (<0.025 mm), more in particular with a dw of 0.03 mm, in particular wherein >80% of themagnesium oxide particles have such a mesh size, such as >90%. Typically also a lower average size may be controlled, such as to larger than 0.005 mm, in particular >0.010 mm.In an exemplary embodiment of the present plant fibre product the polyphosphate and phosphate comprise a cation selected from ammonia, sodium, potassium, hydrogen, and combinations thereof, in particular ammonia.In an exemplary embodiment of the present plant fibre product the polyphosphate is selected from pyrophosphate (n=2), triphosphate (n=3), tetraphosphate (n=4), pentaphosphate (n=5), hexaphosphate (n=6), heptaphosphate (n=7) and octaphosphate (n=8), such as NP 10-34 or NP 11-37, or NP 12-40. NP as used herein refers to number (N) of phosphates (P) comprised in the polyphosphate.In an exemplary embodiment of the present plant fibre product the phosphate is orthophosphate (HiPC ).In an exemplary embodiment the present plant fibre product comprises 0.2-5 wt.% of a boric acid or salt thereof, preferably of tetra boric acid, such as a monovalent salt thereof, such as a sodium salt.In an exemplary embodiment the present plant fibre product comprises 0.1-15 wt.% additives, in particular 0.3-5 wt.%, wherein additives are preferably selected from natural colorants and natural pigments, such as natural oxides, from carboxylic acids, such as citric acid, from CaO, and from CaCCh.In an exemplary embodiment of the present plant fibre product the plant fibre comprises 1-90 wt.% waste plant material, preferably obtained from wood or vegetables.In an exemplary embodiment of the present plant fibre product the lignocellulosic biomass comprises lignin, cellulose, hemicellulose, pectin, xylem tracheid, vessel elements, and cells.In an exemplary embodiment of the present plant fibre product the lignocellulosic biomass comprises 5-100% open cells, in particular 10-95% open cells,In an exemplary embodiment of the present plant fibre product, the lignocellulosic biomass comprises open cells with a cell volume of 10'15-10'12m3.In an exemplary embodiment of the present structural product, the structural product has a density of 100-400 g / dm3, preferably of 200-400 g / dm3.In an exemplary embodiment of the present structural product, the structural product has a density of 0.5-1.8 kg / dm3, preferably of 0.7-1.5 kg / dm3, in particular wherein the density is given by the formula density=wt.% fibre*-0.014 + 2.04 ±10%.In an exemplary embodiment of the laminate product as taught herein, the thermal insulation material comprises the plant fibre product as taught herein.In an exemplary embodiment of the laminate product as taught herein, the thermal insulation material has a density of 100-400 g / dm3, preferably of 200-400 g / dm3.In an exemplary embodiment of the laminate product as taught herein, the first and second structural products have a density of 0.5-1.8 kg / dm3, preferably of 0.7-1.5 kg / dm3, in particular wherein the density is given by the formula density=wt.% fibre*-0.014 + 2.04 ±10%.In an exemplary embodiment of the laminate product as taught herein, the first structural product has a first thickness of 0.3-2.7 cm, in particular of 0.5-1 cm.In an exemplary embodiment of the laminate product as taught herein, the second structural product has a second thickness of 0.3-2.7 cm, in particular of 0.5-1 cm.In an exemplary embodiment of the laminate product as taught herein, the thermal insulation layer has a thickness of 3-30 cm, in particular 5-20 cm, such as 7-12 cm, in particular wherein the wt.% plant fibre in the first structural product is higher than the wt.% plant fibre product in the second structural product, more in particular 2-10 wt.% higher.In an exemplary embodiment of the method of producing a plant fibre product, the plant fibre comprises 10-100% freshly cut plant fibre selected from wood and vegetables, in particular 90-99% freshly cut plant fibre, more in particular 95-98% freshly cut plant fibre, more in particular wherein freshly cut fibre is selected from plants of the plant families of Fagaceae, such as Quercus. SaHcaceae. such as Populus and Salix, Betulaceae, Rosaceae, Pauwlowniaceae, Poaceae, Cucurbitaceae, and Solanaceae, and from roadside grass.In an exemplary embodiment of the present method of producing a plant fibre product, the plant fibre is obtained from freshly cut trees, or grass, or bush, such as with a cross-section of a trunk thereof of 1-40 cm, in particular 8-30 cm, in particular wherein the bark is partly or fully removed therewith obtaining a debarked trunk, more in particular wherein the debarked trunk is processed into fibres with a fibre length of smaller than 20 cm, in particular smaller than 15 cm, in particular smaller than 90 mm, in particular a fibre length of 10-60 mm, more in particular 13-24 mm, a fibre width of < 30 mm, in particular a fibre width of 10-20 mm, and a fibre thickness of < 8 mm, in particular a fibre thickness of 1-5 mm, more in particular wherein a fibre length:fibre thickness ratio is maintained at >6, in particular a ratio of >10. more in particular a ratio of >15, such as by using a turbo rotor at a rotational speed of >500 rpm with a turbo rotor of size 50 cm diameter.In an exemplary embodiment of the present method of producing a plant fibre product, mixing is performed at a temperature of 0-30 °C.In an exemplary embodiment of the present method of producing a plant fibre product, after mixing the obtained mixture is subjected to a pressure of between 200-8000 kPa, preferably between 500-6000 kPa, more preferably between 750-5000 kPa, in particular during a press time of 3-120 minutes. In an exemplary embodiment of the