Wood-like material from bast fiber plant stalks having reduced binder content, method for producing the same, and use of shive blockers

Abstract

A subject of the invention is a wood-like material comprising a shive blocker closing shive pores, made from essentially longitudinally split strands of bast fiber plants, in particular annual bast fiber plants, with reduced binder content. The invention also relates to a method for producing a wood-like material from essentially longitudinally split strands of bast fiber plants by bonding and pressing them together, wherein, during the production of wood-like material the non- adhesive shive pore blockers are used, and use of thereof, including for the production of wood- like materials.

Description

[0001] WOOD-LIKE MATERIAL FROM BAST FIBER PLANT STALKS HAVING REDUCED BINDER CONTENT, METHOD FOR PRODUCING THE SAME, AND USE OF SHIVE BLOCKERS

[0002] TECHNICAL FIELD

[0003] The invention relates to a wood-like material comprising shive blocker, which seals or closes the shive pores, made from essentially longitudinally split stalks of bast fiber plants, in particular, annual bast fiber plants, having a reduced binder content. The invention further relates to a method for producing a wood-like material from substantially longitudinally split stalks of bast fiber plants by adhesive bonding and compaction them together, wherein shive blockers are used during the production process, the invention additionally relates to the use of shive blockers, including their use in the production of wood-like materials.

[0004] BACKGROUND OF THE INVENTION

[0005] According to known approaches, bast fiber plants, in particular the stalks of annual plants, are processed into wood substitute products using whole, broken, partially opened, or completely split stalks, by adhesively bonding the plant material using a binder, in particular, in the form of various adhesives and resins, optionally in combination with pressing.

[0006] The most suitable raw material to produce wood-like products from processed plant material of bast fiber plants, particularly annual plants, comprises stalks of bast fiber plants that retain their naturally occurring fibers and shives in an essentially intact and undivided form. The visual appearance of the finished product is also important; due to the preservation of fibers and shives in the raw material, the resulting material exhibits a grain pattern resembling natural wood, thereby providing high aesthetic value, and making the material suitable for applications such as furniture manufacturing. An additional advantage of retaining an adequate amount of bast fiber plants that have not been separated from the stalk in the raw material is the ability to produce wood substitute products having a broad range of densities depending on market requirements.

[0007] According to known methods for producing wood-like materials from bast fiber plant stalks as raw material, preferably the annual plants, the binder is typically applied either by soaking the plant material in the binder or by spraying it onto the surface of the raw material. In the case of raw material containing unsplit or partially split stalks, the binder does not sufficiently penetrate the internal structure of the stalks. As a result, the finished wood substitute material exhibits non-uniform density and reduced mechanical strength across its entire surface; this is particularlyimportant in the case of large (structural) elements, which constitutes a disadvantage when such wood-like materials are intended for construction purposes, including the production of skeletal elements for construction applications or for use in furniture and joinery frameworks.

[0008] Known methods of bonding bast fiber plant stalks require substantial amounts of binder, and binder consumption increases further when the stalks are completely split. The reason for the high consumption of binder when bonding partially or fully split stalks is the facilitated penetration of its shives having a naturally porous structure, which readily absorb the binder.

[0009] The physical parameters of pores in hemp shives, including the microstructure of cell walls and their size distribution, are known from the publication by Y, Jiang et al. 2018 [1],

[0010] The shives of bast fiber plants, including hemp, mainly consist of conducting vessels. The vessels are about 100 pm in diameter. The vessels are typically distributed throughout the crosssection of hemp bast shive structure. The microstructure of hemp bast shives exhibits pores having diameters of approximately 50 pm connected to pores of about 10 pm in diameter through connecting pores having diameters of approximately 1 pm. Consequently, the binder must reach all the cell empty spaces in the hemp bast shives, such as the vessels, and the voids within the cell wall.

[0011] Removing part of the shives to reduce the amount of binder consumption results in excessive waste generation and disrupts the natural bonds between the phloem and the shives. In addition, the aesthetic values of finished products made from wood-like materials as a substitute for wood are also significantly impaired, due to the loss of the light-colored surfaces formed by the shives.

[0012] Wood substitute materials having acceptable density and mechanical strength, which are produced according to known methods from the stalks of annual bast fiber plants, generally require adhesive contents of at least approximately 12% by weight to achieve for the raw material adhesively bonded, although adhesive contents substantially above 30% by weight are commonly used. High adhesive binder consumption in wood-like products produced according to known methods is also caused by the necessity to bond large quantities of chipped or partially broken shive particles.

[0013] European patent EP3532671 discloses a method for producing a wood substitute using raw material derived from hemp fiber. Hemp strands, essentially longitudinally arranged, formed from at least partially split hemp stalks, containing an added adhesive, especially glue, are subjected to pressing. This method involves the use of adhesives in quantities resulting in adhesive content level of 5% to 49% by weight in the finished product.

[0014] Chinese patent CN102218758B describes lightweight, high-strength hemp timber and a method for its production. After industrial hemp stalks are shredded into chips, 0.5% to 5 % of adhesive is added, and then lightweight insulation materials are produced by hot pressing. Theseproducts, despite their low level of adhesion and high strength, do not exhibit all the features of a wood substitute. In particular, the physical and mechanical parameters of hemp timber according to this approach, such as static bending strength and bending modulus values, as well as its appearance, are typical of plywood. Materials produced by this method are not suitable for use as wood substitutes, as they do not meet the relevant strength or aesthetic requirements, and furthermore, they do not resemble wood in appearance.

[0015] Due to the characteristics of the binding substances used for adhesive bonding, the raw material intended for the production of wood-like products should have low moisture content, preferably below 10%, and it is therefore subjected to additional drying. However, removing excess moisture is associated with the undesirable phenomenon of drying out the structures of the fibers, wherein the pore system has characteristics like a sponge, as a result of which they shrink during forced drying, creating voids. This process further weakens the mechanical integrity of the wood shives, increases their absorbency, and consequently increases the binder consumption in the production of wood-like materials using conventional methods.

[0016] DISCLOSURE OF THE INVENTION

[0017] In view of the prior art discussed above, the objective of the present invention is to provide an improved wood-like material and improved methods of production the same by using the shive blockers I shive pore blockers in the manufacture of wood-like material; wherein by filling the naturally occurring intercellular pores and other voids in the shive structures of fully or partially split stalks of bast fiber plants, the shive pore blockers allow the production of wood-like material with the reduced binder consumption. At the same time, such wood-like material produced by the production method employing shive pore blockers, despite its very low content and unlike materials known from the state of the art, exhibits high aesthetic value and satisfies the physical, mechanical and strength properties required for its use as a wood substitute. Its production is also more economically advantageous due to the significantly reduced binder consumption. Moreover, the products obtained by this method are more environmentally friendly than those known from the prior art, particularly when the binder used is a natural adhesive, such as a protein-based adhesive or a plant-based adhesive.

[0018] The invention relates to a wood-like material comprising plurality of adhesively bonded strands of bast fiber plant stalks, wherein the essentially completely longitudinally split strands of bast fiber plant stalks, have at least partially filled naturally occurring intercellular pores and remaining voids in the shive structures of the stalk as well as densified shive structures containing a shive blocker in the form of a non-adhesive particulate substance having an mean particle size ranging from 0.01 pm to 70 pm ±10%, wherein the resulting a wood-like material contains a binder in an amount ranging from 1.5 to 4.9% by weight, more preferably in the range of 2-4 % by weight more preferably in the range of 2.5-4% by weight relative to the total weight of the wood-likematerial, and moreover amount of substantially completely longitudinally split strands of bast fiber plant stalks is more than 60% by weight, more preferably more than 70% by weight, preferably more than 80%, more preferably more than 90% by weight, of the wood-like material, wherein the wood-like material has a substantially uniform density in the range of 300 kg / m3to 1250 kg / m3; and wherein the wood-like material is suitable for use as a wood substitute in terms of appearance and technical properties.

[0019] Preferably, in a wood-like material according to the invention, the shive blocker is a substance capable of swelling upon exposure to moisture and / or temperature, wherein substance capable of swelling upon exposure to moisture is preferably selected from starch, cellulose, carboxymethylcellulose, protein, collagen, a polymer (e.g., polyacrylamide); or mixtures thereof, while the substance capable of swelling upon exposure to temperature is preferably selected from polypropylene (PP), acrylic, poly(methyl methacrylate) (PMMA); or a mixture thereof.

