CELLULOSE-CONTAINING MASS
The invention concerns a method for producing a cellulose-containing mass comprising an organic material, the method comprising the steps a) preparation of an input comprising organic material and a liquid content, and b) exposing said input to a wet-mixing procedure at a temperature in the range of 40 to 90° C. preferably 50 to 80° C. and most preferred around 60° C. or exposing said input to an active zone of an electromagnetic field According to a further embodiment of the present invention cellulose of different types is added to the input Moreover a method for producing a composite material that is based on said cellulose-containing mass is disclosed as well as a product produced of said composite material
Latest PHILIPPE SAINT GER AG Patents:
The present invention is directed to a method for producing a cellulose-containing mass according to claim 1, a cellulose-containing mass according to claim 17, a method for producing a composite material according to claim 18, a composite material according to claim 23 and a product according to claim 24.
The method may be employed for a diversity of practical uses. For instance, production of new building materials, different hardware, trimmings, interior stuff, various finishing coats of high resistibility and fastness etc. from farm waste of cereals (for example maize, rye, wheat, oats, barley, sorghum, rape, rice etc. and combinations thereof), staple fibers (cotton, flax, hemp, etc.), what makes such production economically compatible due to low price of inputs.
BACKGROUND OF THE INVENTIONCurrently there are several composite materials of organic origin known which are for example suitable for packaging and construction applications. While wood fibers are quite common other natural fibers from crop or grain are used occasionally as fibrous fillers.
U.S.2006043629A proposes to produce a reinforced bio-composite by processing of natural fibers (such as grass, rice straw, wheat straw, industrial hemp, pineapple leaf fibers) with a matrix of soy based bioplastic, by employing a coupling agent, i.e. a functional monomer modified polymer. Moreover the use of modified soy flour with functional monomers is explained in the context of industrial applications such as reactive extrusion and injection molding.
U.S. 2008/181969 A addresses discoloration and structural, that is chemical or mechanical, degradation of composite materials comprising cellulosic components such as wood fibers, straw, grasses and other organic material that is cross linked by means of coupling agents to polymer components. The coupling agents, such as grafted-maleic anhydride polymers or copolymers, incorporate functionality capable of forming covalent bonds within or between the polymer and cellulosic components.
PROBLEM TO BE SOLVEDIt is an object of the present invention to provide an improved method of production of cellulose-containing masses, to provide said cellulose-containing masses and to provide methods for producing high-strength composite materials comprising original structures of organic materials, preferably originating from higher plants, which evolve their natural forms (e.g. stalks) through intracellular and intercellular structural linkage between different polymers and/or their moieties of different substances, functional groups, side chains and/or rests.
SUMMARY OF THE INVENTIONThe invention relates to production of high-strength composite materials and various items made of cheap organic raw-materials, preferably of stalk parts of higher plants, cell envelopes or membrane that contain sufficient quantity of cellulose, i.e. a high-molecular polysaccharide or glucan composed of β-1,4-linked D-glucose, or chitin, a glycan composed of beta-1,4-linked N-acetyl-D-glucosamine. In the present application the term cellulose-containing mass, input and/or composite shall comprise also chitin containing masses, inputs and/or composites or mixtures of cellulose and chitin containing masses, inputs and/or composites. Cellulose—the most common organic compound on Earth—is a high-molecular polysaccharide (glycan) with formula [C6H7O2(OH)3]n structured into polymer chains of β-glucose units, where n ranges from hundreds to some thousands. The invention allows to produce composite materials without requiring the use of exogenous polymeric components for bonding the organic materials, for example the plant particles to each other. In the context of the present application, the term exogenous denotes that the polymeric component origins not from the organic raw material being processed. It is an essential feature of the novel method of producing a cellulose-containing mass that the organic material is exposed to an active zone of an artificial electromagnetic field.
The new method for producing a cellulose-containing mass that may be used for producing a composite material being suitable for a high-strength product comprises at least the steps of
a) preparation of an input comprising organic material and a liquid content; and
b) exposing said input to a wet-milling procedure at a temperature in the range of 70 to 120° C., preferably 80 to 100° C., and most preferred at about 92 to 94° C.
According to preferred embodiments said input is further to step b) or alternatively to step b) exposed to an active zone of an artificial electromagnetic field.
