PRESS FOR SUBLIMATIC THERMOPRINTING

Abstract

 A press (10) for sublimatic thermoprinting, comprising two superimposed plates (11, 12), a first plate (11) and a second plate (12), of which at least one can move in order to close on the other, defining between them, in the closed configuration, a printing chamber (13) adapted to operate in a partial vacuum, at least one of such plates (11, 12) being provided with heating means (14) for sublimation. In the printing chamber (13) there is at least one removable rigid body (15), which rests on the bottom (16) of the printing chamber (13) so as to define a working surface (19) and is adapted to support, in succession, an article (17) being processed and at least one layer of printing paper (18) which bears the pattern to be printed, there being also a reinforcement structure (27) for the first plate (11), the one provided with the working surface (19), which comprises a series of parallel profiled elements (29) which are fixed below the first plate (11).

Description

[0001] The present invention relates to a press for sublimatic thermoprinting.

[0002] Sublimatic thermoprinting is a method, now widespread in the textile sector, in particular in the printing of rugs, casual knitwear and other garments and clothing accessories, as well as in other industrial sectors where printing is to be done on metallic material, wooden material, ceramic material etc.

[0003] According to this method, a sheet on which the print pattern (a design, writing, or a logo) is impressed is placed in contact with the surface of the object to be printed and the two elements are compressed between two plates, one of which is heated to a temperature such that the ink of the designs of the printing paper undergoes the sublimation effect, whereby the vapors are deposited on the surface of the material to be printed, in so doing producing the desired print.

[0004] Nowadays sublimatic thermoprinting is carried out with presses that comprise a plate, known in the sector as a "heated plate", against which a printing surface is pressed, on which the garment to be printed and the printing paper are arranged.

[0005] Such method enables an even distribution of the colors on the surface of the garment, but not a satisfactory penetration of the inks into the fibers of the garment itself. Substantially, the color is fixed only to the superficial part of the garment; therefore, if the weft of the fabric is splayed, especially if it is elastic, fibers can be seen which have no color.

[0006] In order to overcome such drawback, the thermoprinting process is executed in a depression, i.e. in a partial vacuum. The vacuum chambers of the presses must ensure a perfect seal of the vacuum and a uniform value of the pressure on the entire surface thereof.

[0007] The degree of vacuum during the thermoprinting process can reach 1 atm of vacuum.

[0008] To compensate the vacuum, in the printing chamber there is an elastic membrane that, under vacuum, is adapted to push the sheet containing the ink and the article to be printed against the heated plate. This prevents the heated plate from bending inward into the chamber.

[0009] Such presses known today, although appreciated, have a number of drawbacks.

[0010] A first drawback is constituted by the fact that during printing, the elastic membrane causes an excessive crushing of the article being processed, especially if the article has a substantial thickness as can be the case with a rug or a carpet, with consequent permanent deformation to the detriment of softness properties.

[0011] A second drawback is the very presence of the elastic membrane, the mounting of which is accompanied by the adoption of other flat elements, for example one or more metallic nets, and of a layer of porous material to support the article being processed.

[0012] The aim of the present invention is to provide a press for sublimatic thermoprinting which is capable of improving the known art in one or more of the abovementioned aspects.

[0013] Within this aim, an object of the invention is to provide a press for sublimatic thermoprinting with which it is possible to make the color penetrate uniformly even into articles of greater thickness, without compromising their initial aesthetic characteristics, like the thickness itself and the softness and at the same time without causing bending of the machine owing to the vacuum conditions.

[0014] Another object of the invention is to provide a press that can be used with articles of different thicknesses.

[0015] A further object of the present invention is to overcome the drawbacks of the background art in a manner that is alternative to any existing solutions.

[0016] Another object of the invention is to provide a press that is highly reliable, easy to implement and low-cost.

