fiberboard

Abstract

The present invention related to a fiberboard (1) and method for producing the same. The method comprises the method steps of chipping of bamboo logs (5) into bamboo chips (15); flaking of the bamboo chips (15) into bamboo flakes (16); pulping of the bamboo flakes into detached bamboo fibers (13); distributing the detached bamboo fibers (13) to form a loose bamboo mat; and hot pressing the bamboo mat into the fiberboard (1).

Description

[0001] P28760PC00 19.09.2025

[0002] 1 / 27

[0003] Fiberboard

[0004] FIELD OF THE DISCLOSURE

[0005] The present disclosure relates to a method for producing a fiberboard from bamboo and a fiberboard made from bamboo in particular for isolation and / or damping.

[0006] BACKGROUND OF THE DISCLOSURE

[0007] The construction industry plays a crucial role in global sustainability efforts. The construction ecosystem, encompassing the entire life cycle of buildings and infrastructure (from design to demolition), significantly contributes to greenhouse gas (GHG) emissions. Building with wood has emerged as a potential solution for decarbonizing construction due to its lower environmental footprint compared to steel and concrete.

[0008] Thereby, wood is commonly processed into fiberboards striking a good balance between sustainability, economy, and reliability. Hereby fiberboards (in order of increasing density) include low-density fiberboards (LDF), medium-density fiberboards (MDF), and hardboard or high-density fiberboards (HDF).

[0009] The low-density fiberboards (LDF) are hereby often used as isolation fiber boards. The manufacturing process of such insulation fiberboards made from wood fibers begins with the selection and preparation of raw materials. Softwood or hardwood residues such as chips, sawdust, and shavings are typically chosen P28760PC00 19.09.2025

[0010] 2 / 27 based on the desired properties of the final product. Next, the cleaned wood materials are subjected to pulping, where they are ground into individual fibers using a refiner. Binders and additives, such as natural or synthetic resins, fire retardants, and water repellents, are then mixed with the fibers to enhance the performance characteristics of the insulation fiberboard. The treated wood fibers are uniformly distributed onto a forming line to create a loose mat which is then pressed together to form a rigid board. In the manufacturing of such wood-based isolation fiberboards, the initial pulping stage is known to be crucial for the eventual structural integrity of the fiberboard. The industry standard is to have minimal variation in the characteristics of the initial pulping material, especially in terms of the size und more particular a consistent thickness distribution, which ensures even product qualities.

[0011] The production of the wood fragments for pulping is preferably conducted such that the compressive damage to the fragments is reduced, which can result e.g. from high stress levels during certain procedures. Next to mechanical benefits in the later isolation fiberboard, wood fragments with a consistent thickness profile are easier to pulp and thus require only a minimal energy consumption. As process of refining wood fragments into pulp demands a significant amount of energy, a primary goal in refining pulping techniques is to reach the required level of refinement while minimizing energy use. For pulp producers, cutting down on energy consumption is critical due to rising electricity costs and environmental concerns. P28760PC00 19.09.2025

[0012] 3 / 27

[0013] Hence, despite their eco-friendly nature, wood-based boards face certain limitations. Regular maintenance is necessary to prevent rot and insect damage. Additionally, wood’s flammability poses safety risks, and its load-bearing capacity is limited compared to other construction materials. Concerns about deforestation impact persist, and moisture sensitivity affects dimensional stability. Finally, cost, energy consumption and availability should be considered.

[0014] Next to wood-based boards, also boards based on bamboo material are known, which have an overall better environmental footprint than wood-based boards. Some examples of such known bamboo boards can be found e.g. in WO20216871A1 published in the name of Markus Bard or WO08052784A1 published in the name of Bard AG. A further example of a board based on bamboo material is given in W010091643A1.

[0015] SUMMARY OF THE DISCLOSURE

[0016] As explained before, the initial size of the fragments before pulping has a significant impact on the structural properties as well as the later pulping process, impacting the overall energy consumption and environmental footprint. It is an object of the disclosure to improve the performance of fiberboards, in particular isolation fiberboards.

