EP2216150A2 - Casting mould components and casting mould - Google Patents

Abstract

The components (40, 41) have a permeable base layer (2) exhibiting base layer-permeability dimensioned for conduction of fluid (W) i.e. water. A permeable filter layer (1) exhibits filter layer-permeability, and extends from a surface of the base layer to a casting chamber (6). A cover layer (8) is arranged on the base layer at a distance from the filter layer, and exhibits cover layer-permeability, which is smaller than the base layer-permeability. The cover layer is sealed against penetration of the fluid and/or pressure medium. An independent claim is also included for a slip casting mold including an opening staying between two mold components.

Description

The invention relates to a mold component with the preamble features of claim 1, to a mold and to a use of such a mold.

A mold as a die-cast mold, particularly a die-cast mold, is used to fabricate e.g. hard metallic or ceramic articles by means of a so-called Schlickergießverfahrens. Usually, at least two mold components are assembled, whereupon a casting space formed therebetween is filled under pressure with slip. The die casting mold consists on the inside of a permeable or porous filter layer, through which the liquid of the slurry passes. On the upper side of the filter layer, this forms from the solid constituents of the slip a broken piece, which forms the metal or ceramic article to be produced after removal and sintering. For discharging the liquid of the slurry of the casting layer adjacent to a base layer is arranged, which provides stability of the casting layer and a conduit means for discharging the liquid.

Also well-known are casting molds for low-pressure casting processes in which molds of plaster are used as casting molds. Slip is introduced into the casting mold virtually without pressure or with slight overpressure. Therefore, such casting methods are referred to as low-pressure casting. The drainage of such a mold is essentially by capillary action in that the material of the mold absorbs the liquid of the slurry.

The conduit means usually serves on the one hand as a drainage system for draining or discharging the liquid of the slurry. On the other hand, the conduit means for releasing the cullet from the mold by compressed air is pressed by the conduit means and the filter layer against the formed cullet in the reverse direction.

Generally known for forming the conduit means is an arrangement of possibly thousands of holes from an outside to just before the surface of the permeable filter layer. The production of such a diecasting mold is correspondingly very expensive. Out US 5,556,587 is a die-casting mold with a complex drainage system known as a conduit device for dewatering and demolding. WO 02/072327 A1 describes a die casting mold with a double wall formed. Below the filter layer is a cavity which is connected to a drainage system. Accordingly, the production of the diecasting mold is associated with a high cost.

DE 37 24 610 C2 respectively. US 4,913,868 show a die-casting mold, which have two superimposed porous layers. To produce the die casting mold, a porous inner layer having an average pore diameter of at most 20 μm and a thickness or thickness of the inner layer of 5-40 mm is cast. On the backside of the porous or permeable layer, an adhesive is applied with a pattern, wherein at least some areas of the backside must remain uncovered by the adhesive, whereupon a coarsely porous outer layer is placed on the rear side of the porous inner layer. The coarsely porous outer layer has a particle size of 0.1 to 5 mm and a thickness of 5 to 30 mm. At least one pipe for discharging water and for blowing air out of or into the coarsely porous outer layer is connected to the coarsely porous outer layer. In addition, the like formed die-casting mold sealed on the outside by means of a resin adhesive. The conduit means for dewatering the porous inner layer or for supplying compressed air through the porous inner layer thus consists of the coarsely porous outer layer and the tube. A disadvantage of this arrangement, however, the complex bonding of the two porous layers together.

EP 0 121 929 B1 respectively. US 4,531,705 describe a very complex process for producing a diecasting mold, in which, after the molding of a raw base body by melting, gaps and pores are formed. DE 42 25 412 C1 describes a mold for producing liquid-containing pressed parts, such as roof tiles made of clay or similar material. The mold has two layers, with the layer coming into contact with the material to be compacted consisting of fine-pored foamed ceramic material, while the layer arranged underneath consists of coarse-pored foamed ceramic material or foamed concrete.

EP 0 294 743 A2 describes a method for producing a casting mold. A first preformed molded article is introduced into a container in which liquid synthetic resin or gypsum is located to form a fine porous layer on the surface of the coarsely porous molded article after it has hardened. However, a manufacturing with such a multi-shell shape does not provide sufficient support of the individual layers together. In addition, such a production with a multi-shell mold is very expensive, since a large number of individual manufacturing steps must be carried out.

EP 0 306 865 A1 describes casting molds for pressure slip casting for the production of moldings from ceramic masses and their preparation. The molds consist of a two-layer structure with a mechanical stable open-pore carrier with a large pore size and with a thin open-pored separating layer of small pore size on the inside of the mold. The preparation takes place in that a large-pore starting form is coated with a separating membrane of the desired pore size and heated until the separating membrane is stretchable and is pressed onto the starting mold. Thus, there are also two separate separate layers whose mutually facing surfaces are interconnected.

JP 01210306 describes a mold whose base body is made of a non-granular metallic material having a high permeability. Subsequently, a viscous mass is spread on this metal body to form an osmosis membrane.

