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(11) | EP 4 194 221 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | METHOD FOR THE SERIAL REPRODUCTION OF RELIEF PATTERNS ON FLEXIBLE LAMINAR MATERIALS |
| (57) A method for the serial reproduction of relief patterns on flexible laminar materials
(P), e.g. natural and synthetic leather, regenerated leather, microfibres, synthetic coated
and layered products, which method provides the steps of a) providing first digital data (3) of original patterns (N) having predetermined shape and size, b) three-dimensional printing of the original patterns (N) with UV ink on the outer surface (S1) of a first sample (1) so as to obtain relief patterns (M), c) forming a first negative three-dimensional polymeric cast (7) of the first sample (1), d) anchoring the first cast (7) to a plate (10) to define a first printing plate (11), e) compressing the first printing plate (11) against a surface (S2 ) of flexible laminar material (P) to transfer the negative patterns (O) of the first cast (7) thereon to obtain a first laminar product (13) with reproduced three-dimensional patterns (Q), and f) modifying said reproduced patterns (Q) obtained on said first product (13) so as to compensate possible deviations (Δ) in shape and size with respect to said original patterns (N), wherein said modifying step f) comprises a sub-step f1) of detecting the size and
shape of the reproduced patterns (Q) to detect said deviations, and a sub-step f2)
of modifying said first digital data (3) to eliminate said deviations and obtain second
digital data (16) to obtain a second sample, a second cast, a second printing plate
and a second modified laminar product.
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Field of the Invention
[0001] The present invention generally relates to the field of industrial printing and it particularly relates to a method for reproducing relief patterns on a visible surface of flexible laminar materials, such as natural and synthetic leather, regenerated leather, microfibres, synthetic coated and layered products.
Background Art
[0002] The use of natural leather, synthetic leather and the like to obtain objects used in various industries, such as for example clothing, footwear, automotive, furnishing industries, etc. has been long known.
[0003] In the specific case of aesthetic objects, there is a high demand for surfaces made of leather which, besides an appropriate pigmentation, also have decorative patterns of various types.
[0004] Such decorative patterns may be predetermined geometric shapes and/or drawings, writings, or imitations of animal skins such as for example crocodile or snake skins.
[0005] Generally, these effects are obtained by using a cylinder on which the pattern to be replicated is engraved, and the leather is subsequently subjected to calandering so as to impress the pattern on the latter.
[0006] Optionally, the pattern may be engraved also on a press which is then brought into contact with the surface of the leather to be treated.
[0007] However, due to the processing temperature and the pressure exerted during the impression, the final pattern obtained on the surface made of leather is distorted with respect to the one engraved on the cylinder or press.
[0008] Should these distortions be significant, they lead to obtaining an object which cannot be sold because of its poor quality.
[0009] In order to at least partly overcome this drawback, JPH07241909A discloses a method for providing a system for processing leather surfaces.
[0010] The method comprises scanning the surface of a leather article whose pattern is to be reproduced, so as to obtain digital data which represent the 3D surface structure.
[0011] Subsequently, such data are processed by a processor and sent to an equipment suitable to manufacture plates for embossing.
[0012] Before manufacturing a plate for embossing, the method allows to display the scanned surface on a computer so as to correct any defects and/or unevenness, such as for example scratches, bulges, etc., by modifying the data corresponding to such positions.
[0013] Furthermore, this allows to carry out corrections considering the degree of deformation due to the thermal shrinkage when transferring the pattern onto the surface made of leather.
[0014] Despite this, such method is not practical and rather costly, given that each pattern to be replicated requires manufacturing a metal plate for embossing.
[0015] Furthermore, after multiple uses, the plate will have deformations, and will therefore require to create a new plate with the relative additional costs.
[0016] In order to reduce the process costs, TW201125754A discloses a method for reproducing a surface pattern starting from a sample by using silicone mixtures.
[0017] The sample made of leather, whose surface pattern is to be reproduced, is placed on a work surface and a part of the surface thereof is delimited by means of a frame.
[0018] Inside the area delimited by the frame a silicone mixture is poured and suitably spread, which once solidified presents a cast of the surface pattern.
[0019] This procedure is subsequently repeated by pouring the mixture on the cast so as to obtain a mould. The latter is then covered with a silicone mixture and treated under vacuum to obtain a template which is a negative of the initial sample.
[0020] The negative so obtained is covered with a polyurethane mixture, polyvinyl chloride mixture, etc., so as to obtain a material similar to the leather having the same surface pattern as the sample.
