AU2009265534A1

AU2009265534A1 - Novel plant-based material

Info

Publication number: AU2009265534A1
Application number: AU2009265534A
Authority: AU
Inventors: Pierre Valere Andreucci; Axel Ferrazzini
Original assignee: ENERGIA SARL
Current assignee: ENERGIA SARL
Priority date: 2008-07-03
Filing date: 2009-07-02
Publication date: 2010-01-07
Also published as: WO2010000983A1; EP2294334A1; IL210426A0; FR2933473B1; MA32446B1; FR2933473A1

Description

1 Novel plant-based material The present invention relates to the field of materials, particularly insulating materials. It relates particularly to a material based on Posidonia, as well as a 5 manufacturing method and uses for this material. Heat and/or sound insulation makes it possible to limit exchanges of heat and sound between two systems. A thermal insulator is a material having a low thermal conductivity; it makes it possible to limit heat losses (cooling) or heat entry (keeping cool). 10 A material which limits sound exchanges makes it possible to insulate against noise by reducing the propagation of sound passing through it. Thermal and sound insulation represents a significant challenge in the field of construction in general; sound insulation is also a significant challenge in the field of roads (in particular motorways), where anti-noise barriers prevent vehicle noise from 15 disturbing nearby residents. It should be noted however that sound and/or thermal insulation is not limited to the field of construction alone, but is involved in many other fields, in which the invention can also be used. During the last few years, and in particular as a result of the problems posed by 20 asbestos, a constant effort has been made to improve the ecological assessments of insulation, with less toxic and less ecotoxic materials that are recycled or can be recycled and have a low energy consumption. Such insulators are increasingly required or encouraged by some local authorities. Good thermal insulation makes it possible to save energy. The environmental 25 issue is significant, more particularly as thermal and sound insulation can be made with so-called "ecological" materials. Since energy is becoming increasingly expensive, and in the case of some sources, increasingly scarce, saving is an important issue. It would be beneficial to develop a good-quality insulation, based on a natural product, having a low cost and moreover capable of using a polluting waste as its main 30 constituent. This is one of the purposes of the present invention. In the present text, by material is meant a rigid and non-deformable product, and by insulating material, a solid material making it possible to limit the heat and/or sound exchanges between two systems, i.e. preventing losses or entry of heat, and/or limiting 35 the propagation of noise. Posidonia (Neptune grasses) is a genus of aquatic plants from the family Posidoniaceae. Although they live underwater, these are not algae, but submarine 2 monocotyledonous flowering plants (angiosperms). Like all flowering plants, they have roots, and reproduce by means of the fruits that they produce. There are 9 species of Posidonia (posidonia angustifolia, posidonia australis, posidonia coriacea, posidonia denhartogii, posidonia kirkmanii, posidonia oceanica, 5 posidonia ostenfeldii, posidonia robertsoniae, posidonia sinuosa), of which 8 are found on the Australian coasts and 1, posidonia oceanica, is endemic to the Mediterranean. When Posidonia die, they are thrown up onto the shore by the sea. These plants form large heaps called banks of Posidonia. These banks constitute a polluting waste and produce an olfactory nuisance. 10 It is understood that there is a need to find a use in order to exploit the by-product constituted by the Posidonia that have accumulated on the shore, and that there is also a need for good quality insulating material that is low-cost, and which is competitive with respect to the products currently existing on the market. As Posidonia have a significant insulation capability, an insulating material based 15 on Posidonia is described in the literature (FR-A-2 556738). However, such material deteriorates over time. Surprisingly and unexpectedly, the inventors have shown that the addition of sodium bisulphite to this material prevents any putrefaction or deterioration of the finished product, and on the basis of this discovery have developed a material based on Posidonia that is capable of use as an insulating material and which does not 20 deteriorate over time. One of the purposes of the present invention is therefore to provide a novel insulating material, based on Posidonia, which does not deteriorate over time. Thus, a subject of the present invention is a material, particularly an insulating material, based on Posidonia and comprising moreover at least one binder and a 25 percentage of sodium bisulphite in order to avoid any putrefaction or deterioration of the finished product. According to the invention, Posidonia can be any plants of the family Posidoniaceae whatever their origin, collected in situ or thrown up by the sea, which once collected or thrown up are cleaned in order to separate them from other detritus present on the shore (sand, plastic materials, wood, glass, string, etc.). The Posidonia 30 which can be used according to the invention can originate from a single species or several species. In the material according to the invention the Posidonia can be in all forms that can be envisaged, such as for example whole plants (leaves, flowers, roots, rhizomes and fruits), parts of the plant such as for example the leaves or also a mixture of different 35 parts of the plant without thereby being considered a whole plant. Advantageously according to the invention, the insulating material is based on whole plants or leaves of Posidonia.