[0017] The herein disclosed fiberboard is thereby made of bamboo instead of wood, thereby offering already an improved environmental performance. As used herein, the term "bamboo" refers to plants in the subfamily of Bambusoideae. P28760PC00 19.09.2025

[0018] 4 / 27

[0019] Bamboo is known for its extremely fast growth and the high photosynthetic efficiency that allows the logs and leaves as well as the root system to absorb a much higher quantity of CO than other trees. Hence, bamboo is a capable tool to reduce CO in the atmosphere and counter global warming. Furthermore, bamboo has remarkable mechanical properties to other materials such as wood. Tensile strength applied perpendicularly to surfaces, is far greater than that of wood. Next to this, bamboo also shows a good degree of compressive strength greater than that of wood and concrete. Furthermore, bamboo is a natural hierarchical cellular material that has good flexural strength along its fiber direction. Because bamboo is a functionally graded natural composite, the interfaces between its various components, including the fibers, parenchyma cells, and lignin matrix, can have a significant effect on its mechanical properties.

[0020] To enable an energy efficient pulping process, the fiberboard is hereby made from bamboo flakes made in a special process as described hereinafter in more detail. This is among others due to the fact, that the described process creates very uniformly and thin bamboo flakes, while providing a consistent and defined fiber length. Next to the advantages for pulping, uniform bamboo fibers further result in a superior performance of the resulting isolation fiberboard.

[0021] In order to produce such bamboo flakes, the bamboo logs as raw product are preferably deglazed first to remove the leaf sheaths before the logs are chopped and sliced into bamboo chips as described hereinafter. The resulting bamboo chips already have a specific length made by a chopping process and a specific width and / or thickness resulting from a slicing process which results in superior performance. P28760PC00 19.09.2025

[0022] 5 / 27

[0023] The length and shape of the bamboo log makes the process susceptible to vibration, which in disadvantageous for using a conventional strander known for cutting wood logs. Therefore, the present disclosure presents a different approach, which minimizes vibrations by mechanically crushing the bamboo logs in longitudinal direction in a crushing process beforehand. The crushing process thus facilitates the subsequent chipping and / or flaking process. Meanwhile it is advantageous to first crush the initial bamboo logs and then slice and chop them, it is also possible to first chop the bamboo log into chopped log sections and then further crush and slice the log sections. The crushing process transforms the initial bamboo log or chopped log sections in at least four at least partially separated log segments. Before the crushing process the initial bamboo log (or the chopped log sections) has an essential round cross-section. However, after the crushing at least four at least partially separated log segments are formed. Each crosssection of the at least four log segments thereby corresponds to a part of the circumference of a hollow cylinder.

[0024] In the chopping process the fibers, extending in a longitudinal direction of the bamboo logs, are severed. Therefore, a chopping plane can be arranged essentially perpendicular to the longitudinal direction of the (initial) bamboo logs or under a certain degree. A specific length of the bamboo chips can be defined in a fiber direction of the respective embedded fibers of the bamboo chips. Good mechanical performance is achieved, if the length of the bamboo chips is between 20 and 200mm, in particular between 20 and 70 mm.

[0025] In the slicing process the (crushed or uncrushed) bamboo logs or the (crushed or uncrushed) chopped log sections are advantageously sliced essentially parallel P28760PC00 19.09.2025

[0026] 6 / 27 to the extension of the embedded bamboo fibers. Hence, a slicing plane can be arranged essentially parallel to the fiber direction. Depending on the process, the slicing plane(s) may further be perpendicular to an outer surface of the bamboo logs, respectively of the chopped log sections. Alternatively, the slicing plane(s) may be arranged essentially perpendicular to a reference plane. Essentially perpendicular is hereby understood to mean that variations in the angle, in particular of about 0 - 10 degrees, are still possible. As a result, the maximal width of the bamboo chips is preferably equivalent to a wall thickness of the tubular bamboo log in the radial direction of the bamboo log. A resulting thickness of the bamboo chips is preferably between 1 and 20, in particular between 1 and 5 mm. The thickness is hereby mainly defined by the distance of the slicing planes in circumferential direction of the bamboo log.

[0027] Advantageously, the majority of the bamboo chips have a width corresponding to the 70% to 100% of the wall thickness of the bamboo log. Thereby, the outer surface of the bamboo log and / or an inner surface of the bamboo log are preferably arranged along the longitudinal edges of the bamboo chips providing additional stability to the chips and thus the fiberboard. Along the outer surface in particular, the bamboo log forms an outer skin with superior structural properties (significantly increased bending strength and therefore breaking load of the material) and a higher fiber density. In addition, the outer skin has significant antibacterial and / or antifungal properties. Hence due to the slicing process as explained above, said outer skin extends partially in a longitudinal direction along an edge of the respective bamboo chips. As a result, the positive properties of the outer skin are partially transferred to the respectively produced detached fibers and evenly distributed throughout the fiberboard. If the width corresponds to P28760PC00 19.09.2025

[0028] 7 / 27 less than 100% of the wall thickness, preferably the outer or the inner surface of the log is arranged along the longitudinal edges of the bamboo chips.