WO 2006/056192 A2 describes a mold having a base layer, a permeable filter layer having a filter layer permeability on a surface of the base layer between the base layer and a casting space, a first conduit means for feeding slurry into the casting space and a second conduit means for discharging liquid from the casting space through Filter layer and / or for supplying a pressure medium for detaching a broken piece formed in the casting chamber. In this case, the base layer is formed of firmly interconnected bulk material having a base layer permeability. The filter layer penetrates from the surface of the base layer a distance in the base layer and is connected in this area with the base layer. The filter layer is poured onto the base layer, brushed or sprayed on, so that the distance of penetration of the filter layer into the base layer encompasses at least one layer of parts of the base layer. The base layer consists of a bulk material, such as limestone chippings. The filter layer is made of polyurethane.

Previous attempts, a mold according to WO 2006/056192 A2 have already led to usable molds. The molds are often very large compared to the dimension of the material to be pressed in order to be able to be used in standard presses with a predetermined minimum size of a mold to be used. Among other things, there are moldings to be molded having a large depth extension, as in the case of water tanks having high side walls starting from a floor. It has been found to be disadvantageous for such situations that a particularly large amount of expensive molded plastic is then required in the production of small-sized goods to be pressed in relation to the mold volume. Also disadvantageous in such cases are relatively long preparation times for heating the molds to an operating temperature near a desired slip temperature of the slip. Furthermore, after casting to detach the molded molding, large amounts of water must be conveyed into the body to clean the mold or to dissolve the casting.

The object of the invention is to propose an improved casting mold, an improved process for producing such a casting mold. Among other things, this is intended to reduce the mold material used and to significantly reduce water and thus energy consumption in production.

This object is achieved by a mold component having the features of claim 1, by a slip casting mold having such a mold component or by a use of such a mold for producing metallic or ceramic slip moldings. Advantageous embodiments are the subject of dependent claims.

Accordingly, preferred is a mold component having a permeable base layer of a base layer material having a liquid layer sized base layer permeability, a permeable filter layer having a filter layer permeability and extending from a surface of the base layer to a casting space, and with a conduit means adapted for draining liquid from the base layer which has flowed out of the casting space through the filter layer and / or for supplying a pressure medium into the base layer and through the filter layer for detaching a sherd formed in the casting space, if a sealing layer of the filter layer objected to the base layer is arranged and viewed from the base layer from behind the sealing layer another layer is arranged or viewed from the filter layer from behind the base layer remaining space of the Gießformko wherein the sealing layer has a sealing layer permeability and wherein the sealing layer permeability is less than the base layer permeability of the base layer or wherein the sealing layer is impermeable to penetration of the liquid and / or the pressure medium.

In principle, it is possible, as viewed from the filter layer, to form the base layer only so thin or with such large grains or parts that sufficient flow is ensured in the base layer, and behind this form the entire remaining space of the mold component as the sealing layer. However, it is already sufficient if the sealing layer is also formed only so thin that it prevents penetration of the liquid phase and / or air sufficiently. In this case, then, viewed from the base layer behind the sealing layer, a further layer is arranged. The further layer is preferably made of the same material as the Base layer formed, in particular the same as the base layer formed, since such a further layer can also absorb high pressure forces.

Under the variant that a space remaining behind the base layer of the mold component is formed as the sealing layer, it is to be understood that this is not just an outside and possibly slightly penetrating into the mold component material coating to the outside sealing, but by a actual body of the mold component.

In this case, the line device can be connected directly to the base layer in a manner known per se as a line device leading to the outside of the casting mold component. The conduit means may e.g. also be formed by a laterally open portion of the base layer, which in the assembled operating condition is opposite to such an open portion of an opposing mold component, the base layer provides access to a leading to outside the mold component conduit means.

When determining such permeabilities, particular preference is given to permeability values when using a liquid phase of a slip-type slip. In particular, such a liquid phase can consist of pure water or have admixtures of other substances. For detachment of a sherd formed on the filter layer, a medium, in particular water or air in opposite air can be pressed through the base layer and the filter layer, which is why, depending on the actual use, if appropriate, air is to be considered as a flowing medium for the permeability.

Ideal but not mandatory is a packing density of the sealing layer of 100%. However, already advantageous is a casting component in which a packing density of the sealing layer is at least 80%, in particular at least 90%.

Under a filling or packing density it is understood in particular a degree of filling of the space with solid matter, which can not be penetrated by liquid and / or air. Accordingly, in particular open pore space is affected, which is available as a guide region for a liquid or gaseous medium. Optionally, correspondingly also free pore space, which is closed to the outside, understood by a filling with a closed packing density, as in such a free, but not accessible from outside pore space neither liquid from the slurry nor air as a pressure medium for detaching a cullet from the filter layer can penetrate. The sealing layer permeability is understood as meaning a permeability which is correspondingly so low that no liquid or only a negligible amount of liquid from the base layer penetrates into the sealing layer.

