WO2016083909A1

WO2016083909A1 - Station for processing the surfaces of ceramic products, punches, dies and processing method

Info

Publication number: WO2016083909A1
Application number: PCT/IB2015/055785
Authority: WO
Inventors: Sauro FERRI
Original assignee: Progetto Futuro S.R.L.
Priority date: 2014-11-27
Filing date: 2015-07-30
Publication date: 2016-06-02

Abstract

A station for working green formed ceramic products (P), or punches and dies for ceramic use, having a surface (S), comprises at least one working seat (3) for at least one product (P), at least one laser emitter (6) for working the surface (S) according to an aesthetic pattern (M) having a predetermined total depth, at least one control unit (8) which controls the laser emitter (6), the control unit (8) controls the operations of activation/deactivation of the laser emitter (6) so as to affect a first zone (pi) of the surface (S) with a radiation (6b) of sufficient power to remove by sublimation a certain amount of material of the product (P), subsequently directing said laser radiation (6b) towards another zone (p2) of the surface (S) sufficiently distant from the zone (pi) so as to allow the cooling of the material in said zone (pi), activation/deactivation of the laser emitter (6) so as to affect said second zone (p2) of the surface (S) with a radiation (6b) of sufficient power to remove by sublimation a certain amount of material of the product (P), repeating the operations of activation/deactivation until a predetermined path (p) or a predetermined area of said surface (S) is completed.

Description

"STATION FOR PROCESSING THE SURFACES OF CERAMIC PRODUCTS,

PUNCHES, DIES AND PROCESSING METHOD" Designated inventor: Rag. Sauro Ferri

TECHNICAL FIELD OF THE INVENTION

The present invention regards a station for working surfaces of green formed ceramic products, i.e. not yet dried/fired in the respective dryers/furnaces, as well as of punches and dies of the type used for example for impressing a pattern or decoration on the surface of such green ceramic products.

The invention also regards a method for working the surface of such products.

STATE OF THE PRIOR ART

At the state of the art, in the field of production of ceramic products such as tiles and the like, it is known to work the visible surfaces of such products, so as to reproduce patterns thereon that have a certain depth and which provide the aesthetic effect of some materials, such as, for example, wood or natural stone. One such in-depth working of the surface usually occurs by means of the use of punches or dies, e.g. metal punches, adapted to impress a pattern or a decoration on a green formed ceramic product (otherwise also named "raw"), in a manner such that this remains impressed on the malleable surface of the product, before drying/firing the same.

Nevertheless, such working only allows obtaining a repetitive pattern on the surface of the product thus impressed, given that the work surface of the punches, intended to be impressed on the green ceramic product, cannot be varied.

The punches or the dies may be completely substituted, or the coating that bears the pattern inside the punch can be substituted; nevertheless, such operation is relatively laborious and requires a certain amount of time.

As an alternative to the use of punches, a fired ceramic product can be directly worked by means of suitable cutting tools, for example diamond tools given the hardness of the fired ceramic product.

However, such tools, in addition to becoming overheated - hence requiring a suitable water cooling system or employing any other suitable fluid - contribute to liberate large quantities of dust in the air, which must be removed to avoid overly contaminating the work area.

In the international patent application WO-2001/10651 , a generic working by means of laser of green formed ceramic products was also proposed, in order to obtain an aesthetic surface pattern.

However, one such working is negatively affected by the drawback of altering the mechanical characteristics of the materials in which such products are obtained, causing the vitrification of the ceramic material at the area hit by the laser.

In the case of working with laser on punches and dies, due to the localized overheating, there is the remelting of the material constituting the punch (or die) after the passage of the laser radiation.

In green formed ceramic products, the vitrification eliminates the pores of the material at the zone hit by the laser radiation, therefore preventing the possibility of absorbing inks or enamels for decorating the ceramic products.

There is therefore the need to provide alternative techniques for working the surface, for green formed ceramic products as well as for punches and dies, which resolve the above-described drawbacks.

OBJECTS OF THE INVENTION

Therefore, the main object of the present invention is to improve the state of the art in the field of working the surface for ceramic products or the surface for punches or dies for ceramic use.

Another object of the present invention is to provide a station for working the surface for green formed ceramic products or punches or dies for ceramic use, which is an alternative with respect to the conventional work stations.