3 According to the invention the Posidonia can be used dry, i.e. free of external water, or also dehydrated, i.e. having lost a large part of their internal water. Preferentially, Posidonia can be used in the dry form. According to the invention, the Posidonia can be used whole or reduced to pieces 5 varying in size. Preferentially according to the invention it is possible to use pieces of Posidonia having a size comprised between 0.1 and 5 cm, preferentially between 1 and 3 cm. According to the invention, the binder can be any product having adequate viscosity characteristics in order to occupy all the interstices when mixed with a product 10 such as for example Posidonia (whole or in fragments), and allowing a rigid and non deformable product to be formed after drying the mixture. Preferentially, the binder is chosen from an adhesive or a resin. A person skilled in the art will know how to dilute the binder according to the viscosity that he wishes to obtain, in order to obtain a homogeneous mixture having a maximum distribution. 15 According to a variant of the invention, the adhesive can be any liquid or gelatinous product of any kind serving to bind the pieces together, which can be of the same or different materials. By way of example there can be mentioned adhesives of plant origin (for example those based on mistletoe, saps of resinous plants), adhesives of animal origin (such as for example those obtained by cooking materials that are rich in 20 collagen such as rabbit skin, bone, nerve, tendon, fish glues), synthetic adhesives (such as for example vinyl adhesives (white adhesive), acrylic, aliphatic, cyanoacrylate, polyurethane, epoxy, neoprene, "hot melt" adhesives). Advantageously according to the invention a vinyl adhesive can be used. Also advantageously according to the invention the adhesive can be a mixture of different 25 adhesives. According to another variant of the invention, the resin can be any type of resin such as for example a natural resin such as caseins, celluloses and their derivatives such as starch or also resins of plant origin, produced by certain plants, in particular the resinous conifers such as Agathis australis or kauri, species of Pinus or Picea conifers, 30 as well as a few species of Callistris which produce the resin known by the name of sandarac, or a synthetic resin such as for example a thermosetting resin. In this regard there can be mentioned phenol-formaldehydes, resorcin-formaldehydes, urea formaldehydes, melamine-formaldehydes, polyurethanes or also adhesives based on thermoplastic resins such as polyamides and polyvinyl ethers. 35 According to the invention, a polyester resin can preferentially be used, for example such as those sold by the company ASHLAND. According to the invention, the volume of binder per volume unit of Posidonia that 4 can be used in the material is a volume that makes it possible to obtain a non deformable and rigid material at the end of the process. Thus according to the invention, the ratio of the volume of binder to the volume of Posidonia capable of being used, before solidification, can be comprised between 0.01 5 and 0.5, preferentially between 0.02 and 0.1. For example when the raw material is constituted only by the leaves of Posidonia, the ratio of the volume of binder to the volume of Posidonia can be comprised between 0.02 and 0.05, preferentially between 0.03 and 0.04. Similarly, when the raw material is constituted by a coarse-chipped or fine-chipped Posidonia, the ratio of the volume of 10 binder to the volume of Posidonia can be comprised between 0.03 and 0.07, preferentially between 0.04 and 0.06. According to the invention, the material can adopt all desired shapes and volumes. A person skilled in the art will know how to adapt the shape and volume of the material according to the invention according to the stresses that it may encounter. Thus the 15 material according to the invention can be in the form of sprayable flakes, slabs, bricks, blocks, all having diverse and varied shapes and volumes. According to the invention, the ratio of the thickness of the material to the volume of Posidonia being capable of use, after solidification can be comprised between 0.001 and 0.1, preferentially between 0.005 and 0.05. 20 Also according to also the invention, the coefficient of thermal conductivity of the final material can be comprised between 0.01 and 0.2, preferentially between 0.05 and 0.15. Also according to the invention, the density of the final material can be comprised between 0.1 and 0.75, preferentially between 0.15 and 0.6. 25 According to the invention, the sodium bisulphite can be in a quantity comprised between 5% and 15%, preferentially between 8% and 12%. A material preferred according to the invention can be a material in which the ratio of the thickness to the volume of Posidonia is greater than 0.05, the ratio of the volume of binder to the volume of Posidonia is less than 0.039, the coefficient of thermal 30 conductivity is less than 0.063 and the density less than 0.35 and which contains 10% sodium bisulphite. The invention relates moreover to a method for manufacturing the material according to the invention which comprises: - a first step during which the previously-collected Posidonia are rinsed, 35 - a second step during which all foreign objects are removed from the Posidonia; - a third step during which the Posidonia obtained in step 2 are dried; - a fourth step during which the Posidonia dried in step 3 are mixed with the 5 binder; - a fifth step of solidification of the mix obtained in step 4. According to the invention, the first rinsing step can be carried out by any means using water, preferentially fresh water, optionally under pressure. Advantageously, this 5 step can be carried out by dipping the Posidonia into a body of water in rapid movements caused by injection of compressed air. According to the invention, the third step of the method can be carried out by any means allowing the drying and/or the dehydration of the Posidonia. There can be mentioned in this regard, drying in the open air or in a dryer, for example a tunnel heated 10 to 60 0 C and ventilated. A simple and effective means of drying Posidonia can be drying in the open air. According to the invention, the fourth step of the method can be carried out by any means allowing a homogenous mix of the binder and the Posidonia obtained in the previous step. By way of example there can be mentioned a manual mix, a mix using a 15 cement mixer, or also industrial types of mixers. Preferentially step 4 can be carried out with a cement mixer, the paddles of which will advantageously have been removed. According to the invention, the mixing step can be interrupted when the mixture is homogeneous and before the binder has dried. According to the invention, the fifth step of the method can be carried out by any 20 means allowing the solidification of the mixture obtained in step 4. According to a variant of the method, the solidification of the mixture can be carried out by drying in the open air for a time comprised between 900 and 4320 minutes, preferentially between 2160 and 2880 minutes. According to a variant of the method, the solidification of the mixture can be carried 25 out by mechanical means such as a kiln, an oven or presses with heated plates. Advantageously the drying can be carried out in a kiln, at a drying temperature which can be comprised between 130 0 C and 170 0 C, preferentially between 145'C and 155'C, for a for a time that can be comprised between 15 and 75 minutes, preferentially between 30 and 60 mn. According to a preferred variant of the invention, the drying can 30 be carried out in a kiln, by adding a second drying step in which the drying temperature can be comprised between 55 0 C and 85 0 C, preferentially between 65'C and 75*C, for a time that can be comprised between 50 and 130 minutes, preferentially between 60 and 120 mn. The step of solidification of the mixture can be carried out on heaps of material. 35 Preferentially, before drying, the material can be made to adopt the desired shapes and volumes. For example said mixture can be introduced into moulds having the desired shapes and volumes, then subjected to the solidification step.