[0020] Preferably, in a wood-like material according to the invention, a shive blocker is a substance capable of naturally binding to the lignins within the shive structures in effect of pressure and / or moisture, and / or temperature, preferably such substances are selected from cellulose, hemicellulose, and mixtures thereof.

[0021] Preferably, in a wood-like material according to the invention, the shive blocker is a substance comprising mechanically processed fragments of bast fiber plants, preferably meal made from ground parts of shives, preferably meal made from shives from flax, hemp, or a mixture thereof. Preferably, in the wood-like material, the binder is selected from adhesive substances, preferably including resin, adhesive, protein-based adhesive, polyvinyl adhesive, polyurethane, epoxy resin, melamine-urea-formaldehyde resin, polyacrylate, cyanoacrylate, polyethylene, polypropylene, natural rubber, or silicone.

[0022] Preferably, in the preferred wood-like material according to the invention, in the essentially completely longitudinally split strands of the stalks of bast fiber plants, more than 50 % of the intercellular pores in the shives layer are sealed, more preferably more than 60%, 70%, 80%, 90%.

[0023] Preferably, in wood-like material according to the invention, the bast fiber plants are annual plants. Preferably, in wood-like material according to the invention, the bast fiber plants is selected from flax, hemp, rice, bamboo, ramie, kenaf, white jute, Jerusalem artichoke, rapeseed, corn, miscanthus or mixtures thereof, preferably flax, hemp, more preferably Cannabis sativa.

[0024] The invention further relates to a method for producing a wood-like material from essentially completely longitudinally split strands of bast fiber plant stalks that are bonded adhesively, wherein said method comprises step b), wherein shive blocker in the form of a nonadhesive substance is introduced on the essentially completely longitudinally split strands of bastfiber plant stalks with naturally occurring intercellular pores and remaining voids in the shive structures of the split stalks, wherein said shive blocker fills between 1% and 90% of the naturally occurring intercellular pores and other voids in the shive structures of the split stalks, wherein the shive blocker has a mean particle size in the range of 0.01-70 pm ±10%, wherein a shive blocker is introduced by pouring, spraying, applying, coating, preferably in combination with applying increased pressure during pouring, spraying, applying, coating; preferably in combination with pressing; preferably in combination with heating; preferably in combination with addition of steam; preferably in combination with the addition of liquid substances that are not a binder (e.g. water, organic solvent, inorganic solvent); and then the step c), in which binder is added in an amount of 0.1% by weight up to 4.9% by weight with relative to the final wood-like material, the resulting material is then compacted, in order to form the final wood-like material.

[0025] In a preferred embodiment, the method for the production of the wood-like material from bast fiber plant stalks, comprises a step a) carried out before step b), wherein in step a) the fiber plant stalk bands are completely longitudinally split strands, whereby the preferred complete splitting is carried out by cutting the fiber plant stalks between a set of cutting rollers. In the preferred embodiment, in step c) of the method for producing wood-like material from the stalks of bast fiber plants, the compaction is carried out by pressing, preferably by pressing in a hydraulic press, preferably by pressing in a hydraulic press with 1-30 cycles of pressure with a force in the range from 50kN to 20000kN, preferably in the range from 100kN to 15000kN, most preferably in the range of 100kN to 8000kN.

[0026] In a preferred method for the production of the wood-like material from bast fiber plant stalks according to the invention the shive blocker substance has a mean particle size in the range of 1-50 pm ±10%, more preferably 40 pm ±10%.

[0027] In a preferred method for the production of the wood-like material with a shive blocker is a substance capable of swelling upon exposure to moisture and / or temperature, wherein substance capable of swelling upon exposure to moisture is preferably selected from starch, cellulose, carboxymethyl cellulose, protein, collagen, polymer (e.g. polyacrylamide); or mixtures thereof, a substance capable of swelling upon exposure to temperature is preferably selected from polypropylene (PP), acrylic, poly(methyl methacrylate) (PMMA); or mixtures thereof.

[0028] In a preferred method for the production of the wood-like material a shive blocker is a substance containing particles that naturally bind to the lignins of the shive structures upon exposure to pressure, or moisture, or temperature, preferably selected from cellulose and hemicellulose, or mixtures thereof.

[0029] In a preferred method for the production of the wood-like material the shive blocker is a substance comprising mechanically processed fragments of bast fiber plants, preferably meal made from ground parts of shives, preferably meal made from shives from flax, hemp, or mixtures thereof.In a preferred method for the production of the wood-like material after the introduction of the shive blocker, the binder is added in an amount of 0.1 % by weight to 4.9% by weight with respect to the final weight of the wood-like material, and then the shape of the wood-like material is formed by compaction of the material, preferably by pressing.

[0030] In a preferred method for the production of the wood-like material, the bast fiber plants are annual plants.

[0031] In a preferred method for the production of the wood-like material, the bast fiber plants are selected from flax, hemp, rice, bamboo, ramie, kenaf, white jute, Jerusalem artichoke, rapeseed, corn, miscanthus, preferably flax, hemp, more preferably Cannabis sativa.

[0032] In a preferred method for the production of the wood-like material bast fiber plants are comprised in at least 60% by weight of the final wood-like material, and wherein the binder represent up to 4.9% by weight of the final wood-like material, wherein the wood-like material has a substantially uniform density in the range of 300 kg / m3to 1250 kg / m3, and wherein the wood-like material is suitable for use as a wood substitute in terms of appearance and technical properties.

[0033] The invention also relates to the wood-like material from bast fiber plant stalks obtained with the method for the production of the wood-like material according to the invention.

[0034] The invention also concerns a use of a shive blocker for the production of the reduced binder content wood-like material from essentially completely longitudinally split strands of bast fiber plant stalks bonded adhesively, wherein a shive blocker is a non-adhesive substance having an mean particle size in the range of 0.01-70 pm ± 10%, more preferably in the range of 1-50 pm ± 10%, even more preferably in the range of 40 pm ± 10%.

[0035] In a preferred use of shive blocker for the production of the reduced binder content wood-like material a blocker is a substance capable of swelling upon exposure to moisture and / or temperature, wherein substance capable of swelling upon exposure to moisture is preferably selected from starch, cellulose, carboxymethyl cellulose, protein, collagen, polymer, polyacrylamide; or mixtures thereof, while substance capable of swelling upon exposure to temperature is preferably selected from polypropylene (PP), acrylic, poly(methyl methacrylate) (PM MA); or mixtures thereof.

[0036] In a preferred use of shive blocker for the production of the reduced binder content wood-like material, a blocker is a substance capable of naturally binding to the lignins within the shive structures in effect of pressure and / or moisture and / or temperature, preferably selected from cellulose, hemicellulose, or mixtures thereof.

[0037] In a preferred use of shive blocker for the production of the reduced binder content wood-like material a blocker is a substance that is mechanically processed fragments of bast fiber plants,preferably meal made from ground parts of shives, preferably meal made from shives from flax, hemp, or mixtures thereof.

[0038] In a preferred use of shive blocker for the production of the reduced binder content wood-like material, the plants are annual plants.

[0039] In a preferred use of shive blocker for the production of the reduced binder content wood-like material, bast fiber plants are selected from flax, hemp, rice, bamboo, ramie, kenaf, white jute, Jerusalem artichoke, rapeseed, corn, miscanthus or mixtures thereof, preferably flax, hemp, more preferably Cannabis sativa.

[0040] The invention also relates to the use of shive blocker to reduce the amount of binder in the wood-like material from bast fiber plants, wherein a shive blocker is a non-adhesive substance having an mean particle size in the range of 0.01-70 pm ± 10%, more preferably in the range of 1-50 pm ±10%, more preferably in the range of 40 pm ±10%.

[0041] In a preferred use of shive blocker to reduce the amount of binder in the wood-like material from bast fiber plant stalks a blocker is a substance capable of swelling upon exposure to moisture and / or temperature, wherein substance capable of swelling upon exposure to moisture is preferably selected from starch, cellulose, carboxymethyl cellulose, protein, collagen, polymer, polyacrylamide; or mixtures thereof, while substance capable of swelling upon exposure to temperature is preferably selected from polypropylene (PP), acrylic, poly(methyl methacrylate) (PM MA); or mixtures thereof.

