EP2566987A1

EP2566987A1 - Method and plant for printing hides

Info

Publication number: EP2566987A1
Application number: EP11727767A
Authority: EP
Inventors: Antonio Polato
Original assignee: Officine Di Cartigliano SpA
Current assignee: Officine Di Cartigliano SpA
Priority date: 2010-05-05
Filing date: 2011-05-05
Publication date: 2013-03-13
Anticipated expiration: 2031-05-05
Also published as: BR112012028262A2; BR112012028262B1; KR101850766B1; CN102947469B; CN102947469A; ITVI20100124A1; AU2011249456B2; ES2473571T3; KR20130092414A; IT1400014B1; PT2566987E; EP2566987B1; WO2011138760A1; AU2011249456A1

Abstract

A device for printing industrial hides comprises a drying chamber (2) internally housing a support surface (3) for at least one hide (P), a cover (10) placed on the top of the support surface (3) in order to define the drying chamber (2), heating means (6) associated with the support surface (3) in order to bring it to a drying temperature, an impermeable flexible membrane (14) placed on the top of the support surface (3) to divide the chamber (2) into an upper portion (21) and a lower portion (2"), pressure means (13) of vacuum type with a suction line (15) connected to the lower portion (2") of the chamber (2) in order to define a pressure difference between the portions (21, 2") of the chamber (2). The drying chamber (2) internally comprises at least one matrix (4) positioned on the surface (3) and having an upper surface (5) reproducing in negative a pattern to be printed on the hide (P). The vacuum pressure means (13) comprise one or more suction passages (17) made in the support surface (3) in a position substantially facing the cover (10) in order to fluidly connect the lower portion (2") with the suction line (15) and to promote the compression of the hide (P) on the matrix (4) for the printing of the ornamental pattern.

Description

METHOD AND PLANT FOR PRINTING HIDES

Field of application The present invention is generally applicable to the technical field of hides working, and has as object a method and a plant for printing hides, in particular for the relief printing of industrial hides.

State of the Art

As is known, industrial hides can be subjected to an operation of printing on the full-grain side in order to confer an aesthetically improved aspect thereto, eliminating the typical surface irregularities. Generally, the printing is executed subsequently to the step of drying the hides, with the same already heat-set and stabilized, by using heated printers.

One of the main drawbacks of these known solutions is represented by the fact that the relatively high temperatures necessary for the printing lead to damaging hide fibers, causing a qualitative deterioration.

In addition, this step involves a non-negligible increase of energy consumption, with clear repercussions on the final product cost.

Not least, the execution of the printing after drying requires further handling of the hides to be worked, with an increase of the working times and with work cycles that are naturally more complex. In order to overcome these drawbacks at least in part, the same Applicant obtained a plant for the relief printing of industrial hides in which the printing is at least partly executed at the same time as the drying step. Such plant is described in its most essential parts in the Italian patent IT1280291 and is essentially composed of a common vacuum drying plant with heating plates, i.e. a plant provided with a vacuum drying chamber internally housing a support surface that is intended to receive a hide to be treated.

In an innovative manner, on the upper face of the heating surface, a matrix is arranged that is adapted to come into contact with the full-grain side of the hide in order to print an ornamental pattern thereon, such pattern reproduced in negative on the matrix itself.

In this manner, the printing is executed at the same time as the vacuum drying, reducing energy consumption and cycle times and ensuring a higher quality of the final product, since the printing of wet fibers allows stabilizing their form without damaging them.

However, this solution does not lack drawbacks.

In particular, the vacuum drying chamber is designed for being fully brought to a constant reduced-pressure value, such that, during operation, the necessary pressure of the hide on the matrix will only be due to the weight of the hide itself.

Such condition was not indicated as sufficient for obtaining an optimal printing.

A further drawback is represented by the fact that the matrix can be subjected to movements, even minimal ones, but in any case damaging the working quality, following the reduced-pressure action.

