Manufacturing method for optimizing heat insulation plate, heat insulation plate and heat insulation structure comprising heat insulation plate

Abstract

The invention relates to a method for manufacturing a heat insulation plate based on grain straws, which is characterized by comprising the following steps: a) mechanically grinding and screening the straws to obtain fiber-separated straws, the average length of fiber bundles of which is between 3mm and 11mm and the average diameter of which is between 0.5 mm and 2.5 mm; b) mixing the fiber-separated straw with a binding material in a weight ratio of 3% to 25%, preferably 4% to 10%, using a mixer; c) injecting compressed air into the mixture to homogenize the mixture; d) heating the heat insulation plate and calibrating the heat insulation plate in the length and width directions; e) calibrating the thickness of the material forming the insulation panel; f) heating the entire thickness of the insulation panel to a temperature of at least 90 DEG C, preferably between 110 DEG C and 150 DEG C, and holding for at least 3 minutes; g) cooling the insulation panel to an ambient temperature; and h) packaging the heat insulation plate.

Description

Technical Field

[0001] The present invention relates to the general technical field of thermal insulation materials for construction (insulating materials). These insulating materials are usually used to cover walls or roofs to provide thermal and acoustic insulation. These insulating materials, for example in the form of rigid or semi-rigid insulating panels, can also be integrated into prefabricated modular structures made of wood or concrete.

[0002] These insulation materials must also comply with national and / or European standards and have a fire resistance rating.

[0003] In France and other countries, public and private tender specifications increasingly require the use of bio-based insulation materials with the lowest possible environmental impact. These insulation materials are made, for example, from renewable and recyclable raw materials such as wood fibers, cellulose batting, textile fibers, expanded cork, hemp, wool or other bio-based materials.

[0004] The term "biobased materials" refers to materials derived from renewable organic matter (biomass) of plant or animal origin.

[0005] The invention more particularly relates to the manufacture of such insulation materials in the form of insulation panels. Background Art

[0006] For example, it is known to use cereal straw to insulate walls or to build such walls from straw bales. These bales must then be combined with siding-like elements to achieve the legally required fire resistance as well as water and air infiltration resistance. The wall thickness of these components is usually thicker than when non-biobased insulation materials are used, in order to compensate for their generally poor thermal conductivity (λ).

[0007] It should also be noted that due to the limited fire performance of most known bio-based insulation materials, they are not suitable or approved for use in buildings above three storeys.

[0008] There are currently many disadvantages to using straw as insulation. These include being suitable only for buildings up to three storeys high, the size of the straw bales, the high amount of dust and debris they generate, the added weight of the structure due to the thicker insulation, the need to add non-bio-based materials such as plasterboard or rock wool, and the fact that it is not an industrially mass-produced product.

[0009] From the document WO 2018 / 018079 A1, a method for manufacturing a board based on a mixture of straw and a phenolic resin-based binder is known. The method requires that the moisture content of the straw be controlled below 12%, and then the board is formed by heating the mixture to a high temperature of more than 150°C and up to 250°C and applying high pressure to it for compression. Such operating parameters are very complex to implement and have a negative impact on the energy costs and profitability of the manufacturing method. The above method requires the use of a fixed press to obtain the required high pressure and temperature, which makes continuous production impossible. Summary of the invention

[0010] Therefore, one object of the present invention is to overcome the drawbacks of the prior art by proposing a new method of manufacturing insulation panels using environmentally friendly, renewable, recyclable raw materials that are available in almost all rural areas.

[0011] Another object of the present invention is to propose a method for manufacturing an insulation panel which is simple to operate and cost-effective.

[0012] Yet another object of the present invention is to provide an insulation panel having excellent fire protection properties as well as thermal and sound insulation properties.

[0013] It is a further object of the present invention to provide an insulation panel having sufficient characteristics and performance to be used in buildings with more than three stories.

[0014] Another object of the present invention is to provide a prefabricated modular insulation element having excellent fire protection properties as well as thermal and acoustic insulation properties.

