MANUFACTURING PROCESS FOR PANELS OR SIMILAR PRODUCTS MADE OF INSULATING MATERIAL AND PANEL OR PRODUCT OBTAINED BY SUCH PROCESS

Abstract: Manufacturing process of panels or finished products, particularly for thermic, sound and similar insulation, by using raw materials like the paper, the Bristol board, the cardboard and similar materials, which are in succession or at deferred times cut to obtain particles with reduced dimensions, mixed to fire-retardant, adhesives, and bonding agents, and additives of various types and compressed at heated or cooled conditions and finally dried and packed. There are described different possibilities of performing the process and different embodiments as well as use modes of the so obtained panels or finished products.

Description: MANUFACTURING PROCESS FOR PANELS OR SIMILAR PRODUCTS MADE OF INSULATING MATERIAL AND PANEL OR PRODUCT OBTAINED BY SUCH PROCESS. The invention concerns a manufacturing process for panels or in general of products of insulating material, in particular thermic insulating material to be installed in habitable buildings, and also concerns a panel or a product of other type obtained by such manufacturing process. There are known panels or products of different type usable for thermic insulation purposes in the habitable buildings, made with different and variable forms and dimensions to allow their installation into the respective ambients by using traditional materials like for example foamed polyurethane , the glass wool, the polystyrene and so on. These panels or finished products are commonly manufactured on industrial scale by using thermic insulating materials specially arranged for the use, or materials residual of other processings (like in the case, for example, the polystyrene and so on... ) which are further treated in a suitable way to adapt them to such function, by requiring therefore the use of relatively onerous raw material , also because of the needed processings for the special treatment for and tendency of the same material. Moreover, these insulating materials are generally submitted to processes which require often the manual operation, with special equipments, so that finally every so obtained panel or product results to be manufactured industrially sometimes in a not much efficient or rational way, also with the use of several labour, which circumstances make this type of manufacturings often poorly productive. The present invention has the object to provide a different manufacturing process for panels or finished products of other type of insulating materials, in particular thermic insulating materials, which makes it possible to eliminate or strongly limit the above specified drawbacks, thus allowing the maximal rationalisation of the required processings with a minimum requirement of labour and manual operations, by utilizing materials available on the market in large quantity and at a low cost. This process is obtained with the characteristics substantially described, with particular reference to the accompanying patent claims, - The present invention will result more comprehensive from the following description, given solely by way of a not limitative example, and with reference to the single enclosed drawing showing schematically a system for the industrial production of panels or similar finished products in accordance with the process of the present invention. The present process is substantially provided for the manufacturing of panels or finished products of various type, form and dimensions to be installed in civil and industrial and promiscuous habitable buildings, for insulation purposes, specially for the thermic insulation of the internal and external ambients of such buildings and for partition and equipped walls. This process substantially provides the use of insulating materials like paper, cardboard, and similar material which are generally rejected after the use and which otherwise would be abandoned or in case recovered for their recycling in other application fields, as for example the manufacturing of recycled paper, cardboard, with per se known methods and uses. These papers, cardboard and the like materials may be of any type, forms, dimensions, specific weights, compositions and quantities and are collected from the collecting and storage places thereof, in order to be treated in the ways and for the purposes hereinafter described. In particular, in the case in which as raw material for the following manufacturing process it is used the paper, it is to point out that such paper may be of any type for example: printing paper for rotogravures, magazines, newspapers of any quality of paper (with or without watermark and so on), paper for several type of 80 uses and the like, any type of Bristol board, rigid and in more layers and the like as well as new paper derived from machinery trim and from paper factory stock or from burnt and extinguished material or from facilitated reading paper or tabulations from computing units. 