[0042] In a preferred use of shive blocker to reduce the amount of binder in the wood-like material from bast fiber plant stalks a blocker is a substance capable of naturally binding to the lignins within the shive structures in effect of pressure and / or moisture and / or temperature, preferably selected from cellulose, hemicellulose, or mixtures thereof.

[0043] In a preferred use of shive blocker to reduce the amount of binder in the wood-like material from bast fiber plant stalks a blocker is a substance that is mechanically processed fragments of bast fiber plants, preferably meal made from ground parts of shives, preferably meal made from shives from flax, hemp, or mixtures thereof.

[0044] In a preferred use of shive blocker to reduce the amount of binder in the wood-like material from bast fiber plant stalks the plants are annual plants.

[0045] In a preferred use of shive blocker to reduce the amount of binder in the wood-like material from bast fiber plant stalks bast fiber plants are selected from flax, hemp, rice, bamboo, ramie, kenaf, white jute, Jerusalem artichoke, rapeseed, corn, miscanthus or mixtures thereof, preferably flax, hemp, more preferably Cannabis sativa.

[0046] A wood-like material according to the invention produced from the split stalks of bast fiber plant by their adhesion bonding and compaction, preferably by pressing, having from 1% to 90%,preferably from 30 to 90%, preferably from 80-90% of naturally occurring intercellular pores and other voids in the shive structures of the stalk filled with non-adhesive particles that are blockers of these spaces (hereinafter also referred to as blockers of the shive pores, shive blockers or simply blockers), which causes the binder to be retained essentially on the surface of the split stalks. Due to the limitation of the penetration of binder into the interior of the shive structures, the binder consumption for the production of wood-like material is much lower. The content of binder (bonding) in the final wood-like material according to the invention ranges from 0.1% by weight to 4.9% by weight, or, preferably from 0.5% by weight up to 4,5 % by weight, from 1 % by weight up to 4 % by weight, from 1 % by weight up to 3% by weight, from 2% by weight up to 4% by weight, preferably from 3% by weight up to 4% by weight, preferably <4.5% by weight.

[0047] Using the method according to the invention, a wood-like material is produced from raw material in the form of essentially longitudinally split stalks of bast fiber plants, clogging from 1% to 90% of naturally occurring intercellular pores and other voids in the structures of split stalks, by introducing particles of a non-adhesive substance, i.e., shive blockers with mean particle size in the range of 0.01 pm ± 10%, preferably 1-50 pm ± 10%, preferably 40 pm ± 10%, whereby shive blockers are introduced by pouring, spraying, applying, coating spraying, applying, coating, preferably in combination with applying increased pressure during pouring, spraying, applying, coating; preferably in combination with pressing; preferably in combination with heating; preferably in combination with addition of steam; preferably in combination with the addition of liquid substances that are not a binder, whereby after the introduction of blockers, binders are then added in an amount of 0.1% by weight to 4.9% by weight with respect to the final weight of the wood-like material, and then the shape of the wood-like material by its compaction, preferably by pressing.

[0048] Shive blockers, due to their size or the properties of the constituent substance, fill naturally occurring intercellular pores and other voids within the structure of the shives of the raw material, which essentially consist of longitudinally split strands of bast-fiber plant stalks.

[0049] Preferably, the blockers of naturally occurring intercellular pores and fillers of remaining voids in the structures of the shive raw materials are substances capable of swelling upon exposure to moisture and / or temperature.

[0050] Examples of shive blockers that are substances capable of swelling upon exposure to moisture are starch, cellulose, proteins (e.g., collagen), or some polymers (e.g., polyacrylamide). The molecules of these substances swell because they bind water in result of hydrogen interactions. Examples of substances that swell under the influence of temperature are polypropylene (PP) and acrylic (PMMA, polymethyl methacrylate).

[0051] The particle sizes of the given illustrative substances depend on the specific structure and molar mass, and therefore indicative values are given for typical cases. In case of starch, amylose and amylopectin molecules form granules of 1-100 pm in size, but the individual chains aresmaller, on the nanometer order (approx. 0.001-0.01 pm). Cellulose microfibrils have a diameter of 0.01-01 pm, but the length can reach several micrometers. Regarding the protein, for example, collagen in the form of a triple helix has a length of approx. 0.3 pm and a diameter of approx.

[0052] 0.0015 pm. An exemplary polymer, such as polyacrylamide, contains molecules whose size depends on the molecular weight and the solvent used. In the dry state, its molecules may measure several nanometers, while after swelling they form gels with micrometer- scale structures (0.1-10 pm). In the case of polypropylene in micronized forms (e.g., for coating or blending applications), the particle size may range from 10 to 100 pm, depending on the grinding process and intended use. Acrylic particles used in applications such as injection molding typically have particle sizes ranging from 20 to 150 pm, although in specific applications (e.g., nanotechnology) they may be smaller, even below 1 pm.

[0053] Preferably, the blockers of naturally occurring intercellular pores and the filler of the remaining voids in the shive structures of the raw material are substances containing particles that are naturally bound to the lignins of the shive structures upon exposure to pressure, or moisture, or temperature.

[0054] Examples of shive blockers that are substances containing particles that naturally bind to the lignins of shive structures upon exposure to pressure or moisture or temperature are cellulose and hemicellulose. In effect of moisture and temperature, hemicellulose can partially decompose or reorganize, which facilitates interactions with lignin. Mechanical pressure (e.g., when pressing stalks) can further tighten these bonds by physically bringing the particles closer together.

[0055] Preferably, blockers of naturally occurring intercellular pores and fillers of remaining voids in the shies structures of the raw material are substances that are mechanically processed fragments of fibrous annual plants.

[0056] Examples of shive blockers, which are substances that are mechanically processed fragments of fibrous annual plants, are meals made from ground parts of flax or hemp shives, the use of which as blockers is essentially justified by the presence of pectins, which are polysaccharides naturally occurring in cell walls, especially in the spaces between fibers and shive tissues. Moisture and temperature can cause pectins to swell, which facilitates their interaction with lignins, and in addition, under certain conditions (e.g., pressure drying) they can form hydrogen bonds with lignins.

[0057] By enriching the raw material with particles of shive blocking substances, not only the naturally occurring intercellular pores within the shive structures are sealed, but also the free spaces formed as a result of pore structure shrinkage during the drying / further drying of the raw material prior to the addition of the binder are filled.

[0058] The use of substances with the natural properties of swelling of particles under the influence of moisture or temperature, where closing of intercellular pores in the raw material ofmore than 90% has been achieved, has proven to be particularly effective. The blocker particles are generally smaller than the diameter of the intercellular pores and, reaching their voids in the shives structure, then expand, causing the pores and voids of the shives to seal.

[0059] In case of the shive blockers, the particles of which belong to substances that naturally combine with water, the additional effect of binding moisture trapped in the structure of the shives was achieved.

[0060] The effectiveness of the solution according to the invention is shown by the level of bonding obtained in the wood-like material, measured in % by weight in the finished produced material, in the range from 0.1% to 4.9%, and therefore significantly lower than in the known solutions for the production of wood substitutes from unfragmented stalks of bast fiber plants, in particular from strands of stalks of bast fiber plants, which are essentially longitudinally split strands of bast fiber plant stalks.

[0061] The effectiveness of the solution for wood-like materials was tested at the Research and Development Centre of the Wood-Based Panel Industry in Czarna Woda (Poland) on samples having the density in the range from 300 kg / m3to 1250 kg / m3, i.e. typical for wood widely and most commonly used in industry as a raw material. The conducted studies demonstrated the effective action as intercellular pore blockers in the bast fiber plant shives, of the following substances: hemp meal, flax meal, corn starch, plant polysaccharides: guar gum, calcium alginate, and semi-synthetic cellulose derivatives: carboxymethylcellulose (CMC), hydroxypropyl methyl cellulose (HPMC) and hydroxypropyl cellulose (HPC).

[0062] When shives meal is used as a blocker, it is usually used, for practical reasons, of the same plant species and having an average particle diameter in the range of 10-30 pm ± 10%, preferably in the range of 20 pm ± 10%. This is due to practical reasons, as it allows for the full management of the generated shives waste, which allows for the return of waste material in theory after appropriate shredding as an important part of the structure of wood-like material produced with the use of such a blocker. However, it is possible to use shives of another plant species or shives meal, which is a mixture obtained from shives of different plant species.