[0015] The object of the present invention is achieved by a method for continuously manufacturing insulation panels based on cereal straw, characterized in that the method comprises the following steps: a) mechanically grinding the straw to obtain fiber-separated straw, wherein the average length of the fiber bundles is between 3 mm and 22 mm, preferably between 3 mm and 11 mm, and the average diameter is between 0.5 mm and 4.0 mm, preferably between 0.5 mm and 2.5 mm; b) using a mixer, mixing the defiberized straw with a binding material introduced into the mixer in a weight proportion of 3% to 25%, preferably 3% to 10%, more preferably 3% to 9%, based on the total weight of the mixture; c) injecting compressed air into the mixture to make the mixture uniform; d) placing the mixture on a conveyor belt; e) calibrating the thickness of the mixture to form a continuous mixed material strip having a determined thickness; f) heating the mixed material strip for a heating period of time d cThe temperature of the entire mixed material strip in the thickness direction is reached and / or maintained at least 90°C, preferably between 110°C and 150°C, more preferably between 110°C and 145°C; g) cooling the insulating tape thus obtained to ambient temperature or close to ambient temperature and calibrating the insulating tape in width and length to form an insulating panel; h) Packing the insulation panels.

[0016] According to one embodiment, in step a), the method is to chop and grind the bundled straw using at least one grinder, wherein the at least one grinder is equipped with adjustable chopping / grinding tools for determining the shape and size characteristics of the obtained fiber-separated straw fiber bundles, wherein the tools include a knife and a hammer in sequence.

[0017] According to one embodiment, in steps b), c) and d), the process uses at least one rotating drum mixer (3) to which a chute is connected downstream.

[0018] According to one embodiment, the method comprises filtering the defiberized straw obtained in step a) to remove dust and other impurities accounting for at least 2%, preferably at least 5% to 10% by weight of the defiberized straw.

[0019] According to one embodiment, in step e), the method applies linear pressure to the insulating panel being formed by a compression roller. According to another example, pressure bars, stainless steel molds or meshes can also be used to calibrate the thickness.

[0020] According to one embodiment, the bonding material comprises a hot melt two-component bonding agent selected from a two-component bonding agent comprising PLA / Co-PLA (polylactic acid / co-polylactic acid), PLA / PBS (polylactic acid / polybutylene succinate) type polylactic acid biopolymer fibers obtained from grains.

[0021] According to another embodiment, the adhesive material comprises a hot melt two-component adhesive comprising polyester / polyethylene and polyester / PBT fibers (polybutylene terephthalate fibers).

[0022] According to one embodiment, the method is to mix the bonding material, or a mixture of fiber-separated straw and the bonding material, with one or more additives containing fungicides, the weight of the additives relative to the total weight of the mixed product being between 0.03% and 11%, preferably between 0.5% and 4%.

[0023] According to another embodiment, after step f), and preferably after longitudinal and transverse shaping of the mixture, the method consists in spraying on each face of the mixture one or more additives comprising a fungicide, the weight of the additives being between 0.03% and 11%, preferably between 0.5% and 4%, relative to the total weight of the mixed product.

[0024] As an example, the additive comprises a flame retardant, the weight of which accounts for 24% to 72% of the total weight of the mixed product. For example, the flame retardant is selected from a series of geo-based products.

[0025] As an example, the flame retardant is in a viscous or liquid state and comprises a metakaolin-type geopolymer.

[0026] Advantageously, the method comprises, before step b), operations of disentangling and aerating the adhesive material.

[0027] According to one embodiment, step f) deeply heats the mixed material strip by a high frequency or microwave heating system, while also heating the free peripheral edge surface of the mixed material strip using an additional heating system, the additional heating system comprising an infrared heating system.

[0028] According to another embodiment, the additional heating system may include infrared and / or forced air heating devices.

[0029] Advantageously, the method controls the conveyor belt's forward speed so that the mixed material strip stays in the active heating zone for at least a minimum heating time d of 3 minutes. c The minimum heating time d c Depending on a number of parameters, including the moisture content of the mix, the density of the mix, the thickness of the mixed strip, the type of binding material used, the amount of heat used and / or the duration of the heat treatment.

[0030] According to one embodiment, the method measures the temperature at the edge of the mixed material strip using at least one sensor and / or probe, and measures the temperature at the center of the mixed material strip using at least one sensor and / or probe, and then continuously controls the heating system based on the values ​​measured by these sensors and / or probes.