Possible is a sealing layer of a different material than that of the base layer. The sealing layer may also be made of the material of the base layer but with a different grain size or in addition parts of finer grain size, in particular bulk grained than in the base layer. The sealing layer is advantageously easy to produce if the sealing layer consists of the base layer material of the base layer and, in addition, a binder and / or a sealing medium other than the base layer material is introduced into the base layer material. In this case, the sealing medium which is other than the base layer material may optionally not only be a chemically diverse one Material but also for example a much finer-grained but otherwise similar material. In particular, use of the base layer material ensures sufficient pressure resistance even of the sealant layer when the mold is clamped under high pressure in a press or slurry is pressed under high pressure into the casting space. The binder used is in particular a dense adhesive layer or lacquer layer. Optionally, the sealant layer may have become full.

When the sealing layer is impermeable to penetration of a carrier medium or a liquid phase of a slip-type slip, it is preferred that it is in particular impermeable to ingress of water.

Such a structure can be achieved particularly simply by not only using a binder, in particular an adhesive, in an amount for firmly bonding the individual grains or parts of the base layer, but instead using so much binder that the free spaces between the individual parts of the sealing layer so that completely or so far filled that penetration of the liquid phase is completely or largely prevented. If the ingress of liquid into the freely accessible open pore space is prevented, a smaller amount of liquid is needed to dissolve the cullet and cyclically clean the mold. A particular advantage consists in the fact that a mold should be heated to the temperature of the slurry before use, which can be significantly reduced by a correspondingly lower open volume in terms of heating time.

In particular, it is particularly advantageous if the sealing layer is impervious to the ingress of air or any other demoulding or flushing medium. Preferably, the seal layer permeability is therefore so low that even compressed air or a liquid such as water to dissolve the cullet and / or to rinse the mold component does not penetrate or only to a small extent in the sealing layer. When detaching a piece of broken glass from the filter layer, a smaller amount of compressed air is then required, which is pressed in the reverse direction through the base layer. Thereby, the amount of injected compressed air can be reduced, which is also advantageous in that to avoid cooling of the mold components below the slip temperature is a lesser amount of compressed air or pressure medium to heat.

The filter layer permeability is preferably lower than the base layer permeability or a pressure difference in the filter layer compared to a pressure difference of the base layer by at least a factor of 2, in particular at least a factor of 5, preferably at least a factor of 10.

The filter layer permeability or the pressure difference in the filter layer layer is in particular determinable via a thickness or thickness of the filter layer and a distance extending relative to the thickness or thickness at least equal in the base layer for determining the base layer permeability or the pressure difference base layer. In particular, this distance in the base layer may be arbitrarily long relative to this thickness or thickness of the filter layer. Appropriately, a narrowest thickness of the filter layer is used, since a minimum pressure resistance for the liquid phase of the slurry is to be expected over this time.

Preferably, a thickness of the base layer relative to a thickness of the filter layer over at least 80%, in particular at least 90% of an extension direction of their connection surface relative to each other within a tolerance of 20%, in particular 10% the same. Such a Construction with a thickness or layer thickness of the base layer which is the same or conformal with regard to the shape structure or relative to the filter layer enables a uniform pressure distribution in both the base layer and in the filter layer. At the same time, the layer thickness of the base layer can be reduced to a minimum. Indirectly, this implies that, in the case of an uneven or contoured connection surface between the base layer and the filter layer, a connection surface between the base layer and the sealing layer also runs correspondingly contoured.

Particularly preferred for household and sanitary ceramics is a mold component in which a thickness of the filter layer is between 1 and 15 mm, a thickness of the base layer between 10 and 40 mm and the remaining mass volumes in the mold component, in particular a volume of the sealing layer and or / the further layer amount to 90% or more of the volume of the mold component.

The sealing layer is preferably applied around the base layer on the back and laterally outside of the mold component, and the filter layer preferably extends outwardly over the base layer so far that the filter layer abuts or engages with its edge portion on a wall of the sealing layer, the base layer completely surrounded by the filter layer and the sealing layer.

In the case of at least two such casting mold components which form a casting mold on the outside, a gap preferably remains between, in particular, in the region of opposite edge sections of the sealing layers, wherein on the inside these opposing edge sections of the sealing layers Direction to the casting room towards opposite edge portions of the filter layers closing the gap, in particular sealingly touching. While the relatively coarse-grained material of the sealing layers leaves an at least partially open gap, the fine-grained material of the filter layer closes the gap for the media used during casting and demolding. Surprisingly, such an arrangement, in spite of the fundamental permeability of the filter material for the media, already provides sufficient sealing to the outside of the casting mold even in the region of the abutting edge regions of the casting component components without further elaborate sealing measures.