[0021] However, due to the repeated copies, such method introduces deformations which affect the pattern of the final object obtained.
[0022] Therefore, such methods are too expensive and complex, and they can however lead to deformations in the final pattern with respect to the initial model intended to be reproduced.
Technical problem
[0023] In light of the prior art, the object of the present invention is to solve the technical problem by providing a method for making a surface pattern on flexible laminar materials that does not incur deformations with respect to the initial sample intended to be reproduced.
Summary of the invention
[0024] The object of the present invention is to solve the aforementioned problem by providing a method for reproducing relief patterns on a visible surface of flexible laminar materials, which method is highly effective and cost-effective.
[0025] A particular object of the present invention is to provide a method for reproducing relief patterns of the type described above which allows to obtain patterns in a simple and quick manner.
[0026] Another object of the present invention is to provide a method for reproducing relief patterns of the type described above capable of obtaining patterns, even complex ones.
[0027] A further object of the present invention is to provide a method for reproducing relief patterns of the type described above in which the patterns are well defined.
[0028] Another object of the present invention is to provide a method for reproducing relief patterns of the type described above which does not ruin the quality of the laminar material used.
[0029] The objects mentioned above and others which will be more apparent hereinafter, are fulfilled by a method for the serial reproduction of relief patterns on flexible laminar materials, such as natural and synthetic leather, regenerated leather, microfibres, synthetic coated and layered products according to the attached claim 1.
[0030] In particular, the method provides the steps of preparing first digital data of original patterns to be printed having predetermined shape and size, three-dimensional reproduction of the original patterns on the outer surface of a first sample so as to obtain relief patterns thereon, forming a first negative three-dimensional cast of the sample made of polymeric material, anchoring the first cast to a plate made of rigid material to define a first printing plate to stabilise the first cast, and compressing the first printing plate against a visible surface of a flexible laminar material to transfer the negative patterns of the first cast thereonto to obtain a first laminar product with reproduced three-dimensional patterns.
[0031] The relief patterns are made on the outer surface of the first sample by means of a three-dimensional printing with UV ink to take a substantially pyramid-like final shape with deviations in shape and size with respect to the original patterns.
[0032] According to a peculiar aspect of the invention, the method also provides a step of modifying the reproduced three-dimensional patterns obtained on the first product to compensate the deviations in shape and size with respect to the original patterns induced during the forming of the first cast and during the compression step.
[0033] Suitably, the step for modifying the patterns comprises a sub-step of detecting the shape and size of the reproduced three-dimensional patterns on the first laminar product to detect the deviations and then a further sub-step of modifying the first digital data to eliminate the deviations and obtain second digital data.
[0034] Advantageously, the modification of the first digital data provides for a computer program dedicated to automatically modify vector files.
[0035] Subsequently, these second digital data are used to obtain a second sample, a second cast, and a second printing plate to obtain a second modified laminar product.
[0036] Possibly, this sampling cycle may be repeated up to obtaining a final laminar product with modified patterns the closest possible to the original ones.
[0037] Conveniently, the method comprises that the printing plate is subjected to the sub-steps of heating to a first predetermined forming temperature maintaining the cast facing upwards, spraying a water or solvent-based polyurethane mixture, possible repetition of the latter two steps and cooling the plate to a second predetermined temperature lower than the first temperature.
[0038] A section made of flexible laminar material is subsequently deposited on the cast by interposing an adhesive in liquid state, mechanically compressing the flexible laminar material against the plate so as to transfer the patterns to be reproduced onto the section, fully evaporating the adhesive and detaching from the plate the section made of flexible laminar material with the reproduced patterns on the surface facing the cast to obtain a printed laminar product.
Brief description of the drawings
[0040] Further characteristics and advantages of the invention will be more apparent in the light of the detailed description of a preferred but not exclusive embodiment of a method for reproducing relief patterns on a visible surface made of flexible laminar materials like the one mentioned above, shown by way of nonlimiting example with reference to the drawings below, wherein:
FIG. 1 is a block diagram of the steps according to the method of the invention;
FIG. 2 is a top view of a sample obtained by 3D printing;
FIG. 3 is a top view of the step of pouring the polymeric resin mixture on the printed surface of a sample;
FIG. 4 is a top view of the step of levelling the polymeric resin mixture on the printed surface of a sample;
FIGS. 5 and 6 are respectively a top view and a perspective view of the step of detaching the polymeric cast from the surface of a sample.