[0031] According to one embodiment, the method measures the moisture content of the mixture during step d) or e) by using at least one sensor and / or probe and controlling the heating system according to the value measured by the sensor and / or probe.

[0032] According to one embodiment, the method comprises the step of applying to at least one face of the insulation panel a fire-proof or flame-retardant coating having a thickness of at least 0.5 mm.

[0033] The object of the present invention can also be achieved by a rigid or semi-rigid insulation board or insulation assembly, which comprises at least one board obtained by the above manufacturing method, wherein the density of the board is 50 kg / m 3 Up to 150kg / m 3 Between, preferably between 60kg / m 3 Up to 100kg / m 3 between.

[0034] The object of the present invention can also be achieved by a rigid or semi-rigid insulation board, which includes a first board obtained by the above-mentioned manufacturing method, and an additional flame retardant board is glued to the first board, and the additional board is also obtained by the same manufacturing method, and the weight of the flame retardant in it accounts for more than 49% of the total weight of the mixed product.

[0035] The objects of the invention are also achieved by a prefabricated modular structure made of wood or a mixture of concrete and wood for building walls or for internal or external cladding of walls of buildings, characterized in that the structure comprises at least one insulating panel manufactured according to the above method.

[0036] The manufacturing method according to the invention has the significant advantage that the insulation board obtained is very uniform throughout its thickness. The method of the invention allows sufficient heating of the central part of the insulation board, so that the insulation board is completely and uniformly polymerized throughout its thickness. This helps to improve the insulation performance and acoustic insulation performance and strength of the insulation board over time.

[0037] Another advantage of the method of the present invention is that the fire protection performance level of the obtained insulation board complies with various current standards and regulations.

[0038] The insulation boards obtained by the method of the invention also exhibit excellent performance. The thermal conductivity λ of these insulation boards is 0.038, which is quite outstanding considering that the thermal conductivity of straw is between 0.052 and 0.080, that of expanded cork is between 0.037 and 0.044, and that of cellulose batt is between 0.037 and 0.042.

[0039] Due to the method of the invention, the insulation boards produced are more convenient to handle and store. In particular, compared with straw bales, these insulation boards are lighter and smaller in size.

[0040] Another advantage of the method according to the invention is that it can be carried out at lower temperatures and pressures than those used in the prior art. It is therefore not necessary to use a stationary press. This makes the production method easier and more cost-effective. Furthermore, continuous production can be achieved in a simple manner.

[0041] Remarkably and unexpectedly, the method of the present invention enables the heat energy supplied to the mixture to be evenly distributed both in the center and at the periphery during continuous manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Other features and advantages of the present invention will become more apparent by reading the following description in conjunction with the accompanying drawings, which are provided as non-limiting examples only, in which: - Figure 1 A schematic diagram of a flow chart of an embodiment of the manufacturing method of the present invention; - Figure 2 A schematic diagram of a flow chart of another embodiment of the manufacturing method of the present invention; - Figure 3 for Figure 2 Schematic diagram of a flow chart of an alternative embodiment shown; - Figure 4 A schematic diagram of a flow chart of another embodiment of the manufacturing method of the present invention; - Figure 5 The present invention is a schematic flow chart of another embodiment of the manufacturing method. DETAILED DESCRIPTION

[0043] In several different drawings, elements having the same structure and function are indicated by the same alphanumeric or numerical designations.

[0044] Figure 1 An example apparatus for implementing a method for making an insulation panel from cereal straw (such as wheat, barley, oats, rapeseed, miscanthus, rice straw, or various mixtures thereof) is shown.

[0045] The device comprises a grinding unit 1 for converting raw straw into fiber-separated straw by chopping and grinding.

[0046] More advantageously, the grinding and fiber separation unit 1 is equipped with a tool for cutting and breaking up the straw fiber bundle. For example, the grinding and fiber separation unit 1 comprises two grinders in sequence. The first grinder is, for example, equipped with a tool for cutting the straw fiber bundle, such as a knife. The second grinder is, for example, equipped with a tool for breaking up the straw fiber bundle, such as a hammer.

[0047] The term "fiber separation straw" refers to a straw comprising cut and broken fiber bundles, the average length of which is between 3 mm and 22 mm, and the average diameter is between 0.5 mm and 4.0 mm. Preferably, the fiber bundles of the fiber separation straw have an average length of between 3 mm and 11 mm, and an average diameter of between 0.5 mm and 2.5 mm.

