Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B28—WORKING CEMENT, CLAY, OR STONE
  • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
  • B28B1/00—Producing shaped prefabricated articles from the material
  • B28B1/26—Producing shaped prefabricated articles from the material by slip-casting, i.e. by casting a suspension or dispersion of the material in a liquid-absorbent or porous mould, the liquid being allowed to soak into or pass through the walls of the mould; Moulds therefor ; specially for manufacturing articles starting from a ceramic slip; Moulds therefor
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
  • C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
  • Y02W30/00—Technologies for solid waste management
  • Y02W30/50—Reuse, recycling or recovery technologies
  • Y02W30/91—Use of waste materials as fillers for mortars or concrete
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2904—Staple length fiber
  • Y10T428/2907—Staple length fiber with coating or impregnation

Definitions

• the present patent application relates to a manufacturing process by molding a matrix part with hydraulic setting and a part obtained by this process.
• glass fiber reinforced cement panels (better known by its acronym in English, GRC for glassfibre reinforced surround) are widely used for covering facades instead of traditional concrete panels, to take advantage of their high mechanical performance, with reduced thicknesses and therefore greater lightness.
• cladding fin panels and architectural elements
• they lend themselves to other applications, such as sanitary (shower trays and related elements) as well as interior elements.
• the first object of the invention is to overcome these drawbacks by proposing a method of manufacturing by molding a matrix part with hydraulic grip which is efficient.
• the invention provides a method of manufacturing a part in a matrix with hydraulic setting by molding comprising the following steps: a) injection of a paste containing a hydraulic binder and so-called mixing water in a mold, b) extraction of kneading water by vacuum, c) demolding of the fresh part.
• the process according to the invention is more compatible with industrial requirements than the processes of the prior art in which demolding takes place dry. In fact, vacuum extraction considerably reduces the occupation time of the mold. This process therefore makes it possible to reduce the quantity of material used as well as the time spent on manufacturing the parts.
• the method according to the invention is simple to implement and can be easily automated.
• a first step in the process according to the present invention may consist in mixing the dough.
• the components of the latter are introduced, for example, into a mixer equipped with a stirring system, and stirring is continued until a homogeneous mixture is obtained.
• the occluded air produced during mixing can be removed inside the pressure tank.
• the dough can be transferred to a tank equipped for example with suitable locking systems which allow the interior to be pressurized.
• the tank can integrate an internal bubble removal system, based on a vacuum process, possibly with the production of vibrations from the outside, if necessary, so that the occluded air is not introduced into the mold with the injected dough.
• the paste is injected into the mo ile, preferably by pressurizing the above-mentioned reservoir.
• the injection can take place at low pressure or at high pressure.
• the operating pressure, for low pressure injection is preferably between 1.5 and 4 bars, while the high pressure is preferably between 4 and 30 bars, depending on the case and taking this pressure into account in the mold design. .
• This injection can also take place by any other conventional means, such as a peristaltic pump or compressed air (in the case of low pressure injection).
• the vacuum is preferably produced by a vacuum pump. Extract the excess water so that the room has the desired humidity levels.
• the final percentage of water represents a compromise which allows problem-free handling of the part while avoiding cracking due to lack of water.
• the water / cement ratio after the vacuum extraction step can be preferably between 0.25 and 0.5.
• the duration of the vacuum extraction step of the process according to the present invention is less than 1 hour, which in particular makes it possible to significantly increase the yield compared to existing processes.
• the process makes it possible to obtain parts - for example for floors - having a thickness for example between 0.2 cm and 5 cm without harming their physical or mechanical properties, which contributes to reducing the quantity of material used, by reducing costs and obtaining lighter parts, which facilitates their handling and installation.
• the manufacturing method according to the invention can comprise the hardening of the part obtained.
• hardening preferably takes place under conditions of humidity and temperature which allow the part to regain the levels of hydration necessary after the loss of water undergone during the vacuum extraction step.