FIGS. 7 and 8 are respectively a top view and a perspective view of a polymeric cast;
FIGS. 9, 10 and 11 are respectively a perspective view, a top view and a lateral view of the steps of superimposing a section made of flexible laminar material to a polymeric cast;
FIG. 12 is a top view of a first product made of flexible laminar material with reproduced relief patterns;
FIG. 13 is a lateral view of a plant for transferring three-dimensional patterns from a cast to a section made of flexible laminar material;
FIG. 14 is a schematic representation of the deviations present between the original patterns and those obtained in a first printed laminar product;
FIG. 15 is a schematic representation of the modifications to the first data to obtain a final modified laminar product.
Detailed description of a preferred embodiment
[0041] With particular reference to FIG. 1, there is shown a method for the serial reproduction of relief patterns on flexible laminar materials P such as natural and synthetic leather, regenerated leather, microfibres, coated and layered products.
[0042] The method provides the steps of a) providing first digital data 3 of original patterns N to be printed having predetermined size and shape and b) three-dimensional reproduction of these original patterns N on the outer surface S1 of a first sample 1 so as to obtain relief patterns M.
[0043] The sample 1 consists of a flexible base material 2 selected from the group comprising natural leather, regenerated leather, coated polyurethane product and the like, on which the original patterns N are reproduced by means of a three-dimensional printing.
[0044] The original patterns N to be reproduced on the outer surface S1 of the sample 1 consist of vector files obtained using algorithms and mathematical equations defining first digital data 3.
[0045] The first digital data 3 are uploaded on a storage unit of a microprocessor device connected to a three-dimensional printing equipment of the plotter type or 3D printer, not shown in the figures.
[0046] Such three-dimensional printing equipment allow to obtain relief patterns M which may be formed by one or more images, writings, symbols, etc., even with considerable geometric complexity.
[0047] Preferably, the printing is carried out by depositing UV ink on the flexible base material 2.
[0048] In a per se known manner, the three-dimensional printing equipment, connected to the microprocessor device, may consist of a compartment inside which there is a first track on which there is mounted a first movable carriage with the printer heads and some UV lamps. Possibly, the lamps may be mounted on a second carriage slidable on a second track arranged adjacent to the first track.
[0049] Below the tracks there is a conveyor belt on which there is placed the flexible base material 2 on which the patterns are to be printed. Alternatively, the flexible material 2 may be placed on a fixed surface while only the carriage with the printer heads and the UV lamps moves.
[0050] Advantageously, the belt or the fixed surface on which the base material 2 is placed has a plurality of holes for applying vacuum so as to stably hold the base material 2 when carrying out the 3D printing.
[0051] The printing equipment receives the first digital data 3 and it starts the printing by advancing the base material 2 in a horizontal direction through the belt, while the first carriage, moving transversely along the first track, deposits the ink on the surface S1 of the base material 2.
[0052] Subsequently to the step for depositing the ink, also the second carriage is moved so as to irradiate the base material 2 and fix the ink onto the surface S1 thereof due to the polymerisation induced by the UV lamps.
[0053] Besides the fact of polymerising rapidly, and therefore shortening the printing step with respect to other 3D techniques, once solidified these inks are however flexible, therefore they are appropriate to be deposited on a laminar substrate without cracking or being ruined.
[0054] The base material 2 continues to advance and the deposition of the ink, followed by the polymerisation, continues until the relief pattern M is made, therefore obtaining the first sample 1.
[0055] Generally, there is provided a substantially square-shaped sample 1 preferably measuring between 50x50 cm and 170x170 cm in size or even larger.
[0056] Given that the printed patterns are designed to obtain an aesthetic effect, they are made with a thin thickness, so as to be a surface pleasant to touch and sight, while at the same time limiting wastage of UV ink.
[0057] Suitably, the relief patterns M are made on the outer surface S1 of the first sample 1 with a maximum thickness of 200 µm.
[0058] After step b), the first sample 1 is subjected to a sub-step b1) of anchoring it to a flat support plain 4 made of substantially rigid material, such as for example a panel made of wood, and a sub-step b2) of delimiting the peripheral edge of the sample 1 with a frame 5 for forming a confinement compartment 6 above it.
[0059] As better visible in FIG. 2, the first sample 1 anchored to the rigid support 4, is placed on a work plane with the relief pattern M printed facing upwards.