Presentation of the invention The object of the present invention is to overcome the abovementioned drawbacks, by providing a plant for printing industrial hides that is particularly effective and economical. A particular object is to provide a plant for printing industrial hides that allows a more effective deformation of the working hides, obtaining a more stable and qualitatively improved final effect.

Still another object of the invention is to provide a method for printing industrial hides that is simple and fast, reducing both the working times and steps with respect to the known solutions.

Such objects, as well as others which will be clearer below, are attained by a plant for printing industrial hides in accordance with claim 1 .

Due to this particular characteristic, the side of the hide to be printed will be subjected, at the same time as the drying, to a greater overpressure than the action produced by its weight alone, with an improved and more defined printing effect.

According to a further aspect of the invention, a method is provided for printing industrial hides in accordance with claim 14.

Advantageous embodiments of the invention are defined in accordance with the dependent claims.

Brief description of the drawings

Further characteristics and advantages of the invention will be clearer in light of the detailed description of some but not exclusive embodiments of a plant for printing industrial hides, illustrated as a non-limiting example with the aid of the drawing table set in which: FIG. 1 is an exploded view in section of a plant according to the invention in a first preferred configuration;

FIG. 2 is a sectional view of the plant of Fig. 1 in operating condition; FIG. 3 is an enlarged view in section of a first detail of the plant of Fig. 2, illustrating a matrix lying on the support plane;

FIG. 4 is an enlarged view in section of a second detail of the plant of

Fig. 2;

FIG. 5 is a top view of a support surface of a plant in a second preferred configuration;

FIG. 6 is a sectional view of the detail of Fig. 5 along the trace plane 6-

6;

FIG. 7 is a top view of a support surface of a plant in a third preferred configuration;

FIG. 8 is an enlarged view of a detail of Fig. 7;

FIG. 9 is a sectional view of the detail of Fig. 7 along the trace plane 9-

9;

FIG. 10 is a sectional view of the detail of Fig. 8 along the trace plane

10-10. Detailed description of a preferred embodiment

With reference to the mentioned figures, a plant for printing industrial hides according to the invention, generically indicated with 1 , can be integrated in a hide working line, the drying station forming a part thereof.

According to the invention, the plant 1 comprises a hermetically-sealed drying chamber 2 internally housing a support plane 3 for one or more hides P to be treated and one or more matrices 4 positioned on the surface 3. Each matrix 4 has an upper surface 5 that reproduces in negative a pattern to be printed on the hides P. In particular, the matrices 4, longitudinally offset from each other, can have respective upper surfaces 5 differently shaped with respect to each other, in order to print respective ornamental patterns on the respective hides P or on a same hide P which is extended over two or more matrices 4.

Associated with the support plane 3 are heating means 6 adapted to bring it to a predetermining drying temperature.

The heating means 6, simply schematized in the figures, can be configured in accordance with any one known manner for industrial hide exsiccation or drying plants.

For example, they can be configured in accordance with any one of the modes described in IT1280291 .

In a preferable manner, the heating means 6 will comprise an electric heating element or coil arranged on the lower side of the support plane 3 or integrated in the same. The coil 6 can be crossed by a heating fluid for heating the upper surface 7 of the support plane 3, the hide P to be exsiccated or dried are arranged on the top thereof.

Also the print matrix 4 can be configured according to the teachings of the same patent.

For example, it can comprise, or it can be constituted by at least one plate made of a material with high thermal conductivity, e.g. copper, nickel, aluminum, on whose upper surface 5 projections 8 and/or recesses 9 are made in accordance with a scheme such to define in negative the pattern to be printed on the hide P. The upper surface 5 of the matrix 4 can also be shaped for obtaining surface finishes of the hide P, such as satinizing or sandblasting.

The shaping of the matrix 4 can be obtained according to any one chemical, mechanical or similar working, without any limitation of the protective scope of the present invention.

Also the plan dimensions and the thickness s of the matrix 4 are not limiting but can be selected according to needs and the type of hide to be worked.

For example, the matrix 4 can have a thickness s comprised between few millimeters, e.g. 5mm, and few centimeters.