According to preferred embodiments during manufacturing natural forms of inputs are destructed, as well as their organic linkages of intracellular and intercellular structures, until a liquid and/or paste mass is produced. This mass is used further as molding sand: it is reshaped with new geometrical form, and structural linkages are recovered while this paste is curing. Cured paste becomes the end-use item.
Hereinafter, the term input is used to refer to the starting substance or mixture of substances that is exposed to the electromagnetic field whereas the term cellulose-containing mass denotes the product produced by the aforementioned method according to the invention. Said product is considered to be an intermediate product (also called output) as it is used further for the production of a wide variety of products.
The idea of the method lies in the fact that during manufacturing natural forms of inputs are destructed, as well as their organic linkages of intracellular and intercellular structures do, until homogenous liquid and/or paste mass is produced. Such a cellulose-containing mass is used further as molding sand: it is reshaped with new geometrical form, and structural linkages are recovered while this paste is curing. Cured paste becomes the end-use item.
According to preferred embodiments, additional cellulose preferably methyl cellulose and/or carboxy methyl cellulose, preferably in the form of a sodium salt, and/or microcrystalline cellulose is added to the cellulose-containing mass. According to a further preferred embodiment of the present invention, the additional cellulose is at least partially added as concentrated cellulose containing fraction generated in the wet-milling procedure. The cellulose containing liquid fraction separated during or after wet-milling can be concentrated by filtration or dehydration until the fraction reaches a desired level of cellulose content in relation to the water content.
In the present patent application, the term organic material is understood to comprise any cellulose containing material. Preferably, the input organic material comprises fibers mixed of cellulose molecules. Advantageously, the organic material origins from higher plants preferably from the group of true grasses of the family Gramineae (Poaceae) such as cereal crop or from cotton, hemp or flax or a mixture thereof. Good results have been produced in tests using at least one of cereal straw or rice straw or mixtures thereof as the organic material.
Preferably, the organic material is reduced to small particles or even pulp in a pre-processing step before the exposure to the electromagnetic field. The organic material of the input is preferably pre-processed/pre-treated depending on the type and conditions of the material. Such conditions are moisture, cleanness, presence of irrelevant natural or artificial elements, the microbial population, the percentage of β-cellulose in the pure input material responsible for generating bundles of micelles in the form of superfine fibrils. Preliminary determination of organic base content between fibrils and cellulose agglutinating these fibrils into the solidest fibers proved to be advantageous. As a rule, organic materials containing agglutinating or gelling substances like pectin are suitable, but organic materials containing substances like suberins or cutin that are by nature more hydrophobic are suitable as well. Alternatively organic materials containing lignin may also be used. Basic features and properties of products or produced items may be predefined by changing correlation of these and other secondary substances in the cellulose-containing mass.
Pre-treatments of the organic material encompass maceration, supplemented by electromechanical, hydrodynamic and ultrasonic exposure, as well as boiling, steaming and other known methods of processing raw plant material. Cellulose fibers have a noted distinction of high resistance against laceration, barely coming short of steel, and resistance against variance of mechanical and physical exposures. In case that the organic material is straw, e.g. rice or wheat or rye straw, a liquid having a pH-value of about 8 or above, more preferably about 8.4 or above may be used for maceration purposes followed and/or accompanied by electromechanical exposure, hydrodynamic exposure, ultrasonic exposure, boiling, steaming or a combination thereof.
It is known from the prior art, for example from WO 08/112191 that in lignocellulosic biomass, crystalline cellulose fibrils are embedded in a less well-organized hemicellulose matrix which, in turn, is surrounded by an outer lignin seal, Contacting naturally occurring cellulosic materials with hydrolyzing enzymes generally results in cellulose hydrolysis yields that are less than 20% of theoretically predicted results. Hence, some “pretreatment” of the biomass is invariably carried out prior to attempting the enzymatic hydrolysis of the polysaccharides (cellulose and hemicellulose) in the biomass. Pretreatment refers to a process that converts lignocellulosic biomass from its native form, in which it is recalcitrant to cellulase enzyme systems, into a form for which cellulose hydrolysis is effective. Compared to untreated biomass, effectively pretreated lignocellulosic materials are characterized by an increased surface area (porosity) accessible to cellulase enzymes, and solubilization or redistribution of lignin. Increased porosity results mainly from a combination of disruption of cellulose crystallinity, hemicellulose disruption/solubilization, and lignin redistribution and/or solubilization. The relative effectiveness in accomplishing some (or all) of these factors differs greatly among different existing pretreatment processes. These include dilute acid, steam explosion, hydrothermal processes, “organosolv” processes involving organic solvents in an aqueous medium, ammonia fiber explosion (AFEX), strong alkali processes using a base such as, ammonia, NaOH or lime, and highly-concentrated phosphoric acid treatment. Those methods known from the art as mentioned above and further known methods for treatment of cellulose containing biomaterials may advantageously be combined with the method steps according to the present invention.