• the relative humidity during hardening can be between 90% and 100%, and the total hardening time can be between 1 and 7 days.
• Other curing systems can be selected, such as steam, autoclave, etc.
• reinforcing fibers cut into the paste are mixed before injection and / or reinforcing fibers are placed in the mold before injection.
• a support element is placed in the mold before injection and the fresh part placed on said support is removed using said support.
• this support can be a metal part, of rigidity adapted to the size of the part and in addition to the shape desired for the part, for example for manufacturing a panel with rounded zones in the form of tiles.
• vacuum extraction can start during the injection of dough.
• the injection and / or extraction can be carried out by one face and / or both sides of a closed molding system comprising a mold and a counter mold. It is possible, for example, to extract the water from the upper face (of the counter mold) and turn the mold over for extraction from the lower face (of the mold).
• the injection and / or extraction can be carried out by one or more separate orifices or not provided in the mold and / or against the mold.
• a mold for implementing the method according to the invention may consist of a closed mold system (mold-countermold) and comprise at least one inlet orifice, through which the paste, preferably homogenized beforehand, is injected and at least a second orifice, separate or not from the first orifice for said extraction.
• the mold In order to avoid system failure, provision may be made for the inclusion in the mold of one or more dough outlet or overflow openings, themselves fitted with locks which make it possible to close them to prevent a fall of pressure during vacuum water extraction.
• the mold is also preferably equipped with a plurality of orifices of diameter less than or equal to 1 cm, which are connected, directly or indirectly, to the extraction system by the empty.
• a support element is placed in the mold, the latter may preferably comprise one or more orifices facing the mold or the counter mold. If the extraction and the injection are carried out via the counter-mold, an element can then be provided, for example magnetic contact with the counter-mold and provided with orifices facing those of the counter-mold.
• the present invention also relates to a matrix part with hydraulic setting obtained by the method described above.
• Its composition includes a weight percentage of hydraulic binder between 2% and 98% of the total mass, a weight percentage of sand between 0.1% and 95% of the total mass, a weight percentage of water between 5% and 75% of the total mass, a weight percentage of reinforcing fibers between 0% and 50% of the total mass (preferably in glass and between 2.5% and 7%), a weight percentage of other fibers between 0% and 50 % of the total mass, a weight percentage of polymers between 0% and 75% of the total mass, a weight percentage of superplasticizer between 0% and 20% of the total mass, a weight percentage of metakaolin between 0% and 50% of the total mass, and possibly other additives selected so as to give the part the required characteristics.
• this part Due to its composition, this part has a high temperature resistance.
• the composition also makes it possible to improve its mechanical properties and to lighten conventional concrete parts. Said parts can be used for the recovery s facades and buildings requiring a high level of fire resistance.
• the process according to the present invention does not only relate to the injection and manufacture of elements based on cement (cement used as a hydraulic binder), and does not envisage only these; it is also considering the possibility of using other hydraulic binders such as gypsum, plaster, lime, calcium silicate. Several binders can also be mixed.
• the matrix can also be made of cement mixed with other agglomerates, gypsum, plaster, lime, synthetic resins, polymers, plastics of various types, thermoplastics, etc.
• the cement used may preferably be quick-setting, with high initial strength, a traditional Portland cement of any strength, aluminous, low in alkali content, and in general any type. cement, the choice of which must be taken into account when designing the part, to always retain its characteristic of hydraulic binder.
• the polymers can be for example of acrylic or synthetic type, resins of various typologies, or any other polymer usable to modify the matrix and to give to the manufactured part a greater capacity according to various aspects of the design and performances than the 'we are waiting for the room.
• the polymers may possibly be added only when the final GRC part is not intended for high temperature applications and will be used only in facade panels and cladding, or in other applications which do not require resistance. peculiar to fire or high temperatures.
