EP0759346B1 - Form zur isostatischen Pressen - Google Patents

Form zur isostatischen Pressen Download PDF

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Publication number
EP0759346B1
EP0759346B1 EP19960202189 EP96202189A EP0759346B1 EP 0759346 B1 EP0759346 B1 EP 0759346B1 EP 19960202189 EP19960202189 EP 19960202189 EP 96202189 A EP96202189 A EP 96202189A EP 0759346 B1 EP0759346 B1 EP 0759346B1
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EP
European Patent Office
Prior art keywords
membrane
control element
pressing
chamber
die
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP19960202189
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English (en)
French (fr)
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EP0759346A1 (de
Inventor
Carlo Antonio Camorani
Maris Algeri
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Individual
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Individual
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Priority claimed from EP95202233A external-priority patent/EP0701889B1/de
Priority claimed from IT95RE000054 external-priority patent/IT1280093B1/it
Priority claimed from IT95RE000061 external-priority patent/IT1280100B1/it
Priority claimed from IT95RE000064 external-priority patent/IT1280103B1/it
Application filed by Individual filed Critical Individual
Priority to EP19960202189 priority Critical patent/EP0759346B1/de
Publication of EP0759346A1 publication Critical patent/EP0759346A1/de
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Publication of EP0759346B1 publication Critical patent/EP0759346B1/de
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B5/00—Presses characterised by the use of pressing means other than those mentioned in the preceding groups
    • B30B5/02—Presses characterised by the use of pressing means other than those mentioned in the preceding groups wherein the pressing means is in the form of a flexible element, e.g. diaphragm, urged by fluid pressure
    • 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
    • B28B3/00—Producing shaped articles from the material by using presses; Presses specially adapted therefor
    • B28B3/003—Pressing by means acting upon the material via flexible mould wall parts, e.g. by means of inflatable cores, isostatic presses
    • 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
    • B28B7/00—Moulds; Cores; Mandrels
    • B28B7/34—Moulds, cores, or mandrels of special material, e.g. destructible materials
    • B28B7/346—Manufacture of moulds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B15/00—Details of, or accessories for, presses; Auxiliary measures in connection with pressing
    • B30B15/02—Dies; Inserts therefor; Mounting thereof; Moulds
    • B30B15/022—Moulds for compacting material in powder, granular of pasta form
    • B30B15/024—Moulds for compacting material in powder, granular of pasta form using elastic mould parts