present method of producing a plant fibre product, the product is dried during a drying period of 1- 48 hours, in particular a drying period of 10-40 hours, more in particular a drying period of 20-30 hours, such as 24 hours. In an exemplary embodiment of the present method of producing a plant fibre product, the product is dried at a temperature of between 5-75 °C, in particular between 10-40 °C, more in particular between 15-30 °C, such as 20 °C.In an exemplary embodiment of the present method of producing a plant fibre product, after mixing the obtained mixture is subjected to the pressure within 300 seconds, in particular within 30 seconds, such as within 10 seconds.In an exemplary embodiment of the present method of producing a plant fibre product, the method is for producing a thermal insulation material, wherein after mixing the obtained mixture is subjected to a pressure of between 10-4000 kPa, preferably between 500-2000 kPa, more preferably between 700-1000 kPa, in particular during a press time of 3-120 minutes. In an exemplary embodiment of the present method, the product is dried during a drying period of 1-48 hours, in particular a drying period of 10-40 hours, more in particular a drying period of 20-30 hours, such as 24 hours. In an exemplary embodiment of the present method, the product is dried at a temperature of between 5-75 °C, in particular between 10-40 °C, more in particular between 15-30 °C, such as 20 °C. In an exemplary embodiment of the present method, after mixing the obtained mixture is subjected to the pressure within 300 seconds, in particular within 30 seconds, such as within 10 seconds.In an exemplary embodiment of the method of producing a laminate product as taught herein, the first and second structural products are provided in a press.The invention is further detailed by the accompanying figures and examples, which are exemplary and explanatory of nature and are not limiting the scope of the invention. To the person skilled in the art it may be clear that many variants, being obvious or not, may be conceivable falling within the scope of protection, defined by the present claims.FIGURESAn embodiment of the invention will now be described, by way of example only, with reference to the accompanying schematic figure in which corresponding reference symbols indicate corresponding parts.Figure 1 shows a schematic representations of an embodiment of the laminate product of the present invention.Figure 2 shows a table regarding different plant fibre product compositions.DETAILED DESCRIPTION OF FIGURESIn the figures:1 first structural product2 second structural product3 layer of thermal insulationL laminate productFigure 1 shows a schematic representations of an embodiment of the laminate product of the present invention. A laminate product L is shown comprising a first structural product (1), a second structural product (2), and in between said first and second structural products a layer of thermal insulation (3). The structural product (1) and the structural product (2) are in particular selected from a panel, a board, and a composition material, comprising the plant fibre product of the present invention. In particular the first and second structural products have a A between 0.13 W / m2K - 0.18 W / m2K. The structural product comprise in particular 90-100 wt.% of the plant fibre product of the present invention. More in particular the said structural products have a Modulus of Rupture (MOR) of 2-35 N / mm2, in particular 3-30 N / mm2. The first and second structural product have a density of 0.5-1.8 kg / dm3, preferably of 0.7-1.5 kg / dm3, in particular wherein the density is given by the formula density=wt.% fibre*-0.014 + 2.04 ±10%. The thermal insulation has in particular a A between 0.03 W / m2K - 0.08 W / m2K. The thermal insulation material preferably comprises the plant fibre product of the present invention and has in particular a density of 100-400 g / dm3. The first structural product (1) of laminate product L preferably has a first thickness of 0.3-2.7 cm, in particular of 0.5-1 cm. The second structural product (2) of laminate product L preferably has a first thickness of 0.3- 2.7 cm, in particular of 0.5-1 cm. The thermal insulation layer (3) has preferably a thickness of 3-30 cm, in particular 5-20 cm, such as 7-12 cm. In particular the wt.% plant fibre in thefirst structural product is higher than the wt.% plant fibre product in the second structural product, more in particular 2-10 wt.% higher.Figure 2 shows a table regarding different plant fibre product compositions. Different plant fibre amounts in wt.% were used. 50 wt.% was known already from prior art, and known to be the highest value possible to be applied. By application of the method of the invention, the inventors surprisingly found that even significantly higher amounts than 50 wt.% of plant fibre were able to be applied, which is a clear advantage over what is known in the technical field to the skilled person. It is therefore demonstrated that significantly higher amounts of fibre were able to be applied, being 60. 70. 80. 90 and 95 wt.% of plant fibre, wherein fibre wt.%’s are based on the total weight of the plant fibre (column 1). In the remainder plant fibre product (100 wt.% minus the fibre wt.%) additional materials can be added as taught herein. In addition to the plant fibre, there were added polyphosphate, water, and Magnesium oxide. As an example polyphosphate, ammonium polyphosphate (APP) was used (NP 10-34). Highest and lowest amounts of APP in wt.% are shown in columns 2 and 3, wherein the wt.