Still another object of the present invention is to provide a station for working the surface for green formed ceramic products or the surface of punches or dies for ceramic use, which allows directly working the surfaces of such products, thus obtaining an aesthetic pattern thereon with a certain depth that can be varied from product to product, with respect to the aesthetic patterns obtained conventionally, which cannot be varied.

Another object of the present invention is to provide a station for working the surface, for green formed ceramic products or for punches and dies, which does not alter the mechanical characteristics of the products thus worked.

A further object of the present invention is to provide a station for working the surface, for green formed ceramic products or for punches and dies, which is easy to obtain.

According to one aspect of the present invention, a station is provided for working the surface, for green formed ceramic products or for punches and dies, according to the enclosed claim 1.

According to another aspect of the present invention, a method is provided for working the surface, for green formed ceramic products or for punches and dies, according to the enclosed claim 15.

The dependent claims refer to preferred and advantageous embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will be clearer from the detailed description of an embodiment of a station for working the surface, for green formed ceramic products or for punches and dies for ceramic use, as well as of a working method obtainable with one such station, given as a non-limiting example in the enclosed drawing tables in which:

figure 1 illustrates a top perspective view of the main components of a station for working green formed ceramic products according to the present invention; figure 2 is a side view, not in scale, of the station of figure 1 ; and

figure 3 shows the surface of a green formed ceramic product or the work surface of a punch or a die, obtained by means of a station according to the present invention.

In the enclosed drawings, equivalent parts or components are marked with the same reference numbers. EMBODIMENTS OF THE INVENTION

With reference to the enclosed figures, it will be observed that a station for working the surface of products P, such as green formed ceramic products or punches and dies, e.g. made of metal or resin, is generally indicated with the reference number 1 and comprises a feeding end 2 for at least one product P to be worked, at least one working seat 3 and at least one outlet end 4 for said product P thus worked.

The working station 3 can be visible or screened from the outside, e.g. by means of a containment casing or lateral flanks (not illustrated in the drawings). It is arranged for working the surface of at least one product P entering the feeding end 2.

The working station 1 also comprises means 5 for handling at least one product P between the feeding end 2 and the outlet end 4. For example, the handling means 5 comprise a conveyor belt 5a slidably mounted on a pair of motorized rollers 5b, 5c: one 5b at the feeding end and one 5c at the outlet end 4.

The handling means 5 could alternatively comprise a roller conveyer (not illustrated in the drawings) or other suitable means.

The handling means 5 are provided for moving the products P set thereon, both continuously and step-by-step or according to combinations of such movement types, according to working requirements.

In addition, as an alternative to continuous movement through the means 5, different loading modes for the products P being worked could also be provided, for example by means of trays (not illustrated) that can carry one or more products P, and which are substituted when working of the products P present on that tray has terminated.

The working station 3 according to the invention comprises at least one laser emitter 6, set for emitting at a field of action 6a thereof at least one laser radiation 6b, towards an upper surface S of a product P, i.e. the surface opposite the support surface of the product itself on the handling means 5.

The laser radiation 6b thus emitted then hits the surface S of the product P, removing part of the product material by sublimation in a controlled manner, and thus achieving a desired aesthetic pattern M with a predetermined depth and which can be variable from product to product.

According to one version of the invention, the laser emitter 6 can be of the optical fiber type, of YAG type or of any other suitable type, whether pulsed or continuous, capable of emitting a laser radiation 6b of power suitable for removing by sublimation the material of the product P on which it hits.

The laser emitter 6 emits a radiation at a specific frequency, modifiable based on the working parameters by means of lenses or optical fibers, comprised in the group indicated in the drawings with reference number 9.

If the laser emitter is of YAG type, the radiation 6b emitted thereby can be of the pulsed type, developing a power sufficient for allowing the working of the green ceramic products or metals, by means of sublimation of the material itself.

As is observed in particular from figures 1 and 2, the working station 1 according to the present invention comprises at least one laser emitter 6, and in particular a plurality of laser emitters 6 arranged one after the other, and also one alongside the other, between the feeding end 2 and the outlet end 4, each operatively controllable, as will be better stated hereinbelow, in a coordinated manner with the others.

The station 1 comprises a plurality of laser emitters 6 arranged one after the other and/or alongside each other between the feeding end 2 and the outlet end 4, to form a matrix of laser emitters, each operatively controllable in a coordinated manner with the others.