[0048] The average diameter is understood to be the largest dimension of the straw fiber bundle in a plane orthogonal to the longitudinal direction of the fiber bundle.

[0049] For example, the fiber defibered straw contained 29%-33% fiber bundles with an average length of 9.633 mm and an average diameter greater than 2 mm, 32%-37% fiber bundles with an average length of 6.951 mm and an average diameter greater than 1 mm, and 16%-20% fiber bundles with an average length of 3.960 mm and an average diameter greater than 0.5 mm.

[0050] The remainder of the sample is considered dust and is preferably removed by filtering using a filter / metering unit 2 .

[0051] Through the flow chart, Figure 1 An embodiment of a method for making an insulation panel from cereal straw (such as wheat, barley, oats, rapeseed, miscanthus, rice straw or various mixtures thereof) is presented.

[0052] The device comprises a grinding and fiber separation unit 1, which converts raw straw into fiber separated straw by chopping and grinding.

[0053] The term "defibrated straw" preferably refers to a straw comprising inhomogeneous fiber bundles having an average length of between 3 mm and 11 mm and an average diameter of between 0.5 mm and 2.5 mm.

[0054] The average diameter is understood to be the largest dimension of the straw fiber bundle in a plane orthogonal to the longitudinal direction of the fiber bundle.

[0055] For example, the fiber defibered straw contained 29%-33% fiber bundles with an average length of 9.633 mm and an average diameter greater than 2 mm, 32%-37% fiber bundles with an average length of 6.951 mm and an average diameter greater than 1 mm, and 16%-20% fiber bundles with an average length of 3.960 mm and an average diameter greater than 0.5 mm.

[0056] The remainder of the example sample is considered dust and is preferably removed by filtering using the filter / metering unit 2 .

[0057] Manufacturing methods such as using Figure 1 The method is implemented by the device shown in the flowchart.

[0058] The device comprises a grinding / shredding unit 1, which is fed with straw packaged in bales, etc. Advantageously, the grinding / shredding unit 1 in turn comprises two grinders, which may be equipped with grinding tools having a specific shape or arrangement.

[0059] Advantageously, these grinders are equipped with adjustable chopping and grinding tools for determining the parameters of the defiberized straw fiber bundles in terms of shape and size.

[0060] According to another embodiment of the device, the grinding / chopping unit 1 includes a cutter for cutting the straw fiber bundle and a hammer for breaking the fiber bundle. As a part of straw chopping and grinding, one or more channels can be provided in the grinding / chopping unit 1. The number of channels depends on the morphology (shape, length and diameter) of the desired fiber separation straw fiber bundle. Therefore, at the outlet of the grinding / chopping unit 1, a fiber separation straw fiber bundle optimized in size and shape can be obtained, which can promote mixing with the bonding material, and can improve the heat insulation, sound insulation and mechanical properties of the obtained solid insulation material.

[0061] According to one embodiment, the device also comprises a filtering and metering unit 2 which directly feeds the mixer 3 .

[0062] The filtering operation is performed, for example, by a vibrating screen and / or a cyclone separator. The cyclone separator can advantageously be used to transfer the defiberized straw to the mixer 3. The filtering can separate the defiberized straw from dust and other impurities by gravity or cyclone filtration.

[0063] The mixer 3 comprises, for example, at least one rotating drum mixer, to which a chute is connected downstream. Advantageously, a plurality of chutes and / or one or more buffer tanks filled with the mixture can be used to ensure the continuity of the delivery supply.

[0064] The device further comprises a first metering and spraying unit 4a for supplying additives to the mixer 3. These additives include at least one biocidal additive F and possibly also a flame retardant additive R.

[0065] The device further comprises a second metering and spraying unit 4 b for supplying the mixer 3 with bonding material.

[0066] Advantageously, the device comprises a disentanglement and aeration unit 5 for loosening the adhesive material before it is metered and sprayed into the mixer 3. The disentanglement and aeration unit 5 comprises, for example, a carding system to separate the constituent fibers of the adhesive material.