6 According to a variant of the method, in step 5, the mix can be introduced into a mould and subjected to a pressure, said pressure possibly depending on the thickness of the mould and the drying temperature. A person skilled in the art will know how to adapt these variables according to the stresses encountered and the material that it is 5 desired to obtain. By way of example, the pressure exerted on the mix can thus vary between 5 and 30 bars, preferentially between 10 and 20 bars, until solidification and drying of the product. According to yet another variant of the invention, the method can comprise moreover an additional step of shredding the Posidonia before use. This step then takes 10 place between step 3 and step 4 of the method according to the invention. According to this variant, the shredding can be carried out by any means or device making it possible to obtain pieces of Posidonia of a size varying from 0.1 to 5 cm, preferentially 1 to 3 cm. By way of example, there can be mentioned garden shredders or industrial shredders. Whatever the method used, the material obtained exhibits very significant 15 insulating qualities, both thermal and sound. Furthermore, the product obtained is non-flammable and will not rot, exhibits an excellent flame resistance and one of the lowest thermal conductivity ratios. A further non-negligible advantage is that the product according to the invention is not noxious and can thus be used without risk in building construction, particularly in 20 flakes as a substitute for asbestos. Yet a further advantage of the invention is that the material is resistant to damp, particularly when the binder is a resin. A further subject of the present invention is an insulating material capable of being obtained by the method according to the invention. 25 A subject of the invention is also the use of a material according to the invention as a thermal and/or sound insulator. The invention can be used in any type of construction in which insulation may be desired, such as for example residential properties, offices, apartment blocks, boats, aircraft, or also in fire doors, noise barriers, as ducting insulation, in laboratories for 30 insulating high technology devices, in the aerospace industry, in any structure requiring flame protection, etc. The following examples illustrate the present application without however limiting it. Samples have been subjected to a flame in order to characterize their fire 35 resistance. Unless stated otherwise, the density of the samples is measured by the ratio of the weight of the sample in kg to the volume of the sample expressed in diM 3