The station 1 for working according to the present invention also comprises means for supporting at least one laser emitter 6, indicated with the reference number 7 in the figure.

The supporting means 7 comprise guide means 7a¹, 7a¹¹, 7a¹¹¹ respectively, transverse and/or longitudinal and/or vertical, and further tilt means 7b.

The supporting means 7 have the function of adjusting the position of the laser emitters 6 with respect to the products P moving on the handling means 5.

The working station 1 according to the present invention also comprises a control unit 8, for example a program control unit, which controls the operation of the laser emitter(s) 6, of the supporting means 7, of the handling means 5 of the products P to be worked, sending/receiving suitable control signals thereto/therefrom.

The station 1 for working the surface of products P according to the invention comprises deflecting means, e.g. one or more adjustable mirrors and/or prisms, movable in real time under the control of the program control unit 8.

Such deflecting means are schematically indicated comprised in the group 9 (already referred to above).

The deflecting means allow directing the laser radiation 6b towards the product P, according to that schematically illustrated in figures 1 and 2.

For such purpose, as will be observed, the more the products P are moved closer to each other on the respective handling means 5, the greater is the portion of the working seat 3 affected by the laser working and, consequently, the greater is the efficiency of the station according to the invention.

The laser radiation 6b can thus affect the field of action 6a of the surface S, according to a desired incidence angle, controllable by the control unit 8 at a desired frequency.

In addition, in the scope of the field of action 6a of the surface S, the laser radiation 6b of each emitter 6 will follow a specific path "p", or a specific area (not illustrated), and an action sequence that the control unit 8 establishes based on the different functioning parameters of the laser radiation, of the material to be affected, of the size and geometry of the aesthetic pattern to be achieved.

In addition, as a function of the speed with which the products P are moved and the depth of the aesthetic pattern to be reproduced, each laser emitter 6, which operates on its own field of action 6a by moving the laser radiation 6b in phase with the movement of the product P, can only affect a part of the total depth of the aesthetic pattern.

Hence the aesthetic pattern, in its final depth, will be achieved by subsequent passages of laser radiations 6b emitted by the different laser emitters 6 which can be adjacent, e.g. one after the other, but they could also not be adjacent.

In this manner, it is possible to reduce the time necessary for obtaining the aesthetic pattern on the products P, which can move at relatively high speeds on the handling means 5.

In addition, there can be any sequence of passages of laser radiation 6b for obtaining the final depth of the aesthetic pattern: the final depth can be reached over the entire surface S to be affected, working subsequent layers of predetermined depth, or the final depth can be obtained first only in some zones of the surface S and then over the entire surface S.

In order to prevent the mechanical and technological characteristics of the material of the worked products P from being altered following the action exerted by the laser radiation 6b, there will be a first action of brief duration, in a first circumscribed zone, while the subsequent laser radiation 6b will occur in a second circumscribed zone at a sufficient distance from the first.

Due to this, the material under the action of the laser radiation will not be overheated so as to arrive at vitrification, in the case of ceramic materials, or remelting with loss of the removed form, in the case of metal materials or resins. The laser radiation 6b will in any case be of duration and intensity such to allow the removal of a certain amount of material by sublimation, but not such to overheat the material; for such purpose, cooling means 10 can also be provided, exemplified in figure 2 by jets of cool air or inert gas directed towards the zone of action of the laser radiation 6b.

Such jets also facilitate the removal of the vaporized material from the zone of action of the laser radiation 6b, and in order to improve such removal means (not illustrated) for suctioning the vaporized material can also be provided.

According to one version of the present invention, the working station comprises, downstream of the working seat 3, and at the outlet end 4, at least one or more brush means (not illustrated in the drawings), of any suitable type and intended to mechanically remove possible product residues removed by sublimation/vaporization, from the surface S of the products P once worked.

It is therefore confirmed that the selection of the operative sequence of the laser radiation emissions is determined by the control unit 8 as a function of the different operative parameters: laser emitter type, material of the product P, size and geometry of the aesthetic pattern to be achieved.

Optionally, upstream of the feeding end 2, the station 1 for working the surface of the products P can comprise at least one punch or one die (not illustrated in the figures), set to impress at least one standard pattern on the surface S of the products P, in the case of the green formed ceramic products.