[0063] Unexpectedly, it turned out that by closing the intercellular pores of the shive structures with a blocker before adding the binder to the raw material, especially in case of the raw material in the form of strands of bast fiber plant stalks constituting essentially longitudinally split strands of bast fiber plant stalks, it is possible to produce wood-like products with a significantly limited amount of binder that binds by adhesion the strands of essentially split stalks of bast fiber plant into wood-like products. As a result, the level of bonding in finished wood-like products is well below 5%, while achieving their homogeneous density and mechanical strength, as well as an attractive appearance resembling wood for the recipient.The wood-like products, according to the invention, show improved properties in relation to products known on the market produced by known methods. These products have a more homogeneous density, have higher mechanical strength than products produced by known methods, are cheaper to produce due to the much lower use of binder for the production of wood substitute, and have an attractive appearance that reflects the appearance of the structure of real wood, which makes such products attractive to consumers. As products with a low adhesive content, wood-like products are perceived by invention as more natural and environmentally friendly.

[0064] DETAILED DESCRIPTION OF THE INVENTION

[0065] The publications cited in the description and the references therein are hereby incorporated in their entirety as references. The following examples illustrate the invention without limiting it in any way.

[0066] BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0067] Illustrative embodiments of the invention are presented in the drawing figures, in which:

[0068] Fig.1 shows a fragment of the structure of the natural intercellular pores of hemp stalk shives, imaged with an optical microscope, at x45 magnification; A - fragment of the structure of the natural intercellular pores of hemp stalk shives; B - fragment of the structure of the natural intercellular pores of hemp stalk shives after filling the pores with hemp meal.

[0069] Fig.2 shows a sample of wood-like material (Mt1) made from hemp as raw material and hemp meal as a blocker - in a wide plane view.

[0070] Fig.3 shows a sample of wood-like material (Mt2) made of common flax as raw material and flax meal as a blocker - in a wide plane view.

[0071] Fig.4 shows a fragment of the structure of the natural intercellular pores of hemp stalk shives imaged with an optical microscope, at x45 magnification; A - a fragment of the structure of the natural intercellular pores of hemp stalk shives; B - a fragment of the structure of the natural intercellular pores of hemp stalk shives after filling the CMC pores.

[0072] Fig.5 shows a wood-like material made from different species of bast fiber plant stalks: hemp and flax, with the use of corn starch as a blocker.

[0073] Fig.6 shows a wood-like material in the form of a beam made of A - hemp with the use of hemp meal as a blocker; B - common flax with the use of CMC as a blocker.

[0074] METHODS OF IMPLEMENTING THE INVENTION

[0075] The following examples are provided solely for the purpose of illustrating the invention and explaining its various aspects, and are not intended to limit the scope of the invention, and should not be considered as representing its entire scope, which is defined in the attached claims.EXAMPLES

[0076] The described experimental examples were made in the Research and Development Center of The True Green S.A. in Turka near Lublin (Poland), where wood-like materials were produced by the method according to the invention described in detail below.

[0077] Using the known method, the raw material was prepared in the form of essentially longitudinally split and essentially unbroken transversely stalks of bast fiber plants selected from: hemp Cannabis sativa var. Sativa and common flax Linum usitatissimum. In addition, a mixed raw material was tested, in the form of longitudinally split stalks derived from various species of bast fiber plants selected from: flax, hemp, rice, bamboo, ramie, kenaf, white jute, Jerusalem artichoke, rapeseed, corn, miscanthus and sorghum. Longitudinal splitting of the stalks was carried out with the use of cutting knives, a set of cutting rollers and other known methods of longitudinal cutting of the stalk of a bast fiber plant.

[0078] After measuring the appropriate amount, the raw material with a measured moisture content of 8% to 17%, respectively, was then enriched by adding a measured amount of blockers selected from: hemp meal, flax meal, corn starch, vegetable polysaccharides: guar gum, calcium alginate and semi-synthetic cellulose derivatives: carboxymethylcellulose (CMC), hydroxypropyl methyl cellulose (HPMC) and hydroxypropyl cellulose (HPC), by pouring them, preferably by pouring with the use of pressure airflow, preferably in combination with pressing, preferably in combination with heating, preferably in combination with addition of steam, preferably in combination with the addition of liquid substances that are not a binder, and then, when formed, subjected to pressing.

[0079] The produced samples of the wood-like hemp material were tested at the Research and Development Centre of the Wood-Based Panel Industry in Czarna Woda (Poland), while the tests of samples of wood-like material from common flax were carried out at the Research and Development Centre of The True Green S.A. in Turka near Lublin (Poland).

[0080] In the working examples of a wood-like material according to the invention presented below, produced samples with an assumed density of the finished material of 750 kg / m3were shown, but samples with other assumed densities in the range from 300 kg / m3to 1250 kg / m3were also tested. Individual samples differed in the type and quantity of the substance used as an intercellular pore blocker, measured by weight as a percentage of the raw material before it was pressed and the amount of added binder, measured by weight as a percentage of the raw material before the raw material was pressed, respectively, making samples of 2% added binder by weight, then 3% added binder by weight, then 4% added binder by weight, then 4.5% added binder by weight.

[0081]

[0082] 1- A wood-like material made from stalks of bast fiber plants with use of shive meal as a shive blocker1.1. Hemp as raw material and hemp meal as a shive blocker

[0083] A sample of wood-like material was produced from hemp stalks (Cannabis sativa var. Sativa) in the amount of 6 kg, in the form of completely split longitudinal strands, essentially unbroken transversely, with a length of between 70 cm and 80 cm, obtained by splitting them between a set of incision rollers, with a moisture content of 11,5%, on which a natural intercellular pore blocker and a filler of the remaining voids in the shives structure in the form of hemp meal crushed to an average particle diameter of 20 pm ± 10% were applied by spraying at a pressure of 3 bar, in the amount of 65 g. The collected samples of raw material in the form of bands before and after the introduction of the shive blockers were subjected to microscopic analysis, which showed that the closure of naturally occurring intercellular pores and the remaining voids of the split stalks of the raw material was closed in 60%. Fig.1 shows images obtained with an optical microscope, A - a fragment of the structure of the natural intercellular pores of hemp stalk shives B - a fragment of the structure of the natural intercellular pores of the hemp stalks after filling the pores with hemp meal. Protein adhesive was applied to the raw material prepared with such method by spraying with protein adhesive as a binder in the amount of 283 g.

[0084] As a result, the raw material was prepared according to the ratio: split hemp stalks 94,5%, blocker 1%, binder 4,5%, which was then formed into a cuboid with dimensions: 135 mm x 800 mm x 120 mm, then it was pressed in a hydraulic press in 7 clamping cycles with a force ranging from 100kN to 8000kN. Depending on the need it is possible to use press in the range from 50kN to 20000kN, preferably in the range from 100kN to 15000kN.

[0085] A finished wood-like beam-shaped material with dimensions of 135 mm x 800 mm x 98 mm, having weight 6.3 kg, with 60% closed natural intercellular pores and shives voids was obtained. A sample of the material was collected from the beam produced using this method, and then subjected to basic measurements, including a general density test, the results of measurements are presented in Tab. 1.

[0086] Tab. 1 - Results of the test on the total density on a sample from wood-like material produced from the stalks of Cannabis sativa var. Sativa using hemp shive meal as a blocker. _

[0087] SAMPLE REFERENCE Mt1

[0088] THICKNESS [mm] 29.85

[0089] LENGTH [mm] 220.24

[0090] WIDTH [mm] 135.08

[0091] WEIGHT [g] 678.16

[0092] AVERAGE SAMPLE THICKNESS [mm] 29.85

[0093] SURFACE WEIGHT [kg / m2] 22.80

[0094] DENSITY 764

[0095]

[0096] Further samples were collected from the produced beam of wood-like material and subjected to a local density test, the results of which are presented in Tab. 2.