.

7 Similarly, the temperature of the faces not exposed to the flames is measured using a thermometer bonded to said face, such as for example an alcohol thermometer used in agriculture. In the following examples the nature of the raw material is described according to RAW MATERIAL - EXCEL: Only the leaves of Posidonia. - B.G.: coarse shreds - B.F.: fine shreds 5 and the binders according to BINDERS - S.D.: undiluted white adhesive - SD+C10 undiluted white adhesive + plus 10% of sodium bisulphite. - A.D.: diluted white adhesive - Medium+C10: white adhesive diluted with 50% water plus 10% sodium bisulphite. - R 100: ASHLAND Polyester S.A.S. resin 4600031 HETRON F 820 A 1866 Example 1. Fire resistance tests in the presence of a flame from a blowtorch: (Sample Al) A sample of material according to the invention of thickness 20 mm and density 0.45 was produced from 7.5 dm 3 of dry raw material of EXCEL quality and 10 0.75 dm 3 of SD+C10 binder, dried in an oven for 1440 minutes at 700C, under a pressure of 10.25 bars, and was subjected to the flame of a plumber's trade standard blowtorch for 3 minutes at a distance of 7 centimetres between the output of the flame and the sample. The sample was not set alight and was carbonized to a maximum depth of 2 mm. 15 Example 2. Fire resistance tests in the presence of a flame from a welding torch: (sample Al 1) A sample of material according to the invention of thickness 20 mm and density 0.43 was produced from 20 dm 3 of dry raw material of EXCEL quality and 0.66 dm 3 of Medium + C10 binder, dried in a kiln for 60 min at 1200C, then 180 min at 70'C, under a pressure of 5.3 bars and was subjected to the flame of a welding torch 20 directed onto a fixed point for 10 minutes at a distance of 10 centimetres from the output of the flame concentrated onto a fixed point of the sample. The sample was not set alight and was carbonized to a depth of 2 mm, without an increase in the temperature on the face not exposed to the flame. L (sample A14) A sample of material according to the invention of thickness 20 25 mm and density 0.46 was produced from 35 diM 3 of dried raw material of EXCEL quality and 1.07 dm 3 of Medium + C10 binder, dried in a kiln for 60 min at 1200C then 180 min 8 at 700C, under a pressure of 12.5 bars, and was subjected to the flame of a welding torch for 15 minutes at a distance of 20 centimetres from the output of the flame concentrated on a fixed point of the sample. The sample was not set alight and was carbonized to a depth of 10 mm. 5 j (sample B1) A sample of material according to the invention of thickness 20 mm and density 0.51, was produced from 10 dm 3 of dry raw material of B.G. quality, and 0.66 dm 3 of Medium + C10 binder, dried in a kiln for 60 min at 1500C then 120 min at 1000C under a pressure of 10.7 bars, and was subjected to the flame of a welding torch for 10 minutes at a distance of 7 centimetres and swept over the whole surface of the 10 sample. The sample was not set alight and was carbonized to a depth of 1 mm, without any flammability being observed, and a carbonisation to a depth of 10 mm. j (sample X2) A sample of material according to the invention of thickness 17mm and density 0.49, was produced from 5 dm 3 of dry raw material of B.G. quality, and 0.5 15 diM 3 of R100 binder, dried in a kiln for 180 minutes at 70*C, under a pressure of 12.5 bars, and was subjected to the flame of a welding torch at a distance of 7 cm between the output of the flame and the sample for 10 min. The material exhibits the appearance of metal, is compact and solid. A slight carbonization to a depth less than 1 mm was noted. Moreover, the material does not exhibit any deformation of its structure after 20 immersion in water for 28 h. Example 3. Heat resistance tests Samples of the material according