Depending on the desired properties of the cellulose-containing mass (i.e. the output) and/or the pre-processing preparation, the endogenous liquid content, i.e. the liquid content provided by the raw organic material itself or originating from the raw organic material, is sufficient so that no exogenous or additional liquid has to be added. In its simplest embodiment, the liquid content is formed by water. However, other liquids, like organic solvents or gases or other fluids may be suitable as liquid contents depending on the demands on the manufacturability and on the characteristics of the article to be formed of the composite material later on. However, it is important that a proper function of the liquid content with the organic material is achievable. In case of liquids other than water it is essential to preferred embodiments of the invention that an excess of the liquid content is extractable in a suitable manner after the cellulose-containing mass is produced, where necessary.
Depending on the intended use and the intended processing method, the liquid content comprises preferably a solvent, e.g. for mellowing the organic material.
Processes of structural linkages recovery appear while homogenous mass is curing in new moulds; such processes are actually an integration of remains of β-glucose n-molecules into molecular compound with common to polymers formula [C6H7O2(OH)3]n. Known presence of glucose molecules of three hydroxyl groups [(OH)3 groups] in each remain makes it obvious that linkage of every remain couple of glucose molecule between each other is happened through lateral hydroxyl groups by abstraction of water molecules from them. Therefore, structural linkages recovery in homogeneous mass is taken place inadvertently when this mass is dehydrated and results in its curing.
Tests have shown that the properties of the cellulose-containing mass hereinafter also called output are enhanced when the input which is exposed in the active zone of an electromagnetic field comprises an amount of ferromagnetic particles.
According to preferred embodiments of the present invention method according to the invention comprises the steps of providing a reactor having a reaction volume, filling said reaction volume of said reactor with a plurality of substances, which take part in a physical and/or chemical reaction, adding a predetermined portion of ferromagnetic particles into said reaction volume, placing said reactor with its reaction volume between at least two inductors, such that the magnetic fields of said inductors interfere with each other in said reaction volume of said reactor, and supplying each of said inductors with an alternating current of predetermined amplitude and frequency.
According to preferred embodiments of the present invention the ferromagnetic particles have an average length in a range of about 0.3 to about 25 mm, preferably in a range of about 3 to 5 mm and diameters of about 0.1 to about 5 mm, preferably of about 0.1 to about 2.5 mm. A ratio of 1:3 to 1:5 between diameter and length of the particles has been shown to be especially advantageous. The particles are cylindrical according to preferred embodiments. Based on the teachings of the present inventions the person skilled in the art will know that the size of the ferromagnetic particles depends upon and can be optimized according to the input material whereby the sizes may be out of the above mentioned ranges.
The size and shape of the ferromagnetic particles may be chosen depending on the properties of the cellulose-containing mass, its workability and/or its producibility. Hence other sizes of the ferromagnetic particles may be suitable for working the present invention, too.
Test have shown, that high quality cellulose-containing masses were obtained when if the ratio of the ferromagnetic particles to the input was about 1 to about 20 weight percent. A liquid content of the input between 0 to about 40 percent. However, in further embodiments of the method, other ratios may be chosen according to particular demands on the workability and/or the producibility of the cellulose-containing mass. They depend upon the type of process (periodic or constant) and within which volume of a container the process is worked. In a preferred embodiment with straw as input material, the working volume of a 2-zone container was 180 millilitres and the amount of the ferromagnetic particles was 14 grams per zone. The particles had the diameter of 250 micrometers on average and a length of 1500 micrometers on average. The ratio of liquid to input was as 1 to 3. The container was of continuous type. The time of exposure was up to 20 seconds.