%’s are based on the total weight of the plant fibre product. Columns 4 and 5 show the amounts recalculated and based on the total weight of the remainder plant fibre product part. Columns 6 and 7 show lowest and highest amounts of Magnesium oxide (MgO) in wt.%, wherein the wt.%’s are based on the total weight of the plant fibre product. Also the amounts of MgO in wt.% are recalculated in view of the total weight of the remainder plant fibre product part, which is demonstrated in columns 8 and 9. In the table of figure 2 it is demonstrated that a highest APP level (col. 2) and a lowest MgO level (col. 6), or a lowest APP level (col. 3) and a highest MgO level (col. 7), and combined with the amount of fibre in wt.% of the same row, together add up to 100 wt.%. The resulting product composition is a structural product having the composition as taught herein and was found to have a Modulus of Rupture (MOR) of 2-35 N / mm2, in particular 3-30 N / mm2, wherein it was even found to manufacture a composition with 95 wt.% of plant fibre, having a MOR value of up to 10. The resulting product further demonstrates characteristics such as being 90-100% recyclable, having a thermal extension coefficient of < 0.005 mm / (m*°C), being fire safe according to NEN class B or class A2, at least 10 years durable, a density of 0.5-1.8 kg / dm3, preferably of 0.7-1, 5 kg / dm3, in particular wherein the density is given by the formula density=wt.% fibre*-0.014 + 2.04 ±10%, processable as an alternative to wood, a stability of > 200 cycles, in particular >100 cycles (measured using ASTM method Cl 186), a moisture uptake of < 10 wt.%, preferably< 5 wt.%, in particular < 2 wt.%, a modulus of elasticity of >10 kN / mm2, and biodegradability.EXPERIMENTSBasic processAn exemplary basic process relates to steps of mixing, pressing, and drying of raw materials, in particular fresh wood, magnesium oxide and ammonium polyphosphate. As a result the following specific properties are obtained in a final product: fire safety, hardly any stretching and shrinkage, fully recyclable, no rotting, constructive properties, processable as wood.Raw materialsFresh woodUse is made of the open structure of wood cells, hence fresh wood is used. A reaction may occur with cellulose, hemicellulose or lignin, being present in the fresh wood fibres. It is found that the open structure of wood takes up the minerals provided in the present method which minerals then react. The open structure is mostly determined by the amount of tracheid’s and the size of the tracheid’s in the cell wall of the wood. The thickness of the wood is considered important, about 0.2mm to a maximum of 8mm thickness is found to be suitable range, as the minerals are found to penetrate into the cells. If there is an overdose of liquid, which may be the case so far, ammonia may be created as a residual product. A higher ratio of fibres in the final product may affect a higher degree of ammonia binding.The raw wood is processed into fibres in the basic process. For this purpose, wooden logs of at least 8cm to 30cm are used. These logs are completely stripped of the bark. These debarked logs are then processed in a Laimet chipper which processes the logs into consistent chips of up to 24mm long, 10-20mm wide and l-5mm thick. These chips are then processed into fibres by a turbo rotor where the goal is to retain as much length as possible at maximum thickness. Long thin fibres are preferred as they positively influence strength properties.Magnesium OxideMagnesium oxide is preferably dead-burned (DBM), that is treated at an elevated temperature; for example MgO briquettes pass through a very hot oven (2200°C) which makes them very compact. Such DBM can be obtained from NedMag B.V. in Veendam. Said DBM has a purity of on average 98.5%. Such dead-burned magnesium oxide providesan improved reactivity; not sufficiently burned magnesium oxide may give rise to a too fast reaction which makes the process technically difficult to mix with the current knowledge.In addition, the particle size is found important; in particular relatively small particles can be absorbed into the cells of the wood fibres. This also depends on the size of the tracheid openings in the fibres. In addition, it is found that in the ratio of raw materials for the final product, a higher amount of wood fibres in the product requires smaller particles of magnesium oxide. The current specifications of a preferred embodiment is to use magnesium oxide of which 90% has a size of 30 microns or smaller.The magnesium oxide does not have to be very pure, certainly not food grade. 90% pure is found enough typically. It is important that an amount of other minerals in the magnesium oxide is preferably in the form of oxides (such as calcium oxide and iron oxide), and that as little silica as possible is present in view of carcinogenicity.(Poly)phosphateThe phosphate, in particular Ammonium polyphosphate (APP), is preferably a liquid for a proper application in the process. Important is the share of polyphosphates, preferably of at least 55%-60%. With a higher percentage of polyphosphate the material shows better properties (more stable, stronger and higher fire safety). In addition, there may be a relationship of the phosphate with the number of fibres; the more fibres the more polyphosphates are needed to bind. There is an influence found of viscosity in absorption by the fibre.Other raw materialsThese other raw materials may complete the basic process:- Calcium oxide, improvement in strength properties- Calcium carbonate, better binding with NH4 in the product- Citric acid, [partly] replacing ammonium polyphosphate- Borax, reaction retardant- Other oxides for colouring the material through and through. Such as iron oxides yellow, red, black and mixed making brown, titanium dioxide white. The addition of these oxides affect the reaction and thus the properties of the material.