The plant 1 will also comprise an upper covering frame or lid 10 which encloses the support surface 3 in order to internally include the same plane 3 and the matrix 4 in a manner so as to create a hermetically-sealed drying chamber 2.

The lower edge 11 of the upper frame 10 can also be provided with seal gaskets.

The drying chamber 2 will then be connected to pressure means 13 adapted to define a determinate pressure therein to promote the printing of the ornamental pattern on the lower side P" of the hide P placed in contact with the upper surface 5 of the matrix 4.

According to the invention, the chamber 2 comprises a flexible membrane 14 placed on the upper part of the matrix 4 in order to divide the chamber 2 into an upper portion 2' and a lower portion 2" enclosing the matrix 4.

The membrane 14 will be made of any one material that is impermeable to air and water, in order to fluidly isolate the two portions 2', 2" from each other. In particular, it can be made of a polymer material, such as PVC.

In addition, the pressure means 13 will be configured for defining a pressure difference between the two portions 2', 2" so as to promote the compression of the hide P on the matrix 4 and the printing of the ornamental pattern on the lower side P" thereof.

The membrane 14 can be fixed to the upper frame 10 at a perimeter portion 14' thereof.

A profile 12 fixed to the perimeter of the lower edge 11 of the upper frame 10 will delimit the drying chamber 2 promoting the adherence of the membrane 14 on the support plane 3 and ensuring the necessary hermetic seal. Suitably, the pressure means 13 will be connected to the drying chamber 2 to define a higher pressure in the upper portion 2' with respect to the lower portion 2", i.e. a higher pressure at the upper side P' of the hide not affected by the printing. According to the preferred but not exclusive configuration, illustrated in the figures, the pressure means 13 will be vacuum means adapted to create a vacuum inside the lower portion 2" of the chamber 2.

The vacuum means 13 will preferably be connected to the lower portion 2" of the chamber 2 in order to define a predetermined reduced pressure therein.

Preferably, the upper portion 2' of the chamber 2 will instead be maintained at a pressure substantially equal to atmospheric pressure. According to an alternative configuration, not illustrated, the pressure means 13 can be connected to the upper portion 2' in order to produce an overpressure in the same. Nevertheless, the creation of an at least partial vacuum in the drying chamber 2 will allow simplifying the drying operation, which can be executed at lower temperatures than those typical for the industrial hide drying plants. According to another variant, the pressure means 13 can be configured to combine both of the above-described effects, i.e. producing an overpressure in the upper portion 2' and an at least partial vacuum in the lower portion 2".

If the pressure means 13 are provided for defining the vacuum in the lower portion 2", they can comprise a suction line 15 connectable to a pump 16 for the vacuum or another similar device.

The lower portion 2" of the chamber 2 will in turn have one or more suction passages 17 obtained in the support plane 3, or in an edge portion 3' thereof, in a position facing the lid 10 for the fluid connection of the lower portion 2" of the chamber 2 with the suction line 15.

Inside the lower portion 2" of the chamber 2, one or more laminar support elements can also be provided, as a non-limiting example two elements 18, 18' as is clearer in Fig. 4, which will be suitably permeable.

The laminar elements 18, 18' will be interposed between the matrix 4 and the membrane 14 in order to maintain the latter spaced from the suction passages 17, so as to prevent these latter from being obstructed, thus hindering the correct functioning of the plant 1.

The laminar elements 18, 18' can be configured for example as nets or grids. In particular, the upper laminar element 18 will be a relatively wide mesh net, e.g. mesh on the order of one or a few centimeters, while the lower element 18' will be a narrow mesh net, e.g. mesh on the order of few millimeters.

In this manner, the lower element 18' will prevent the upper element 18 from coming into contact with the hide P, impacting its upper side P', while the upper net 18 will allow the correct evacuation of the moisture.

In addition, the laminar elements 18, 18' can be fixed to a lower frame 19 by means of spacing blocks 20 which maintain them spaced from the support surface 3 in order to prevent the obstruction of the suction passages 17.