[0067] The device also comprises a compressor 6 for injecting compressed air into the mixer 3, thereby promoting homogenization and aeration of the mixture.

[0068] The device also comprises a unit 7 for at least shaping and calibrating the thickness of the mixture at the outlet of the mixer 3. The shaping and calibrating unit 7 is capable of producing a mixed strip with a specific shape and thickness, for example by molding.

[0069] The device further comprises a heating unit 8 for heating the entire thickness of the mixed material strip, so as to achieve cross-linking of the bonding material and further harden the mixed material strip or the preformed insulation board.

[0070] The device further comprises a unit 9 for cooling the mixed strip or the thermal insulation board at the outlet of the heating unit 8. The cooling unit 9 can be, for example, a conveyor belt in the ambient air, which transports the thermal insulation board to the packaging unit 10. The cooling unit 9 can also comprise an intermediate storage area, in which the thermal insulation board is stored for the required cooling time.

[0071] Figure 2 is a schematic flow diagram of another embodiment of a method for manufacturing an insulation board. To this end, the device comprises a gluing unit 11 for gluing an additional rigid fire-retardant board to the rigid or semi-rigid insulation board downstream of the cooling unit 9. This additional board is for example made of known materials, for example based on gypsum or the like.

[0072] According to another embodiment of the method, this additional board is also obtained by the manufacturing method of the present invention. In this case, it is more advantageous that the weight of the flame retardant product accounts for more than 49% of the total weight of the mixed product. Then, this additional board has a higher density and a smaller thickness than the first rigid or semi-rigid insulation board. In this way, an assembly with excellent thermal and acoustic insulation properties and good fire protection properties is obtained.

[0073] Figure 3 is a schematic flow diagram of another embodiment of a method for manufacturing an insulation panel. To this end, the apparatus comprises a coating unit 12 for coating a rigid or semi-rigid insulation panel with a flame retardant or fireproof coating downstream of a cooling unit 9. The coating is made, for example, of a known flame retardant product.

[0074] The insulation board is then placed in a drying unit 13 before being conveyed to the packaging unit 10 .

[0075] Figure 4 is a flow chart showing a further embodiment of the manufacturing method of the present invention. The apparatus for implementing the method comprises a heating and supplementary mixing unit 7a at the outlet of the mixer 3. More advantageously, the heating and supplementary mixing unit 7a comprises a chute into which the preheated air is injected.

[0076] According to one embodiment, infrared lamps and / or air heated by electrical resistance may be used to heat the mixture in the chute.

[0077] Downstream of the chute, the device comprises a conveyor belt and a calibration and heating unit 8a, for example in the form of a heating mould, into which the mixture coming from said chute is transferred by gravity or conveying.

[0078] Therefore, the heating operation continues before the cooling operation, during and / or after the thickness calibration of the mixed strip. The mixture is continuously heated to maintain the temperature for at least the minimum heating time d c , thereby achieving optimal crosslinking of the bonding materials in the mixture.

[0079] In step f), according to another embodiment, the calibration and heating unit 8a comprises a system for generating hot air which is injected under pressure into the insulating panel which has been preformed at least in terms of thickness.

[0080] Heating the mixture causes the binding material to cross-link, thereby forming a three-dimensional rigid network in which the fiber bundles of the fiber separation straw and the fibers of the binding material are bound together.

[0081] As the fiber bundles of the defibrated straw are cut and broken up, they are also mechanically fixed in place in a rigid network of cross-linked binding material.

[0082] Figure 5 FIG. 2 is a schematic flow diagram of another embodiment of the manufacturing method of the present invention. In this embodiment, the device comprises a first mixer 3a and a second mixer 3b in sequence.

[0083] At the outlet of the filtering and metering unit 2, the defibrated straw is conveyed to a first mixer 3a, and the binding material is conveyed to the mixer at the outlet of the second metering and spraying unit 4b.

[0084] Depending on the specific properties desired for the insulation panel, the mixture A prepared in the first mixer 3 a , possibly with the addition of a biocidal additive F, is conveyed to the forming and calibration unit 7 (arrow A).

[0085] The mixture A prepared in the first mixer 3a, possibly with the addition of a biocidal additive F, is conveyed to the second mixer 3b, depending on the other specific properties required of the insulation panel.