to the invention were tested for their heat resistance. This was carried out using a forge furnace. The samples tested were cut out according to the shape of the door of the forge furnace used; The furnace was heated to 25 between 6500C and 7000C and the samples were placed in the opening of the furnace. The depth of carbonization of the face corresponding to the inside of the furnace after a time of 10 min exposure is determined, and the temperature increase on the other face is measured. Two samples were used: 30 i (sample A6) A sample of material according to the invention of thickness 30mm and density 0.43, was produced from 8 dm 3 of dry raw material of EXCEL quality, and 0.965 diM 3 of Medium+C10 binder, and dried in a kiln for 30 minutes at 1000C then 120 min at 600C, under a pressure of 400 bars. j (sample J2.3) A sample of material according to the invention of thickness 35 35 mm and density 0.64, was produced from 15 dm 3 of dry raw material of B.G. quality and 0.750 dm 3 of medium+C10 binder, dried in a kiln for 160 min at 1200C, under a pressure of 5 bars. The samples tested were cut out according to the shape of the door of the 9 forge furnace used; The furnace was heated to between 6500C and 7000C and the samples were placed in the opening of the furnace. After 15 min, a carbonization of the face corresponding to the inside of the furnace of the order of half a millimetre is observed, while on the opposite face, the temperature remained acceptable, of the order 5 of 40C above ambient temperature. Example 4. Calculation of the coefficient of thermal conductivity: In the practical calculations, it is generally accepted that the variation of the thermal conductivity of the material as a function of the temperature is linear, and the "lambda" coefficient which characterizes the conductivity of the substance is related to 10 its density "d" by empirical formulae such as the following: LAMBDA = 0.9 (d/5+d 4 /30); (lambda represents a units system based on consideration of the kilocalorie). The values are given in W.(m).(*k)-' and in k.cal.(m)-1.(h)-1.(Ok)-. (References: Encyclopedie internationale des sciences and techniques, volume 7) The coefficient of thermal conductivity is determined by subjecting the sample of 15 material according to the invention to a temperature of 1050C obtained by a stream of hot air originating from a hairdryer placed at 20 cm from the surface of the material, for a time of 30 mn. - (sample J2.4) A sample of material according to the invention of thickness 10 mm and density 0.53, is produced from 5 dm 3 of dry raw material of B.G. quality and 20 0.25 dm 3 of Medium+C10 binder, and dried in a kiln for 160 minutes at 1200C, under a pressure of 10 bars. The coefficient of thermal conductivity of the sample is 0.098 k.cal.(m)-1.(h).(*k)l, for a temperature of 120C, and a downstream temperature of 1050C, which puts it within the category of materials such as Eternit. 25 i (sample X2) A sample of material according to the invention of thickness 17mm and density 0.49, was produced from 5 dm 3 of dry raw material of B.G. quality, and 0.5 dm 3 of R100 binder, dried in a kiln for 180 minutes at 70*C, under a pressure of 12.5 bars, and subjected to the flame of a welding torch with a distance of 7 cm between the output of the flame and the sample for 10 min, exhibits a coefficient of thermal 30 conductivity of 0.069 k.cal.(m)-1.(h) 1 .( k) 1 , for a temperature of 1070C, and a downstream temperature of 7.50*. This puts it in the category of materials like felts, bituminous corks, magnesia. The inventors' experiment allowed them to draw up Table B on the basis of an evaluation of each criterion according to Table A below, with the understanding that 1 star = mediocre, 2 stars = good, 3 stars = very good, 4 stars = 35 excellent.