Definitions

  • the invention concerns an isobaric die for ceramic tiles, particularly suitable for forming tiles with a uniform pressing intensity and controlled thickness.
  • IT-A-1104511 describes a die in which the ceramic tiles are pressed with the action of an elastic modelling membrane, for example made of rubber, delimiting a chamber in a relative semi-die into which an incompressible fluid, for example oil, is introduced; with such a die it is possible to achieve a homogeneous density of the pressed tile thereby limiting undesirable dimensional variations in the tile during the subsequent firing.
  • an elastic modelling membrane for example made of rubber
  • EP-A-0556163 describes an isostatic die having a membrane, or rubber plane, underneath which there are chambers positioned close to each other and intercommunicating, the membrane being securely anchored to the outside edge of the die and to the ribs defined by the partition walls of the various chambers, said chambers being filled with incompressible fluid.
  • the membrane in the areas corresponding to the chambers, is able to move sufficiently to transmit the pressing force to the tile in a uniform manner; at the ribs separating one chamber from the adjacent one, where the membrane with its rigid response remains constantly level, there are imprints which form the support appendages on the rear of the tile.
  • a first part consists of a plate with perforations in the areas corresponding to the chambers: the membrane is vulcanised on this perforated plate with the use of two matrixes, one reproducing the form of the surface of the rear of the tile, the other having a number of appendages, or protuberances, that define the inside of each chamber.
  • the first part of the die is then assembled, by means of numerous screws and seals, to a second part of the die that has channels which render the chambers intercommunicating.
  • EP-A-0620089 proposes obtaining said chambers on the face of a single die body, creating the intercommunication channels on the base of said chambers, isolating the upper part of the each chamber with a plug made of elastic material, then vulcanising the membrane on top using a low pressure matrix.
  • IT-A-MO930162 describes an analogous die in which, in order to avoid filling the chambers during vulcanisation, there is a layer of sand covered with a sheet of plastic material, it being possible to eliminate the layer of sand after vulcanisation.
  • a serious problem with tiles pressed with prior art isostatic dies is the highlighting of the support appendages on the front face of the tile after firing: this is due to the fact that, during pressing, if in one area of the tile there is not enough powder, or the powder has a lower density, the areas corresponding with the appendages will be pressed considerably less than the areas between said appendages. This gives rise to an unacceptable alteration in the surface lustre on the opposite side of the tile reproducing the design of the underlying appendages.
  • This highlighting is accentuated by the fact that the elastic membrane tends to become bulged, concave, substantially spherical in form, with considerable lack of homogeneity of pressing between the central zone and the outside zones close to the appendages.
  • the liquid seal being achieved by means of seals sliding against the seat, the seals will be subject to extrusion and the pistons, which for isostatic operation have to perform their axial movements at the maximum pressure, will have their movements severely hampered by the friction of the seal against the seat.
  • passages made by cutting, at four points in each chamber, by means of a small radial milling cutter whose axis of rotation is orthogonal to the face of the die.
  • the technical problem of this invention is that of inventing an isostatic die that makes it possible to eliminate pressing defects in ceramic tiles.
  • a further aspect of the technical problem is that of inventing an isostatic die that may be constructed in a very simple and economic manner in which, in particular, it is possible to obtain the chamber communication ducts in an extremely simple manner.
  • the invention resolves said technical problem by adopting pressing means, particularly for the isostatic pressing of ceramic tiles, comprising at least one die having a plurality of communicating chambers containing incompressible fluid and closed by an elastic membrane which has an external surface that reproduces the rear of the tile and an internal surface anchored to walls separating said chambers, inside each chamber there being inserted, in an intermediate position between said fluid and said membrane, a control element for controlling the deformation of the membrane, characterised in that each said control element is anchored to said membrane and has a zone close to said membrane detached from said walls so as to define an elastic peripheral joint in said membrane connecting said control element to said respective walls, said control element co-operating with respective positioning means that maintain each said control element in a predetermined position within the relative chamber during the formation of the membrane.
  • the control element for controlling the deformation of the membrane is advantageously made of a stiffer material than that of the membrane.