[0097] Tab. 2 - Results of the local density test on samples from wood-like material produced from the stalks of Cannabis sativa var. Sativa using hemp shive meal as a blocker. _

[0098] SAMPLE Mt1 Mt1.1 Mt1.2 Mt1.3 Mt1.4 Mt1.5 Mt1.6 MEAN NUMBER THICKNESS [mm] 29.85 29.11 29.09 29.38 29.19 29.31 29.35 29.24 LENGTH [mm] 220.24 60.56 60.32 60.21 60.45 60.32 60.19 60.34 WIDTH [mm] 135.08 60.45 60.28 60.45 60.58 60.47 60.51 60.46 WEIGHT [g] 678.16 79.79 78.26 81.17 80.30 83.04 84.20 81.12 AVERAGE 29.85 29.11 29.09 29.38 29.19 29.31 29.35 29.24 SAMPLE THICKNESS [mm]

[0099] SURFACE 22.80 21.80 21.52 22.30 21.93 22.77 23.12 22.24 WEIGHT [kg / m2]

[0100]

[0101] DENSITY [kg / m3] 764 749 740 759 751 777 788 761

[0102] The conducted tests confirmed that the samples produced using hemp meal as a shive blocker show the feature of uniform density distribution throughout the entire sample crosssection. The sample of the wood-like material produced in this example in the wide plane view is shown in Fig. 2.

[0103] 1.2. Common flax as raw material and flax meal as the shive blocker

[0104] A sample of wood-like material was produced from common flax stalks (Linum usitatissimum) in the amount of 8 kg, in the form of completely split longitudinal strands, essentially unbroken transversely, obtained by splitting them between a set of cutting rollers, with a moisture content of 13%, on which a natural intercellular pore blocker and a filler of the remaining voids in the shives structure in the form of flax meal crushed to an average particle diameter of 10 pm ± 10% were applied by spraying at a pressure of 5 bar, in the amount of 83 g.

[0105] Protein adhesive in the amount of 250 g was applied to the raw material prepared with such method by spraying.

[0106] As a result, the raw material was prepared according to the ratio: split hemp stalks 96%, blocker 1%, binder 3%, which was then formed into a cuboid with dimensions: 135 mm x 800 mm x 120 mm, after which it was pressed in a hydraulic press in 7 clamping cycles with a force ranging from 100 kN to 8000 kN

[0107] A finished wood-like beam-shaped material with dimensions of 135 mm x 800 mm x 98 mm, weight of 8.33 kg, with 75% closed natural intercellular pores and shive voids was obtained.A sample of the material was collected from the beam produced in this way and then subjected to basic size and weight measurements and a general density test, the results of which are presented in Tab. 3.

[0108] Tab. 3 - Results of the study of the total density of a sample of wood-like material made from common flax stalks with the use of flax stalk meal as a blocker.

[0109] SAMPLE REFERENCE Mt2

[0110] THICKNESS [mm] 30.11

[0111] LENGTH [mm] 220.15

[0112] WIDTH [mm] 135.28

[0113] WEIGHT [g] 672.04

[0114] AVERAGE SAMPLE THICKNESS [mm] 30.11

[0115] SURFACE WEIGHT [kg / m2] 22.57

[0116] DENSITY [kg / m3] 749

[0117]

[0118] Further samples were collected from the produced beam of wood-like material and subjected to a local density test, the results of which are presented in Tab. 4.

[0119] Tab.4 - Results of local density testing of samples of wood-like material produced from the stalks of common flax Linum usitatissimum with the use of flax meal as a blocker

[0120] SAMPLE Mt2 Mt2.1 Mt2.2 Mt2.3 Mt2.4 Mt2.5 Mt2.6 MEAN NUMBER THICKNESS [mm] 30.11 30.12 30.09 30.08 30.10 30.15 30.08 30.10 LENGTH [mm] 220.15 60.521 60.325 60.232 60.41 60.50 60.55 60.347 WIDTH [mm] 135.28 60.41 60.49 60.34 60.38 60.35 60.25 60.37 WEIGHT [g] 672.04 81.01 84.268 84.29 83.47 78.61 79.41 81.85 AVERAGE 30.11 30.12 30.09 30.08 30.10 30.15 30.08 30.10 SAMPLE THICKNESS [mm]

[0121] SURFACE 22.57 22.27 23.12 23.16 22.88 21.53 21.77 22.46 WEIGHT [kg / m2]

[0122] DENSITY [kg / m3] 749 739 768 770 760 714 724 746

[0123]

[0124] The tests conducted confirmed that the samples produced with the use of flax meal as a shive blocker show features of uniform density distribution throughout the entire sample crosssection. The wood-like material sample produced in this example in the wide plane view is shown in the Fig. 3.

[0125] Example 2 - A wood-like material made from stalks of bast fiber plants with use of carboxymethylcellulose (CMC) as a blocker of natural intercellular pores and filler of the remaining voids in the structure of shives2.1. Cannabis sativa var. Sativa and CMC as the shive blocker

[0126] A sample of the wood-like material produced consisted of hemp stalks (Cannabis sativa var. Sativa) in the amount of 6 kg, completely longitudinally split strands, essentially unbroken transversely, obtained by cutting them between a set of cutting rollers, with a moisture content of 16%, on which a natural intercellular pore blocker and a filler of the remaining voids in the shives structure in the form of carboxymethyl cellulose (CMC) powder of low viscosity LV, with an average particle diameter of 15 pm ± 10%, in the amount of 37 g were applied. The collected samples of raw material in the form of bands before and after the introduction of the shive blockers were subjected to microscopic analysis, which showed that the naturally occurring intercellular pores and the remaining voids of the split stalks of the raw material were closed in 90%. Fig. 4 show imaged with an optical microscope, at x45 magnification A - a fragment of the structure of the natural intercellular pores of hemp stalk shives B - a fragment of the structure of the natural intercellular pores of the shives of cannabis stalks after filling the pores with CMC.

[0127] Protein adhesive in the amount of 123 g was applied to the raw material prepared with such method by spraying.

[0128] As a result, the raw material was prepared according to the ratio: split hemp stalks 97.4%, blocker 0.6%, binder 2%, which was then formed into a cuboid with dimensions: 135 mm x 800 mm x 120 mm, after which it was pressed in a hydraulic press in 7 clamping cycles with a force ranging from 100kN to 8000kN.

[0129] A finished wood-like beam-shaped material with dimensions of 135 mm x 800 mm x 98 mm, weight of 6.1 kg, with 90% closed natural intercellular pores and hollow shive voids was obtained.

[0130] 2.2. Common flax and CMC as the shive blockers

[0131] The produced sample of the wood-like material consisted of flax (Linum usitatissimum) stalks in the amount of 10 kg, split completely longitudinally, essentially unbroken transversely, obtained by cutting them between a set of cutting rollers, with a moisture content of 17%, on which a natural intercellular pore blocker and a filler of the remaining voids in the shives structure were applied in the form of low viscosity LV carboxymethyl cellulose powder, with an average particle diameter of 15 pm ± 10%, in the amount of 52 g.

[0132] Protein adhesive was applied to the raw material prepared with such method by spraying with protein adhesive as a binder in the amount of 417 g.

[0133] As a result, the raw material was prepared according to the ratio: split hemp stalks 95.5%, blocker 0.5%, binder 4%, where said raw material was then formed into a cuboid with dimensions: 135 mm x 800 mm x 120 mm, after which it was pressed in a hydraulic press in 7 clamping cycles with a force in the range of 100 kN to 8000 kN.A finished wood-like beam-shaped material with dimensions of 135 mm x 800 mm x 98 mm, weight of 10.04 kg, with 85% closed natural intercellular pores and shive voids was obtained.

[0134] Example 3 - Wood-like material made from different species of stalks of bast fiber plants using corn starch as a blocker of natural intercellular pores and filler of the remaining voids in the structure of shives

[0135] The prepared sample of the wood-like material consisted of flax stalks (Linum usitatissimuni) in the amount of 4,5 kg and hemp stalks (Cannabis sativa var. Sativa) in the amount of 5,5 kg, split completely lengthwise, essentially unbroken transversely, obtained by cutting the stalks between a set of cutting rollers, with a moisture content of 15%, on which a natural intercellular pore blocker and a filler of the remaining voids in the shives structure, in the form of corn starch, having an average particle diameter of 10 pm ± 10%, in the amount of 210 g, were applied by spraying at a pressure of 3 bar. The microscopic analysis of collected sample of the raw material in the form of strips was conducted before and after the introduction of the shive blocker; the analysis showed the closure of naturally occurring intercellular pores and remaining voids of split cannabis stalks in 85% and flax stalks in 70%.