[0029] After the chipping the bamboo chips can be subjected to a further flaking process. During flaking the bamboo chips are reduced further in size, and in particular reduced in thickness. The flaking is hereby preferably performed by a knife ring flaker. The knife ring flaker typically comprises a centrally arranged distribution disc onto which the bamboo chips impact and from there are distributed into a rotating drum, however also other introduction procedures exist. Sweeping elements as well emerging centrifugal forces may further move and orient the bamboo chips, such that the majority of the chips lie with the embedded fibers (lengthwise) in direction of the rotational axis of the knife ring flaker. Hereby the bamboo chips lie with a contact surface on a circumferential inner surface on the ring flaker. The ring flaker further comprises at least one set of knives. The knifes may protrude from circumferential inner surface into the rotating drum or can be otherwise attached. The flakes are then preferably (longitudinally) sliced to further reduce the thickness or the bamboo chips. Hereby, the length and width of the chips are advantageously essentially maintained (for a majority of the flakes). Hence the bamboo flakes have a reduced thickness than the bamboo flakes. Thus, the outer surface of the bamboo log and / or an inner surface of the bamboo log are preferably still arranged along the longitudinal edges of the bamboo flakes. The thickness of the bamboo flakes are preferably between 0, 5 - 5mm and in particular between 0.5 - 3mm.

[0030] After flaking, the bamboo flakes are subjected to pulping. Bamboo contains three main components (apart from water): cellulose fibers, lignin (a three-dimensional P28760PC00 19.09.2025

[0031] 8 / 27 polymer that binds the cellulose fibers together) and hemicelluloses (shorter branched carbohydrate polymers). The aim of the pulping is to break down the bamboo flakes to obtain detached bamboo fibers. Different methods can be used for the pulping. As an example, the pulping may include one or more of the following: mechanical pulping, thermo-mechanical pulping, steam explosion, orga- nosolv pulping, biological pulping, enzyme pre-treatment and the use of pulping chemicals. Some of these processes are also known as defibering.

[0032] In mechanical pulping the bamboo flakes are physically ground and refined to separate the fibers. This process may involve applying mechanical forces such as grinding, milling, or beating to break down the bamboo structure and liberate the fibers. However, the resulting fibers tend to have a wide range of sizes and shapes due to the variability in the mechanical forces applied. Furthermore, mechanical pulping is less energy-efficient compared to thermo-mechanical, chemomechanical and thermo-chemo-mechanical methods because it relies solely on mechanical energy. Furthermore, thermal and / or chemical treatments reduce the amount of strength loss suffered by the fibers. Therefore, in context of the present disclosure, thermo-mechanical, chemo-mechanical and thermo-chemo-mechan- ical pulping is preferred.

[0033] Thermo-mechanical pulping combines heat and mechanical forces to separate the fibers. Therefore, the bamboo flakes can be preheated with steam to soften the lignin and facilitate fiber separation, as lignin acts as a natural adhesive holding the fibers together. After steaming, the softened bamboo flakes may be mechanically treated, as explained above in context with mechanical pulping, which P28760PC00 19.09.2025

[0034] 9 / 27 allows for easier and more efficient fiber separation. Performing the process further under heat can result in fibers with more uniform properties. Furthermore, the resulting detached fibers are generally stronger and more uniform than those produced by mechanical pulping, making them suitable for higher-quality products.

[0035] Depending on the application, the pulping may comprise steam explosion, i.e. a high-pressure steam treatment followed by rapid depressurization to separate the fibers. As an example, the high-pressure steam treatment may include treatment of the flakes with steam (typically saturated steam) at a pressure of at least 0.1 MPa, preferably from 0.2 to 2.5 MPa. The pressure may e.g. be applied for a duration of at least 1 minute, preferably from 1 to 20 minutes. Typically, the subsequent pressure relief is momentarily performed to cause the bamboo to be blasted in the steam explosion apparatus in 5 to 20 ms. Optionally, the material is then instantaneously cooled to 40-80 °C. Typically, the steam explosion pulping is performed without any added pulping chemicals. If the pulping comprises chemical pulping and steam explosion, they are typically performed subsequently and not simultaneously.