  • a plurality of intercommunicating chambers containing incompressible fluid and closed by an elastic membrane having an external surface that reproduces the rear of the tile and an internal surface anchored to walls separating said chambers, inside each chamber there being inserted, in an intermediate position between said fluid and said membrane, a substantially rigid control element for controlling the deformation of the membrane; said control element has, at its end close to said membrane, a peripheral zone detached from the walls of the chamber where there is an elastic sealing joint; said control element being anchored to said membrane and co-operating with respective positioning means that maintain each said element in a predetermined position within the relative chamber during the forming of the membrane.
  • Said positioning means may consist of a collapsible positioning element, that is to be collapsed by means of a force acting on the membrane after said membrane has been formed.
  • Said substantially rigid element may also have oscillating movements, that is, not constrained to parallelism.
  • the seal against the incompressible fluid between said mobile rigid element and the wall of the corresponding chamber is obtained by the presence of a joint which is securely anchored to said rigid element and to the wall of the corresponding chamber, said joint permitting axial movements of the rigid element purely by elastic deformation, that is, without sliding contact between different surfaces.
  • Said joint may advantageously be made of the same material as said membrane and be integrated with it.
  • a method is now described for the vulcanisation of the membrane onto the body of the die with the use of a matrix, forming the external and active face of the die, placed in a position below said die.
  • the product constituting the elastic membrane should preferably be in liquid form prior to vulcanisation, such that it may take on a horizontal surface configuration naturally when it is poured.
  • the forming matrix is placed, on the lower face of a normal vertical axis heating press, with the forming face facing upwards, said matrix having an external perimetric edge protruding upwards and such that the body of the die to be vulcanised may easily enter inside it.
  • a measured quantity of liquid substance constituting the membrane is poured and which is contained by said external edge; once the surface of said substance has become level the body of the die with the chambers facing downwards is made to descend until it comes into contact with the external edge of the matrix; during this phase the system may be pressurised with the introduction of compressed gas, that is pressurised, in one of the communication holes: this in order to aid the conformation of the membrane to the matrix, adhesion of membrane in the areas of contact with the die and the elimination of any bubbles of gas.
  • the side of the die to be vulcanised will have been previously sanded and treated with suitable adhesive substances applied by brush or spraying.
  • the isostatic die for tiles comprises a metallic body 1, on whose active surface there are chambers 2 intercommunicating by means of straight connecting ducts 108. Inside the chambers 2 is inserted a rigid element 4 which is maintained in position axially, during the vulcanisation of the membrane 12, by means of a wire-like collapsible positioning element 14 made of a metal that may subjected to plastic deformation, for example, copper, inserted in a suitable seat 15, 15a made in the base of the chamber 2; the seat 15, 15a may also be made in the element 4 and the wire-shaped element 14 may be inserted in the relative seat before the rigid element 4 is inserted in its chamber 2.
  • the wire-shaped element 14, acting as a strut, is positioned between the base of each chamber 2 and the relative rigid element 4 for controlling the deformation of the membrane 12.
  • the collapsible element may consist of a tessera 25 having a quadrangular plan view shape, provided with folds 25b, obtained, for example, directly from stamped plate.
  • the folds 25b form protuberances on which the rigid membrane control element 4 is placed during the vulcanisation of said membrane.
  • the collapsible positioning element 14 may consist of a wire-shaped element 16, 16a suitably folded in the form of a ring (for example made of copper, lead or tin) and placed on the base of the chamber 2, it being possible for said wire-shaped element to have a square cross-section.
  • the axial positioning elements may consist of protuberances 17 arranged radially around the control element 4 which are destined to be sheared with the forced movement of the element 4 as described earlier.
  • the positioning element consists of a flat metal sheet 18 that may be subjected to plastic deformation obtained by punching and therefore extremely economical; the forced movement of the control element 4 in this case causes permanent deformation of the edge 18a of said sheet.
  • Figure 7 shows a positioning element consisting of a piece of wire 19 (or a small bar) with its extremities inserted in suitable hollows 20 made in the walls of the chamber 2 and which is destined to be sheared by the relative control element 4 after vulcanisation.
  • the positioning element consists of a concave tessera 21 obtained, for example, by punching-drawing from sheet metal that may be subjected to plastic deformation and which is destined to be flattened against the base of the chamber 2, as shown on the right side of said Figure; naturally, said concave tessera 21 may also be introduced up-side-down and, moreover, it may have any other suitable shape.
  • the positioning element is divided into two parts, that is it comprises a collapsible element, here shown as a plurality of spheres 27, made of a material that may be subjected to plastic deformation, for example, lead, above which there is a rigid tessera 28 which supports the seal 22 around the control element 4; it is to be noted how said collapsible element 27 may also be replaced by any one of the other types of collapsible elements already described or described herewith.