Such a mold component is advantageous, in particular, if the base layer is formed from firmly bonded bulk material, if the base layer material consists of individual parts and at least 70% of the parts of the base layer material have an average diameter less than or equal to 5 mm, in particular less than or equal to the longest part extension 3.5 mm, if these parts of the base layer material in the longest part extension have a maximum diameter less than or equal to 5 mm, in particular less than or equal to 3.5 mm, preferably less than or equal to 3.0 mm, in particular less than 2.5 mm, if at least 70% of the parts of the base layer material in the shortest part extension have a maximum diameter of at least 0.5 mm, in particular of at least 0.8 mm, in particular at least 1.0 mm and more, if the proportion of the parts with the respective part extension at least 95%, preferably at least 98% gt and / or if the bulk material is formed from parts of a pressure-resistant and mineral material, in particular stone or glass, and / or a plastic material. If the grain diameters are too small, the problem may arise that the filter layer material can not penetrate far enough between the individual parts of the base layer, in particular an engagement of at least the parts of the first layer Base layer is no longer or not sufficiently done. For diameters greater than 3.0 mm, there may be a problem that the capillary portion of the mutual influence of the base layer and the inflowing filter layer material is too small, and thus the worst case entire core or base layer with the filter layer material runs full.

Such a base layer provides a base layer permeability, which is large enough to transport the liquid and / or the printing medium with little, in particular negligible, pressure resistance within the base layer. The bulk material is formed for the connection of, for example, parts of the bulk material glued together, for which purpose the bulk material is preferably glued to a binder which wets the surface of the parts of the bulk material.

Such a mold component is advantageous if the permeable filter layer penetrates from the surface of the base layer a distance in the base layer and is connected or interlocked in this area with the base layer and if the distance of penetration of the filter layer in the base layer at least one layer of parts of the Base layer encompasses or engages behind, if the base layer permeability of the base layer is more than a power of ten greater than the filter layer permeability of the filter layer, if the filter layer is formed of a filter layer material, which with the base layer material and / or with a coating over the base layer material is bonded, if the filter layer material consists of a plastic, in particular of polyurethane or Polymetylmetacrylat and / or if the finished filter layer has a permeability and / or porosity with channels of 5 to 50 μ.

The filter layer is for this purpose for example formed of a material which adheres to the material of the base layer and / or with a coating over the material of the base layer.

The filter layer permeability corresponds in a manner known per se preferably to a permeability or an open or open porosity, as is known from filter layers per se. The base layer permeability or a corresponding base layer porosity is preferably chosen in relation to the filter layer permeability such that there is a slight or negligible pressure resistance in the base layer for the liquid or the slip relative to the ratios in the filter layer complex piping system in the preferably entire base layer always to provide the same pressure conditions.

Due to the usability of the mold in standard presses especially when casting relatively small sized goods between the filter layer and an outside wall of the mold a very large space, which preferably not completely with only the material of the highly permeable base layer, which has a correspondingly large open channel and Pore volume has, is filled. This otherwise liquid receiving open space is reduced by the fact that in a barrier region formed by the sealing layer between the filter layer and the outside wall or spaced from the filter layer material is filled, which is at least partially permeable to the highly permeable base layer or even closed , By significantly less permeable or even closed is meant, in particular, that liquid does not or only to a negligible extent penetrate into this barrier area under the pressure or underpressure conditions applied during the slip casting. In particular, should not liquid through the Barrier area can flow. In addition to filling a material which differs from the base layer material, the base layer material itself may also be used to form the sealing layer itself with a mixed-in further material, in particular encapsulated adhesive. This results in a dead space reduction of the open porosity, which has a beneficial effect on a lower air and liquid requirements and a shorter drainage and thus a shorter cycle time. In addition, preparatory warm-up times are reduced.

Fig. 1

eine Schnittansicht einer Gießform aus zwei bevorzugten Gießformkomponenten für ein Schlickergussverfahren; und

Fig. 2

einen Ausschnitt einer derartigen Gießformkomponente gemäß einer gegenüber Fig. 1 modifizierten Ausführungsform.

The invention will be explained in more detail with reference to the drawing. Here, various embodiments with respect to common components and functions will be described together. Show it:

Fig. 1

a sectional view of a casting mold of two preferred mold components for a slip casting process; and

Fig. 2

a section of such a mold component according to one opposite Fig. 1 modified embodiment.

How out Fig. 1 and 2 As can be seen, a casting mold as a die-cast casting mold or for a low-pressure casting process for manufacturing in particular ceramic and / or metallic articles consists essentially of generally two or more casting components 40, 41. The casting mold components 40, 41 each consist of a casting layer or filter layer 1, a base layer 2 for supporting and supporting the filter layer 1, a sealing layer 8. The sealing layer 8 preferably forms at the same time an outside wall of the mold components 40, 41 from. Also provided is conduit means 50-55. Typically, to manufacture a ceramic article, two or more such mold components 40, 41 are facing one another Filter layers 1 arranged to form a casting space 6 between the filter layers 1.

The filter layer 1 is preferably but not necessarily formed of an open porous or permeable plastic, which is used for filtering slurry S, which is thus impermeable to the solid components of the slurry S. The base layer 2 is particularly permeable to liquid components of the slurry S which penetrate the filter layer 1 and to a flushing and / or pressure medium such as compressed air or water or water.