[0036] Depending on the application, the pulping can further include the use of pulping chemicals. Pulping chemicals serve to break down the lignin and hemicellulose bonds between fibers, making it easier to separate them mechanically. Depending on the application, different pulping chemicals can be used, including for example one or more of the following: sodium hydroxide, sodium carbonate, sodium bisulfite, sodium sulfite, sodium sulfide, p-toluenesulfonic acids and others. It is understood that if a mixture of pulping chemicals is used, they are chosen such P28760PC00 19.09.2025

[0037] 10 / 27 that they are compatible with each other. For example, acids and bases are typically not applied subsequently to and not simultaneously with each other. The chemicals can e.g. be applied to the bamboo flakes by impregnating the bamboo flakes with the pulping chemicals and cooking the bamboo flakes to loosen the fiber before the mechanical or thermo-mechanical pulping. Depending on the application, the pulping chemical can comprise or consist of water, alkali and anthraquinone or alternatively be a mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na2S). The weight of the bamboo flakes is advantageously be adjusted to 1 : 3.5 - 6.0 (bamboo : agent). The cooking temperature is preferably 130-210 °C. Furthermore, the cooking time is advantageously within the range of 90 - 120 minutes.

[0038] Depending on the application, the pulping chemicals can either be used to refine the fibers and make them easier to be removed in a separate step (e.g. a subsequent mechanical or thermomechanical step, where the fibers are removed in the mechanical or thermomechanical step), or the fibers can be refined and removed in a single chemical process. The latter variant (i.e. removing the fibers in the chemical process) typically requires harsh conditions (e.g. kraft pulping, high temperatures, strong acids or bases, etc.) and is therefore less preferable in the process of the present disclosure. For example, removing the fibers in a chemical process may require chemically breaking down the lignin without seriously degrading the cellulose fibers, which may involve kraft pulping and / or soda pulping.

[0039] In some variants, the pulping comprises an organosolv pulping, which uses organic solvents, typically at temperatures above 140 °C, to break down ligning and P28760PC00 19.09.2025

[0040] 11 / 27 hemicellulose into soluble fragments. The pulping liquor is easily recovered by distillation.

[0041] Depending on the application, the pulping may further comprise an enzymatic pre-treatment and / or a biological pulping. The enzymatic pre-treatment may for example include treatment of the bamboo flakes with enzymes to selectively degrade lignin and / or hemicellulose, while leaving the cellulose fibers intact. The biological pulping may include treating the bamboo flakes with fungi or bacteria to selectively degrade the lignin and / or hemicellulose, while leaving he cellulose fibers intact.

[0042] Before further processing, a washing and / or centrifugation process may be done after the pulping. The detached fibers are washed and / or centrifuged to remove any unreacted substances and impurities. This step ensures that the fibers are clean and ready for further processing.

[0043] Furthermore, additives, such as fire retardant materials and / or water repellents materials and / or glue, can be mixed with the fibers to enhance the performance characteristics of the insulation fiber board, as explained in more detail later on. This is in particular done before the pressing process. Preferably the additives are applied in such a way, that they form a coat around the individual fibers.

[0044] In a next step, the (detached) bamboo fibers and the additives if present are uniformly distributed to create a loose mat. The loose mat can hereby be much thicker than the final isolation fiber board. This mat may be pre-pressed to reduce P28760PC00 19.09.2025

[0045] 12 / 27 its thickness and increase its density. This process step in particular removes air pockets and improves the fiber bonding.

[0046] The loose mat or the pre-pressed mat is then subjected to hot pressing, where heat and pressure are applied to bond the fibers together and form a rigid isolation fiberboard. The temperature, pressure levels, and pressing duration are chosen according to achieve the desired board properties. The pre-pressing and / or the hot pressing may be performed in a continuous manner on a band press. Preferably the pre-pressing and the hot pressing are performed on the same band press.

[0047] After pressing, the fiberboard may be subjected to a drying process to reduce moisture content to acceptable levels. The drying process is typically done in kilns or continuous drying ovens.

[0048] Furthermore, and in particular after drying, the fiberboard can be trimmed to the required dimensions and / or sanded to achieve a desired surface quality.

[0049] The disclosed steps can further vary depending on the desired end product. The goal is to achieve a high-performance material with the desired properties for its intended application.

