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
  • B28B1/265—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 pressure being applied on the slip in the filled mould or on the moulded article in the mould, e.g. pneumatically, by compressing slip in a closed mould

Definitions

• the invention relates to the field of ceramic containers and their manufacture.
• the object of the invention is to provide a method of manufacturing ceramic containers that would be applicable to the manufacture of narrower opening containers than their interior space by solving the aforementioned problems, including the inaccuracy of the dimensions of the part defining the opening of the container.
• the subject of the invention is a method of manufacturing a ceramic container, according to which a porous mold is used in at least three parts, comprising at least two lateral parts and an upper part provided with a penetrating appendage.
• a pressurized slip is introduced inside the mold and the wall of the container is formed by evacuation of the liquid phase from the slip through the parts of the mold, the mold is opened and the container finishing operations are carried out, characterized in that:
• the appendage is penetrated into the space delimited by the lateral parts only over a fraction of the height of the said space, so that, after the formation of a wall of the container having the desired thickness, the excess slip remains inside the mold; and in that when said desired thickness of the wall of the container is reached, aspiration of the excess slip is carried out before the opening of the lateral parts of the mold.
• the upper part of the side parts of the mold Before aspirating the excess slip, the upper part of the side parts of the mold can be separated. Said appendix and said side walls are preferably separated by a distance equal to the target thickness for the wall of the container in the corresponding zone defining the opening of the container.
• the invention also relates to a device for the manufacture of ceramic containers of the type comprising a porous mold in at least three parts, namely at least two side portions and an upper portion provided with an appendage penetrating into the defined space by the lateral parts, and means for introducing and maintaining under pressure a slip in the interior space of the mold, characterized in that said appendix penetrates into said space delimited by said lateral parts only on a fraction of the height of said space, and in that said device comprises a tube connected to suction means which can extract the excess slip present in the interior space of the mold after interruption of its pressurization.
• the invention is based on the use of a pressure casting process of the ceramic container, by means of a porous mold in several parts, namely at least three, preferably four.
• the outer dimensions of the container are determined by at least two side mold parts (or, in addition, a bottom portion), applied against each other.
• a third mold portion said upper portion, closes the interior space defined by the side portions, and has a portion penetrating into this interior space so as to strictly define the dimensions of the space available for the formation of the wall of the container near its opening.
• the gap between the penetrating part of the third mold part and the two other mold parts makes it possible to define the maximum thickness of the container wall in the zone of its opening.
• This third part also comprises a channel through which a slip is introduced under pressure into the interior space of the mold.
• This pressurization has the effect, as is conventional in die casting processes, of gradually depositing a layer of ceramic on the walls of the mold parts, the water initially contained in the ceramic being discharged through the mold due to the porosity of it.
• this layer has reached the desired thickness, preferably when it makes it possible to fill the gap between the penetrating part of the third mold part and the two other mold parts so as to to obtain a very precise dimensioning of the opening area of the container, the pressurization is interrupted and the third mold part is removed.
• a tube connected to a suction installation is then introduced into the slip, so as to evacuate the excess slurry without the need to return the mold to empty it.
• the conventional operations of finishing the container are then carried out by drying and finishing the surfaces.
• the upper part of mold does not contribute here to shape at most as the opening area of the container, because otherwise it would be impossible to remove the upper part of the mold after casting.
• FIG. 1 schematically shows a longitudinal sectional view of a container provided with a neck, being manufactured by the method according to the invention, during the die casting phase;
• FIG. 1 schematically shows a die-casting installation for implementing the method according to the invention.
• the mold consists of four parts, namely:
• an upper part 4 which closes the mold on its upper face, and which comprises a channel 5 connected by a line 6 to a tank 7 containing a slip 8 constituting the raw material from which the container is made and comprising a liquid phase , generally aqueous, and a phase solid generally based on clays or kaolins, or other mineral materials conventionally intended for the manufacture of traditional ceramics (dishes, sanitary ware, tiles) or techniques.
• the reservoir 7 is pressurized, so that the liquid phase of the slip escapes through the mold parts 1, 2, 3, 4 which are porous, allowing a solid phase layer to gradually settle on their internal walls. which will constitute the container 9.
• the side portions 1, 2 define, in their upper region, an elongated interior space (cylindrical in the example shown), intended to form a neck or neck 11 for the final container 9.
• the upper part 4 of the mold has an appendage 12 penetrating into this inner space 10.
• the gap "e" between the appendix 12 and the side mold parts 1, 2 is preferably equal to 1 thickness that it is desired to confer on the wall of the container 9 at its neck.
• the lower end of the appendage 12 may, as shown, be rendered non-porous by the deposition of a sealing layer 13, so as to avoid that a layer of solid material is also deposited on it, which would risk to close the container 9 during its manufacture.
• Figure 1 shows the installation at the end of the die casting phase of the container itself.
• the solid phase layer deposited on the walls 1, 2, 3, 4 of the mold has reached the thickness that it is desired to impart to the wall of the container 9.
• the space of width "e Separating the appendage 12 from the upper mold part 4 and the side mold parts 1, 2 is completely filled by the solid phase.
• the pressurization of the reservoir 7 is then interrupted and the upper mold part 4 is removed. Then, as shown in FIG. 2, a tube 14 connected to a suction device is introduced into the interior space of the mold.
• the tube 14, as shown in Figure 2 can then suck the slip 8 in the mold, and it is returned to the reservoir 7 (or in another tank, at the option of the operator).
• this slip 8 in excess can be removed without the need to turn the mold, and also without coming into contact with the layer forming the container 9 in the region of the neck 11.
• This It therefore certainly keeps the dimensions and the surface condition that it had at the time of removal of the upper part 4 of the mold. It can therefore be manufactured with a better dimensional accuracy than by the conventional method using a plaster mold open at its upper part that is returned to extract the slip in excess.
• the mold is opened by spacing the side portions 1, 2, and the container 9 is taken to the other stations of the manufacturing facility to undergo the conventional finishing operations, to namely namely, successively: a heating, for example by blowing hot air inside and outside the container 9, to firm it;
• FIG. 1 and 2 show the manufacture of a container 9 in the form of a bottle provided with a neck or neck 11.
• the method according to the invention can be used to manufacture containers of all shapes, the open part of which is less locally a volume against undercut, which can in particular result in a reduced width relative to the largest width of the interior space of the container.
• FIG. 3 shows the manufacture of a cup-shaped container 9 whose upper part 16 has a narrowing of the cross-section with respect to the part of the cup. body of the container 9 to which it follows.
• the appendage 12 of the upper part 4 of the mold penetrates into the space separating the lateral parts 1, 2 on a small height, so as to shape the lip 17 of the opening of the container.
• Such a configuration is also within the scope of the invention, since it would not be possible to reliably achieve it by another known method.
• a variant of the method which has been described consists in leaving in place the upper mold part 4 during the suction operation of the excess slip 8 and introducing the tube 14 through the orifice 5. In this way, during this operation, it avoids any deformation of the opening area of the container 9 which could be due to a still insufficient stiffening of this area.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Ceramic Engineering (AREA)
• Dispersion Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Producing Shaped Articles From Materials (AREA)
• Press-Shaping Or Shaping Using Conveyers (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (3)

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Family Cites Families (7)

• 2006
  • 2006-10-25 FR FR0609377A patent/FR2907705B1/fr not_active Expired - Fee Related
• 2007
  • 2007-10-22 WO PCT/FR2007/001742 patent/WO2008050005A2/fr not_active Ceased
  • 2007-10-22 EP EP07866418A patent/EP2094457A2/de not_active Withdrawn

Non-Patent Citations (1)

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