The conduit device 50-55 consists of a first conduit device 50-52 and preferably of each casting component 40, 41 of at least one second conduit device 53-55. The first conduit device 50-52 consists of a tube 50 which passes through the wall or sealing layer 8, the base layer 2 and the filter layer 1 leads to the casting space 6 in order to introduce the slip S into the casting space 6 from the outside. On the outside, a closure or valve device 52 is connected to the tube 50, above which a slip container 51 for providing the slurry S is arranged. Alternatively, however, for example, a hose which leads to such a Schlickerbehältnis 51, depending on the needs of the outwardly opening pipe 50 are connected. Also, a pump 56 may be interposed between the slurry tank 51 and the pipe 50 to pump the slurry S under pressure p 2 into the casting space 6.

According to a preferred embodiment, the second conduit device 53-55 can consist of a tube 53 which leads through the wall or sealing layer 8 of the corresponding casting component 40, 41 as far as the base layer 2 or optionally also into it. In principle, it is also possible, the pipe 53rd and / or other pipes or pipes branching off thereof into the permeable base layer 2 and / or the permeable filter layer 1.

In the case of a casting component without its own second conduit means leading outside the casting mold 0, the second conduit means of such a casting component may alternatively be e.g. be formed by a conduit between the base layers of the mold components adjacent to each other, so as to form a pressure and flow connection to the base layer 2 of the other mold component, which has its own second conduit means.

Under the line system is to be understood as an arbitrarily designed line system. Under pipe is not just a common rigid pipe made of plastic or metal, but to understand an arbitrarily designed line system, which is suitable for conducting liquid and air or gas. In particular, in the case of a low-pressure casting process, a pump 54 may be connected to the outside of the tube 53, which pump serves to apply a negative pressure p1 in order to draw off liquid W. Via an outlet 55 of the pump 54, the liquid W is discharged from the pump 54.

The slurry S introduced into the casting chamber 6 consists of solid constituents for forming a body and of liquid constituents in the form of the liquid W. This liquid is produced by applying the negative pressure p1 by means of the pump 54 from the casting space 6 through the permeable filter layer 1 and the Base layer 2 pulled out. In addition, the amount of liquid W is reduced, which remains after such a casting process in the mold.

The combination of the negative pressure p1 via the second line device 53-55 and inner overpressure p2 in Gießraum 6 via the first conduit means 50 - 52 leads to a significantly increased cycle number in the manufacture of ceramic articles. In the case of a low-pressure casting process, differential pressures of less than 2.5 bar, in particular low differential pressures of approximately 1.5 bar, acting on the permeable filter layer 1 are particularly preferred.

The overpressure p2 in the casting chamber 6 results in the absence of a pump 56 for pressing in the slurry S with the valve 52 open by a height h of the slurry above the casting chamber 6 in the first conduit means and optionally the slurry container 51. Optimum negative pressures p1 can be dependent of material of the shape, consistency of the slurry S and the geometry of the produced piece or ceramic article individually determine.

In the manufacture of a ceramic article, the slip is introduced into the casting space 6 above or adjacent to the filter layer 1 in the case of a low-pressure casting process under low pressure. In the case of a pressure casting process, the slip S is injected under high pressure. The solid constituents of the slip settle on a surface 7 of the filter layer 1, the surface 7 of the filter layer facing the casting space 6. The liquid W in the slurry penetrates through the filter layer 1 into the base layer 2 and from the base layer 2 via the conduit means 53-55 to the outside. The remaining on the surface 7 solid components of the slurry form a body, which is sintered after removal from the mold 0 in a subsequent operation.

In addition, the output-side pump 54 for demolding a molded article may also preferably be used for injecting compressed air L in the reverse direction. For demolding the shards is on the at least second Line system 53 - 55 a gaseous medium, in particular compressed air L, or a liquid, in particular water pressed into the base layer 2. From the base layer 2, the compressed air L or the water penetrates through the filter layer 1 and presses the broken pieces away from the surface 7.

To produce such a casting component 40, 41, the base layer 2 is formed from a bulk material. The bulk material used is a solid, preferably mineral material, for example chippings, stones, etc. However, materials such as glass beads or glass pieces, expanded clay, plastic granules and the like can also be used as bulk material. Individual parts T of the bulk material are connected to each other. For bonding serves as a binder B is preferably an adhesive. In a particularly simple manner, the parts T of the bulk material can be immersed in a bath of the binder B and then brought into a desired shape in the desired shape.

The adhesive as the binder B preferably cross-links the surfaces of the individual parts T of the bulk material in such a way that on the one hand sufficient strength is ensured and on the other hand the highest possible permeability k 2 is made possible. The permeability k2 in the base layer 2 is preferably large compared to a permeability k1 in the filter layer 1. The permeability k2 of the base layer 2 is preferably so large by appropriate selection of the bulk material and the binder B, that in the entire base layer 2, a uniform structure of an overpressure when supplying the compressed air or the liquid or a negative pressure during the discharge of the liquid is made possible. It is also possible to construct a base layer 2 with a permeability or porosity decreasing towards the filter layer 1.