[0136] Protein adhesive was applied to the raw material prepared with such method by spraying with protein adhesive as a binder in the amount of 280g.

[0137] As a result, the raw material was prepared according to the ratio: split stalks of hemp and flax 95.3%, blocker 2%, binder 2.7%, which was then formed into a cuboid with dimensions: 135 mm x 800 mm x 120 mm, after which it was pressed in a hydraulic press in 7 clamping cycles with a force ranging from 100 kN to 8000 kN.

[0138] A finished wood-like beam-shaped material with dimensions of 135 mm x 800 mm x 98 mm, with weight of 10.04 kg, having an average of 77.5% closed natural intercellular pores and shive voids.

[0139] A sample of the wood-like material in this embodiment example is shown in Fig. 5. Example 4 - A method for producing a wood-like material using hemp meal as a intercellular shive pore blocker

[0140] As a raw material, strands formed from completely split hemp stalks of hemp Cannabis sativa var. Sativa with a length of 120 cm to 160 cm, a diameter of 20 mm to 25 mm were used. The moisture content of the raw material measured using the Tanel WPS-2 moisture meter was 14%.

[0141] The hemp strands in a measured amount of 20 kg were laid out on a table with a steel mesh top with a mesh size of 4 cm x 4 cm, essentially with the shives side facing up. Using a hand-held gun for sandblasting materials and an air pressure of 3 bar, hemp meal with a grain size of 10 pm ± 10% to 10 pm ± 10% in the amount of 80g was applied to the shive of the rawmaterial. Then, binder in the form of protein adhesive was added to the raw material in the amount of 826 g. The binder was fed by spraying, and then, after forming the shape, it was pressed with a single-column hydraulic press with a force applied in 7 cycles in the range from 100 kN to 8000 kN, until the shape of a beam with a homogeneous set density was produced. A photograph of a beam being, for example, a wood-like material made with the method according to the invention was shown in Fig. 6A.

[0142] Example 5 - A method for producing a wood-like material using carboxymethylcellulose as a blocker of intercellular shive pores

[0143] As a raw material, strands made of completely split stalks of common flax Linum usitatissimum with a length of 70 cm to 120 cm, with a diameter of 2 mm to 4 mm were used. The moisture content of the raw material measured using the Tanel WPS-2 moisture meter was 16.5%.

[0144] The linen strands in a measured amount of 20 kg were laid out on a table with a steel mesh top with a mesh clearance of 4 cm x 4 cm, essentially with shives side facing up. Using a sieve, a thin layer of LV sodium carboxymethylcellulose in the amount of 297 g was applied in a loose form, and then, in order to dry the raw material, it was subjected to hot air with forced circulation at a temperature of 160°C in 240 seconds, the hot air was generated in a heating chamber equipped with a fan. The moisture content of the raw material measured after drying was 11%. Then, binder in the form of protein adhesive was added in the amount of 600 g to the raw material. The binder was fed by spraying, and then, after forming the shape, it was pressed with a single-column hydraulic press with a force applied in 7 cycles in the range from 100 kN to 8000 kN, until the shape of a beam with a homogeneous set density was produced. A photograph of a beam constituting, for example, a wood-like material produced with the method according to the invention is shown in Fig. 6B.

[0145] Example 6 Tests of the physical and mechanical properties and the level of the adhesive bonding of finished products produced with the use of shive blockers of wood-based materials

[0146] 6.1. The physical and mechanical properties and the level of bonding of the finished product were tested using the samples of the wood-like material produced as in Examples 1.1, 1.2, 2.1, 2.2, 3 and the samples of the wood-like material made in a manner according to the invention as in Examples 4 and 5, wherein the tests were carried out at the Technical -Technological Laboratory of the Research and Development Center for the Wood-Based Panel Industry in Czarna Woda in cooperation with the Environmental Research Laboratory belonging to the Lukasiewicz Research Network - Poznan Institute of Technology, Poland.A detailed summary of the results of tests of samples of wood-like material according to the invention is presented below, in terms of physical and mechanical properties and the level of bonding of the finished product for embodiments of hemp stalks, and in terms of the level of bonding of the finished product for an embodiment consisting in production from common flax stalks, respectively.

[0147] The obtained samples were analyzed for total nitrogen content in order to determine the level of the adhesive bonding using the method specified in standard PN / EN ISO 16948: 2015-07, based on the difference between the nitrogen (N) content in the dry state in a given sample and the nitrogen content in the unprocessed raw material before the addition of the binder. The result, expressed in g N, was related to the dry weight of the adhesive in 1 kg of sample. The test result showed an adhesive bonding level of 2.59% by weight in the final woodbased product produced. In the case of the common flax beam, the level of bonding was shown to be 4.55% by weight in the final wood-based product produced. A detailed presentation of the test results is provided in Tab. 5 below.

[0148] Tab. 5 - test results for contents % by weight (adhesive bonding) corresponding to the final amount of the binder / adhesive in the sample of the wood-like material produced. _

[0149] Fiber bast plant Cannabis sativa var. Linum usitatissimum - Sativa- (hemp) (common flax) Sample designation Strumber 750 Strumber Flax 750 Sample density 750 kg / m3750 kg / m3N [% by weight] 0.39 0.89 Total g N / kg of the material 3.90 8.90

[0150] g N of hemp raw material / 1 kg 3.25 7.75

[0151] g N of adhesive / 1 kg (difference) 0.65 1.15 Amount of dry mass of adhesive 25.91 45.53 corresponding to the amount

[0152] difference of N [g]

[0153]

[0154] Adhesive bonding [%] 2.59 4.55

[0155] Physical and mechanical tests of samples obtained from a wood-like beam manufactured according to the methods of the invention were performed in accordance with the requirements of standards PN-EN 310:1994 / Ap1:2002: “Wood-based panels” for determining the bending strength modulus and bending strength" [2] and PN-EN 323:1999 / Ap1:2002: “Wood-based panels” for determining density [3], The values presented in the test results include the determination of mechanical properties in the form of destructive force expressed in N, static bending strength expressed in MPa, and bending modulus of elasticity expressed in MPa. A detailed presentation of the test results for wood-like material from split hemp stalks for samples using hemp meal and using CMC, with 2%, 3%, 4% and 4.5% sealing are shown in Tab. 6, Tab.

[0156] 7, Tab.8, Tab.9, respectively, and additionally the result of the sample density test was presented in Tab. 10. Similar results in terms of mechanical properties were observed for wood-like materials made of split stalks of flax.Tab. 6 - test results for the mechanical properties of samples with adhesive bonding of approximately 2 % by weight (sealing) for samples with the use of hemp meal (MK) and carboxymethylcellulose (CMC). The spacing of the lower supports was L=250 mm.

[0157] Sample Sample Sample Destructive Static bending Static bending number width thickness force strength elasticity module [mm] [mm] Fr [N] Rg [MPa] E [MPa] Mt2% MK1 50.12 20.35 1092 19.9 7059 Mt2% MK2 50.16 20.34 1143 20.7 7365 mean 50.14 20.35 1118 20.3 7212 Mt2% CMC1 50.01 20.21 1514 27.8 8374 Mt2% CMC2 50.12 20.16 1413 30.0 7973

[0158]

[0159] mean 50.07 20.19 1464 28.9 8174

[0160] Tab. 7 - results of tests on the mechanical properties of samples with a bonding of approximately 3% by weight (sealing) for samples with the use of hemp meal (MK) and carboxymethylcellulose (CMC). The spacing of the lower supports was L=250 mm.

[0161] Sample Sample Sample Destructive Static bending Static Number Width Thickness force strength bending [mm] [mm] Fr [N] Rg [MPa] elasticity module E [MPa] Mt3% MK1 50.01 20.21 1523 28.0 8816 Mt3% MK2 50.12 20.27 1455 26.5 8875 Mean 50.07 20.24 1489 27.3 8846 Mt3% CMC1 50.09 20.18 1784 32.8 8145 Mt3% CMC2 50.15 20.11 1832 33.9 7656

[0162]

[0163] Mean 50.12 20.15 1808 33.3 7901

[0164] Tab. 8 - results of tests on the mechanical properties of samples with a bonding of approximately 4% by weight (sealing) for samples with the use of hemp meal (MK) and carboxymethylcellulose (CMC). The spacing of the lower supports was L=250 mm.