The ferromagnetic particles support the disintegration of the organic material supra- and subcellular level, as well as the breaking of organic linkages of intracellular and/or intercellular structures. The stirred fluidized bed of ferromagnetic particles is energetically charged, and has increased capacities to destruct the whole range of organic materials in comparison to means known in the art. By mechanical crushing, breaking and/or grinding the until a more homogenous cellulose-containing mass is produced. Disintegration of the organic material is a key point of the invention.
A further advantage of the inventive method resides in the mechanical stirring effect of the ferromagnetic particles. Said ferromagnetic particles contribute to a mixing and milling effect of the liquid content, the solvent, if any, and the organic material such that the quality of the cellulose-containing mass is further improved.
The cellulose-containing mass forms the base material for a vast range of composite products with a wide range of shapes, forms and designs. Said composites may be produced by direct shaping methods like casting, moulding, pressing or extruding or by subsequently machining the afore mentioned.
The active zone of the electromagentic field is located between at least two linear electromagnetic inductors which are separated from each other by a gap measuring about 1 mm to about 5 m, preferably about 50 mm to about 1 m.
Depending on the requirements that have to be fulfilled by the cellulose-containing mass and/or the composite article the amount of ferromagnetic particles of non-retentive, i.e. low-coercive materials are added to the the input material before and/or during exposure of the input to the electromagnetic field.
According to preferred embodiments in which the production is set to a batchwise mode, a non-ferromagnetic mixing container may serve as the receptacle during the exposure of the input to the electromagnetic field, Depending on the requirements said mixing container may stretch over the whole distance between the inductors such that a stirred fluidized bed in the whole space of the zone is generated. Other receptacles or a passage for a continuous production mode are also suitable for working the present invention.
The presence of ferromagnetic particles of non-retentive, i.e. low-coercive materials in input to be processed in the active zone is particularly advantageous in large scale operations, where the distance between the inductors is about up to 1 or even several meters. In case of such large distances between the inductors it is preferred to increase the amount of ferromagnetic particles accordingly.
The linear electromagnetic inductors generate alternating electromagnetic fields that run towards each other from opposite directions. At every point in the active zone the inductors excite common alternating electromagnetic field with circular or elliptic podograph of intensity of magnetic component, spinning around a common axis that is situated between inductors. The magnitude of magnetic component at every point of the axis equals to zero, but in every other direction and/or points it grows up to an amplitude value predetermined in the inductor. Tests proved that good results are achievable with amplitude values of about 0.2 Tesla (SI-Unit: T) to 0.25 T in the center of a 50 mm gap between the inductors with 14 g ferromagnetic particles present in a 180 ml container and an active zone between inductors of 50×165×80 mm and a magnetic force of about 0.03 T. The duration of exposure of the input to the magnetic field was about 20 seconds.
The destructive influence of the ferromagnetic particles on the particles of the organic material in the active zone is explained in more detail below. The impact of those ferromagnetic particles on intracellular and intercellular structures by means of its magnetic components A (A is vector potential of magnetic field), and B (B is magnetic field induction; A and B are related by formula B=rotA) is amplified through reduction of reluctance R within the active zone resulting in an increase of the magnetic flux in this active zone. The term rotA denotes the rotation of the vector potential.
The ferromagnetic particles increase the magnitude Bi under Hi=constant at every point i such that the active value of gradA is increased, GradA denotes a gradient A.
Depending on the input and the desired characteristics of the cellulose-containing mass, the electromagnetic field produced by the at least two electromagnetic inductors has a force of about 0.01 to about 20 T, preferably about 0.01 to about 10 T, most preferred about 0.03 to about 1.2 T.
The exposure time of the input to the electromagnetic field is depending on the magnetic force applied and the material treated. Good results, that means cellulose-containing masses with superior properties have been achieved with a duration of said exposure measuring about 1 second to about 3 hours, preferably about 5 seconds to 5 minutes, most preferred about 20 seconds. The degree of the homogeneity of the cellulose-containing mass is adjustable by the electric parameters of the inductors.
According to preferred embodiments the wet-milling procedure is performed with high-speed cutting mills with high frequency cutting strokes for the fine grinding of the cellulose-containing input, for example straw. A fine cutting mill of the CONDUX CS 500 or CS 1000Z type, available from Netzsch-Condux Mahltechnik GmbH, Rodenbacher Chausee 1, D-63457 Hanau/Wolfgang, Germany which is intended for dry milling was adapted and used for wet-milling of the input at elevated temperatures.