After sufficiently curing the binder B or solidifying the base layer 2, the filter layer 1 is formed on the surface of the base layer 2. For this purpose, the liquid material of the filter layer 1 is poured onto the surface of the base layer and / or brushed and brought into the desired shape. The consistency of the filter layer material 11 for forming the filter layer 1 when applied to the surface of the base layer 2 is such that a portion of the filter layer material 11 for forming the filter layer 1 penetrates a distance into the surface of the base layer 2 and in particular with the in the drawing upper layer of parts T of the base layer 2 firmly connects. The consistency of the filter layer material 11 for forming the filter layer 1 is selected such that the distance over which the filter layer material 11 penetrates into the base layer 2, preferably only as far as is necessary for building a sufficiently strong, in particular toothed or engaging behind Connection of base layer 2 and filter layer 1 to each other.

As filter layer material 11 for the filter layer 1, conventional materials can be used for this purpose. For example, at present, polyurethane or polymethyl methacrylate (PMMA) is preferably used as a molding compound for forming the filter layer 1. With this filter layer material 11, a fine porous filter layer 1 having a low permeability for passing the liquid and the compressed air but for retaining the solid components of the slurry can be formed. The thickness or thickness h1 of the filter layer 1 is preferably but not necessarily 1 to 40 mm in the case of pressure casting molds for producing currently conventional ceramic articles. The porosity or permeability of the filter layer 1 is preferably 5 to 50 μ as a permeable free space for conducting the liquid and / or air. As a result of the partial penetration of the filter layer material 11 of the filter layer 1 into the filter layer material 11 of the base layer 2, a transition region 3 is created, which enables a firm connection of the filter layer 1 and the base layer 2 to one another. Preferably, the transition region 3 has a thickness of one layer or a few layers of grains or parts T of the base layer 2. Due to the toothing effect in the transition region 3 can between the two layers on additional adhesive, which would be impermeable to liquid and compressed air, in an advantageous manner be waived.

Under a bulk material as the base layer material is in particular a pourable good to understand, for example, a granule, grains or other particles. The bulk material may consist of various, especially pressure-resistant and liquid-resistant materials. Dimensions are preferably in terms of average dimensions. The specified lower limits refer to a section enlargement in Fig. 1 outlined grain or part T of the base layer material in a non-spherically symmetric part T on an extension in the shortest dimension extension y of the three part or dimension extents x, y, z.

The lower limit in the shortest dimension extension y represents the largest length of the part T within the shortest dimension extension y or dimension direction transverse to this dimension extension y. The lower limit is preferably at least 0.5 mm or more, in particular 0.8 mm and particularly preferably 1 , 0 mm. Accordingly, the specified upper limits of a grain or part T of the base layer material in a non-spherically symmetric part T refer to an extension in the longest or widest or highest dimension extension x of the part T. Below a mean diameter in the largest dimension dimension x or dimension of Part of the middle length is within understood this dimension dimension x or dimension direction. The upper limit is preferably at most 5 mm, in particular at most 3.5 mm or less, in particular 3.0 mm and particularly preferably 2.5 mm. Preferably, all dimensions of the respective parts considered extend completely between said limits.

Based Fig. 1 a first preferred embodiment is shown in which the sealing layer 8 extends from the back of the base layer 2 over the remaining space of the mold component and fills it. Shown here is a sealing layer 8 made of a highly compacted material or a material which has no or only a smaller freely accessible open pore space.

This material for forming the sealant layer 8 may be e.g. are applied around the shaped base layer 2 on the back and laterally outside of the later mold component and allowed to harden before the filter layer 1 is formed. The filter layer 1 preferably does not extend laterally so far beyond the base layer 2 that the filter layer 1 rests with its edge portion on an inner side wall of the sealing layer 8 or engages in this. As a result, the base layer 2 is completely surrounded by the filter layer 1 and the sealing layer 8.

At the same time, the two mold components 40, 41 combined in the casting mold 0 form outer edge portions opposite one another, between which a gap 9 remains, in particular in the region of the relatively coarse-grained opposing edge portions of the sealing layers 8. On the inside of these oppositely disposed edge sections of the relatively coarse-grained sealing layers 8, they touch each other in the direction of the casting space 6 towards the opposite edge portions of the relative fine-grained filter layers 1 preferably so that they seal the gap 9. Relatively coarse-grained material of the sealing layer 8 or relatively fine-grained material of the filter layer 40, 41 is thus to be seen here in relation to the sealing ability of the gap 9 for the media used in casting and demolding.

Also possible is an embodiment in which in the production in a first step, the base layer material is filled into a mold manufacturing container and is filled with the binder so that no accessible open pore space or only a negligible accessible open pore space remains. In a subsequent step, the base layer is then applied with a correspondingly very large open pore space or a very high base layer permeability before the filter layer is applied. Finally, the finished casting component is then removed from the mold manufacturing container. Optionally, as such a mold manufacturing container, a container can be taken, which finally remains as a kind of outer wall of the Gießfomkomponente.