Each of the blocks 20 will comprise one or more hooks 21 , 22 which will engage respective eyelets made at corresponding edge portions of the laminar elements 18, 18'.

In Figs. 5 - 10, two further preferred but not exclusive configurations are illustrated for plant 1 according to the invention, in particular for the assembly constituted by the support plane 3 and the matrices 4.

In both configurations, three matrices 4 are illustrated that are associated with a same support plane 3, but it is evident that there can be a smaller number thereof, for example a single matrix 4, or a greater number thereof. In both configurations, means 23 are advantageously present for the stable and removable anchoring of the matrices 4 to the support plane 3.

Due to this configuration, the matrices 4 will be stably positioned on the plane 3, preventing even minimal undesired movements thereof due to the effect of the pressure of the membrane 14 on the hide P and also deformations of the matrix 4, e.g. bending of the same, which can especially occur in the presence of matrices 4 with reduced thickness s.

In the configuration of Fig. 5, it is observed that the matrices 4 are fixed to the support plane 3 by means of a fixing frame 24 formed by a pair of longitudinal elements 25', 25" joined by at least a pair of transverse elements

26', 26" adapted to be positioned at the edge portion 3' of the plane 3 in order to abut against the peripheral portion 4' of the matrix 4.

If multiple matrices 4 are present, the frame 24 can comprise additional intermediate transverse elements 26"', 26^IV designed to be positioned on corresponding edges of the matrices 4.

The anchoring means 23 will comprise a plurality of first coupling elements 27 associated with the peripheral portion 3' of the support plane 3 and a plurality of second coupling elements 28 associated with the frame 24 and adapted to removably engage corresponding first coupling elements 27.

As is visible in Fig. 6, in a preferred but not exclusive embodiment of the invention, the first elements 27 can be blind holes made in the support plane 3.

The second coupling elements 28 can in turn comprise through holes 29 made in the frame 24 and arranged along the same to be aligned with corresponding holes 27 and corresponding fixing members, e.g. fixing screws 30 adapted to removably engage the holes 27 and 29 by tightening/shutting the frame 24 on the plane 3.

Advantageously, the frame 24 will have a cross section that is constant over its entire extension, with an external portion 24' in which the through holes 29 are made, such portion having thickness s' greater than that s" of the internal portion 24" thereof.

In this manner, a peripheral interspace 31 is defined for the positioning of the peripheral portion 4' of the matrix 4, which will be retained due to the tightening/shutting of the frame 24.

In Figs. 7 - 10, a further preferred variant is illustrated for the plane 3 and the matrix 4. In particular, it is observed that the support plane 3 has a substantially flat peripheral portion 3' and at least one hollow seat 32 with shape complementary to that of the corresponding matrix 4, more clearly visible in Fig. 9.

In the illustrated configuration, three hollow seats 32 are present that are adapted to house respective matrices 4 with the corresponding upper surfaces 5 substantially flush with the upper surface 7 of the peripheral portion 3' of the support plane 3.

This particular configuration will have the advantage that the membrane 14 will not press on the edge, generally with sharp corner, of the matrix 4, in the other configurations causing possible damage of the membrane 14 after a high number of work cycles.

Preferably, the anchoring means 23 will be of quick coupling/release type.

In particular, as is observed in Figs. 8 and 10, the quick coupling/release anchoring means 23 will comprise a plurality of blind holes or slots 33 made at edge portions of said hollow seat, a plurality of through holes or slots made at edge portions 32' of the hollow seats 32, preferably at the corners thereof.

In addition, the matrix 4 will have a corresponding plurality of through holes or slots 34, they too preferably at the corners in order to be aligned with corresponding blind holes 33.

The anchoring means 32 will also comprise a plurality of coupling elements 35 adapted to removably engage corresponding mutually-aligned blind 33 and through 34 holes or slots for the removable anchoring of the matrices in the respective hollow seats 32. In the configuration of the figures, merely exemplifying of the invention, the hollow seats 32 will be provided with substantially cylindrical blind holes 33 while the matrices 4 will be provided with elongated slots. The coupling elements 35 will comprise a boss 36 fixed to the matrix 4, it too provided with a slot that is identical to and aligned with that of the matrix 4, and a pin 37 adapted to be inserted in the through hole 34 and in the blind hole 33 in order to be locked by rotation with respect to the same, also by means of the opposing action of the spring 38, so as to tighten the matrix 4 on the hollow seat 32.