85 In the case in which as raw material for the following manufacturing process be utilized cardboard or paper for packing in general, there may be used for example cardboard boxes for every packaging use, paper for external covering, Kraft and test paper, duplex or 90 chamois colour paper, corrugated paper ( semichemical , straw paper, raw paper ), microwave board, corrugated board or similar cardboards, of same type of materials or with variable combinations of single components of paper, cardboards, Bristol boards and the like, printing shop 95 scraps and sanitary paper. Likewise, in addition to these raw materials it may be used the cellulose, separately or in combination with the above mentioned raw materials, at different and variable ratios thereof. Preferably, the cellulose may be obtained 100 from the recovery and further treatment of papers, Bristol boards, cardboards and similar aforesaid materials, in a conventional way, and it may be used in a solid and/or liquid state, or it may be obtained directly from the natural wood or from vegetables of various kind 105 like for example the foliage, the tree fruits (pine- cones, chestnut husks etc... ), underwood products, vegetable essences in general, seaweeds, plant derivatives as rice and leguminouses etc... by submitting these components to suitable and per se known treatments 110 for obtaining such cellulose. In alternative, instead of these raw materials there may be used also waste and scraps from processes of materials and fabrics of the most different types and uses, with cloths of natural and/or synthetic fabrics, 115 for example assigned to the clothing, industrial field etc... , which components may be used separately or in combination with the previously mentioned raw materials of paper, cardboard, Bristol board and cellulose. All the raw materials which are used in accordance with 120 the present invention are previously drawn from the respective stocking and collecting sites with loading and transport machines, vehicles and equipments of per se known kind and transferred toward the selected sites for the raw material treatment with the methods and purposes 125 hereinafter described. Firstly, on these sites such raw materials are submitted to a heating process at suitable times and temperatures to insure satisfactory drying of the humidity and water or other liquids contained therein. Advantageously, for performing this operation 130 there are used appliances, plants and machines suitable for this purpose and of common use as for example various type of heating and/or dehydrating appliances and systems (stoves, ovens, radiant lamps, microwaves, convectors, ventilation systems, natural or forced air circulation 135 drying systems, which air is heated or not with high or low pressures, vacuum pumps systems, hygroscopic agents etc. ), and such operation in case may be divided in two steps, respectively a first step of partial or total drying of raw materials as previously considered, before 140 to start the treatment steps which will be specified, for obtaining finished products, and a second step of partial or total drying of such finished products. Afterwards, during the first step of the present process, the raw materials submitted to a partial or total drying 145 are manually or automatically transferred, for example by means of suitable conveyors of per se known type, toward one or more triturating, grinding, crushing systems and the like to define a triturating, grinding, shredding or the like operation adapted to produce preferably a 150 plurality of pieces, strips, fibres with reduced forms and sizes, said conveyors and triturating, grinding, crushing systems and the like being indicated by way of example in a subsequent part of the description, with reference to the treatment plant shown in the figure of 155 the present patent.- The object of this first manufacturing step is to triturate, mince, and grind the differently used raw materials in parts of reduced dimensions, so as to be able to treat them suitably as it will be described in detail in the other manufacturing 160 steps of the present process, depending on the respective finished products to be manufactured. In the second manufacturing step of the process according to the invention, the so dried, triturated, minced etc. raw materials are mixed with adhesives, bonding agents or 165 the like means, which are adapted to bind indissolubly the raw material small pieces thereamong, with the possible addition of special materials or additives with specific functions, for the purposes and in the manners hereinafter described. This mixing can be done either 170 directly on the triturated, minced, ground etc... mass of raw materials, in the course of the previous manufacturing step and without the use of specific mixing equipments, or by using these mixing equipments, of the types which will be described with reference to 175 the treatment plant. In particular, these adhesives, bonding agents and the like are suitable to provide for a close and uniform amalgamation thereof with the raw material small parts and the other used special substances and/or additives, which will be hereinafter 180 described by way of example, and are collected, transferred toward the application place and applied on position by means of suitable systems and equipments (swinging nozzles, dispensers etc. ) suitable to spray and lead adequately such adhesives , bonding agents, and the 185 like onto the mass of the triturated, minced, ground etc... raw materials. As adhesives and bonding agents there may be used advantageously polyurethanic adhesives with or without solvent or in aqueous leakage suspension, finishing for 190 synthetic skin manufacturing, glucoses, isoglucoses, dextroses, caramels, simple starchs , modified and esterificated starchs and derivatives thereof, dextrines, sorbitols, mannitols, maltitols, xilose, xilitol, gluten, bran, maize raw oils, rubber solutions and the like, 195 monocomponent and multi-component polyurethanic sealing agents, self-levelling with low