[0165] Sample Sample Sample Destructive Static bending Static bending Number Width Thickness force strength elasticity [mm] [mm] Fr [N] Rg [MPa] module E [MPa] Mt4% MK1 49.91 20.39 1744 31.5 8820 Mt4% MK2 49.82 20.28 1524 27.9 8381 Mean 49.86 20.34 1634 29.7 8601 Mt4% 50.01 20.56 2105 37.3 6568 CMC1

[0166] Mt4% 50.00 20.41 2230 40.2 7772 CMC2

[0167]

[0168] Mean 50.00 20.49 2168 38.8 7170

[0169] Tab. 9 - results of tests on the mechanical properties of samples with a bonding of approximately 4.5% by weight (sealing) for samples with the use of hemp meal (MK) and carboxymethylcellulose (CMC). The spacing of the lower supports was L=250 mm.Sample Sample Sample Destructiv Static bending Static Number Width Thickness e force strength bending [mm] [mm] Fr [N] Rg [MPa] elasticity module E Mt4,5% MK1 50.08 20.43 1606 28.8 7792 Mt4,5% MK2 50.11 20.39 1668 30.0 8444 Mean 50.10 20.41 1637 29.4 8118 Mt4,5% CMC1 50.14 20.29 2075 37.7 7697 Mt4,5% CMC2 50.09 20.21 1712 31.4 7460

[0170]

[0171] Mean 50.12 20.25 1894 34.6 7579

[0172] Tab. 10 - Results of the density test of the samples of wood-like material produced from the stalks of Cannabis sativa var. Sativa using hemp shives meal (MK) and carboxymethylcellulose (CMC) as blockers.

[0173] SAMPLE Mt2% Mt2% Mt3% Mt3% Mt4% Mt4% Mt4,5% Mt4,5% NUMBER MK3 CMC3 MK3 CMC3 MK3 CMC3 MK3 CMC3 THICKNESS [mm] 20.52 20.48 20.65 20.42 20.79 20.52 20.33 20.53 LENGTH [mm] 300.11 300.32 300.06 300.33 300.41 300.36 300.37 300.08 WIDTH [mm] 50.31 50.17 50.14 50.22 50.24 50.28 50.18 50.22 WEIGHT [g] 256.70 246.80 265.60 245.60 258.00 271.70 268.40 251.30 AVERAGE 20.52 20.48 20.65 20.42 20.79 20.52 20.33 20.53 SAMPLE THICKNESS [mm]

[0174] SURFACE 17.00 16.38 17.65 16.28 17.09 17.199 17.81 16.68 WEIGHT [kg / m2]

[0175] DENSITY [kg / m3] 829 800 855 797 822 877 876 812

[0176]

[0177] 6.2. Samples of wood-like material originating from different production batches, manufactured as described Example 2.1 (hemp and CMC used as a shive blockers) were subjected to tests determining the bonding level of the finished product. The tests were commissioned by the Applicant and carried out by the Warsaw University of Life Sciences, Warsaw in cooperation with the Lukasiewicz Research Network, Poland. The bonding level was established based on the total nitrogen content determined in accordance with the method specified in standard PN-EN ISO 16948:2015-07. The method was based on determining the difference between the nitrogen (N) content of a given sample, expressed on a dry basis, and the nitrogen (N) content of unprocessed hemp raw material (hemp straw) prior to the addition of the binder. Samples of the wood-like product of the Strumber Hemp type, with a density of 750 kg / m3and a target bonding level corresponding to a binder content of 3.9 wt.% of the produced wood-like material (sample ZM23082025), as well as samples with a target bonding level corresponding to a binder content of 1.9 wt.% of the produced wood-like material (sample ZM19092025), were tested. The test results are presented in Tab. 11.Tab.11. Determination of the N (nitrogen) content in the tested material and determination of the degree of adhesion in the tested wood-like material. _

[0178] Test material N total N of Degree of samples sealing [g / kg] adhesive (amount of binder % by weight [g / kg] in the produced wood-like material)

[0179] Hemp Straw - 1 2.1 - - Hemp Straw - 2 2.0 - - Hemp Straw - 3 1.6 - - Average of the results for 1.9 - - Hemp straw (from samples 1-3)

[0180] Sample: Strumber Hemp 2.7 0.8 3.85% ZM23082025

[0181] Sample: Strumber Hemp 2.3 0.4 1.92% ZM23082025

[0182] EA02 Adhesive 20.8 - -

[0183]

[0184] The lower binder content in the wood-like material according to the invention compared to known wood-like materials has a positive effect, making finished products made from it more natural and therefore more valued by the buyers.

[0185] Unexpectedly, it turned out that the use of shive blockers not only allowed to reduce the amount of binder used to produce wood-like material, but at the same time it became possible to control the density of wood-like material by changing the amount and types of substances used as intercellular pore blockers or using mixtures of them. It has also been shown that the use of shive blockers, in particular, using carboxymethyl cellulose as a blocker, significantly improves the physical and mechanical properties of the wood-based material.

[0186] REFERENCES:

[0187] 1. Y, Jiang et al. 2018 (Cell wall microstructure, pore size distribution and absolute density of hemp shiv, Royal Society Open Science, 04.04.2018)

[0188] 2. Standard PN-EN 310:1994 / Ap1:2002: „Plyty drewnopochodne” dla oznaczania modulu wytrzymalosci przy zginaniu i wytrzymalosci na zginanie” - "Wood-based panels" for the determination of flexural strength modulus and flexural strength” (https: / / sklep.pkn.pi / / pn-en-310-1994p.html)

[0189] 3. Standard PN-EN 323:1999 / Ap1:2002: „Plyty drewnopochodne” dla oznaczania g^stosci -"Wood-based panels" for density determination” (https: / / sklep.pkn.pI / / pn-en-323-1999p.html).

Claims

CLAIMS1. A wood-like material comprising:multiple strands of bast fiber plant stalks bound together by a binder, which are essentially completely longitudinally split strands of bast fiber plant stalks,characterized in that the essentially completely longitudinally split strands of the bast fiber plant stalks have partially filled naturally occurring intercellular pores and remaining voids in the shive structures of the stalk and a densified shives structure with a shive blocker in the form of a non-adhesive substance having a mean particle size in the range of 0.01-70 pm ±10%;wherein the resulting wood-like material contains a binder content in the range of 1.5 to 4.9%, preferably in the range of 2-4% by weight, more preferably in the range of 2,5-4% by weight of the wood-like material; andwherein an amount of essentially completely longitudinally split strands of bast fiber plant stalks is more than 60% by weight, preferably more than 70% by weight, preferably more than 80%, more preferably more than 90% by weight, of the wood-like material; wherein the wood-like material has a substantially uniform density in the range of 300 kg / m3to 1250 kg / m3; andwherein the wood-like material is suitable for use as a wood substitute in terms of appearance and technical properties.

2. The wood-like material according to claim 1, characterized in that the shive blockers are substances capable of swelling upon exposure to moisture and / or temperature, wherein - substances capable of swelling upon exposure to moisture are preferably selected from starch, cellulose, carboxymethylcellulose, protein, collagen, a polymer (e.g., polyacrylamide), or mixtures thereof,- substances capable of swelling upon exposure to temperature are preferably selected from polypropylene (PP), acrylic, poly(methyl methacrylate) (PMMA), or mixtures thereof.

3. The wood-like material according to claim 1, characterized in that the shive blockers are substances that naturally bind to the lignins of the shive structures in effect of pressure and / or moisture, and / or temperature, preferably selected from cellulose and hemicellulose, or mixtures thereof.

4. The wood-like material according to claim 1, characterized in that the shive blockers are substances that are mechanically processed fragments of bast fiber plants, preferably mealmade from ground parts of shives, preferably meal made from flax shives, hemp shives or a mixture thereof.

5. The wood-like material according to claims 1-4, characterized in that the binder is selected from adhesive substance, resin, adhesive, protein adhesive, polyvinyl adhesive, polyurethane, epoxy resin, melamine-urea-formaldehyde resin, polyacrylate, cyanoacrylate, polyethylene, polypropylene, rubber, silicone.