After the wet-milling step, the intermediate product can—according to further preferred embodiments—be mixed with additional cellulose, for example in a high-performance Ringlayer Mixer CoriMix® CM available from Gebr. Lödige Maschinenbau GmbH, Elsener Straβe 7-9, 33102 Paderborn, Germany. Such mixers are actually not only mixing but also further homogenizing and comminuting. Their preferred performance is based on the high peripheral speed of the mixing mechanism of up to 40 m/s. The resultant centrifugal force forms a concentric annular layer of the input comprising the least one organic material and the hot liquid content. The profile of the annular layer features a high mixing intensity, which is caused by the high differential speed between the rotating specially shaped mixing tools and the mixer wall. The product is moved through the mixing chamber in a plug-like flow, with the residence time being influenced by the degree of filling, the number of revolutions, the geometry and adjustment of the mixing tools as well as the mixing vessel length and the volume flow rate, The mixing chamber may be divided into zones of different shear intensity, and preferably the mixer is combined with a turbulent mixer also known from and available from Lödige Maschinenbau GmbH.
It has been shown in a series of experiments that it is advantageous to add cellulose in the form of microcrystalline cellulose (MCC), a highly crystalline particulate cellulose consisting primarily of crystallite aggregates obtained by removing amorphous (fibrous cellulose) regions of a purified cellulose source material by hydrolytic degradation, to the cellulose containing mass, 5 to 10 weight percent, preferably 7 weight percent of MCC were added to each batch in each experiment.
The addition of microcrystalline cellulose, especially when added to inputs containing primarily cereal straw, resulted in cellulose-containing mass which were preferably used for producing composite materials of high strength, Said composite materials produced form microcrystalline cellulose containing masses have increased hardness and tensile strength when compared to similar composites produced without the addition of microcrystalline cellulose.
After termination of the mixing the cellulose-containing mass is ready to be used for producing a composite material and for producing a desired product of said cellulose-containing mass.
The technology and technique of producing products in accordance with preferred embodiments of the invention include at least the following basic steps:
1. Preliminary preparation of inputs (comprising additives/improvers where necessary) including the previously described additional techniques of manufacturing;
2. electromagnetic exposure;
3. post-processing by at least one of curing and molding of the cellulose-containing mass until a product (end-use item) is produced.
According to the present invention, step number 2, is optional.
The term products encompasses end-products, such as for example panels, as well as semi-products, e.g. a core material of a laminated construction such as a sandwich construction, for example. In case of the latter, certain properties of the product may be improved for example in that at least one liner is adhesively bonded to said semi-product. An advantage of such sandwich constructions is that different properties such as structural strength, light-weight construction, fire resistance or a combination thereof are conferrable to a product. Depending on the embodiment of the product, one or several layers or liners may be made of metal, glass or carbon fibers or meshing.
Such non-organic fibers may be even added to the input or added later on to the cellulose-containing masses according to the invention.
Alternatively and/or in addition thereto, the cured composite material may be subject to suitable surface treatment that is discussed later on in this description.
The process of drying and/or curing denotes an extracting of excessive liquid from the cellulose-containing mass. Processes of structural linkage recovery appear while the cellulose-containing mass is shaped, for example by curing in casts or molds. Such processes are actually an integration of remains of β-glucose n-molecules into molecular compound with common to polymers formula [C6H7O2(OH)3]n. The presence of glucose molecules with three hydroxyl groups [(OH) groups] in each rest allow that linkage between said rests is facilitated through lateral hydroxyl groups by abstraction of water molecules from them. Therefore, structural linkage recovery of the organic material in the cellulose-containing mass takes place as soon as excessive liquid of the cellulose-containing mass is extracted, for example by desiccation or drying in case of water, resulting in a curing process.
In case of water being used as the liquid content the dehydration process is carried out under a predetermined temperature by any of a range of known suitable techniques. Such techniques are comprising and/or combining compression, extrusion and filtration as well as absorption, vacuum drying, blowdrying, heating, radiation, patting, vaporization under blower and other methods of desiccation, including natural air drying for example. Selection of a specific method of dehydration depends upon the specific requirements on the process and/or the article to be molded.