Fig. 2 shows an alternative embodiment in which the sealing layer 8 extends only over a small layer thickness. In other words, from the viewpoint of the casting space 6, a sequence of the filter layer 1 with the filter layer permeability k1, the transition layer 3, the base layer 2 with the base layer permeability k2, followed by the sealing layer 8 with a sealing layer permeability k8 and then one further layer 2 *. The further layer 2 * preferably fills the remaining space of the mold component up to a rear wall. The back wall can be processed by especially outside filling with fine material and smooth milling.

The further layer 2 * may in particular also have the base layer permeability k2. If the sealing layer permeability k8 is dimensioned sufficiently, nevertheless no liquid W and preferably also no compressed air penetrates into the further layer 2 *.

In this case, the filter layer 1 preferably has a thickness h1 or thickness of 1 to 15 mm. A thickness h2 of the base layer 2 is preferably 10 to 40 mm in order to achieve a sufficiently low pressure loss. As a result of the embodiment, the sealing layer 8 or the space sealed by the latter is preferably 90% or more of the volume of the remaining space regions of the casting component 40, 41.

In particular Fig. 1 is removable, an embodiment is preferred in which the thickness h1 of the filter layer 1 over at least 80%, in particular at least 90% of an extension direction of their common connection surface relative to each other within a tolerance of 20%, in particular 10% is the same. In other words, the filter layer 1 and the base layer 2 each have a more or less constant thickness h1 or h2 in relation to one another and therefore also run close to the contour relative to each other. This extension direction from the common connection surface relative to one another can alternatively also be defined by a main throughflow direction through the filter layer 1.

Fig. 2 shows preferred pressure conditions when using such a casting component, if slip S is pressed with an overpressure p2 from the casting chamber 6 against the filter layer 1. As a result, a broken piece 9 forms on the surface of the filter layer 1, while liquid components of the slurry S penetrate through the filter layer 1 into the base layer 2. In the Base layer 2 there is a pressure, in the case of an externally applied negative pressure, a negative pressure p1 at which the liquid W is transported away.

The layer arrangements are selected so that the filter layer permeability k1 with respect to the base layer permeability k2 and / or a pressure difference d1 in the filter layer 1 with respect to a pressure difference d2, d2 * within the base layer 2 by at least a factor of 2, in particular by a factor 5 and more preferably by a factor of 10 is lower. The difference in pressure d1 in the filter layer 1 is understood as meaning a difference between the pressure or overpressure p2 in the casting space 6 and a base layer pressure p1a within the base layer 2 at a point D in the base layer 2, the point D being an entry point C in the filter layer 1 on the shortest possible path. The pressure difference d2 in the base layer 2 is understood in particular to mean a pressure difference between two points D, F within the base layer 2 in the flow direction of the liquid W derived therein, the two points D, F having at least one spacing corresponding to the thickness h1 of the filter layer 1. Preferably, however, an arbitrarily long distance within the base layer 2 for defining the pressure difference d2 * within the base layer 2 for the ratio can be attached, which is sketched by two exemplary points E *, F. This results in the base layer 2 for the pressure difference d2 = p1b - p1c or d2 * = p1b * - p1c. Such pressure ratios are particularly advantageous for a uniform detachment of the formed cullet or molding by means of compressed air L.

A pressure difference d8 across the sealing layer 8 is preferably large or very large against the pressure difference d2 within the base layer 2, so that liquid and preferably also compressed air does not penetrate into the sealing layer.

The illustrated sealing layer 8 is formed of a material having different sized parts so that spaces between large sized ones of the parts are sealed by smaller sized parts. Additionally or alternatively, the sealing can also take place by applying or introducing a sealing binder in order to reshape a surface of the section lying thereunder, possibly composed of base layer material, with the further layer 2 * to form the sealing layer 8. In general, for all layers, their permeability decreases with decreasing part size. With decreasing part size and with a longer layer thickness to be flowed through, a pressure loss increases correspondingly over a section to be flowed through.

Claims (15)