10 Table A ThicknessNolume of raw material Ratio x<0.005 0.005<x<0.05 ** x> 0.05 Binder volumeNolume of raw material Ratio x> 0.066 * 0.039<x< 0.066 ** x< 0.039 Coefficient of thermal conductivity ctc> 0.12 * 0.12 >ctc> 0.09 ** 0.09>ctc> 0.063 ctc< 0.063 Density d> 0.55 * 0.45 < d < 0.55 ** 0.35 < d < 0.45 d< 0.35 11 Table B Sample I II III IV V VI VII Vill IX Al ** * ** ** ** *** * *** 16 A2 ** * ** ** ** * * * 12 A6 * ** ** ** *** * *** 17 A7 ** * ** ** ** ** * * 13 A10 ** * * * * *** * *** 13 All * ** ** ** *** * *** 17 A12 * *** * ** A13 * ** ** ** *** * *** 17 A14 * *** *** *** *** *** * ** 19 B1 ** ** *** *** *** ** * ** 18 B2 ** *** *** *** ** * * 18 B3 ** ** *** *** *** *** * *** 20 B4 ** ** *** *** *** ** * ** 18 C3 ** ** ** ** ** * * 15 D1 ** ** *** *** *** ** * * 17 D3 ** ** ** * ** J2.3 ** ** *** *** *** * * * 16 J2.4 ** ** *** *** *** ** * ** 18 LI ** ** *** *** *** *** * *** 20 L2 ** ** *** *** *** *** * *** 20 X2 * **** **** **** *** *** ** 24 5 1: Ratio of the thickness of the material to the volume of Posidonia. II: Ratio of the volume of binder to the volume of Posidonia. Ill : Resistance to compression IV. Resistance to traction V: Resistance to impacts 10 VI. Coefficient of thermal conductivity VII : Resistance to damp ViII. Density IX. Quality level (total number of stars) 15 Sample A2: Material according to the invention of thickness 17 mm and density 0.65, was produced from 7.5 dm3 of dry raw material of EXCEL quality, and 0.75 dm 3 of 12 Medium+C10 binder, and dried in a kiln for 144 minutes at 700C plus 192 min at 500C, under a pressure of 16 bars. Sample A7: Material according to the invention of thickness 20 mm and density 0.625, was produced from 8 dm 3 of dry raw material of EXCEL quality, and 1.115 dm 3 of 5 MEDIUM+C10 binder, and dried in a kiln for 40 minutes at 120*C plus 60 min at 700C, under a pressure of 20 bars. Sample A10: Material according to the invention of thickness 15 mm and density 0.35, produced from 10 dm 3 of dry raw material of EXCEL quality, and 1.1 dm 3 of MEDIUM+C10 binder, under a pressure of 10 bars. 10 Sample A12: Material according to the invention of thickness 20 mm and density 0.46, was produced from 20 dm 3 of dry raw material of EXCEL quality, and 0.750 dm 3 of MEDIUM+C10 binder, and dried in a kiln for 60 minutes at 120 0 C plus 180 min at 70 0 C, under a pressure of 6.25 bars. Sample A13: Material according to the invention of thickness 17.5 mm and density 0.6, 15 was produced from 20 dm 3 of dry raw material of EXCEL quality, and 0.7 dm 3 of MEDIUM+C10 binder, and dried in a kiln for 60 minutes at 120 0 C plus 180 min at 70 0 C, under a pressure of 10.7 bars. Sample B2: Material according to the invention of thickness 24 mm and density 0.56, produced from 10 dm 3 of dry raw material of B.F. quality and 0.395 dm 3 of 20 MEDIUM+C10 binder, dried in a kiln for 60 minutes to 120 0 C plus 120 minutes at 100 0 C, under a pressure of 10.7 bars. Sample B3: Material according to the invention of thickness 20 mm and density 0.45, produced from 10 dm 3 of dry raw material of B.F. quality and 0.450 dm 3 of MEDIUM+C10 binder, dried in a kiln for 60 minutes at 120 0 C plus 180 minutes at 70 0 C, 25 under a pressure of 15 bars. Sample B4: Material according to the invention of thickness 19 mm and density 0.51, produced from 10 dm 3 of dry raw material of B.F. quality and 0.450 dm 3 of MEDIUM+C10 binder, dried in a kiln for 60 minutes at 120 0 C plus 180 minutes at 70 0 C, under a pressure of 15 bars. 30 Sample C3: Material according to the invention of thickness 20 mm and density 0.6, produced from 10 diM 3 of dry raw material of B.F. quality and 0.340 dm 3 of MEDIUM+C10 binder, dried in a kiln for 60 minutes at 120 0 C plus 180 minutes at 70 0 C, under a pressure of 15 bars. Sample D1: Material according to the invention of thickness 20 mm and density 0.49, 35 produced from 10 dm 3 of dry raw material of B.F. quality and 0.45 diM 3 of MEDIUM+C10 binder, dried in a kiln for 60 minutes at 120 0 C plus 180 minutes at 70 0 C, under a pressure of 15 bars.