coefficient of elasticity, hydrocarbon-proof or not, acrylic, siliconic, polysulphidic , butylic and vinylic sealing agents (generally employed for alimentary and industrial uses), 200 cold siliconic rubbers, granulated thermoplastic materials with ethylene vinyl acetate, polyurethanic materials, polyester, polyamide, hot melts, powdered or liquid thermosetting materials as ureic resins, melaminic resins, phenolic resins, polyester resins, epoxy resins, 205 novolacquers, bonding materials derived from synthesis of animal, vegetables, mineral and chemical products in general, bonding materials from fish or bones, adhesive pastes, carboxid etylcellulose , liquid or powdered metylcellulose , vinylic hotmelts, special adhesives for 210 bookbindery, sugars, starchs, SBS rubbers, SBR rubbers, neoprenic rubbers, chlorine caoutchouc rubbers, acrylic rubbers, ethylenic rubbers, vegetables adhesives, animal glues, caseine glues, tannin glues, pure silicates or silicates which are catalyzed or combined with other 215 materials, colophonic resins, single hydrocarbonic resins or combined with other materials, hydraulic adhesives, asphalts, primers, liquid sheats, dextrines, skin gelatines, sealing agents and adhesives in general, stuccoes, adhesives deriving from waste materials and 220 adhesives, recycling and expanding rubbers, for alimentary or not alimentary use and also with processings of natural resins.- These adhesives and bonding materials can be added at variable ratios thereof with respect to the triturated, minced, ground etc... 225 mass of raw materials, preferably comprised, between approximately 5% and 100% weight or volume. Of course, for this invention there may be used also other kind of adhesives and bonding agents for obtaining the previously cited objects. - 230 Further materials which during the second manufacturing step of the present process are mixed, contemporaneously of the aforesaid bonding agents and adhesives, with the mass of the triturated, minced, ground, etc... raw materials are fire-retardant materials suitable to make 235 self - extinguishing, and high temperature resistant such fire-retardant mass. These fire-retardant materials, which give features of combustion inhibition to the aforesaid mass, and which advantageously have also marked features of absorption of 240 the atmospheric humidity, are generally constituted by carbonates, silicates, urea, micronized silicas, and the like, and also by additive agents like borax and boron derivatives, antimony dioxide and trioxide, kaolins, silica based fire-retardants , aluminium hydrates, 245 chloride materials, talc, bentonites, wherein these fire- retardant materials can be mixed with the mass of triturated, minced, ground etc... raw materials, with a variable ratio preferably comprised from 0,2% to about 50% volume or weigh of the same materials with respect to 250 that of such mass. Advantageously, moreover, a finished product as for example a thermoinsulating panel obtained with the present manufacturing process may contain by way of example only a volume or weigh ratio comprised from 7% to 255 10% of borax and from 20 to 30% of kaolin with respect to that of the mass of triturated, minced, ground etc... raw materials . Also in this case, as previously, there may be employed fire-retardant materials of different and per se known 260 kind to obtain the same above mentioned objects. Moreover, the mass of triturated, minced, ground, etc... raw materials and mixed with the adhesives and bonding materials as well as the above mentioned fire-retardant materials, can be mixed also with further additive 265 materials, of per se known type, suitable to confer special features to the same mass, as for example water- repellent or humidity absorbing substances, the condensate, the mildews, the liquids in general and the animal, vegetable, chemical, and mineral based solutions, 270 anti-corrosive, and anti-odour substances, not putrescible on the time, and stable substances, bactericide, disinfectant, sterilizing and similar substances, fuels and toxic materials, harmful-toxic, explosives, and reagent absorbing substances, 275 oily pollutant, petroliferous substances, substances derived from physical and mechanical treatments of various kind as well as derived from natural emissions (resins) or from processings drainings and decantations , osmotic processes arising from raw materials and semi- 280 finished products of any natural process or from handicraft and industrial manufacturings with plants and equipments of various type, dye and painting absorbing substances, alcohol, disinfectants, essences and perfumes, extracts, natural and industrial greases, inks, 285 oils, industrial fuels, mineral fuels, natural and vegetable fuels, pharmaceutical products etc.- The mixture, amalgamation or knead of triturated, minced, ground etc... raw materials with such fire-retardant and additive substances is obtained in such a way as to get 290 compositions suitable for the needed features that the panel or the finished product in general must have, for the special use to which it is assigned. Such compositions, therefore, may be obtained with several and variable combinations and percentages of the 295 single components (raw materials and bonding agents, adhesives, water and/or steam, dyes, raw materials already referred to etc. ), depending on the final results to be obtained. Moreover, in accordance with the present manufacturing 300 process, the addition of the adhesives, bonding agents, and similar means may be performed advantageously with two different criteria, in such a way to permit to obtain always the above mentioned objects.