[0050] Naturally, the fiberboards can be customized to various thicknesses, densities, and additional features such as increased fire or moisture resistance, making them suitable for various construction and industrial applications. Therefore, the before mentioned additives are crucial. Depending on the application, the additive can be a fire retardant material. The fire retardant material preferably shows high P28760PC00 19.09.2025

[0051] 13 / 27 thermal stability at temperatures ranging from 160°C - 270°C. The fire retardant material can be added in dry or liquid form to the bamboo flakes or particles before adding the glue. Hereby, the fire retardant material can account for up to 25%, in particular 15 - 20% of the total weight of the fiberboard. However, the concentration of the fire retardant material in a central layer may be chosen to be lower than the concentration of the fire retardant material in an outer layer. For an easy recognition of the fire retardant properties, a further color additive can be applied in the fiberboard.

[0052] Depending on the application, different fire retardant materials or a combination thereof can be used. Typically, the fire retardant material comprises or consists of at least one fire retardant agent. In some variants, the fire retardant agent may e.g. make up from 25 wt.-% to 100 wt.-% of the fire retardant material. An environmental friendly approach is a fire retardant material that causes a mineralization of the respective layer in which the fire retardant material is present. For example, the fire retardant material may comprise one or more precursors which undergo a chemical reaction (such as a salt metathesis) that leads to formation of a fire retardant agent, which may e.g. be at least one essentially insoluble salt. The essentially insoluble salt (which is essentially insoluble in water) may e.g. impart fire retardant properties. The essentially insoluble salt may e.g. be a sulfate, such as barium sulfate. Alternatively or in combination, in some variants, the first fire retardant agent may comprise or primarily consists of a salt, in particular a guanidine salt or a mixture of guanidine salts. In some variants, the fire retardant material may comprise (or even consist of) one or more of the following fire retardant agents: ammonium (poly)phosphates, melamine (poly)phosphate, am- P28760PC00 19.09.2025

[0053] 14 / 27 monium sulfate, ammonium chloride, ammonium sulfamate, guanidine phosphate, guanidine sulfamate, guanidine carbonate, methylene urea, urea phosphate and alkaine earth phosphates or any mixture thereof. The salts may e.g. be formed in situ from appropriate precursors (e.g. a chemical reaction may be initiated once the precursors are in contact with the bamboo flakes and / or bamboo particles), or the salts may be added as such. In the final product, the salts are typically present as such. In some variants, the fire retardant material can comprise a phosphorus material and optionally a carrier. The phosphorus material is preferably based on a stabilized and micro-encapsulated red phosphorus powder. However, also sulfur-based compounds, boron-based compounds, ammonium-based compounds, guanidine-based compounds, citric acid based compounds, mineral hydroxides, or combinations thereof can be used.

[0054] Depending on the application, the fire retardant material may comprise further components besides the fire retardant agent. For example, in some variants, the fire retardant material comprises a carrier. The carrier can for example be a polypropylene carrier or polyolefine carrier or an EVA carrier (Ethylene-vinyl acetate).

[0055] In some variants, the fire retardant material may further comprise a smoke suppressing agent, which may for example make up from 0 wt.-% to 25 wt.-% of the fire retardant material.

[0056] Alternatively or in combination, the fire retardant material may further comprise a pH regulating compound, which may for example be configured to maintain the pH of the fire retardant material between 3.5 and 8.5. In some variants, the pH P28760PC00 19.09.2025

[0057] 15 / 27 regulating compound is configured to maintain the pH of the fire retardant material between 6.0 and 8.0.

[0058] In some variants, the fire retardant material may further comprise an amine, such as monoethanolamine. The monomethanolamine may e.g. be present in the fire retardant composition such that a weight ratio between monomethanolamine and the fire retardant agent or fire retardant agents is between 1 :5 and 1 :50. Monomethanolamine may e.g. be added to control solubility or dispersibility of the fire retardant material.

[0059] Furthermore, the fire retardant material can e.g. be used as described in WO22243332A1 or WO18122406A1 for the application of wood fibers for the bamboo flakes and / or particles as described within the present disclosure. Both these documents are incorporated herein by reference in their entirety.