- Latex, increases the malleability of the final product. Material becomes softer in structure and more wood-like. Can be partially used to replace ammonium polyphosphate.The addition of latex improves the ammonia binding in the material.ProcessProduction samplesSamples are made in a cooled environment of minimum 5 degrees Celsius typically to maximum 30 degrees Celsius. Magnesium oxide and ammonium polyphosphate come from a storage at a temperature below 0 degrees Celsius, wood fibre is typically cooled to around 5 degrees Celsius, typically not colder than 0 degrees Celsius. The raw materials are stored under these lower temperature conditions to slow down the exothermic reaction which occurs upon mixing.Mix 175 grams of wood fibre with 60 grams of magnesium oxide and 60 grams of APP, this is mixed well until the powder is visually completely mixed with the fibre. Then 133 grams of liquid, typically water, is added via a nebulizer, from then on the mixture is mixed in 1 minute. The mixture is dosed into a steel mould and pressed under a workshop press with a pressure between 2 and 30 bar (200 and 3,000 kPa). The pressed slab is held in the press for 15 minutes and then dried at 65 degrees Celsius for one hour. Drying at 45 degrees Celsius for 24 hours is also possible. The released moisture and ammonia are disposed of.Tests with samples: ratio of liquid to powder is reduced and as far as possible an amount of fibres is increased.Production pilot line - batch wiseSamples are made in a cooled environment of minimum 5 degrees Celsius to maximum 20 degrees Celsius. Magnesium oxide and ammonium polyphosphate come from storage with temperature below 0 degrees Celsius, wood fibre is cooled around 5 degrees Celsius, not colder than 0 degrees Celsius. The fibres are supplied on a conveyor belt to the mixer, spread out as much as possible and are preferably minimally hooked together. The powder is supplied to the mixer via a feeder. The fibres and powder are introduced into the mixer at the same location. In the mixer, the liquid is dosed and mixed. 2 seconds later, the mixture falls onto a belt that carries the mixture to the press. Under the press, the mixture is pressed under pressure and then dried.- Pressure is as mentioned above- Ratio of raw materials (when mixing is consistent it is only really possible to investigate ratios in relation to properties) may vary as claimed- Addition of alternative raw materials (see other raw materials) may be as claimed- Drying process (long drying with a lower temperature or quick drying with a higher temperature) may be as claimed- Ambient temperature may be as claimedOther factors considered to be less relevant:- Properties of raw materials, as for example: o Different types of woodFibre length / thickness [as long as within the claimed boundaries] o Moisture percentage fibre as claimed o Different particle size powder as claimed o Temperatures and time of burning magnesium oxide, as obtained o Influence of purity of magnesium oxide as described o Influence polyphosphate content as described o Influence APP colour- Temperature of raw materials for mixing (e.g. cooling of powder)- Temperature control of production process (e.g. heated press)Continuous productionSame setup as batch production with own management for processing raw materials.Difference between full continuous and batch production: continuous supply of raw materials, continuous mixing and continuous press. All previous steps in temperature regime. Drying and capture of ammonia depending on the results achieved.Properties final productThese properties are tested for validation.Dimensional stability based on heat and moisture:- At + / - 10% moisture absorption by weight limited dimensional increase therefore hardly any expansion due to temperature and humidity.- Hardly any expansion due to temperature increase.Strength properties have now been reached:- Modulus of Elasticity [MOE] - 50% fibre: >1500 N / mm2typically >5000 N / mm2- Modulus of rupture [MOR] - 2 / 35 N / mm2.Higher strength properties can be achieved after an optimal ratio of raw materials.Fire safety class B, A2 achievable depending on optimization.End product does not rot anymore, due to modification of the wood fibres.Recyclability of the end product:- Technical recycling: grinding of the product a percentage can be used to replace the magnesium oxide.- Biological recycling: grinding of the product so that it can be absorbed by the soil and released as a fertilizer. In case of Beyond Wood, this fertilizer also includes fibre, which may contribute to the soil structure.Processing the end product as building material:- Processable as wood, sawing, screwing, shooting. Depending on the quantity of fibres, it is easier to process (without pre-drilling).- In comparison, when shooting, at corner of a product, wood cracks open, whereas concrete folds open. The present material does not show either of these.- Material is good for gluing.Maintenance:- Material suffers less (e.g. degree of brittleness) due to low stretch / shrinkage.- Low elongation / shrinkage also results in less deterioration of coatings.- No infestation by insects and / or rodents.Experimental resultsThe following tests are performed giving some initial results.- MOR (modulus of rupture): 27.21 N / mm2(60% fibre)- MOE [Young’s]: 2.850 kN / mm2- Fire class: B - required value FIGRA < 120 W / s; measured 12,8 W / s required value THR 600s < 7,5 MJ; EN ISO 1716:2018 = 6,02 MJ / kg SI- required value SMOGRA < 30 m2 / s2; measured 2,59 m2 / s2required value TSP 600s < 50 m2; measured 25,9 m2- Freeze - thaw: according to ASTM-C1186-08