Such punch (or die) carries out the function of impressing a standard pattern on the surface of the product P, not necessarily detailed, which is subsequently detailed by means of the laser working in the working seat 3.

Due to the subsequent working by means of the laser, the surfaces of the products P can thus be obtained each different from the other, individually for every product P moving on the handling means 5.

The operation of the station 1 for working the surface of a product P, described above, comprises the following steps of:

feeding, over the handling means 5, at least one product P to be worked;

activating/deactivating, in a controlled manner, the laser emitter(s) 6, in the field of action 6a, in phase with the movement of the products P;

removing the product P thus worked from the working seat 3, at the outlet end 4. The step of activating/deactivating the laser emitter(s) 6, along with the movement of the handling means 5, are controlled by the control unit 8.

The unit 8 in particular controls the laser emitter 6 or the laser emitters 6 arranged one after the other along the advancing direction A of the products P, or arranged in a matrix, in a manner such that they are activated/deactivated in a coordinated manner with respect to each other upon passage of the products P in the respective field of action 6a.

As specified above, in order to prevent the mechanical characteristics of the material of the worked products P from being altered following the action exerted by the laser radiation 6b, the control unit 8 controls the operations of activation/deactivation of each laser emitter 6 according to the steps (reference is made to figure 3): 1) emitting a laser radiation 6b on a first zone "pi" sufficient to remove, by sublimation, a certain amount of material of the product P without altering the mechanical characteristics thereof;

2) directing the laser radiation 6b towards another zone "p2" sufficiently far from the zone "pi" previously hit, so as to allow the cooling of the material in such previous area;

3) emitting a laser radiation 6b on the other zone "p2" in a manner sufficient to remove, by sublimation, the material of the product P without altering the characteristics thereof, and

4) repeating by the control unit 8 the steps 2) and 3), until a predetermined path "p" or a predetermined area (not illustrated) is completed.

In addition, each abovementioned step of emitting a laser radiation 6b, 1) and 3) can be followed by a step of cooling the respective treated zones, by means of the cooling means 10. If desired, the cooling step can also occur at the same time as the step of emitting the laser radiation 6b.

Furthermore, at the end of the steps of emitting laser radiations 6b, a step may follow for brushing the products P in order to mechanically remove possible product residues removed by sublimation/vaporization, from the surface S of the products P.

As stated above, such brushing step is obtained by means of at least one or more brush means (not illustrated in the drawings), of the type suitable for not damaging the surface S of the products P.

Hence, by operating the laser radiation 6b at zones sufficiently far from each other, the above-described drawbacks of vitrification or remelting of the material are avoided, if the product P is, respectively, a green formed ceramic product P, or a punch or a die, e.g. made of metal or resin, thus attaining the objects of the invention.

The above-described method optionally provides for a preliminary step of working the product P, by means of punch or die, if this is a green formed ceramic product, such that the product undergoes a first working of the surface and bears a preliminary, not necessarily detailed pattern on the surface S.

The working of the surface according to the station 1 will modify the preliminary pattern so as to obtain, as final effect, a detailed pattern that can vary for each single product, which produces without repetitions the aesthetic effect of some materials, such as wood or natural stone.

Therefore, it is observed that the invention attains the pre-established objects.

The working station according to the invention allows working, varying for each product the aesthetic pattern, the surface of ceramic products P and punches or dies, without altering the mechanical characteristics thereof.

The present invention was described according to preferred embodiments, but equivalent variants can be conceived without departing from the protective scope offered by the following claims.

Hence, for example, the means 5 for handling the products P between the feeding end 2 and the outlet end 4 of the station according to the invention can be moved in the working seat 3 along a transverse and/or longitudinal and/or vertical direction, with respect to the advancing direction A of the products P.

The control unit 8 can therefore impart suitable control signals thereto, so as to obtain the mutual approaching/moving away between the surface S of a product P to be worked and the respective laser emitter 6.