Preferably, the matrix 4 will be formed by a lower support layer 39 made of a first base material, e.g. aluminum, and an upper layer 40 made of a second base material, e.g. copper or nickel, made integral with the first layer 39 by means of welding, gluing or mechanical anchoring.

The upper layer 40 will have a lesser surface extension than that of the lower layer 39 to leave a peripheral portion thereof free on which the through slots 34 will be made.

Nevertheless, it is clear that the anchoring means 32 described herein could be substituted by equivalent means, e.g. of screw type.

In a non-illustrated embodiment variant, such means 32 can be of magnetic type and associated with the support plane 3 and/or the matrices 4 as a function of the respective materials.

According to a further aspect of the invention, a method is provided for printing industrial hides that can be implemented, even if in a non-exclusive manner, with a plant 1 of the above-described type.

In particular, in the execution of the method, the use of the impermeable membrane 14 or other equivalent means might not be provided for, as is more clearly specified below.

The method provides for, not necessarily in the reported sequence and with reference, for the sake of simplicity, to the figures, a step for positioning an industrial hide P with relatively high moisture content inside a drying chamber 2.

The latter internally houses one or more matrices 4, with shaped upper surfaces 5 which reproduce in negative a respective ornamental pattern to be printed on the hide P.

In particular, the hide P to be treated is positioned with its side to be printed P" in contact with the shaped surface 5 of the matrix 4 in order to identify an upper portion 2' and a lower portion 2" in the chamber 2.

In this manner, it will be possible to execute the drying of the hide P by means of suitable heating means 6 provided in the chamber 2, to bring it to a relatively low moisture level.

In an at least partially simultaneous manner, a pressure difference is applied between the upper portion 2' and the lower portion 2" of the chamber 2, thus promoting the printing of the ornamental pattern on the lower side P" of the hide P.

As described for the plant 1 , the step of applying the pressure difference can be executed by achieving an overpressure inside the upper portion 2' of the chamber 2, i.e. at the upper side P' of the hide P, and/or by producing an at least partial vacuum at the lower side P".

For example, if one wishes to produce an overpressure at the upper side P' of the hide P, one can use any one mechanical or fluid pressing means, adapted to interact directly with the hide P, with or without the interposition of the membrane 14 and/or possible interface elements.

Given that described above, it is evident that the invention attains the pre- established objects and in particular that of providing a plant for printing industrial hides which is particularly economical and which allows increased working quality and stability with respect to the known solutions.

The plant and the method according to the invention are susceptible to numerous modifications and variants, all falling within the inventive concept expressed in the enclosed claims. All the details can be substituted with other technically equivalent elements, and the materials can be different according to needs, without departing from the scope of the invention. Even if the plant and the method were described with particular reference to the enclosed figures, the reference numbers used in the description and in the claims are employed for improving the comprehension of the invention and do not constitute any limitation of the claimed protective scope.

Claims

1 . A plant for printing industrial hides, comprising:

- a hermetically-sealed drying chamber (2) internally housing a support plane (3) for at least one hide (P) to be treated;

- a lid or covering frame (10) upperly placed to said support plane (3) to define said drying chamber (2);

- heating means (6) associated with said support plane (3) to bring it to a predetermined drying temperature;

- an impermeable flexible membrane (14) placed over said support plane (3) to divide said chamber (2) into an upper portion (2') and a lower portion (2") in mutual fluidic isolation;

- pressure means (13) connected to said chamber (2) to define a pressure difference between said portions (2', 2") of said chamber (2), wherein said pressure means (13) are of vacuum type with a suction line (15) connected to said lower portion (2") of said chamber (2);

characterized in that said drying chamber (2) internally comprises at least one matrix (4) positioned on said plane (3) and having an upper surface (5) reproducing in negative a pattern to be printed on the hide (P), said vacuum pressure means (13) comprising one or more suction passages (17) made in said support plane (3) in a position substantially facing said lid (10) to fluidically connect said lower portion (2") of said chamber (2) with said suction line (15) in such a manner to promote the compression of the hide (P) on the matrix (4) for the printing of the ornamental pattern.