[0017] This aim and these and other objects which will become more apparent hereinafter are achieved by a press for sublimatic thermoprinting, comprising two superimposed plates, a first plate and a second plate, at least one of said first and second plates being configured to move in order to close on the other, said first and second plates defining between them, in the closed configuration, a printing chamber adapted to operate in a partial vacuum, at least one of said plates being provided with heating means for sublimation, said press being characterized in that in said printing chamber there is at least one removable rigid body, which rests on the bottom of said printing chamber so as to define a working surface and is adapted to support, in succession, an article being processed and at least one layer of printing paper which bears the pattern to be printed, there being also a reinforcement structure for said first plate that is provided with said working surface, which comprises a series of parallel profiled elements which are fixed below said first plate.

[0018] Further characteristics and advantages of the invention will become more apparent from the description of a preferred, but not exclusive, embodiment of the press according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings wherein:

• Figure 1 is a transverse cross-section of the press according to the invention, in the open configuration;
• Figure 2 is an enlarged view of the cross-section of Figure 1;
• Figure 3 is a transverse cross-section of the press according to the invention, in the closed configuration;
• Figure 4 is a perspective view of the press according to the invention;
• Figure 5 is a longitudinal cross-sectional view of the press according to the invention.

[0019] With reference to the figures, the press according to the invention, generally designated by the reference numeral 10, comprises two superimposed plates 11 and 12, a first plate 11 and a second plate 12, of which at least one can move in order to close on the other, defining between them, in the closed configuration, a printing chamber 13 adapted to operate in a partial vacuum. One of these plates 11, 12, for example the second 12, is provided with heating means 14 for sublimation, described below.

[0020] The printing chamber 13 operates in a depression or "partial vacuum" and in it there is at least one removable rigid body 15, which rests on the bottom 16 of the printing chamber 13 itself and is adapted to support, in succession, an article 17 being processed and at least one layer of printing paper 18 which bears the pattern to be printed, as indicated in the cross-sectional views in Figure 1 and in Figure 2.

[0021] In particular, the first plate 11 is the lower one, which presents the bottom 16 on which rigid bodies 15 are placed so as to define a working surface 19, as shown in Figure 4.

[0022] The press 10 shown is constituted by a double working surface 19, as shown in Figure 5, with the second plate 12, the upper one, being moved alternately from one working surface 19 to the other, in order to prevent downtimes during operation.

[0023] There is also advantageously a reinforcement structure 27 for the first plate 11, the one which presents the working surface 19, which comprises a series of parallel profiled elements 29 fixed below of the first plate 11.

[0024] The press 10 according to the invention also has another reinforcement structure 28, for the second plate 12, the one that supports the heating means 14 for sublimation, which comprises a frame of profiled elements 30.

[0025] For the first plate 11 the parallel profiled elements 29 are double-T-shaped, preferably IPE.

[0026] For the second plate 12 the frame of profiled elements 30 comprises C-shaped profiled elements on the perimeter and double-T-shaped profiled elements inside the perimeter.

[0027] The reinforcement structure 28 for the second plate 12 also comprises threaded reinforcement bars 31 which are parallel to the core of the profiled elements 30, and are anchored in order to maintain the flatness of the plate 12, thus preventing the bending thereof.

[0028] The reinforcement structures 27 and 28 keep the working surface 19 and the platelet 20 parallel in order to obtain a homogeneous print, preventing bending of the plates 11 and 12 during operation, when the degree of vacuum reaches 1 atm of depression.

[0029] The second plate 12 is fitted with the heating means 14, which in the example shown consist of heating elements distributed behind a platelet 20, heating it. In the closed configuration of the press 10, the platelet 20, which faces the printing chamber 13, transmits the heat to the printing paper 18, sublimating its color.

[0030] Figure 3 shows a transverse cross-section of the press 10 in the closed configuration: the printing chamber 13 can be identified between the lower surface of the platelet 20 and the bottom 16.

[0031] In a conventional manner, the press 10 has a supporting frame 21, designated in the longitudinal cross-sectional view of Figure 5, and the working surface 19 is mounted for example on pistons, or other similar and equivalent means that provide for the closure of the machine and therefore of the printing chamber 13.