13 Sample D3: Material according to the invention of thickness 15 mm and density 0.55, produced from 10 dm 3 of dry raw material of B.F. quality and 0.450 dm 3 of MEDIUM+C10 binder, dried in a kiln for 60 minutes at 120 0 C plus 180 minutes at 70 0 C, under a pressure of 15 bars. 5 Sample Li: Material according to the invention of thickness 10 mm and density 0.375, produced from 5 dm 3 of dry raw material of B.F. quality and 0.3 dm 3 of MEDIUM+C10 binder, dried in a kiln for 60 minutes at 120 0 C plus 120 minutes at 70*C, under a pressure of 12.5 bars. Sample L2: Material according to the invention of thickness 20 mm and density 0.417, 10 produced from 10 diM 3 of dry raw material of B.F. quality and 0.6 dm 3 of MEDIUM+C10 binder, dried in a kiln for 60 minutes at 120 0 C plus 120 minutes at 70 0 C, under a pressure of 12.5 bars.

Claims

1.) Material, particularly insulating material, comprising Posidonia and at least one binder and sodium bisulphite. 5 2.) Material according to claim 1, characterized in that the Posidonia are chosen from the species posidonia angustifolia, posidonia australis, posidonia coriacea, posidonia denhartogii, posidonia kirkmanii, posidonia oceanica, posidonia ostenfeldii, posidonia robertsoniae, posidonia sinuosa, preferentially posidonia oceanica. 10 3.) Material according to one of claims 1 or 2, characterized in that the Posidonia are in the form of the whole plant, parts of the plant such as for example the leaves or also a mixture of different parts of the plant, preferentially in the form of whole plants or leaves.

4.) Material according to one of claims 1 to 3, characterized in that the Posidonia are 15 used dried or also dehydrated, preferentially dried.

5.) Material according to one of claims 1 to 4, characterized in that the Posidonia can be used whole or reduced to pieces of a size comprised between 0.1 and 5 cm, preferentially between 1 and 3 cm.

6.) Material according to one of claims 1 to 5, characterized in that the binder is an 20 adhesive or a resin.

7.) Material according to claim 6, characterized in that the adhesive is chosen from adhesives of plant origin, adhesives of animal origin, synthetic adhesives, preferentially a vinyl adhesive.

8.) Material according to claim 7, characterized in that the resin is chosen from natural 25 resins such as caseins, celluloses and their derivatives such as starch or also resins of plant origin, produced by certain plants, in particular resinous conifers such as Agathis australis or kauri, species of Pinus or Picea conifers, as well as a few species of Callistris which produce the resin known as sandarac, or a synthetic resin such as for example a thermosetting resin such as phenol-formaldehydes, 30 resorcin-formaldehydes, urea-formaldehydes, melamine-formaldehydes, polyurethanes or also adhesives based on thermoplastic resins such as polyamides and polyvinyl ethers.