[0086] The supplementary spray metering unit 4c can then inject the flame retardant additive R into the second mixer 3b. This results in a mixture B, which is conveyed to the forming and calibration unit 7. The mixture B can then produce an insulation board with enhanced flame retardant properties, depending on the nature and weight proportion of the flame retardant additive R used.

[0087] Therefore, a plate-shaped thermal insulation material is manufactured according to one embodiment of a manufacturing method described in detail below.

[0088] The method for manufacturing thermal insulation material based on cereal straw comprises step a), i.e. grinding, chopping or mechanically cutting the straw to obtain fiber separated straw, the average length of the fiber bundles of which is preferably between 3 mm and 11 mm, and the average diameter is between 0.5 mm and 2.5 mm.

[0089] Advantageously, the method comprises filtering the defiberized straw obtained in step a) to remove dust and other impurities accounting for at least 2%, preferably 5% to 10% by weight of the defiberized straw. Thus, undesirable residues, dust or other substances that affect the performance of the thermal insulation material can be separated by gravity, for example using a vibrating screen, or cyclone filtration. Such filtration and separation advantageously reduces the risk of explosions at the manufacturing site due to dust concentrations in the air.

[0090] According to step b), the defiberized straw is mixed using a mixer 3 with a binding material introduced into the mixer 3 (eg by spraying) in a weight proportion of 3% to 25%, preferably 3% to 10%, more preferably 3% to 9% of the total weight of the mixture.

[0091] According to a more advantageous embodiment, the method comprises, before step b), an operation of disentangling and aerating the two-component adhesive material. For example, the preparation of this adhesive material comprises a carding operation. This disentanglement and aeration phase can be carried out, for example, separately or directly in the mixer 3 before the introduction of the adhesive material.

[0092] Then, after the bonding material, the defiberized straw is sequentially introduced into the mixer 3 or the first mixer 3a.

[0093] According to step c), compressed air is injected into the mixture, more precisely into the mixer 3, the first mixer 3a and, if applicable, the second mixer 3b, in order to homogenize the mixture.

[0094] Then, according to step d), the mixture is deposited by gravity on a conveyor such as a conveyor belt.

[0095] According to the subsequent step e), the thickness of the mixture is calibrated to form a continuous strip with a determined thickness. For example, a linear pressure is applied to the mixed strip by a compression roller to calibrate the thickness.

[0096] Next, according to step f), the mixed strip is heated to or maintained at a temperature of at least 90°C, preferably between 110°C and 150°C, more preferably between 110°C and 145°C, throughout its thickness for a heating time dc of at least 3 minutes.

[0097] Then, according to step g), the insulating strip thus obtained is cooled to ambient temperature or close to ambient temperature. During this step g), the insulating board obtained by cutting the peripheral rigid or semi-rigid insulating strip is also calibrated in width and length. This operation is carried out in a manner known per se, for example by sawing.

[0098] Finally, according to step h), the insulation panels are packaged.

[0099] According to a preferred example, step f) heats the mixture strip deeply by a high frequency or microwave heating system, and also heats the free peripheral edge surface of the mixture strip by an additional heating system. For example, the mixture is at least partially heat treated by a high frequency heating system. The frequency used is, for example, 13.56 MHz. According to another embodiment, the mixture is at least partially heat treated by a microwave heating system. The frequency used at this time is, for example, 915 MHz or 2450 MHz.

[0100] Advantageously, the additional heating system comprises an infrared radiation heating system.A plurality of infrared radiation heating systems can be used to irradiate all peripheral surfaces, in particular the free peripheral edge surfaces of the mixed material strip.

[0101] Advantageously, the manufacturing method comprises controlling the advancement speed of the conveyor belt so that the time during which the mixed material strip being conveyed stays in the active heating zone corresponds to the minimum heating time dc.

[0102] Advantageously, the manufacturing method comprises measuring the temperature at the edge of the mixed strip using at least one sensor and measuring the temperature at the center of the mixed strip using at least one sensor. The heating system and the additional heating system are then continuously controlled based on the values ​​measured by these sensors. Maintaining a minimum temperature at the edge of the mixed strip ensures that the bonding material is evenly crosslinked even at the edge of the mixed strip.