[2016] for a type A Grade II material- Assessment of adhesive system for bonding of cladding panels o Method:14 days curing of adhesive at 23°C and 50% RH7 days soaking in demineralized water at 23°C; 2 hours drying at 23°C3 days storage at -30°C; 2 hours drying at 23 °C3 days storage at 80°C; 2 hours drying at 23°C7 days cataplasma at 70°C and 95% RHWhen carrying out a suited procedure, the material can be glued well- Boiling test.- DMA (dynamic mechanical analysis)o Twinson contains PVC with a Tg of 78.4°C, which causes a clear decrease of the storage modulus o The present plant fibre product (BeyondWood™) contains no thermoplast, consequently no Tg, thus no sharp decrease in stiffness. o It takes up to 98°C for the modulus of Beyond Wood to drop to the same stiffness as Twinson at room temperature- Linear thermal expansion- Surface temperatureIt should be appreciated that for commercial application it may be preferable to use one or more variations of the present system, which would similar be to the ones disclosed in the present application and are within the spirit of the invention.Comparative Example:The example of the invention was repeated albeit that instead of Magnesium Oxide, Dolokal ex Triferto (i.e. dolomite (CaMg(COs)2) comprising 5% magnesium oxide), was used. Samples were made in at room temperature. Dolokal and ammonium polyphosphate came from a storage at room temperature (18 degrees Celsius); wood fibre was also at room temperature.Plant fibre (willow) was mixed with Dolokal and ammonium polyphosphate (APP) in a weight ratio of 33,33% each (total weight 300 grams). The mixture was mixed well until the powder was visually completely mixed with the fibre. Then 100 grams of water, was added via a nebulizer, from then on the mixture was mixed for 1 minute. The mixture was dosed into a steel mould and pressed under a workshop press with a pressure between 2 and 30 bar (200 and 3,000 kPa). The pressed slab was held in the press for ten minutes and then dried at 65 degrees Celsius for one hour. The released moisture and ammonia were disposed of. The resulting panel was divided into two samples (DOL1 and DOL2). The dry samples had the characteristics as mentioned below:Table 1 :Test No Sample Width Thickness Bending Bending Strain @ Bending(mm) (mm) Modulus Strength Peak (%) Strength (N / mm2) @ Peak @ Break (N / mm2) (N / mm2)1 DOL 1 68.24 10.86 395.884 1.217 0.497 0.8532 DOL 2 69.0 9.95 475.297 1.358 0.464 0.951Min 68.24 9.95 395.884 1.217 0.464 0.853Mean 68.62 10.405 435.59 1.287 0.48 0.902Max 69.0 10.86 475.297 1.358 0.497 0.951S.D. 0.537 0.643 56.153 0.099 0.024 0.07BendingStrain @ ModulusTest No Break (N / mm2) (%)1 1.749 395.8842 1.384 475.297Min 1.384 395.884Mean 1.567 435.59Max 1.749 475.297S.D. 0.258 56.153As shown in Table 1, MOR is max. 1,4 N / mm2. These results are significantly worse as compared to a similar sample which comprises MgO (with MOR being >15 N / mm2).It is noted that it was not possible to prepare a product from plant fibre (willow), Dolokal, and APP, comprising a weight percentage of plant fibre in the range according to the invention (i.e. a wt% above 51 wt%). To be able to obtain a product of which the above-mentioned properties could be measured, the amount of 33.3 wt% plant fibre had to be chosen.Furthermore, the sample was soaked in demineralized water at 23 °C for 4 hours. The sample could not be tested on the above-mentioned properties as it had filled up with water and disintegrated upon handling.