  • a collapsible element here shown as a plurality of spheres 27, made of a material that may be subjected to plastic deformation, for example, lead, above which there is a rigid tessera 28 which supports the seal 22 around the control element 4; it is to be noted how said collapsible element 27 may also be replaced by any one of the other types of collapsible elements already described or described herewith.
  • the positioning element consists of a bevel ring 29, suitably drawn to diverge towards the membrane 12, matched to the peripheral form of the respective chamber 2: the ring 29, during the forming phase of the membrane, also holds up the seal ring 22.
  • Figure 13 shows a particular version of rigid element 4, obtained from stamped plate: the rigid element has a hollow form facing the respective chamber 2 suitable for receiving the incompressible fluid: this enables the rigid element 4 to be easily obtained with any plan view shape, even non-circular, and already provided with, at the edge facing the membrane 12, a suitable seat for the seal 22.
  • the positioning element 30 consists of a tessera having a recessed seat suitable for centring the rigid element 4; the tessera may be drilled to enable the free passage of incompressible fluid when in the collapsed position.
  • said positioning element 31 is analogous to the preceding one, though, in this case, the centring coupling is made in the control element 4.
  • the control element in Figure 15 also has a centring recess, but the collapsible element 32 is initially drawn so that it diverges towards the base of the respective chamber 2 and is destined to be flattened on the base of the chamber after vulcanisation.
  • Figure 14 shows a positioning element in two parts 28, 29, as in Figure 9, in which however the seal against the elastomer is achieved by means of a flat seal 33.
  • Figures 16 and 17 show a system for the positioning the element 4 in such a way that it is effective even with the die turned upside-down, this being necessary to carry out the forming of the membrane with the matrix 7 positioned underneath; this system offers the particular advantage of not requiring the means 22, 23 for obtaining the seal against the liquid elastomer. Also, as the element 4 only requires a rough surface finish, the rigid element 4 in this case may advantageously be obtained from plate by punching or cutting with water jet, or laser beam, without further machining. Furthermore, positioning with secure constraints on element 4 is not required as the forming of the membrane takes place with very low loads on element 4.
  • the annular positioning element 26 may be obtained directly by cutting a sheet of elastomer material thereby also being extremely economical.
  • the preparation is also extremely simple in that it involves introducing into each chamber 2 an element 26 that has to enter without interference with a small amount of lateral clearance; subsequently, a rigid element 4 has to be placed on each element 26, then, using a flat thruster the elements 4 are made to enter, with automatic axial levelling, into the respective annular element 26; the introduction may be achieved without folding the internal edge of the element 26 or, instead, by causing it fold as shown on the right side of Figure 16, in either case the positioning is guaranteed in that as the element 26 expands elastically it becomes blocked against the lateral walls of the chamber; this slight blocking though, does not impede the normal movement the element 4 needs to be able to perform during operation.
  • the seal against the incompressible fluid F between said mobile rigid element 4 and the wall of the corresponding chamber 2 is obtained with the presence of a joint 12a securely anchored to said rigid element and to said wall of the corresponding chamber, said seal enabling axial movements of the rigid element 4 purely by elastic deformation, that is, without sliding contact between different surfaces.
  • Figures 19 and 26 highlight a particular problem in the movements of the element 4 in conjunction with toroidal seal 22. If the seat for said seal 22 is made in the element 4 ( Figure 19), element 4 is free to descend into the chamber 2, as shown in Figure 20, in that an empty zone is created above the seal 22; on the other hand, upward movement of element 4, that is, out of the chamber 2, is prevented in that this can only occur if the membrane 12 tears or it detaches from the edge 35.
  • a further important advantage of the invention as described in the preceding versions with respect to the prior art, is that it is possible, in an extremely precise and simple manner, to assign a maximum stroke to the movement of the element 4 towards the base of the chamber 2: this is possible by suitably sizing the collapsible support elements.
  • each control element 4 may have smooth lateral surfaces and be inserted with a considerable amount of clearance in the respective seats, or chambers 2, who also have smooth lateral surfaces.
  • the bottom of each control element 4 may be made to co-operate with a collapsible support element 65 consisting of a flat central element 66, provided with an axial through hole 67, and peripherally provided with a concave annular edge defining a seat for centring the relative control element 4.
  • the central hole 67 has to be situated correspondingly with the hole 60 in the body 1 to enable the passage of the fluid F through the relative distribution duct 61.