[0060] In most applications, at least one additive is used in form of glue. The glue used to interconnect the detached bamboo fibers contributes preferably less than 10% of the weight of the fiberboard. However, for a better water resistance or even waterproofing of the fiberboard the glue can be chosen to have a higher percentage in the outer layers than in the central layer. E.g. the glue may contribute between 10 - 20 % of the weight of the fiberboard. Depending on the application, the glue is formaldehyde free (NAF non added formaldehyde). Since bamboo, unlike wood, does not contain formaldehyde, the fiberboard itself can be formaldehyde-free by choosing a formaldehyde-free glue. As a result, the fiberboard has a lower emission class than the E1 emission class defined for wood-based panels (defined as not releasing more than 0.10 ppm of formaldehyde into the P28760PC00 19.09.2025

[0061] 16 / 27 indoor air). Advantageously, the glue comprises or consists of PMDI (Polymethylene Diphenyl Diisocyanate). Alternatively, also MDI (Methylene Diphenyl Diisocyanate) may be used. This means that the fiberboard is in line with the requisites of NAF certification (no-added-formaldehyde). Furthermore, no harmful additives are used, such as cadmium, lead, chromium VI, mercury, arsenic and selenium with a concentration greater than 0.010% in weight, phthalates, or substances identified as “Substances of Very High Concern” (SVHCs) pursuant to art.59 of Regulation (EC) no. 1907 / 2006 with a concentration greater than 0.10% weight / weight. Avoiding these substances provides an ecofriendly fiberboard, which allows for it to be completely recycled at the end of its service life. However, in some cases also urea glue can be used. E.g. MUF glue (Melamine Urea Formaldehyde) with a melamine content between about 10% and about 30%.

[0062] It is to be understood that both the foregoing general description and the following detailed description present embodiments and are intended to provide an overview or framework for understanding the nature and character of the disclosure. The accompanying drawings are included to provide a further understanding and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments, and together with the description serve to explain the principles and operation of the concepts disclosed.

[0063] BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The herein described disclosure will be more fully understood from the detailed description given herein below and the accompanying drawings which should not P28760PC00 19.09.2025

[0065] 17 / 27 be considered limiting to the disclosure described in the appended claims. The drawings are showing:

[0066] Fig. 1 A first variation of isolation fiberboard according to the disclosure;

[0067] Fig. 2 A second variation of isolation fiberboard according to the disclosure; Fig. 3 A bamboo log;

[0068] Fig. 4 A crushed bamboo log;

[0069] Fig. 5 A crushed and sliced bamboo log;

[0070] Fig. 6 A schematic view on the slicing planes;

[0071] Fig. 7 A chipped bamboo section; Fig. 8 A bamboo chip;

[0072] Fig. 9 Two bamboo flakes;

[0073] Fig. 10 An illustration of the flaking process;

[0074] Fig. 11 A process diagram of the manufacturing of the isolation fiberboard according to the disclosure. P28760PC00 19.09.2025

[0075] 18 / 27

[0076] DESCRIPTION OF THE EMBODIMENTS

[0077] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, in which some, but not all features are shown. Indeed, embodiments disclosed herein may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Whenever possible, like reference numbers will be used to refer to like components or parts.

[0078] Figure 1 schematically shows a first version of a fiberboard 1 , in particular an isolation fiberboard, according to the disclosure. The fiberboard 1 comprises detached bamboo fibers 13 as well as optionally additives 14 such as e.g. glue. The additives 14 may be distributed though the fiberboard 1 , as illustrated. An outer skin 4 such as e.g. an additional coating or a veneer can be arranged on the respective outer sides of fiberboard.

[0079] Figure 2 schematically shows a second version of a fiberboard 1 , in particular an isolation fiberboard, according to the disclosure. Here, the detached bamboo fibers 13 are present in a central layer 2 as well as outer layers 3 of the fiberboard 1. However, further additives 14 in form of e.g. a fire retardant material are only arranged in the outer layers 3 of the fiberboard 1 . Depending on the application, some additives, such as e.g. glue may also be arranged additionally distributed through the whole fiberboard. An outer skin 4 such as e.g. an additional coating or a veneer can also here be arranged on the respective outer sides of fiberboard 1. P28760PC00 19.09.2025

[0080] 19 / 27

[0081] Figure 3 schematically shows a part of a bamboo log 5 prior to the production of the fiberboard 1 according to Figure 1 or Figure 2. The bamboo log 5 comprises several log sectors 10 arranged in longitudinal direction of the log 5 behind one another. The log sectors 10 are divided from another by partition walls 11. The log sectors 10 are hollow-cylindrical with a circumferential wall having an outer and an inner surface 7, 8. Along the outer surface 7 the bamboo log 5 features outer skin. In the bamboo log wall embedded fibers 9 (schematically indicated by a dashed line), extend in the longitudinal direction of the bamboo log 5.