- A first criterion of addition thereof is based on the fact to add to the mass 305 of triturated, minced, ground etc... raw materials, together with the above mentioned fire-retardant substances and additive substances, such adhesives and bonding agents at the solid state, powdered or granulated, at not heated conditions namely at the 310 ambient temperature and preferably by using the specific mixing equipments, so to obtain a homogeneous knead of such adhesives and bonding agents as well as fire- retardant and additive substances with the mass of triturated, minced, ground etc... raw materials, which 315 knead thence lends itself for the next manufacturing steps which will be described. A second criterion of addition thereof is based on the fact to spray, wet or pour such adhesives, bonding agents or similar means at the liquid state or at a liquid dispersion thereof, in 320 case diluted with suitable diluents and at not-heated conditions namely at the ambient temperature, together with said fire-retardant and additive substances, onto the mass of the triturated, minced, ground etc... raw materials, which operation in the case of spraying, 325 wetting etc... is performed by means of common spraying devices, provided with orientable and or fixed nozzles and possible dispensers for the quantity of the adhesives and bonding agents, thereby leading them adequately and directly onto the aforesaid mass with suitably regulated 330 spraying pressures, in order to obtain the desired density, quantity, weights, and dimensions thereof, before to submit this aggregate to the subsequent treatment steps which will be described. The present manufacturing process comprises also a third 335 manufacturing step, where the mass of triturated, minced, ground etc... raw materials mixed with said bonding substances, adhesives, fire-retardant and additive substances is transferred by conveyor means toward at least a moulding or pressing station, adapted to press 340 such mixed mass with settled pressures and at heated or cooled conditions with pre-established temperatures, such as to obtain the melting or crystallization of the adhesives and bonding agents, in order to make a panel or finished product of various type, having forms, 345 dimensions and structural characteristics required for the foreseen functions. In particular, the moulding or pressing operation is effected within the time and with the temperatures needed for melting or crystallizing such adhesives and bonding agents and the close amalgamation 350 thereof with the triturated, minced, ground etc... raw materials and also with the above cited fire-retardant and additive substances, with such pressures as to keep all the aforesaid component parts of these panels or finished products of various kind closely and 355 indissolubly adherent to each other, and by utilizing suitable machines as i.e. injection moulding presses with closed moulds, having different moulding pressures, mechanical, hydraulic and automatic bending and not- bending presses, calenders, presses with open dies 360 (gravity die castings), or other machines, equipments and plants commonly used for this kind of processings. - Moreover, as support for this moulding, pressing and the like operation there may be used also plants, machines and equipments adapted to obtain some additional 365 processings of the so obtained panel or finished product, as for example : turnings, millings, shearings, grindings, shapings, headings, coatings and any other suitable processing for the most different uses in the moto-rcar, motor-cycle fields, building, industry, 370 furniture making field for the interior furnishings, and the complementary component parts thereof, effective thermic and sound insulations, and at different combinations thereof as the manufactures of building fittings, the reinforced panels for several uses, tubing 375 and piping insulation coverings, the effective tubings, the floorings and counter-ceilings, the artificial ornamental trees, in combination with refractory support materials for any finished product, the manufactures of pots, fertilized humus and containers adapted for the 380 germination of cultivation trees and flowers, the biodegradable bulkheads etc...- The transport of the mass of triturated, minced, ground etc... raw materials mixed with the fire-retardant, adhesive, bonding and additive substances toward the moulding or pressing station is 385 done directly, after the second manufacturing step, in the case in which the adhesive and bonding substances be added with the above mentioned first addition criterion thereof and by using advantageously at least a passing tube or conduit before the addition of the adhesives and 390 bonding agents with the above mentioned second addition criterion thereof, so as to permit to compact the mass itself for the following spraying of such adhesives and bonding agents thereon. In alternative, instead of being obtained with a 395 continuous operative cycle as described, the mixed mass to be mould or pressed may be obtained also separately with similar manufacturing operations performed in advance and in different places, for example by means of maceration and pulper additivation of the paper raw 400 material and the subsequent preheating thereof, by dissecting the additivated and glued paper raw material etc.. , and thereafter such mixed mass can be directly