Claims

Claims:

1. A plant fibre product, in particular a wood fragment product, comprising(a) 51-95 wt.% plant fibre, in particular 70-95 wt.%, more in particular 80-94 wt.% plant fibre, more in particular 90-93 wt.% plant fibre, and 90-99 vol.% plant fibre, in particular 95-98 vol.% plant fibre, or in particular 52-70 wt.%, more in particular 53-68 wt.% plant fibre, more in particular 55-65 wt.% plant fibre, and 60-80 vol.% plant fibre, in particular 65-75 vol.% plant fibre, wherein the plant fibre comprises 2-32 wt.% lignocellulosic biomass, in particular 5-30 wt.%, wherein the plant fibre comprises 2-40 wt.% water, in particular 4-25 wt.%, more in particular 6-22 wt.%, such as 15-18 wt.%, wherein plant fibre wt.%’s are based on the total weight of the plant fibre, wherein the fibres have a cross section of 0.2-8 mm (using image analysis with QICPIC), in particular 0.3-7 mm, such as 0.5-5 mm,(b) and a remainder plant fibre product part of 5-49 wt.%, the remainder plant fibre product part comprising(bl) 25-75 wt.% magnesium oxide particles, in particular 29-72 wt.%, more in particular 35-55 wt.%,(b2a) 7-30 wt.% phosphate selected from polyphosphate and phosphate, in particular 9-25 wt.%, with the proviso that at least 6 wt.% of the phosphate is polyphosphate, in particular wherein 40-95 wt.% of the phosphate is polyphosphate, wherein phosphate wt.% are based on the polyphosphate / phosphate content, more in particular 55-90 wt.% polyphosphate, and(b2b) 18-45 wt.% water, and wherein the remainder plant fibre product part wt.%’s are based on the total weight of the remainder plant fibre product part.

2. The plant fibre product according to claim 1, comprising1-30 wt.% of an aqueous dispersion, in particular 2-5 wt.%, the dispersion comprising polymer microparticles, the polymer being selected from natural and synthetic rubbers.

3. The plant fibre product according to claim 2, wherein the polymer is selected from natural rubbers, in particular from latex.

4. The plant fibre product according to any of claims 1-3, wherein magnesium oxide particles comprise < 1 wt.% Mg(0H)2, and / or wherein the magnesium oxide particles areobtained by heating to a temperature of > 973 K during a heating period of > 60 minutes, and / or wherein magnesium oxide particles comprise < 2 wt.% Si, in particular < 0.3 wt.% Si, and / or wherein magnesium oxide particles comprise >60 wt.% Mg on a metal :metal basis, in particular > 85 wt.% Mg, more in particular > 90 wt.% Mg, such as > 95 wt.% Mg.

5. The plant fibre product according to any of claims 1-4, wherein the magnesium oxide particles have a mesh size of <200 Mesh (<0.077 mm Sieve size ISO 565: 1990 and ISO 3310-1 :2000), preferably of <325 Mesh (<0.044 mm), more preferably of <500 Mesh (<0.025 mm), in particular wherein >80% of the magnesium oxide particles have such a mesh size, such as >90%.