Depending on the characteristics of the cellulose-containing mass and/or the requirements on the composite material or the product to be produced thereof, the post-processing of the cellulose-containing mass is performed by at least one of molding, compression molding, injection molding. However, other shaping techniques for producing the product may be suitable.
In case of a post-processing by compression molding it is conceivable that the mixing container or a part thereof form a half of the mold at the same time, As general molding techniques are known to the person skilled in the art there a detailed description thereof is omitted.
Depending on the demands and the manufacturability, the molding and curing operation are carried out together or in sequence.
Further post-processing may be performed, e.g. for improving the resistance of the article made of the composite material against moisture or water, or to enhance its durability against chemically aggressive environments, the microbiological resistance, to confer the composite material and/or the product with required characteristics in view of a special type of resistance, a specific color, a particular smell or a combination thereof. For this purpose, specific modifiers and/or additives may be added into the input and/or the cellulose-containing mass prior to the extraction of any excessive liquid content.
Depending on the requirements, said specific modifiers and/or additives may be employed for achieving a particular homogeneity of the cellulose-containing mass and/or the composite material.
Special attention shall be paid to the fact, that several types of plant cells are encrusted by or containing compounds like inorganic minerals, for example silicates, or organic minerals like oxalates. The directed selection of organic materials containing certain amounts of said compounds like for example minerals can be used to provide cellulose-containing masses and composite materials according to the invention providing certain properties demanded by end-users. For instance, by selecting raw materials with employing the ability that the mentioned materials can acquire or significantly improve such characteristics and properties as conductance, transcalency (i.e. the thermal conductivity), soundproofness, resistance against moisture deformation, chemical and microbiological exposure and so on. In addition exogenous modifiers may be added if the cellulose-containing mass does not satisfy the requirements on the composite material.
Production of materials with predetermined properties (resistance, hydropathy, durability against chemically aggressive milieu, microbiological resistance, additional and/or special type of resistance, color, smell etc.) including those required by consumer's priorities is achieved by adding specific modifiers into homogeneous mass before dehydration and/or using special supplemental techniques while preparing homogeneous mass for curing.
Now, a few possibilities for surface treatment shall be addressed in brief. Depending on the requirements on the product made of the composite material, certain characteristics are achievable e.g. by applying one or several coatings with an impregnation, e.g. by way of immersion. Moreover, a coating layer with a specific color is applicable likewise.
All declarations in the description above apply likewise for the cellulose-containing mass, the method for producing the composite material, the composite material itself as well as for the produced thereof.
EXAMPLE 1As a raw organic material the stalk part of cereal crop is chosen. Preferably the spike of the crop is missing. Preferably the straw is taken after harvest. In this example straw of wheat is used.
The straw has been pre-treated by chopping up the stalks of straw until the straw pieces had an average size of about 5 to 7 millimeters, mixing them with water and macerating them until the organic particles in the input had an average size of about 0.8 to 1 mm. In this example, the pH-value of the aqueous mixture was brought to a value of more than 8.4 and macerated for 1.5 to 2 hours. In further examples the time of maceration was reduced to 1.5 to 2 minutes. One part of water was added to three parts of straw (weight/weight).
After maceration the input comprising the straw mass was poured into a stainless steel container serving as a mixing container to be put in the active zone between two inductors,.
An amount 14 g of ferromagnetic particles with cylindrical forms having an average diameter of 250 μm, an average length of 1500 μm were added to the straw-and-water mixture in the container prior to exposing the cellulose-containing mass to the electromagnetic field in order to increase the magnitude Bi under Hi=constant at every point i such that the active value of
An alternating electromagnetic field was generated such that it penetrated the active zone of 80 cm3 between the inductors (50 mm gap width) in the mixing container. The magnetic field provided that a vector of magnetic component created a circle or/and elliptic hodograph at any i point within that space excluding points of central axis defined between the inductors such that Bi=μ*Hi where divBi=0, and, therefore, rotAi=Bi. The intensity of the magnetic component was equal to zero at any j point on the central axis and the condition Hj=0, Bj=0 and rotAj=0 was satisfied. So, activity of vector potential A of magnetic field with amplitude value from Aj to Ai was generated within the alternating electromagnetic field, such that gradA took effect in the space between the inductors.