submitted to moulding or pressing operations upon additivation of such fire-retardant and additive 405 substances and, in the case in which they are absent, also with adhesives and bonding agents. Then, when the moulding or pressing operations are concluded, the so manufactured panel or finished product is transferred by means of conveyor means to a drying zone to provide for 410 the full drying thereof with per se known appliances, plants, and machines and generally of the same type described previously for the preventive drying of the raw materials. Subsequently, the panel or finished product is packed in a traditional way and predisposed for the 415 dispatch and delivery to the utilization place. It is to point out that, instead of being packaged as panel or finished product, it is also possible to package panels or semi-finished products with different forms (sheets, coils, multilayers, etc .. ) and formed by the 420 raw materials mixed with fire-retardant substances, adhesives and bonding agents as well as additives, and not yet submitted to the moulding or pressing operations, so that to send these products or semi-finished panels to transforming supplier factories for performing with 425 quality and quantity such moulding or pressing operations, so as to obtain panels or finished products and in case also further treatment processing thereof of the same type previously described. The so obtained panels can be advantageously used as 430 thermic insulating panels, sound absorbing panels etc... , to be installed on habitable, civil, and industrial, and promiscuous buildings, for purposes of insulating external and internal ambients as well as partition walls, equipped walls, and the like, and they can also 435 have the most different and variable forms, dimensions and weights, and different aspects also thanks to the possibility to submit the same panels obtained with moulding or pressing operations to further more suitable processings. Additional uses of the panels may be for 440 absorbing humidity, condensate, mildews, water, pollutant substances, dyes, paints, and as humid or humidified ground to prepare intensive vegetable cultures (mushrooms etc .. ), and similar. The finished products attainable therefrom, in addition to the use thereof as insulating 445 materials, and in particular thermal, sound etc... insulating materials, may be employed for the most different uses as for instance for animal beds, transport containers for liquid chemical products, stuffings, finishing panels for furnishings and counter-ceilings, 450 counter-walls, coverings for corners, columns and surfaces for accident preventing uses, statues, tailor's dummies, working and drawing tables, tapestry for home and cars, supports of different type, aquarium insulating materials, preformed and shaped parts for transporting 455 machinery, tools, plants, equipments, orthopaedic devices, bumper elements, flower-culture and tree- nurseries, greenhouses, pots, fertilizing materials, base supports for cultivations of mushrooms, trees, vegetables, vines, printed dressing complements, clothes, 460 garments and clothes in general, exhibition dressing, games and toys in general , amalgams and agglomerated materials, gliders, albums, folders, files, sound-proof boxes, sound amplifying, equipment anchorage, stop and sealing rings and gaskets, target firing shapes, anti- 465 deflagrating complements, components for equipments, materials, and plants for accident and fire prevention, anti-vibrating devices, air-conditioning and climatisation, drying and refrigerating systems, cinema, theater, laboratory, naval field furnishings; sacred and 470 urban furnishings; school and community furnishings; furnishings for terraces, offices, shops for commercial business, goods to be disposed of, carnival articles, funerary and gift articles, remembering, sport articles; technical industrial articles, lifts etc .. - 475 The present manufacturing process, therefore, permits to obtain such panels and finished products by simple and almost completely automatized processings, which still being manufacturing panels or finished products with sophisticated technology and quality, may be obtained 480 with simple machines, plants and equipments easy to be found and which can be utilized by skilled workers having a lowest specific training, and thus lend themselves for being exploited even on scarcely or not industrialized zones and territories, like i.e. the nations under 485 development, said processings being requiring also reduced manual interventions by utilizing rejected raw materials which can be found on large scale on the market and at reduced costs, which raw materials can be also utilized and recycled again when the panels and finished 490 products would be used for further uses, and involving a subsequent processing thereof and which moreover do not originate any waste pollution ( smogs, powders etc... ) during their processing and production. According to the present invention, a manufacturing 495 process adapted to manufacture panels and/or finished products as from the process preferred to, could be formed, as evident from the drawing, by plurality of treatment stations interconnected by at least one transport and conveying means of per se known type and 500 including in succession a trituration, mincing and/or grinding station 1 in which the collected raw materials are submitted to the trituration, mincing, grinding and similar processes in order to obtain a plurality of parts, strips, fibres of