6. The plant fibre product according to any of claims 1-5, wherein the polyphosphate and phosphate comprise a cation selected from ammonia, sodium, potassium, hydrogen, and combinations thereof, in particular ammonia.

7. The plant fibre product according to any of claims 1-6, wherein the polyphosphate is selected from pyrophosphate (n=2), triphosphate (n=3), tetraphosphate (n=4), pentaphosphate (n=5), hexaphosphate (n=6), heptaphosphate (n=7) and octaphosphate (n=8), such as NP 10-34 or NP 11-37, or NP 12-40. and / or wherein the phosphate is orthophosphate.

8. The plant fibre product according to any of claims 1-7, comprising 0.2-5 wt.% of a boric acid or salt thereof, preferably of tetra boric acid, such as a monovalent salt thereof, such as a sodium salt.

9. The plant fibre product according to any of claims 1-8, comprising 0.1-15 wt.% additives, wherein additives are preferably selected from natural colorants and natural pigments, such as natural oxides, such as metal oxides, from carboxylic acids, such as citric acid, from CaO, and from CaCCh.

10. The plant fibre product according to any of claims 1-9, wherein the plant fibre comprises 1-90 wt.% waste plant material, preferably obtained from wood or vegetables.

11. The plant fibre product according to any of claims 1-10, wherein the lignocellulosic biomass comprises lignin, cellulose, hemicellulose, pectin, xylem tracheid, vessel elements, and cells.

12. The plant fibre product according to any of claims 1-11, wherein the lignocellulosic biomass comprises 5-100% open cells, in particular 10-95% open cells, and / or wherein the lignocellulosic biomass comprises open cells with a cell volume of 10'15-10'12m3.

13. A structural product, in particular selected from a panel, a board, and a composition material, comprising the plant fibre product according to any of claims 1-12, in particular comprising 90-100 wt.% of said plant fibre product, more in particular wherein said structural product has a Modulus of Rupture (MOR) of 2-35 N / mm2, in particular 3-30 N / mm2, and / or wherein the structural product has a density selected from 100-400 g / dm3and 0.5 -1.8 kg / dm3.

14. A laminate product comprising a first structural product (1) according to claim 13, and a second structural product (2) according to claim 13, in particular wherein the first and second structural products have a A between 0.13 W / m2K - 0.35 W / m2K, and in between said first and second structural products a layer of thermal insulation (3), in particular wherein the thermal insulation has a A between 0.03 W / m2K - 0.08 W / m2K, and / or wherein said thermal insulation material comprises the plant fibre product according to any of claims 1-12, and / or wherein the thermal insulation material has a density of 100-400 g / dm3, and / or, wherein the first and second structural products have a density of 0.5-1.8 kg / dm3, in particular wherein the density is given by the formula density=wt.% fibre*-0.014 + 2.04 ±10%.

15. A laminate product according to claim 14, wherein the first structural product has a first thickness of 0.3-2.7 cm, in particular of 0.5-1 cm, and / or wherein the second structural product has a second thickness of 0.3-2.7 cm, in particular of 0.5-1 cm, and / or wherein the thermal insulation layer has a thickness of 3-30 cm, in particular 5-20 cm, such as 7-12 cm, in particular wherein the wt.% plant fibre in the first structural product is higher than the wt.% plant fibre product in the second structural product, more in particular 2-10 wt.% higher.

16. Method of producing a plant fibre product according to any of claims 1-12, comprising providing 51-95 wt.% plant fibre, wherein the plant fibre comprises 2-32 wt.% lignocellulosic biomass, wherein the plant fibre comprises 5-40 wt.% water, wherein the fibres have a cross section of 0.2-8 mm (as measured using QICPIC (ISO 13320)),and a remainder plant fibre product part of 5-49 wt.%, the remainder plant fibre product part comprising25-75 wt.% magnesium oxide particles,7-30 wt.% phosphate selected from polyphosphate and phosphate, with the proviso that at least 6 wt.% of the phosphate is polyphosphate, wherein the phosphate wt.% is based on the polyphosphate / phosphate content, and18-45 wt.% water, and wherein the remainder plant fibre product part wt.%’s are based on the total weight of the remainder plant fibre product part, mixing the plant fibre, the magnesium oxide, phosphate, and water during a mixing time and at a mixing temperature, therewith forming a homogeneous mixture, pressing the homogeneous mixture during a pressing time and pressing temperature under a pressure of 10-10.000 kPa, and drying the product at an elevated temperature of 20-80 °C during a drying time to remove volatile compounds, such as ammonia.