The magnetic force measured about 0.3 T was applied. The input was exposed for 20 seconds to said alternating magnetic field. The electric source had 50 Hz.
Upon applying of the magnetic field, the ferromagnetic particles churned the input in the container lively. In this process every ferromagnetic particle performed a role of micro-mixer and micro-grinder due to its interaction with different hodographs of intensity vector Hi at different i points within the container.
After termination of the exposure of the input to the electromagnetic field, the particles with an average particle size of the organic material remained in the cellulose-containing mass measured not less than 1 μm. However the magnetic treatment ensured a sufficient disintegration of the input material, so that sufficient numbers of cells and intra- and intercellular structures are destroyed.
Then, the cellulose-containing material was carried over from the mixing container to a mold, in the form of a Büchner Funnel. Suction filtration was used to increase the speed of filtration and subsequently the cellulose-containing mass was left to dry so that the dry and solid piece of composite material is left remaining. In this example, the evaporation process encompassed a combined method of filtration and natural drying until the weight mass of the composite material became permanent at a temperature of 30° C. Drying was controlled by a gravimetrical method until the sample product underwent structural and strength tests.
EXAMPLES 2 To 13In the present example No. 2 and the following examples No. 3 to 13 the following basic settings were employed.
Wheat straw was pre-treated by chopping up the stalks of straw until the straw pieces had an average size of about 5 to 7 millimeters. 100 g of chopped straw were mixed with 1000 ml of a master solution in order to produce a trial batch. All trial batches were allowed to settle for 6 hours before further treatment steps.
In each of the experiments 2 to 13 Carboxy Methyl Cellulose (CMC) was used, The Carboxy Methyl Cellulose (CMC) used in the present experiments was obtained from Fischer Chemicals Chemicals AG, Riesbachstrasse 57, CH-8034 Zurich, Switzerland with the CAS Number 9004-32-4. 7 g of CMC were added to and mixed with each trial batch in each experiment. In further experiments microcrystalline cellulose (MCC) was used which had according to preferred embodiments a mean size range of about 15 to 40 microns.
In four of the experiments the input was exposed to an active zone of an electromagnetic field generated between linear electromagnetic inductors as described above. The time of exposure to the electromagnetic filed is listed in column “Inductor” in Table 1 below.
In experiments 3, 6, 9 and 12 the straw material in the master solution is cooked for 3 hours as indicated in Column Cooking below. The NaOH based mixture of example 12 is neutralized after cooking.
All experimental samples were transferred onto a paper filter afterwards. Excess water was pressed off and the remaining filter cake was allowed to settle for 2 hours.
The samples of experiments 2, 5, 8 and 11 were exposed to the active zone between the inductors for 1 Minute before transferring them to the filter.
All samples were dried afterwards at temperatures between 80 to 85° C. for 16 or 24 hours as indicated in column Drying.
Non-standardized mechanical tests preformed on the resulting test blocks of experiments 2 to 13 revealed that the materials produced according to examples 2 and 5 are hardest and strongest. All the samples according to experiments 2 to 8 and 11 to 13 resulted in cellulose-containing masses suitable for the production of shaped composites. However the inherent strength and stability of the test blocks produced with the cellulose-containing masses according to examples 9 and 10 were considerable lower.
EXAMPLE 14Wheat straw was pre-treated by chopping up the stalks of straw until the straw pieces had an average size of about 5 to 7 millimeters. 100 kg of chopped straw were mixed with 1000 l of hot water in order to produce a trial batch. All trial batches were wet-milled immediately after production of the batches in CONDUX Fine cutting mills CS 500, available from Netzsch-Condux. The preferred temperature range of the water straw mixture during wet milling was kept at about 92 to 94° C. The milling product was of excellent fineness and homogeneity and already suitable for the production of a composite material and for producing a desired product of said cellulose-containing mass.
EXAMPLE 15Wheat straw was pre-treated by chopping up the stalks of straw until the straw pieces had an average size of about 5 to 7 millimeters, 100 kg of chopped straw were mixed with 1000 l of hot water in order to produce a trial batch. All trial batches were again wet-milled immediately after production of the batches in CONDUX Fine cutting mills CS 500, available from Netzsch-Condux, The preferred temperature range of the water straw mixture during wet milling was kept ate about 92 to 94° C. During wet-milling, an aqueous, liquid cellulose-containing fraction was separated and drained from the mill. Said hot liquid fraction can be recycled to the mill. According to preferred embodiments however, it was further concentrated by filtering or by dehydration and added during mixing. The mixing was again performed in a a high-performance Ringlayer Mixer CoriMix® CM available from Gebr, Lödige Maschinenbau GmbH.