  • Figure 32 shows an isobaric punch 1, inserted in a matrix M of a die for ceramic tiles during the pressing of a tile 41 by means of punch PZ.
  • the membrane may be limited to the set of annular joints 12a, that is, the control elements 4 may even not be covered with the elastomer material on the active face during pressing, as shown in Figure 38.
  • the collapsible support 65 may be shaped as in a saucer 69 ( Figures 30 and 33, left side), possibly with a central hole for occluding element 70, acting as control element 4, destined to be an integral part of the membrane 2.
  • the occluding element may also consist of a sphere 71, as shown on the right side of Figure 33.
  • the surface of the collapsible element 65 facing the membrane 2 may advantageously be coated with a layer of non-stick material in order to prevent the undesirable adhesion, during vulcanisation, of the collapsible supports to the membrane.
  • Figure 34 shows a collapsible support element 111 having, on the side facing the membrane, a shape which is complementary to that of the respective control element 4, that is, with a flat central surface and raised edges for centring the control element.
  • the collapsible support element 111 may be made of a material that may be volumetrically reduced, such as for example, expanded polystyrene, destined to be flattened, as shown in 111a, on the base of the respective chamber 2 after the membrane 2 has been formed.
  • Figure 37 shows a flat temporary collapsible support element, for example, in the shape of a ring 31, positioned with overhang in a stepped seat 73 made in the alveolus, or chamber 2.
  • the ring 31 may be deformed in the direction of the base of the seat 2 by means of a preliminary pressing stroke P: to make such a deformation possible, the width of each tessera 48 is preferably less than the minimum width D2 of the relative chamber 2.
  • Figure 38 shows how the control elements 4a may be exposed on the pressing surface, in this case there being a corresponding break in that part of the membrane 12: the tesserae 4a are each connected to the respective chambers 2 by means of annular joints 12a.
  • the collapsible support element may also consist of a panel 90 ( Figure 39) of composite material, comprising a pair of external layers 91 between which a reducible layer 92 is inserted, for example, made of a corrugated metallic material.
  • the reduction of element 90 may be achieved by flattening on the base of the respective cavity 2.
  • Figure 40 shows an isostatic die for ceramic tiles during forming using the method as described in the present invention.
  • the metallic body 1 is prepared, on whose active face there are the chambers 2, interconnected by means of communication channels 62.
  • a matrix 204 ( Figure 41) for forming the active face of the body 1 has its surface coated with non-stick material; the matrix has a perimetric frame 205 for containing the liquid elastomer material 210, (for example, a polymer such as CYANAPREME of the American company AIR PRODUCTS of ALLENTOWN) that is poured into it.
  • the liquid elastomer material 210 for example, a polymer such as CYANAPREME of the American company AIR PRODUCTS of ALLENTOWN
  • the body 1 Once the liquid elastomer in the filled and possibly preheated matrix 204 is perfectly level, the body 1, previously treated with an adhesive substance and preheated, is brought into contact with it and maintained in position, as shown in Figure 42. After the vulcanisation the matrix 204 may be detached leaving the die ready with the empty spaces 215 in the chambers 2 to be filled with the incompressible fluid through the holes 61, 62 provided.
  • the press is useful in applying the detaching action of the matrix, or, in the case it should be necessary to apply a higher pressure for the introduction of a fluid, for example compressed gas, during the vulcanisation phase; said fluid, introduced through holes 61, can aid the adaptation of the elastomer 210 to the matrix 204, reduce the formation of bubbles and improve the adhesion of the elastomer 210 to the ribs 208; it can also enable the use other different types of elastomer, not in liquid form.
  • a fluid for example compressed gas
  • This forming method enables the die to be made in other advantageous versions, some of which are described in the preceding Figures (for example, Figure 16, 17) in which there are elements for controlling the deformation of the membrane inserted in the respective cavities.
  • the communication channels may be obtained by cutting the ribs 208 along their entire height by means of a disc milling cutter with axis parallel to the plane of the face of the die, possibly mounted in series for a more rapid execution.
  • the relative cuts may also be made by means of an angle cutter, in this way the four cuts in the respective four ribs will be carried at the same time.
  • the external part 209a of the cuts 209 will be filled with elastomer, whereas in the lower part 209b - that is, the part closer to the base of the cavity - will remain empty to allow the passage of the liquid. It is to be noted that, given the considerable width of the cut 209, the elastomer contained in it will not be able to move in an appreciable and damaging manner, said cut will instead improve anchorage of the membrane 12 to the ribs 208.
  • the membrane 12 inside each chamber 2 is associated with a preferably rigid element for controlling the deformation of the membrane 4.
  • the control element 4 is maintained in position during the vulcanisation phase by means of an elastic support 212, already vulcanised, or simply glued to the relative element 4; the pre-assembled unit 213 is then positioned, applying a slight pressure, in each seat 214, said seat being shaped in such a way as to keep the element 4 centred and to permit lowering to the base of the cavity 2.