[0103] Advantageously, the manufacturing method comprises measuring the moisture content of the mixture during step d) or e) using at least one sensor and controlling the heating system according to the value measured by the sensor. The moisture content of the mixture is advantageously between 5% and 40%, preferably between 12% and 30%, more preferably between 13% and 25%. By controlling the moisture content and the temperature at the edge and the center of the mixed strip, the heating energy provided by the heating system can be significantly reduced, since the heat energy to be uniformly dissipated in the mixed strip depends on the moisture content.

[0104] The duration of the mixing operation depends on the size of the device, in particular the size of the mixer 3 .

[0105] According to one embodiment, in step a), the method comprises chopping and grinding the bales of straw using at least one grinder, the at least one grinder comprising adjustable chopping / grinding tools for determining the characteristics of the obtained defiberized straw fiber bundles in terms of shape and size.

[0106] More advantageously, the mixers 3, 3a and 3b are rotating cylinders connected downstream to a chute.

[0107] According to one embodiment, the bonding material comprises a bonding agent containing hot melt bicomponent fibers, polyester / polyethylene or polyester / PBT fibers. More advantageously, these hot melt bicomponent fibers have a relatively low melting point of about 110°C.

[0108] According to another embodiment, the bonding material comprises polylactic acid biopolymer fibers of the PLA / Co-PLA, PLA / PBS type obtained from corn. More advantageously, these hot-melt bicomponent fibers have a melting point between 130°C and 164°C.

[0109] According to one embodiment, the method comprises mixing a binding material, or a mixture of defiberized straw and a binding material, with one or more additives comprising a fungicide, the weight of the additives being between 0.03% and 11%, preferably between 0.5% and 4%, relative to the total weight of the mixed product.

[0110] According to another embodiment, the method comprises, after step f), and preferably after longitudinal and transverse shaping of the mixture, spraying on each side of the mixed strip one or more additives comprising a bactericide, the weight of the additives being between 0.03% and 11%, preferably between 0.5% and 4%, relative to the total weight of the mixed product. Figure 1 .

[0111] For example, the mixed strip is formed longitudinally and transversely by means of a peripheral cutting operation.

[0112] According to another embodiment, the additive comprises a flame retardant in an amount ranging from 24% to 72% by weight of the total weight of the mixed product.

[0113] According to another embodiment, the flame retardant comprises a viscous or liquid geopolymer. This may be metakaolin, for example.

[0114] According to one embodiment, the method comprises the step of applying to at least one face of the insulation panel a fire-proof or flame-retardant coating having a thickness of at least 0.5 mm.

[0115] The present invention also relates to a composite thermal insulation board, which comprises the thermal insulation board obtained according to the above manufacturing method and has an additional flame retardant board pasted thereon.

[0116] The invention also relates to a prefabricated modular structure made of wood for building walls or for external or internal cladding of building walls. This structure comprises at least one insulating panel obtained according to the manufacturing method described above.

[0117] The invention also relates to a prefabricated modular structure made of a mixture of wood and concrete, used for building walls or for external or internal cladding of building walls. This structure comprises at least one insulating panel obtained according to the above-described manufacturing method.

[0118] For example, the method according to the invention can produce a semi-rigid insulation board having a density of 50 kg / m 3 Up to 150kg / m 3 Between, preferably between 60kg / m 3 Up to 100kg / m 3 Density is between 50kg / m 3 Up to 100kg / m 3 The insulation board between them mainly has thermal insulation performance, and the density is 100kg / m 3 Up to 150kg / m 3 The insulation panels between them mainly have fireproof and sound insulation properties.

[0119] Therefore, the insulation panels obtained by the method of the invention can have very different technical characteristics. The same manufacturing method can be used to obtain panels suitable for different application scenarios. According to these technical characteristics, the panels can be applied to roofs, walls or floors.

[0120] It goes without saying that this specification is not limited to the examples explicitly described, but also covers other embodiments and / or implementations. Therefore, without departing from the scope of the invention defined by the claims, the described technical features or method steps may be replaced by equivalent technical features or steps where applicable.