[0032] The rigid body 15 is constituted by a tile which can be arranged side by side with other, similar tiles so as to create the working surface 19 (as shown in the perspective view of Figure 4), with a resting surface for the article 17 being processed.

[0033] The rigid body 15 itself is made of metallic material, adapted to withstand the compression that the article 17 receives when the press 10 is closed and before aspiration from the printing chamber 13 is begun. Not being deformable, the rigid body 15 is not capable of deforming the article by compressing it further with the increase of the vacuum within the printing chamber 13. Furthermore, the metallic material of which the rigid body 15 is made is preferably aluminum, for its high thermal conductivity and for the lightness that facilitates its handling.

[0034] The aspiration is carried out using adapted suction means, designated schematically in Figure 1, which comprise a vacuum pump 22 and aspiration ducts 23 with connectors 24 on a perimetric frame 25, which connect the vacuum pump 22 with the printing chamber 13.

[0035] Conveniently there is also a perimetric gasket 26, above the perimetric frame 25, which is adapted to be pressed against the second plate 12, so as to determine the airtight seal of the printing chamber 13.

[0036] The distance between the bottom 16 of the first plate 11 and the lower surface of the platelet 20 of the second plate 12 defines the height of the printing chamber 13. By replacing the rigid bodies 15 that provide the working surface 19 with rigid bodies of different thickness as a function of the thickness of the article to be printed (greater thickness of the article corresponds to lesser thickness of the rigid bodies), the printing chamber 13 is adapted in each instance to print on articles of even very different thicknesses, with a pre-established and stable pressure that does not modify their appearance by making them thinner or compromising their softness.

[0037] Use of the press, according to the invention, is evident from the foregoing description and explanation.

[0038] In practice it has been found that the invention fully achieves the intended aim and objects by providing a press for sublimatic thermoprinting with which it is possible to make the color penetrate uniformly into the articles being worked, independently of their thickness, without compromising the characteristics of their initial appearance.

[0039] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

[0040] In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

[0041] The disclosures in Italian Patent Application No. 102020000004393 from which this application claims priority are incorporated herein by reference.

[0042] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A press for sublimatic thermoprinting, comprising two superimposed plates (11, 12), a first plate (11) and a second plate (12), of at least one of said first and second plates being configured to move in order to close on the other, said first and second plates defining between them, in the closed configuration, a printing chamber (13) adapted to operate in a partial vacuum, at least one of said plates (11, 12) being provided with heating means (14) for sublimation, said press (10) being characterized in that in said printing chamber (13) there is at least one removable rigid body (15), which rests on the bottom (16) of said printing chamber (13) so as to define a working surface (19) and is adapted to support, in succession, an article (17) being processed and at least one layer of printing paper (18) which bears the pattern to be printed, there being also a reinforcement structure (27) for said first plate (11) that is provided with said working surface (19), which comprises a series of parallel profiled elements (29) which are fixed below said first plate (11).

2. The press according to claim 1, characterized in that it comprises a further reinforcement structure (28), for said second plate (12) that supports the heating means (14) for sublimation, which comprises a frame of profiled elements (30).

3. The press according to one or more of the preceding claims, characterized in that said at least one rigid body (15) is constituted by a tile which can be arranged side by side with other, similar tiles so as to create a working surface (19), with a resting surface for said article (17) being processed.

4. The press according to one or more of the preceding claims, characterized in that said rigid body (15) is made of metallic material.

5. The press according to one or more of the preceding claims, characterized in that said rigid body (15) is made of aluminum.

6. The press according to one or more of the preceding claims, characterized in that said parallel profiled elements (29) are double-T-shaped.

7. The press according to one or more of the preceding claims, characterized in that said frame of profiled elements (30) comprises C-shaped profiled elements on the perimeter and double-T-shaped profiled elements inside the perimeter.

8. The press according to one or more of the preceding claims, characterized in that said further reinforcement structure (28) for said second plate (12) comprises reinforcement bars (31) which are parallel to the core of said profiled elements (30).

Drawing