6. The wood-like material according to claims 1-5, characterized in that in the essentially completely longitudinally split strands of bast fiber plants the amount of the filled intercellular pores in layer of shives is more than 50%, more preferably more than 60%, 70%, 80%, 90%.

7. The wood-like material according to claims 1-6, characterized in that bast fiber plants are annual plants.

8. The wood-like material according to claims 1-7, characterized in that bast fiber plants are selected from flax, hemp, rice, bamboo, ramie, kenaf, white jute, Jerusalem artichoke, rapeseed, corn, miscanthus or mixtures thereof, preferably flax, hemp, more preferably Cannabis sativa9. A method for producing a wood-like material from essentially completely longitudinally split strands of bast fiber plant stalks bonded adhesively, characterized in that said method comprises step, wherein(b) the shive blocker in the form of a non-adhesive substance is introduced on the essentially completely longitudinally split strands of bast fiber plant stalks with naturally occurring intercellular pores and remaining voids in the shive structures of the split stalks, wherein the shive blocker fills from 1% to 90% of the naturally occurring intercellular pores and other voids in the shive structures of the split stalks, wherein the shive blocker have mean particle size in the range of 0. QI- 70 pm ±10%;wherein the shive blocker is introduced by pouring, spraying, applying, coating, preferably in combination with applying increased pressure during pouring, spraying, applying, coating; preferably in combination with pressing; preferably in combination with heating; preferably in combination with addition of steam; preferably in combination with the addition of liquid substances that are not a binder;c) binders are added in the amount of 0.1% by weight to 4.9% by weight in relation to the weight of the final wood-like material, then the shape of the woodlike material is formed by its compaction.

10. The method for producing of a wood-like material from bast fiber plant stalks according to claim 9, characterized in that before the step b) a step (a) is carried out wherein the bast fiber plant stalk strands are completely longitudinally split strands, preferably by cutting the fiber plant stalks between a set of cutting rollers.

11. Method of production of wood-like material from the stalks of bast fiber plants according to the claims 9-10, characterized in that in the step c) compaction is carried out by pressing, preferably by pressing in a hydraulic press, more preferably by pressing in a hydraulic press with 1-30 clamping cycles with a force in the range from 50kN to 8000kN, preferably in the range from 100kN to 15000kN, the most preferably in the range of 100kN to 8000kN.

12. The method for producing a wood-like material from bast fiber plant stalks according to claims 9-11, characterized in that the substance of the shive blocker has a mean particle size in the range of 1-50 pm ±10%, more preferably 40 pm ±10%.

13. The method for producing a wood-like material from bast fiber plant stalks according to claims 9-12, characterized in that the shive blocker is a substance capable of swelling upon exposure to moisture and / or temperature, wherein- substance capable of swelling upon exposure to moisture is preferably selected from starch, cellulose, carboxymethyl cellulose, protein, collagen, polymer, polyacrylamide, or mixtures thereof,- the substance capable of swelling upon exposure to temperature is preferably selected from polypropylene (PP), acrylic, poly(methyl methacrylate) (PMMA), or mixtures thereof.

14. The method for producing a wood-like material from bast fiber plant stalks according to claims 9-13, characterized in that the shive blocker is a substance containing particles that naturally bind to the lignins of the shive structures upon exposure to pressure or moisture or temperature, preferably selected from cellulose and hemicellulose, or mixtures thereof.

15. The method for producing a wood-like material from bast fiber plant stalks according to claims 9-14, characterized in that the shive blocker is a substance that is mechanically processed fragments of bast fiber plants, preferably meal made from ground parts of shives, preferably common flax meal or hemp meal or mixtures of thereof.

16. The method for producing a wood-like material from bast fiber plant stalks according to claims 9-15, characterized in that bast fiber plants are annual plants.17 The method for producing a wood-like material from bast fiber plant stalks according to claims 9-16, characterized in that bast fiber plants are selected from selected from flax, hemp, rice, bamboo, ramie, kenaf, white jute, Jerusalem artichoke, rapeseed, corn, miscanthus, preferably flax, hemp, more preferably Cannabis sativa.

18. The method for producing a wood-like material from bast fiber plant stalks according to claims 9-17, characterized in that bast fiber plants are comprised in at least 60% by weight of the final wood-like material, and wherein the binder represents up to 4.9% by weight of the final wood-like material;wherein the wood-like material has a substantially uniform density in the range of 300 kg / m3to 1250 kg / m3; andwherein the wood-like material is suitable for use as a wood substitute in terms of appearance and technical properties.

19. A wood-like material from the stalks of bast fiber plants, characterized in that it is produced by the method as defined in claim 9-18.

20. A use of shive blocker for the production of the reduced binder content wood-like material from essentially completely longitudinally split strands of bast fiber plant stalks bonded adhesively, wherein a shive blocker is a non-adhesive substance having an mean particle size in the range of 0.01-70 pm ±10% , more preferably in the range of 1-50 pm ±10%, more preferably in the range of 40 pm ±10%.

21. The use of the shive blocker for the production of the reduced binder content wood-like material according to claim 20, characterized in that shive blocker is a substance capable of swelling upon exposure to moisture and / or temperature, wherein- substance capable of swelling upon exposure to moisture is preferably selected from starch, cellulose, carboxymethyl cellulose, protein, collagen, polymer, polyacrylamide; or mixtures thereof,- substance capable of swelling upon exposure to temperature is preferably selected from polypropylene (PP), acrylic, poly(methyl methacrylate) (PMMA); or mixtures thereof.

22. The use of shive blocker for the production of the reduced binder content wood-like material according to claim 20, characterized in that the shive blocker is a substance capable of naturally binding to the lignins within the shive structures in effect of pressure and / or moisture and / or temperature, preferably selected from cellulose, hemicellulose, or mixtures thereof.

23. The use of shive blocker for the production of the reduced binder content wood-like material according to claim 20, characterized in that the blocker is a substance that is mechanically processed fragments of bast fiber plants, preferably meal made from ground parts of shives, preferably meal made from shives from flax, from hemp or mixtures thereof.

24. The use of shive blocker for the production of the reduced binder content wood-like material according to claims 20-23, characterized in that the plants are annual plants.

25. The use of shive blocker for the production of the reduced binder content wood-like material according to claims 20-23, characterized in that bast fiber plants are selected from flax, hemp, rice, bamboo, ramie, kenaf, white jute, Jerusalem artichoke, rapeseed, corn, miscanthus or mixtures thereof, preferably flax, hemp, more preferably Cannabis sativa .

26. The use of shive blocker to reduce the amount of binder in the wood-like material from bast fiber plants, wherein the shive blocker is a non-adhesive substance having an mean particle size in the range of 0.01-70 pm ±10%, more preferably in the range of 1-50 pm ±10%, more preferably in the range of 40 pm ±10%.

27. The use of shive blocker to reduce the amount of binder according to claims 26, characterized in that the shive blocker is a substance capable of swelling upon exposure to moisture and / or temperature, wherein- substance capable of swelling upon exposure to moisture is preferably selected from starch, cellulose, carboxymethylcellulose, protein, collagen, polymer, polyacrylamide, or mixtures thereof,- substance capable of swelling upon exposure to temperature is preferably selected from polypropylene (PP), acrylic, polymethyl methacrylate (PMMA), or mixtures thereof.

28. The use of shive blocker to reduce the amount of binder according to claims 26, characterized in that the shive blocker is a substance capable of naturally binding to the lignins within the shive structures in effect of pressure and / or moisture and / or temperature, preferably selected from cellulose, hemicellulose, or mixtures thereof.

29. The use of shive blocker to reduce the amount of binder according to claims 26, characterized in that the shive blocker is a substance that is mechanically processed fragments of bast fiber plants, preferably meal made from ground parts of shives, preferably meal made from shives from flax, from hemp, or mixtures thereof.

30. The use of shive blocker to reduce the amount of binder according to claims 26-29, characterized in that the plants are annual plants.

31. The use of shive blocker to reduce the amount of binder according to claims 26-29, characterized in that bast fiber plants are selected from flax, hemp, rice, bamboo, ramie, kenaf, white jute, Jerusalem artichoke, rapeseed, corn, miscanthus or mixtures thereof, preferably flax, hemp, more preferably Cannabis sativa.

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