9.) Material according to claim 8, characterized in that the resin is a polyester resin.

10.) Material according to one of claims 1 to 9, characterized in that the ratio of the 35 volume of binder to the volume of Posidonia, before solidification, is comprised between 0.01 and 0.5, preferentially between 0.02 and 0.1.

11.) Material according to one of claims 1 to 10, characterized in that the ratio of the 15 thickness of the material to the volume of Posidonia, after solidification, is comprised between 0.001 and 0.1, preferentially between 0.005 and 0.05.

12.) Material according to one of claims 1 to 11, characterized in that the coefficient of thermal conductivity of the final material is comprised between 0.01 and 0.2, 5 preferentially between 0.05 and 0.15.

13.) Material according to one of claims 1 to 12, characterized in that the density of the final material can be comprised between 0.1 and 0.75, preferentially between 0.15 and 0.6.

14.) Material according to one of claims 1 to 13, characterized in that the quantity of 10 sodium bisulphite is comprised between 5% and 15%, preferentially between 8% and 12%.

15.) Material according to one of claims 1 to 14, characterized in that it exhibits a ratio of the thickness to the volume of Posidonia that is greater than 0.05, a ratio of the volume of binder to the volume of Posidonia less than 0.039, a coefficient of 15 thermal conductivity less than 0.063 and a density less than 0.35, and which contains 10% sodium bisulphite.

16.) Method for manufacturing a material according to one of claims 1 to 15, characterized in that it comprises: a. a first step during which the previously-collected Posidonia are rinsed, 20 b. a second step during which all foreign objects are removed from the Posidonia; c. a third step during which the Posidonia obtained in step 2 are dried; d. a fourth step during which the Posidonia dried in step 3 are mixed with the binder; 25 e. a fifth step of solidification of the mix obtained in step 4.

17.) Method according to claim 16, characterized in that the first rinsing step is carried out with water, preferably fresh water, optionally pressurized, advantageously by dipping the Posidonia into a body of water in rapid movements caused by injection of compressed air. 30 18.) Method according to any one of claims 16 or 17, characterized in that the third step of the method is carried out by drying in the open air or in a dryer, preferentially in the open air.

19.) Method according to any one of claims 16 to 18, characterized in that the fourth step is carried out by manual mixing or by mixing using a cement mixer, or also 35 using an industrial-type mixer, preferentially a cement mixer, from which advantageously the paddles are removed.

20.) Method according to any one of claims 16 to 19, characterized in that the fourth 16 step of the method is carried out by drying in the open air for a time comprised between 900 and 4320 minutes, preferentially between 2160 and 2880 minutes.

21.) Method according to any of claims 16 to 20, characterized in that the fifth step of solidification of the mixture is carried out by mechanical means such as a kiln or an 5 oven or a press with heated plates.

22.) Method according to claim 21, characterized in that the solidification of the mixture is carried out in a kiln, at a drying temperature which can be comprised between 130'C and 1700C, preferentially between 145 0 C and 155 0 C, for a time comprised between 15 and 75 minutes, preferentially between 30 and 60 mn. 10 23.) Method according to claim 22, characterized in that it comprises a second drying step in which the drying temperature can be comprised between 55 0 C and 85 0 C, preferentially between 65 0 C and 75 0 C, for a time that can be comprised between 50 and 130 minutes, preferentially between 60 and 120 mn.

24.) Method according to one of claims 15 to 23, characterized in that in step 4, the mix 15 is moreover introduced into a mould and subjected to a pressure, comprised between 5 and 30 bars, preferentially between 10 and 20 bars.

25.) Method according to one of claims 15 to 24, characterized in that it comprises moreover an additional step of shredding the Posidonia before use before step 4.

26.) Method according to claim 24, characterized in that after shredding, the pieces of 20 Posidonia have a size comprised between 0.1 and 5 cm, preferentially between 1 and 3 cm.

27.) Material capable of being obtained by the method as described in any one of claims 15 to 26.

28.) Use of a material according to one of claims 1 to 14 and 27, as insulating material. 25