2. Plant as claimed in claim 1 , characterized in that said upper portion (2') of said chamber (2) is maintained at a pressure substantially equal to the atmospheric pressure.

3. Plant as claimed in claim 1 or 2, characterized by comprising at least one permeable laminar element (18) interposed between said matrix (4) and said membrane (14) to separate said membrane (14) from said at least one passage (17) and allow the air suction through the latter.

4. Plant as claimed in claim 3, characterized by comprising at least one spacing block (20) coupled with said at least one laminar element (18) to maintain it raised with respect to said suction passage (17).

5. Plant as claimed in any preceding claim, characterized in that said lid or covering frame (10) has a peripheral profile (12) adapted to engage a peripheral edge (14') of said membrane (14) to hermetically press it on said support plane (3).

6. Plant as claimed in any preceding claim, characterized by comprising anchoring means (23) for removably anchoring said at least one matrix (4) to said support plane (3).

7. Plant as claimed in claim 6, characterized in that said anchoring means (23) comprise a plurality of first coupling means (27) associated with at least one peripheral portion (3') of said support plane (3).

8. Plant as claimed in claim 7, characterized in that said anchoring means (23) further comprise a fixing frame (24) adapted to be placed on a peripheral portion (4') of said at least one matrix (4) and provided with a plurality of second coupling elements (28) adapted to removably engage corresponding first coupling elements (27).

9. Plant as claimed in claim 6, characterized in that said support plane (3) has a substantially flat peripheral portion (3') and at least one hollow seat (32) complementarily shaped with respect of said at least one matrix (4) for the housing of the same in such a manner to bring the upper surface (5) of said matrix substantially flush with the upper surface (7) of said peripheral portion (3').

10. Plant as claimed in claim 9, characterized in that said anchoring means (23) are of quick coupling/release type.

1 1 . Plant as claimed in claim 10, characterized in that said quick coupling/release anchoring means (23) comprise a plurality of blind holes (33) made at edge portions (32') of said hollow seat (32), a plurality of through holes or slots (34) made at edge portions (4') of said matrix (4) and adapted to be aligned with corresponding blind holes (33) and a plurality of coupling elements (35) adapted to removably engage corresponding couples of mutually-aligned blind holes (33) and through holes (34) for anchoring said matrix (4) in said hollow seat (32).

12. Plant as claimed in claim 1 1 , characterized in that said matrix (4) has a lower support layer (39) made of a first base material and an upper active layer (40) designed to interact with the hide (P) to be printed, which upper layer (40) being made of a second base material and integral with said first layer (39).

13. Plant as claimed in claim 12, characterized in that said upper active layer (40) of said matrix (4) has a surface extension less than that of said lower support layer (39) to define a free peripheral portion on which said through holes or slots (34) are positioned.

14. A method for printing industrial hides, wherein an industrial hide

(P) with relatively high moisture content is introduced into a drying chamber (2) internally housing a matrix (4) with a shaped surface (5) that reproduces in negative a pattern to be printed on the hide (P), wherein the method comprises the following steps:

a) positioning said hide (P) in said chamber (2) with its side to be printed (P") in contact with said shaped surface (5) of said matrix (4);

b) drying said hide (P) to bring it to a relatively low moisture content; c) applying a pressure difference between the side to be printed (P") and the opposite side (Ρ') of said hide (P) to promote the printing of said ornamental pattern on said side to be printed (P");

wherein said step (c) of applying pressure is at least partially executed at the same time as said drying step (b), and comprises a step of producing at least a partial vacuum at said side to be printed (P") of the hide (P).