  • Suitable calibration of the dimensions of the seat 214 and of the height of the support 212 enables a maximum lowering stroke C to be determined for the element 4. In this way it is possible to prevent the surface of the tile within the ribs from passing beyond the ideal plane formed by the extremities of said appendages.
  • Figure 46 shows a different method for keeping the element 4 in position during the vulcanisation phase: in this case the base of the chamber 2 is shaped in such a way as to keep the element 4 centred when it is inserted in the chamber and the element remains attached to the base of the chamber 2 by means of movable means of connection, for example, magnets.
  • the body 1 is de-magnetised and so the elements 4, falling, will partially sink into the elastomer and be held by it; the distance D will therefore be principally determined by the vulcanisation temperature and the moment when the de-magnetisation is carried out.
  • Figure 47 shows a further advantageous system for keeping the element 4 positioned during the vulcanisation phase by means of a collapsible element 216 fixed, for example by gluing, to the base of the chamber 2 and to the control element 4; at the end of the vulcanisation operation the collapsible element 216 is flattened on the base of the cavity 2 with the action of pressure applied to the membrane 12, the expansion of the perimetric part of said collapsible element 216 in contact with the element 4 will cause it to detach and to be securely positioned on the base of the cavity, without any subsequent interference with the movement of element 11.
  • FIG. 48 and 49 A further advantageous version for keeping the control elements 4 in position is shown in Figures 48 and 49; a spring in the shape of a ring made of steel wire, suitably shaped to keep the element 4 centred and positioned axially is inserted in a groove 217 made in the lateral part of the chamber 2.
  • the walls of the chamber 2 next to the outer edge may be provided with a suitable inclination 219 in order to aid the insertion of said ring 218 and to obtain a joint 12a (not shown here) which is wider and less restrictive at the point where the membrane has to flex;
  • said groove 217 may also be made in the external wall of the element 4 instead of in the wall of the chamber;
  • the spring 218 may be replaced by an elastomer seal ring, in this case it will be necessary to prevent the formation of a seal against the liquid, for example, by cutting a piece of said seal ring.
  • a rigid element 4 is inserted inside the chambers 2 which has appendages 305 that interfere with the walls of the chamber 2 at the corners 306 so enabling the rigid element 4 to be maintained in a predetermined axial and radial position during the vulcanisation phase.
  • the vulcanisation this case has to be obtained using the forming matrix placed in a position underneath the die, as already described with reference to the method of Figures 40, 41, 42.
  • the appendages 305 may be positioned within a chamber 2 without any axial reference as shown on the left side of Figure 50 and 51, or on locators as shown on the right side of the same Figures, said locators advantageously aiding a more rapid and precise positioning of the control element 4 when it is inserted.
  • Each appendage 305 may be an integral part of the element 4, that is, it may be made of the same material, or it may be made of a different material fixed to the control element 4.
  • said control element 4 will be provided with appendages 308 ( Figure 53) which, as well as having the positioning function, will also perform the function of containing the mass of liquid elastomer, said appendages will therefore be suitably matched in suitable seats 309 in the chambers 2.
  • the pressure exerted on the rigid element 4 is considerably higher, it may be convenient to momentarily support said rigid element 4 with a collapsible element - one of those already described - for example, a sphere 310 made of malleable material, such as lead or copper, placed in a suitable seat 311 and destined to be permanently deformed after vulcanisation.
  • control element 4 may protrude with respect to the appendage 308 towards the membrane 12, this in order to aid anchorage of the element 4 to the membrane. Furthermore, as shown on the right side of Figure 54, the base of the control element 4 may be inserted so that it may slide inside a seat 313, this in order to constrain the parallelism of the rigid element during the movement of the membrane 12.
  • control element 4 may be provided with a positioning element in the form of a ring 31, analogous to that of Figure 12, but inserted in a stepped seat made in the part of the element 4 closest to the membrane 12.
  • the external edge of the ring 31 sits in a stepped seat made correspondingly on the walls of the relative cavity 2.
  • This version makes it possible, in a simple manner, to obtain straight ducts 108, or ducts in the form of a "V" 62, in the walls 208 at the base of each cavity 2 in order to make said cavities intercommunicating and to allow the passage of the fluid F during pressing.
  • Figure 57 shows a support element comprising a ring 31 coupled internally with a concave element 4b with concavity facing the membrane 12 and the external edge resting on the internal edge of the ring 31.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Heating, Cooling, Or Curing Plastics Or The Like In General (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)