Claims

1. A method for continuously manufacturing insulation panels based on cereal straw, characterized in that The following steps are involved: a) mechanically grinding the straw to obtain a fiber-separated straw, wherein the average length of the fiber bundles is between 3 mm and 22 mm, preferably between 3 mm and 11 mm, and the average diameter is between 0.5 mm and 4.0 mm, preferably between 0.5 mm and 2.5 mm; b) using a mixer (3), mixing the defiberized straw with a binding material introduced into the mixer (3) in a weight proportion of 3% to 25%, preferably 3% to 10%, more preferably 3% to 9% based on the total weight of the mixture; c) injecting compressed air into the mixture to homogenize the mixture; d) placing the mixture on a conveyor belt; e) calibrating the thickness of the mixture to form a continuous mixed material strip having a determined thickness; f) heating the mixed material strip so that it is heated for a heating time d c A temperature of at least 90°C, preferably between 110°C and 150°C, more preferably between 110°C and 145°C, is reached and / or maintained throughout the thickness; g) cooling the insulating strip thus obtained to ambient temperature or close to ambient temperature and calibrating the insulating strip in width and length to form an insulating panel; h) Packing the insulation panels.

2. The method according to claim 1, characterized in that In step a), the bundled straw is chopped and ground using at least one grinder, the at least one grinder comprising adjustable chopping / grinding tools for determining the obtained defiberized straw fiber bundles in terms of shape and size, the tools comprising in turn a knife and a hammer.

3. The method according to claim 1 or 2, characterized in that: In steps b), c) and d), at least one rotating drum mixer (3) is used, to which a chute feeding the conveyor belt is connected downstream.

4. The method according to any one of claims 1 to 3, characterized in that The defiberized straw obtained in step a) is filtered to remove dust and other impurities accounting for at least 2%, preferably at least 5% to 10% by weight of the defiberized straw.

5. The method according to any one of claims 1 to 4, characterized in that The adhesive material comprises a hot melt two-component adhesive selected from a two-component adhesive comprising PLA / Co-PLA, PLA / PBS type polylactic acid biopolymer fibers obtained from grains.

6. The method according to any one of claims 1 to 4, characterized in that The adhesive material includes a hot melt two-component adhesive containing polyester / polyethylene or polyester / PBT fibers.

7. The method according to any one of claims 1 to 6, characterized in that The binding material, or a mixture of defiberized straw and the binding material, is mixed with one or more additives containing fungicides, the weight of the additives being between 0.03% and 11%, preferably between 0.5% and 4%, relative to the total weight of the mixed product.

8. The method according to any one of claims 1 to 6, characterized in that After step f), and preferably after longitudinal and transverse shaping of the mixture, one or more additives comprising a fungicide are sprayed on each side of the mixture, the weight of the additives being between 0.03% and 11%, preferably between 0.5% and 4%, relative to the total weight of the mixed product.

9. The method according to any one of claims 1 to 8, characterized in that The additive comprises a flame retardant in an amount ranging from 24% to 72% by weight of the total weight of the mixed product.

10. The method according to claim 5 or 6, characterized in that: The step b) includes disentangling and aerating the bonding material.

11. The method according to any one of claims 1 to 10, characterized in that Step f) deeply heats the mixed material strip by a high frequency or microwave heating system, and also heats the free peripheral edge surface of the mixed material strip by an additional heating system, the additional heating system comprising an infrared heating system.

12. The method according to any one of claims 1 to 11, characterized in that The temperature of the edge of the mixed material strip is measured using at least one sensor and / or probe, and the temperature of the center of the mixed material strip is measured using at least one sensor and / or probe, and the heating system is continuously controlled based on the values ​​measured by these sensors and / or probes.

13. The method according to any one of claims 1 to 12, characterized in that During step d) or e), the moisture content of the mixture is measured using at least one sensor and / or probe, and the heating system is controlled based on the value measured by the sensor and / or probe.

14. A thermal insulation panel or thermal insulation assembly, which is semi-rigid and comprises at least one panel obtained by the manufacturing method according to any one of claims 1 to 13, the density of the panel being between 50 kg / m 3 Up to 150kg / m 3 Between, preferably between 60kg / m 3 Up to 100kg / m 3 between.

15. Prefabricated modular structures made of wood or a mixture of concrete and wood for use in the construction of walls or for external or internal covering of building walls, characterized in that: The structure comprises at least one insulating panel manufactured according to the method of any one of claims 1 to 13.

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