Claims

1. A station for working green formed ceramic products (P), or punches and dies for ceramic use, having a surface (S), comprising at least one working seat (3) for at least one product (P), at least one laser emitter (6) for working said surface

5 (S) according to an aesthetic pattern (M) having a predetermined total depth, at least one control unit (8) which controls said at least one laser emitter (6), characterized in that said control unit (8) controls the operations of activation/deactivation of said at least one laser emitter (6) so as to affect a first zone (pi) of the surface (S) with a radiation (6b) of power sufficient to remove by l o sublimation a certain amount of material of the product (P), subsequently directing said laser radiation (6b) towards another zone (p2) of the surface (S) sufficiently far from the zone (pi) so as to allow the cooling of the material in said zone (pi), activation/deactivation of said at least one laser emitter (6) so as to affect said second zone (p2) of the surface (S) with a radiation (6b) of power sufficient to

15 remove by sublimation a certain amount of material of the product (P), repeating said operations of activation/deactivation until completing a predetermined path (p), or a predetermined area of said surface (S).

2. A station according to claim 1, comprising a plurality of laser emitters (6), each emitter being intended to emit at least one laser radiation (6b) at a respective

20 zone or field of action (6a) of said at least one surface (S) of said at least one product (P), so as to remove by sublimation a certain amount of material of the product (P) for a part only of the total depth of the aesthetic pattern (M).

3. A station according to claim 2, wherein said laser emitters (6) of said plurality are arranged in succession with respect to each other or are arranged in a

25 matrix in said working seat (3), and are expected to be activated/deactivated in a coordinated manner with respect to each other, in such a way as to obtain said overall aesthetic pattern (M) throughout its depth.

4. A station according to any previous claim, comprising at least one feeding end (2) for at least one product (P) to be worked and at least one outlet end (4) of

30 said product (P) thus worked, at least handling means (5) for said at least one product (P) in said working station (3) between said at least one feeding end (2) and said at least one outlet end (4).

5. A station according to any previous claim, wherein said at least one laser emitter (6) is of the YAG type and emits a pulsed laser.

6. A station according to any claim 1 to 4, wherein said at least one laser emitter (6) is of the optical fiber type.

7. A station according to any previous claim, comprising supporting means (7) provided with guide means transversal and/or longitudinal and/or vertical, respectively, and/or further tilt means (7b) for adjusting the position of said at least one laser emitter (6).

8. A station according to any previous claim, comprising deflecting means (9) for said at least one laser radiation (6b) towards said at least one product (P), to be chosen between at least one adjustable mirror or at least one prism, movable in real-time under the control of said at least one program control unit (8).

9. A station according to any previous claim, wherein said at least one product (P) is a green formed ceramic product or a product for ceramic use.

10. A station according to claim 9, wherein said product for ceramic use is a metal or resin punch or die that can be used to impress a pattern onto a ceramic product.

11. A station according to any previous claim, comprising at least one punch, upstream of said feeding end (2), designed to impress at least one standard pattern on said surface (S) of said at least one product (P), said product (P) being a green formed ceramic product.

12. A station according to any previous claim, comprising cooling means (10), at said at least one working seat (3), with jets of cool air or inert gas directed towards said zone or field of action (6a) of said laser radiation (6b), said jets also helping the removal of said material thus removed from said zone of action (6a).

13. A station according to any previous claim, comprising suction means of said material removed by sublimation.

14. A station according to any previous claim, comprising, downstream of said working seat (3), close to the outlet end (4), at least one or more brush means intended to mechanically remove from said surface (S) of each product (P) any product residues removed by sublimation/vaporization.

15. A method of working the surface (S) of a green formed ceramic product (P), or a punch and/or a die for ceramic use, by means of a station according to any claim 1 to 14, comprising the steps of:

positioning at least one product (P) to work in one working seat (3);

activating/deactivating in a controlled manner said at least one laser emitter (6); removing said product (P) thus worked from said working seat (3).

16. A method according to claim 15, wherein said step of activating/deactivating at least one laser emitter (6) comprises:

emitting a laser radiation (6b) on a first zone (pi), for a time interval sufficient to remove the material of said at least one product (P) without overheating said material and without altering its mechanical characteristics;

directing said laser radiation (6b) to another zone (p2), far enough away from the zone (pi) previously affected, so as to allow the cooling of the material in said previous area;

emitting a laser radiation (6b) on said other zone (pi), for another time interval sufficient to remove said material of said at least one product (P) without overheating said material and without altering its mechanical characteristics; and

repeating the steps of directing and emitting up to complete with said laser radiation (6b) a predetermined path (p) or a predetermined area of said surface (S).