17. The method according to claim 16, wherein the plant fibre comprises 10-100% freshly cut plant fibre selected from wood and vegetables, in particular 90-99% freshly cut plant fibre, more in particular 95-98% freshly cut plant fibre, more in particular wherein freshly cut fibre is selected from plants of the plant families of Fagaceae, such as Quercus, SaHcaceae. such as Populus and Salix, Betulaceae, Rosaceae, Pauwlowniaceae, Poaceae, Cucurbitaceae, and Solanaceae, and from roadside grass.

18. The method according to any of claims 16-17, wherein the plant fibre is obtained from freshly cut trees or bush with a cross-section of a trunk thereof of 1-40 cm, in particular 8- 30 cm, in particular wherein the bark is partly or fully removed therewith obtaining a debarked trunk, more in particular wherein the debarked trunk is processed into fibres with a fibre length of smaller than 20 cm, in particular smaller than 15 cm, in particular smaller than 90 mm, in particular a fibre length of 10-60 mm, more in particular 13-24 mm, a fibre width of < 30 mm, in particular a fibre width of 10-20 mm, and a fibre thickness of < 8 mm, in particular a fibre thickness of 1-5 mm, more in particular wherein a fibre length:fibre thickness ratio is maintained at >6, in particular a ratio of >10. more in particular a ratio of >15, such as byusing a turbo rotor at a rotational speed of >500 rpm with a turbo rotor of size 50 cm diameter.

19. The method according to any of claims 16-18, wherein mixing is performed at a temperature of 0-30 °C.

20. The method according to any of claims 16-19, wherein after mixing the obtained mixture is subjected to a pressure of between 200-8000 kPa, preferably between 500-6000 kPa, more preferably between 750-5000 kPa, in particular during a press time of 3-120 minutes, and / or wherein the product is dried during a drying period of 1-48 hours, in particular a drying period of 10-40 hours, more in particular a drying period of 20-30 hours, such as 24 hours, and / or wherein the product is dried at a temperature of between 5-75 °C, in particular between 10- 40 °C, more in particular between 15-30 °C, such as 20 °C.

21. The method according to any of claims 16-20, wherein after mixing the obtained mixture is subjected to the pressure within 300 seconds, in particular within 30 seconds, such as within 10 seconds.

22. The method according to any of claims 16-21, for producing a thermal insulation material, wherein after mixing the obtained mixture is subjected to a pressure of between 10-4000 kPa, preferably between 500-2000 kPa, more preferably between 700-1000 kPa, in particular during a press time of 3-120 minutes, and / or wherein the product is dried during a drying period of 1-48 hours, in particular a drying period of 10-40 hours, more in particular a drying period of 20-30 hours, such as 24 hours, and / or wherein the product is dried at a temperature of between 5-75 °C, in particular between 10- 40 °C, more in particular between 15-30 °C, such as 20 °C, and / or wherein after mixing the obtained mixture is subjected to the pressure within 300 seconds, in particular within 30 seconds, such as within 10 seconds.

23. Product obtained by a method according to any of claims 16-22, wherein the product comprises at least one characteristic selected from 90-100% recyclable, a thermal extension coefficient of < 0.005 mm / (m*°C), fire safe according to NEN class B or class A2, at least 10 years durable, a density of 0.5-1.8 kg / dm3, in particular wherein the density is given by the formula density=wt.% fibre*-0.014 + 2.04 ±10%, processable as an alternative to wood, a stability of > 200 cycles, in particular >100 cycles (measured using ASTM methodCl 186), a moisture uptake of < 5 wt.%, in particular < 2 wt.%, a modulus of elasticity of >10 kN / mm2, a modulus of rupture of at least 2 N / mm2, in particular at least 3 N / mm2, in particular at least 5 N / mm2, more in particular at least 10 N / mm2, in particular according to NEN-EN 14080 / NEN EN 338, and biodegradability.

24. A method of producing a laminate product comprising a first structural product (1) according to claim 13, a second structural product (2) according to claim 13, and in between said first and second structural products a layer of thermal insulation (3), comprising providing said first and second structural products, placing the structural products at a distance of 5-30 cm from each other, in particular by providing spacers at the sides of the first and second structural products therewith forming an enclosed space, filling the space in between said first and second structural product with thermal insulation material, providing a pressure to the first and second structural products and the thermal insulation material of 2-10 MPa, in particular 4-5 MPa, in particular wherein the insulation material comprises the plant fibre product according to any of claims 1-12, in particular wherein the thermal insulation material has a density of 100-400 g / dm3.

25. The method according to claim 24, wherein the first and second structural products are provided in a press.