• the other additives can be, inter alia, accelerators, retarders, emulsifiers, aerators, air entrainers, stabilizers, antioxidants, thinning or thickening agents, such as cellulose, fiber cellulose, cellulosic hydroxides of any type and other chemical thickeners, in addition to starches or natural products which can be used to improve the cohesion and stability of the injected pulp, and in general any additive intended to modify the matrix according to the n design and performance requirements expected from the part, as well as possible production requirements.
• accelerators such as cellulose, fiber cellulose, cellulosic hydroxides of any type and other chemical thickeners
• the reinforcing fibers can be cut fibers, whole, a mat of any class of cut reinforcing fibers, a mat of continuous fibers, such as Cem-FIL® sold by the company SAINT GOBAIN, woven grids.
• the reinforcing fibers can be synthetic fibers, such as polyamide, rayon, nylon, PVA, polypropylene and, in general, any organic, natural fiber (such as coconut fibers, fibers based on treated plant, cellulose fibers, sysal fibers) or synthetic fibers of any class; mineral fibers, such as carbon fiber, basalt fibers and, in general, any mineral fiber of any class; glass fibers of type E, Z, C, or resistant to alkalis or AR and, in general, any glass fiber of any composition; metallic fibers, such as copper, steel, stainless steel, iron, cast iron, ductile iron and, in general, any metallic type fiber.
• the other fibers can be insulation fibers, for example rock wool or glass fibers.
• Table 1 below presents some examples of compositions for parts, for example in GRC according to the present invention, by comparison with the parts in conventional GRC.
• the proportions of the different types of fibers are adjusted so as to allow good performance of the application and obtaining different levels of mechanical strength.
• the combination of different types of fibers are studied for an adjustment compatible with the other components of the matrix, in order to allow an injection of the mixture without major problems.
• the materials constituting the reinforcement (fibers) can be used in any proportion depending on the advantages or the performances which it is desired to obtain with the injected part.
• Preferably, 12 mm long AR glass fibers are used, between 2 and 3% of the total mass.
• a preferred embodiment is described below; note however that it does not limit the invention.
• the tank incorporates an internal bubble removal system, based on a vacuum process, possibly producing vibrations from the outside, if necessary, so that the occluded air is not introduced into the mold with the injected dough.
• the mold is prepared for injection.
• filter paper or any other conventional filtration system can be interposed between said orifices and the paste.
• filter paper or special films are placed over a support or lower jacket arranged on the mold and intended for easy removal of the fresh part.
• a woven reinforcement grid for example of fiberglass of suitable shape, is preferably placed. in the mold.
• the mold consists for example of a closed mold system (mold-countermold) and comprises for example nine orifices on the mold and the counter mold preferably uniformly distributed and facing each other, through which the homogenized dough is injected and / or extracted. is carried out.
• a closed mold system mold-countermold
• the reservoir is filled via the orifices with the paste obtained previously, it is closed and pressurized. After having obtained a pressure of 2.5-3 bars, the outlet slurry outlet valves are opened, so that the material flows to the mold.
• the vacuum source is connected and the injection stopped.
• one or more orifices have a diameter less than or equal to 1 cm and are connected, directly or indirectly, to the vacuum extraction system.
• the total vacuuming time is 15 minutes, which produces a final water / cement ratio which varies between 0.35 and 0.40.
• open the mold unmold the part and introduce this part into the hardening chamber to obtain the required level of hydration and hardening of the part. Hardening takes place at room temperature and at humidity relative greater than 95% for 7 days.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Ceramic Engineering (AREA)
• Dispersion Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Inorganic Chemistry (AREA)
• Materials Engineering (AREA)
• Structural Engineering (AREA)
• Organic Chemistry (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Producing Shaped Articles From Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

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• 2003
  • 2003-10-03 ES ES200302301A patent/ES2251857B1/es not_active Expired - Fee Related
• 2004
  • 2004-10-01 CN CNA2004800360321A patent/CN1890072A/zh active Pending
  • 2004-10-01 AR ARP040103574 patent/AR047945A1/es unknown
  • 2004-10-01 IN IN1132KON2006 patent/IN2006KN01132A/en unknown
  • 2004-10-01 EP EP04805722A patent/EP1670625A2/fr not_active Withdrawn
  • 2004-10-01 WO PCT/FR2004/050479 patent/WO2005032780A2/fr active Application Filing
  • 2004-10-01 TW TW93129859A patent/TW200523049A/zh unknown
  • 2004-10-01 US US10/574,504 patent/US20080113193A1/en not_active Abandoned
  • 2004-10-01 JP JP2006530454A patent/JP2007507371A/ja active Pending

Non-Patent Citations (1)

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