Claims (9)

  1. Preßmittel, insbesondere zum isostatischen Pressen von Keramikfliesen (41), mit zumindest einer Form (1), die eine Mehrzahl von miteinander kommunizierenden Kammern (2) aufweist, die ein inkompressibles Fluid (F) enthalten und durch eine elastische Membran (12) geschlossen sind, die eine äußere Oberfläche, die die Rückseite der Fliese (41) reproduziert, und eine innere Oberfläche aufweist, die an Wänden (208) verankert ist, die die Kammern (2) trennen, wobei innerhalb jeder Kammer (2) in einer Zwischenposition zwischen dem Fluid (F) und der Membran (12) ein Steuerelement (4, 4a, 4b, 70, 71) zum Steuern der Verformung der Membran (12) eingesetzt ist, dadurch gekennzeichnet, daß jedes Steuerelement (4, 4a, 4b, 70, 71) an der Membran (12) verankert ist, so daß es Bewegungen der Membran (12) während des Pressens folgt, und einen der Membran (12) benachbarten Bereich aufweist, der von den Wänden (208) signifikant beabstandet ist, um in der Membran (12) ein perimetrisches elastisches Bindeglied (12a) zu definieren, das das Steuerelement (4, 4a, 4b, 70, 71) mit den jeweiligen Wänden (208) verbindet, wobei das Steuerelement (4, 4a, 4b, 70, 71) mit jeweiligen Positioniermitteln (14, 16, 25, 17, 18, 19, 21, 26, 27, 28, 29, 30, 31, 65, 69, 111, 90, 212, 216, 218, 305, 308) zusammenwirkt, die während des Bildens der Membran (12) jedes Steuerelement (4, 4a, 4b, 70, 71) in einer vorbestimmten Position innerhalb der betreffenden Kammer (2) hält.
  2. Preßmittel nach Anspruch 1, bei denen jedes Steuerelement (4, 4a, 4b, 70, 71) aus einem Material gefertigt ist, das steifer ist als dasjenige der Membran (12).
  3. Preßmittel nach Anspruch 1, bei denen die Positioniermittel (14, 16, 25, 18, 19, 21, 25, 27, 28, 29, 30, 31, 65, 111, 90, 216) dauerhaft verformt werden können, sobald die Membran (12) gebildet worden ist, um von dem jeweiligen Steuerelement (4, 4a, 4b, 70, 71) außer Eingriff zu kommen.
  4. Preßmittel nach Anspruch 1, dadurch gekennzeichnet, daß die Positioniermittel (17) unter der Wirkung einer Preßkraft zerbrochen werden können, um von dem jeweiligen Steuerelement (4, 4a, 4b, 70, 71) außer Eingriff zu kommen.
  5. Preßmittel nach Anspruch 1, bei denen die Positoniermittel (212, 308) unter der Wirkung einer Preßkraft elastisch verformt werden können.
  6. Preßmittel nach den Ansprüchen 3, 4 oder 5, bei denen die Positioniermittel (17, 26, 218, 305) jeweils zwischen den Wänden (208) der jeweiligen Kammern (2) und dem jeweiligen Steuerelement (4, 4a, 4b, 70, 71) positioniert sind.
  7. Preßmittel nach Anspruch 3, 4 oder 5, bei denen die Positoniermittel (14, 16, 25, 17, 18, 19, 21, 25, 27, 28, 29, 30, 31, 65, 111, 90, 212, 216, 308) jeweils zwischen der Basis der jeweiligen Kammer (2) und dem jeweiligen Steuerelement (4, 4a, 4b, 70,71) positioniert sind.
  8. Preßmittel nach einem der vorhergehenden Ansprüche, bei denen jedes Steuerelement (4, 4a, 70, 71) mit jeweiligen Ringmitteln zum Verschließen (22, 23, 31, 33, 32) in Verbindung steht, die den Durchgang von Fluidmaterial zum Bilden der Membran (12) während der Vulkanisierung verhindert.
  9. Preßmittel nach Anspruch 8, sofern dieser von Anspruch 7 oder Anspruch 6 abhängig ist, bei denen ein Stützelement (28) für die Mittel zum Verschließen (22, 23, 31, 33, 32) zwischen dem Steuerlement (4) und den jeweiligen Positioniermitteln (14, 16, 25, 17, 18, 19, 21, 25, 26, 27, 28, 29, 30, 31, 65, 111, 90, 208, 212, 216, 305, 308) positioniert ist.
EP19960202189 1995-08-18 1996-08-05 Form zur isostatischen Pressen Expired - Lifetime EP0759346B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP19960202189 EP0759346B1 (de) 1995-08-18 1996-08-05 Form zur isostatischen Pressen