[0082] Figure 4 shows the bamboo log 5 after it has been mechanically crushed in a longitudinal direction of the bamboo logs 5. The crushed bamboo log 5 forms at least four at least partially separated log segments 6 which can be easier chipped than the bamboo log 5. As indicated in Figure 5, and depending on the application, the bamboo chips 15 may be produced by chopping and slicing of the separated log segments 6. The slicing process could be performed after the chopping process or before that. In the slicing process the bamboo logs 5 are preferably sliced essentially parallel to the fiber direction of the embedded fibers 9 of the respective bamboo logs 5. The slicing may thereby be performed essentially perpendicular to a reference plane. Essentially perpendicular is hereby understood to mean that small variations in the angle are still possible, as illustrated in Figure 6.

[0083] Figure 7 illustrates one log segment 6 after the chipping process. As can be seen also in Figure 8, illustrating a single bamboo chip 15, the resulting bamboo chips 15 are having a width W corresponding to a thickness of the wall of the respective bamboo log 5. Meanwhile, the thickness T of the bamboo chips 15 is defined from P28760PC00 19.09.2025

[0084] 20 / 27 the distance between adjacent slicing planes 12. The thickness T is thereby preferably smaller than the width of the bamboo chips 15. Due to the arrangement of the slicing planes 12, the log outer surface 7 extends at least partially in a longitudinal direction along the edges of the respective bamboo chips 15 giving the bamboo chips additional strength, which is beneficial for further processing.

[0085] Figure 9 und Figure 10 indicated the possible further size reduction due to flaking. The single bamboo chip 15 illustrated in Figure 9 is further cut in the shown example into two bamboo flakes 16 (other amount of flakes are also possible). For the flaking a knife ring flaker can be used. If such a knife ring flaker is used, the bamboo chips 15 introduced in the ring flaker will be first moved radially outwards by centrifugal forces within the ring flaker. The majority of the bamboo chips 15 will thereby be oriented in a similar manner with the embedded fibers 9 arranged parallel to the rotational axis of the ring flaker. During flaking, the (oriented) bamboo chips 15 traverse around an inner circumference of the ring flaker (as indicated by the arrow in Figure 10), thereby passing at least one knife 18. The majority of the bamboo chips 15 are thereby preferably sliced along a longitudinal slicing plane 17 (essential parallel to the embedded fibers) due to contact with the knife 18. The thickness of the bamboo flakes can thereby be adjusted by adjusting the distance of the knife(s) 18 with respect to the inner surface 19 of the ring flaker.

[0086] Figure 11 illustrates a process diagram of the manufacturing of the fiberboard 1 according to the disclosure. For chipping the bamboo logs are hereby first crushed. After the crushing, at least four at least partially separated log segments are formed, which are then subsequently sliced. The sliced log segments are then P28760PC00 19.09.2025

[0087] 21 / 27 chopped into bamboo chips of an appropriate length. However, depending on the application the chopping may also be performed before the slicing and / or crushing process. If necessary, the bamboo chips can be sieved according to their size or quality. In a next step, the (selected) bamboo chips are flaked. Again, the bamboo flakes can be sieved according to their size or quality. After that, the bamboo flakes are subjected to a pulping process, as explained above. During pulping, the embedded fibers of the bamboo flakes are detached from each other into individual fibers. Further additives such as e.g. glue, color additives and / or fire retardant material, may be added to the detached fibers. Afterwards the fibers and, if present, the additives are distributed and / or layered onto a forming line to create a loose mat. This mat can be pre-pressed to reduce its thickness and increase its density, removing air pockets and improving fiber bonding. The loose mat or pre-pressed mat is then subjected to hot pressing, where heat and pressure are applied to bond the fibers together and form a rigid fiberboard. The prepressing and hot pressing can be performed in a continuous manner on a band press. The temperature, pressure levels, and pressing duration are carefully controlled to achieve the desired fiberboard properties.

[0088] After pressing, the boards can be dried to reduce their moisture content to acceptable levels, typically done in kilns or continuous drying ovens. Once dried, the boards may further be trimmed to the required dimensions and sanded to achieve a smooth surface.