reduced form and sizes; a 505 collecting and loading hopper 2 for the triturated, minced, and/or ground etc... raw materials, adapted to transfer the same, with the aid of possible exhaust fans (not shown) to a storage bin or container 3 for their temporary stocking; a weighing or volumetric metering 510 device 4 adapted to meter opportunely the different quantities of raw materials with those of the fire- retardant and additive agents which are used, and which are admitted together with such raw materials on the requested ratios thereof, depending on the panel or 515 finished product to be obtained; a mixing container 5 (for example of the rotary blades or scroll types) to mix opportunely the aggregate raw materials-fire-retardant and additive substances; an atomizer-sprayer device 6 for the wetting and/or steaming treatment of said aggregate 520 so that to knead adequately the same aggregate, and for the possible sterilization thereof, with subsequent evaporation of said aggregate on an evaporator-dryer 7; a sprayer-atomizer 8 for liquid adhesives and bonding agents for the impregnation of the aggregate, so as to 525 obtain a pre-formed product; a heated (or cooled) moulding or pressing station 9 with fixed compression forces, for obtaining respective panels or finished products; a drying oven 10 for fully drying such panels or finished products and a packaging station (or 530 strapping station) 11 for the packing and shipment to the destination places of the panels or finished products. Of course, it is possible to foresee manufacturing plants also different of that described only by way of example, provided that there are always provided manufacturing 535 steps which are identical and in case deferred in the time with respect to those previously described, thus without departing from the protection field of the present invention. 540 545 550 555 560 565

Claims: 570 CLAIMS 1. Manufacturing process of various types of panels or finished products for the most different uses, particularly for thermic and sound insulating of internal and external habitable ambients of buildings as well as 575 for partition and equipped walls, characterized in that there are employed raw materials like the paper, the Bristol board, the cardboard, and similar materials, rejected or not rejected after their use and of different types, in case combined also with cellulose at different 580 and variable ratios thereof, and preferably submitted to preventive drying in a per se known manner and to submit in succession or at different periods said raw materials to a first manufacturing step, in which they are cut on particles of reduced dimensions with the form of strips 585 and fibres etc... by trituration, crushing, grinding and similar systems of per se known kind, to a second manufacturing step in which said particles of raw materials are mixed, preferably within mixing-containing devices of per se known type, with adhesives and bonding 590 agents or similar means, fire-retardant substances and additive materials of various kind, like water-repellent or liquid and/or mildews absorbing substances, corrosion- proof, anti-odour substances, not-putrescible substances, bactericide, disinfectant, sterilizing, fertilizing and 595 similar substances, at different and variable ratios of the single components, and to a third manufacturing step in which said mixed particles are submitted to compression operations like moulding, pressing and the like to obtain the panel or the finished product with the 600 desired forms, aspects and dimensions, which subsequently is dried, packed and delivered to the respective destination places. 2. Process according to claim 1, characterized in that said adhesives, bonding agents or similar means are added 605 to said particles of raw materials preferably at the solid state or at the liquid dispersion thereof, and melted (or crystallized) by amalgamating them together with the same particles and said fire-retardant and additive substances, at pre-established compression 610 pressures. 3. Process according to claim 2, characterized in that said panels or finished products may be submitted to further traditional processings by utilizing per se known machines, systems and equipments. 615 4. Panel or finished product of various type and for the most different uses, particularly for thermic and sound insulating of internal and external habitable ambients of buildings as well as for partition and equipped walls, which may be obtained by the manufacturing process 620 according to the claims 1-3, characterized in that it is formed by particles of reduced dimensions of raw materials like the paper, the Bristol board, the cardboard, and similar materials, rejected or not rejected after their use and of different types, in case 625 combined also with cellulose at different and variable ratios thereof and mixed with adhesives and bonding agents or similar means, fire-retardant substances and additive materials of various kind, like water-repellent or liquid and/or mildews absorbing substances, corrosion- 630 proof substances, anti-odour, not-putrescible substances, bactericide, disinfectant, sterilizing, fertilizing and similar substances, at different and variable ratios of the single components thereof. 635 640 645

Inventors: DE SANTI PIERO, DE SANTI, PIERO
Applicants: ELISA DI DE SANTI PIERO, SANTI PIERO DE, DE SANTI, PIERO
Application year: 1993
Main classification: B29B17
IPC codes: B09B3, B27N3, B29B11, B29B13, B29B17, B31D1, D21H23, D21J1, D21J3, E04B1, E04C2