Applications Claiming Priority (9)

Application Number Priority Date Filing Date Title
EP95202233A EP0701889B1 (de) 1994-09-13 1995-08-18 Form zum isostatischen Pressen von Keramikfliesen und Verfahren zum Herstelllen der Fliesen
EP95202233 1995-08-18
IT95RE000054 IT1280093B1 (it) 1995-09-29 1995-09-29 Metodo per fabbricare stampo isobarico per piastrelle ceramiche e relativo stampo cosi' ottenuto
ITRE950054 1995-09-29
ITRE950061 1995-10-11
IT95RE000061 IT1280100B1 (it) 1995-10-11 1995-10-11 Perfezionamenti allo stampo isobarico per piastrelle ceramiche
IT95RE000064 IT1280103B1 (it) 1995-10-24 1995-10-24 Stampo isobarico perfezionato per piastrelle ceramiche
ITRE950064 1995-10-24
EP19960202189 EP0759346B1 (de) 1995-08-18 1996-08-05 Form zur isostatischen Pressen

Publications (2)

Publication Number Publication Date
EP0759346A1 EP0759346A1 (de) 1997-02-26
EP0759346B1 true EP0759346B1 (de) 2001-11-21

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EP19960202189 Expired - Lifetime EP0759346B1 (de) 1995-08-18 1996-08-05 Form zur isostatischen Pressen

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT202100014210A1 (it) * 2021-05-31 2022-12-01 Annovi S R L Tampone isostatico per la pressatura di polveri ceramiche

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1292690B1 (it) * 1997-03-18 1999-02-11 Annovi S R L Punzone isobarico per la pressatura di piastrelle ceramiche e metodo per la fabbricazione di detto punzone.
DE19731146C1 (de) * 1997-07-21 1999-02-25 Dietrich Engmann Isostatischer Preßstempel zum Herstellen keramischer Fliesenrohlinge und Presse mit diesem Preßstempel
ES2155965T3 (es) * 1997-12-11 2001-06-01 Entwicklungsgesellschaft Wolfg Procedimiento y aparato para la fabricacion de productos de hormigon con materiales inertes expuestos.
ITMO20020264A1 (it) * 2002-09-24 2004-03-25 Alfredo Missana Semistampo per la pressatura unidirezionale di materiali
ITRE20050033A1 (it) * 2005-03-25 2006-09-26 Cbm Srl Punzone ceramico tipo marca
ES2745575A1 (es) * 2018-08-30 2020-03-02 Asitec Ceram S L Punzon isostatico
CN110696157A (zh) * 2019-09-29 2020-01-17 唐山森兰瓷科技有限公司 卫生洁具生产设备

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0736363B1 (de) * 1993-03-17 1997-12-03 Maris Algeri Form, insbesondere zum Pressen von Keramikfliesen

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT202100014210A1 (it) * 2021-05-31 2022-12-01 Annovi S R L Tampone isostatico per la pressatura di polveri ceramiche

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