[0089] Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the scope of the disclosure. P28760PC00 19.09.2025

[0090] 22 / 27

[0091] LIST OF DESIGNATIONS

[0092] 1 Fiberboard 12 Slicing plane

[0093] 2 Central layer 13 Detached fiber

[0094] 3 Outer layer 14 Additive

[0095] 4 Skin 15 Bamboo chips

[0096] 5 Bamboo log 16 Bamboo Flakes

[0097] 6 Log segments 17 Longitudinal slicing plane

[0098] 7 Outer surface 18 Knife

[0099] 8 Inner surface

[0100] 9 Embedded fiber W Width

[0101] 10 Log sector L Length

[0102] 11 Partition wall T Thickness

Claims

P28760PC00 19.09.202523 / 27PATENT CLAIMS1. A fiberboard (1 ) for isolation and / or damping, the fiberboard (1 ) produced by following method steps: a. Chipping of bamboo logs (5) into bamboo chips (15); b. Flaking of the bamboo chips (15) into bamboo flakes (16) c. Pulping of the bamboo flakes (16) into detached bamboo fibers (13); d. Distributing the detached bamboo fibers (13) to form a loose bamboo mat; e. Hot pressing the bamboo mat into the fiberboard (1 ).

2. The fiberboard (1 ) according to claim 1 , wherein chipping further comprises a. a chopping process to create a specific length L of the bamboo chips (15), and b. a slicing process to create a specific width W and thickness T of the bamboo chips (15), wherein c. the width W of the bamboo chips (15) corresponds to the wall thickness of the bamboo logs (5) from which the respective bamboo chip (15) is made.P28760PC00 19.09.202524 / 273. The fiberboard (1 ) according to claim 1 or 2, wherein the chopping process is performed before or after the slicing process.

4. The fiberboard (1 ) according to claim 2 or 3, wherein in the chopping process the bamboo logs (5) are chopped essentially perpendicular to a fiber direction of embedded fibers (9) of the respective bamboo logs (5).

5. The fiberboard (1 ) to any one of the claims 1 to 4, wherein in the slicing process the bamboo logs (5) are sliced essentially parallel to a fiber direction of embedded fibers (9) of the respective bamboo logs (5).

6. The fiberboard (1 ) according to any one of the claims 1 to 5, wherein the bamboo logs (5) are mechanically crushed, in particular in a longitudinal direction of the bamboo logs (5), before the slicing process.

7. The fiberboard (1 ) according to any one of the preceding claims, wherein the flaking is performed in a knife ring flaker.

8. The fiberboard (1 ) according to any one of the preceding claims, wherein a majority of the bamboo flakes (16) have a reduced thickness T with respect to the bamboo chips (15), but the same length L and / or width W.

9. The fiberboard (1 ) according to any one of the preceding claims, wherein the method further comprises the method step of pre pressing of the loose bamboo mat to reduce the thickness and increase the density of the bamboo mat.P28760PC00 19.09.202525 / 2710. The fiberboard (1 ) according to any one of the preceding claims, wherein the method further comprises the method step of trimming the insulation board to a required dimensions and / or sanding the insulation board to a required surface roughness.

11. The fiberboard (1 ) according to any one of the preceding claims, wherein an additive is added to the detached bamboo fibers (13) before pressing of fiber mat.

12. The fiberboard (1 ) according to claim 11 , wherein one additive is a fire retardant material, which in particular accounts for up to 25% of the total weight of the fiberboard (1 ).

13. The fiberboard (1 ) according to claim 11 or 12, wherein one additive is a glue, in particular comprising Polymethylene Diphenyl Diisocyanate.

14. Method to produce a fiberboard (1 ), the method comprising the following method steps: a. Chipping of bamboo logs (5) into bamboo chips (15); b. Flaking of the bamboo chips (15) into bamboo flakes (16); c. Pulping of the bamboo flakes (16) into detached bamboo fibersP28760PC00 19.09.202526 / 27 d. Distributing the detached bamboo fibers (13) to form a loose bamboo mat; e. Hot pressing the bamboo mat into the fiberboard (1 ).

15. The method according to claim 14, wherein the chipping encompasses a. a chopping process to create a specific length L of the bamboo chips, and b. a slicing process to create a specific width W and thickness T of the bamboo chips (15), wherein c. the width W of the bamboo chips (15) corresponds to the wall thick- ness of the bamboo logs (5) from which the respective bamboo chip(15) is made.

Images