Mold component (40, 41) with a permeable base layer (2) of a base layer material, which has a liquid layer sized base layer permeability (k2), a permeable filter layer (1) having a filter layer permeability (k1) and extending from a surface of the base layer (2) to a casting space (6), and - A conduit means (53 - 55), for discharging from the casting chamber (6) through the filter layer (1) through liquid from the base view (2) and / or for supplying a pressure medium into the base layer (2) and through the Filter layer (1) is formed for detaching a broken pieces formed in the casting chamber (6),
characterized in that - a sealing layer (8) of the filter layer (1) spaced in or on the base layer (2) is arranged and viewed from the base layer (2) from behind the sealing layer (8), a further layer (2 *) is arranged or viewed from the filter layer is formed of a space of the mold component remaining behind the base layer (2) as the sealing layer, - wherein the sealing layer (8) has a sealing layer permeability (k8) and wherein the sealing layer permeability (k8) is less than the base layer permeability (k2) of the base layer (2) or wherein the sealing layer (8) is impervious to penetration of the liquid (W) and / or the pressure medium. Casting component according to Claim 1, in which a packing density of the sealing layer (8) is at least 80%, in particular at least 90%. A mold component according to any preceding claim, wherein the sealing layer (8) consists of the base layer material of the base layer and additionally a binder (B) and / or a sealing medium other than the base layer material is introduced into the base layer material. A mold component according to any preceding claim, wherein the sealing layer (8) is impermeable to penetration by a carrier medium or a liquid phase of a slip-slurry, in particular being impermeable to ingress of water. A mold component according to any preceding claim, wherein the sealing layer (8) is impermeable to air or demoulding or flushing medium. Casting component according to any preceding claim, wherein the further layer (2 *) is formed from the same material as the base layer (2), in particular the same as the base layer (2). A mold component according to any preceding claim, wherein the filter layer permeability (k1) to the base layer permeability (k2) or a pressure difference (d1) in the filter layer (1) is at least opposite to a pressure difference (d2, d2 *) of the base layer (2) by a factor of 2, in particular by at least a factor of 5, preferably at least by a factor of 10 is lower. A mold component according to claim 7, wherein the filter layer permeability (k1) or the pressure difference (d1) in the filter layer layer (1) is determinable over a thickness (h1) of the filter layer (1) and at least relative to the thickness (h1) equally long in the base layer (2) extending distance for determining the Base layer permeability (k2) or the pressure difference (d8) of the base layer (2). A mold component according to any preceding claim, wherein a thickness (h2) of the base layer (2) relative to a thickness (h1) of the filter layer (1) exceeds at least 80%, in particular at least 90% of an extension direction of its joint surface relative to each other within a tolerance of 20%, in particular 10% is the same. A mold component according to any preceding claim, wherein a thickness (h1) of the filter layer (1) is between 1 and 15 mm, a thickness (h2) of the base layer (2) is between 10 and 40 mm and the remaining mass volumes in the mold component (40 , 41), in particular a volume of the sealing layer (8) and / or one of the further layer (2 *), amount to 90% or more of the volume of the mold component. A mold component according to any preceding claim, wherein - The sealing layer (8) around the base layer (2) on the back and laterally outside of the mold component (40, 41) is applied around and the filter layer (1) extends on the outside over the base layer (2) so far that the filter layer (1) rests with its edge section on a wall of the sealing layer (8) or engages in it, - Wherein the base layer (2) is completely surrounded by the filter layer (1) and the sealing layer (8). Casting component according to any preceding claim, - wherein the base layer (2) is formed of firmly interconnected bulk material, - wherein the base layer material consists of individual parts (T) and at least 70% of the parts (T) of the base layer material in the longest part extension (x) have an average diameter of less than or equal to 5 mm, in particular less than or equal to 3.5 mm, - These parts (T) of the base layer material in the longest part extension (x) have a maximum diameter less than or equal to 5 mm, in particular less than or equal to 3.5 mm, preferably less than or equal to 3.0 mm, in particular less than 2.5 mm . - wherein at least 70% of the parts (T) of the base layer material in the shortest part extension (y) have a maximum diameter of at least 0.5 mm, in particular of at least 0.8 mm, in particular at least 1.0 mm and more, - Wherein the proportion of the parts (T) with the respective part extension (x or y) is at least 95%, preferably at least 98%, and - Wherein the bulk material of parts (T) of a mineral material, in particular stone or glass, and / or a plastic material is formed. Casting component according to any preceding claim, - wherein the permeable filter layer (1) from the surface of the base layer (2) from a distance penetrates into the base layer (2) and is connected or interlocked in this area with the base layer (2) and wherein the distance of penetration of the filter layer (1 ) in the base layer (2) at least one layer of parts (T) of the base layer (2) engages around or behind, wherein the base layer permeability (k2) of the base layer (2) is more than a power of ten greater than the filter layer permeability (k1) of the filter layer (1), wherein the filter layer (1) is formed from a filter layer material (11) which is adhesively bonded to the base layer material and / or to a coating (B) over the base layer material, - wherein the filter layer material (11) consists of a plastic, in particular polyurethane or Polymetylmetacrylat and - Wherein the finished filter layer (2) has a permeability and / or porosity with channels of 5 to 50 μ. A slip casting mold (0) having at least one casting component (40, 41) according to any preceding claim. Casting mold according to Claims 11 and 14, in which the at least two casting mold components (40, 41) form on the outside mutually opposite edge sections, between which a gap (9) remains, in particular in the region of opposite edge sections of the sealing layers (8) and on the inside of these opposing edge portions of the sealing layers (8) in the direction of the casting space (6) towards mutually opposite edge portions of the filter layers (1) sealingly touch the gap (9).

Images