The above listed experiments show that according to the present invention the addition of cellulose based adhesives and binders, preferably in a water-soluble form as methyl cellulose and carboxy methyl cellulose enhances the properties of the produced masses and materials.
In further preferred embodiments microcrystalline cellulose and/or powdered cellulose is added to achieve further desired properties.
Claims
1. A method for producing a cellulose-containing mass, the method comprising the steps of:
- preparing an input comprising at least one organic material and a liquid content; and
- exposing said input to a wet-mixing procedure at a temperature in the range of 70 to 120° C.
2. The method according to claim 1, further comprising the step of separating an aqueous liquid cellulose-containing faction during or after the wet-mixing procedure.
3. The method according to claim 1, further comprising the step of adding additional cellulose to the cellulose-containing mass,
- or adding cellulose by returning a cellulose containing fraction generated in the wet-mixing procedure after concentration or dehydration.
4. The method according to claim 1, wherein the input is exposed to an active zone of an electromagnetic field and the input comprises a plurality of ferromagnetic particles.
5. The method according to claim 4, wherein an average length of the ferromagnetic particles is in a range of about 0.3 to about 25 mm and wherein an average diameter of the ferromagnetic particles is in a range of about 0.1 to about 5 mm.
6. The method according to claim 4, wherein the ferromagnetic particles have a ratio of diameter to length of about 1:3 to about 1:5 and an essentially cylindrical form.
7. The method according to claim 4, wherein a ratio of the ferromagnetic particles to the input is about 1 to about 25 weight percent.
8. The method according to claim 4, wherein said active zone is generated between linear electromagnetic inductors generating electromagnetic fields that run towards each other from opposite directions.
9. The method according to claim 8, wherein the electromagnetic inductors are separated from each other by a distance measuring 1 mm to about 5 m.
10. The method according to claim 8, wherein a magnetic force of the electromagnetic inductors measures about 0.01 to about 20 Tesla.
11. The method according to claim 4, wherein the duration of said exposure measures about 1 second to about 3 hours.
12. The method according to claim 11, wherein the organic material comprises fibers.
13. The method according to claim 11, wherein the organic material originates from higher plants, selected from the group consisting of: true grasses of the family Gramineae (Poaceae), cotton, hemp. flax, and mixtures thereof.
14. The method according to claim 13, wherein the organic material originates from at least one of cereal straw and rice straw.
15. The method according to claim 2, wherein the liquid content comprises at least one of water and a solvent.
16. The method according to claim 2, wherein the organic material is pre-treated by at least one of: maceration in a liquid having a pH-value of about 8, electromechanical exposure, hydrodynamic exposure, ultrasonic exposure, boiling, and steaming.
17. A cellulose-containing mass produced by a method according to claim 1.
18. A method for producing a composite material comprising a cellulose-containing mass according to claim 17.
19. The method according to claim 18, wherein at least one additive or a modifier is added to at least one of the input or the cellulose-containing mass.
20. The method according to claim 18, wherein the cellulose-containing mass is homogenized.
21. The method according to claim 18, wherein the cellulose-containing mass is post-processed by at least one of molding, compression molding, and injection molding.
22. The method according to claim 21, wherein an excessive portion of the liquid content is extracted by at least one of drying and curing.
23. A composite material produced by a method according to any claim 17.
24. A product produced from a composite material according to claim 23.
25. The product according to claim 24, wherein the product is coated with an impregnation.
26. The product according to claim 24, comprising at least one liner adhesively bonded to the post-processed cellulose-containing mass.
Type: Application
Filed: Sep 24, 2010
Publication Date: Aug 2, 2012
Applicants: PHILIPPE SAINT GER AG (Walchwil), (Moscow)
Inventor: Vadim Gogichev (Moscow)
Application Number: 13/498,870
International Classification: D21H 11/12 (20060101); D21J 3/00 (20060101); D21C 5/00 (20060101);