[0060] Subsequently, the edges of the sample 1 are delimited with a frame 5, preferably made of aluminium, which has a greater thickness than that of the sample 1, so as to create a confinement compartment 6 above the surface of the sample 1, as shown in FIG. 3.
[0061] Furthermore, the method provides a step c) of forming a first negative three-dimensional cast 7 of the sample 1 made of polymeric material.
[0062] To obtain this first cast 7 initially is carried out a sub-step c1) of pouring a polymeric resin mixture 8 in liquid state into the confinement compartment 6, a sub-step c2) of levelling the polymeric resin mixture 8 by means of a blade 9 or the like, shown in FIG. 4, so as to complementarily cover the confinement compartment 6, and lastly a sub-step c3) in which is carried out the cross-linking and detachment of the first cast 7 from the compartment 6, shown schematically in FIGS. 5 and 6.
[0063] During step c3) the resin mixture 8 is therefore left to stand in the confinement compartment 6 under standard conditions for about 24 hours so as to allow the full cross-linking of the polymers to form a first silicone cast 7 which represents the negative of the relief patterns M present on the surface S1 of the first sample 1.
[0064] Advantageously, the cross-linking step c3) may be quickened maintaining the first cast 7 at a temperature higher than the environmental one for a predetermined time.
[0065] Preferably, the polymeric resin mixture 8 is prepared separately and comprises at least two silicone compounds.
[0066] The method continues with a step d) of anchoring the first cast 7 to a plate 10 made of rigid material to define a first printing plate 11 to stabilise the first cast 7.
[0067] As better visible in FIGS. 7 and 8, as the cast 7 is flexible, it is coupled with the rigid plate 10 keeping the negative patterns O facing upwards, so as to form a first printing plate 11 with sufficient structural stability so that it can be used in the subsequent steps of the method.
[0068] Suitably, the step d) of anchoring the first cast 7 to the plate 10 is carried out by interposition of a cloth.
[0069] Preferably, the plate 10 made of metal material is made of aluminium, with plan dimensions at least equal to those of the silicone cast 7, and a thickness measuring a few tenths of millimetres.
[0070] Subsequently, the first printing plate 11 obtained by the coupling between the first cast 7 and the metal plate 10 is subjected to a refining process.
[0071] In this step there is provided a sub-step d1) of heating the first plate 11 to a first predetermined forming temperature keeping the first cast 7 facing upwards.
[0073] Subsequently, a water or solvent-based polyurethane mixture is sprayed on the first plate 11 in a spraying sub-step d2).
[0074] Furthermore, there is provided a sub-step d3) in which the optional repetition of the previous steps d1) and d2) is carried out, so as to spray a predetermined amount of polyurethane mixture, and subsequently cool the first plate 11 to a second predetermined temperature lower than the first temperature.
[0076] At this point, the first printing plate 11 is suitable to be used in the last steps of the method in which the patterns are reproduced on a visible surface S2 made of flexible laminar material P.
[0077] As shown in FIGS. 9 to 11, there is provided a sub-step d4) of depositing a flexible laminar material P on the first cast 7 by interposing an adhesive 12 in liquid state.
[0078] Suitably, the adhesive 12 in liquid state may be prepared on the cast 7 or on the laminar material P, and it may be possibly pre-dried to improve the adhesion.
[0079] The layer formed by the adhesive 12 and by the polyurethane mixture will therefore take the shape of the cast 7 and of its negative patterns O.
[0080] Preferably, the flexible laminar material P deposited on the first cast 7 in the sub-step d4) is a section T made of flexible laminar material P.
[0081] Subsequently, a step e) of compressing the first printing plate 11 against an exposed surface S2 of the flexible laminar material P is carried out to transfer the negative patterns O of the first cast 7 thereon, to obtain a first laminar product 13 with reproduced three-dimensional patterns Q.
[0082] Specifically, this compression step e) provides a sub-step e1) of mechanically compressing the section T made of flexible laminar material P against the first plate 11 so as to impress and transfer the negative patterns O on the latter, and a sub-step e2) of fully evaporating the adhesive 12 and detaching the first plate 11 from the section T made of flexible material P with the reproduced relief patterns Q on the visible surface S2 facing the first cast 7 to obtain the first laminar product 13 as shown in FIG. 12.
[0083] More precisely, during the compression step e1), the layer formed by the adhesive 12 and by the polyurethane mixture is adhered to the surface S2 of the section T made of flexible material P by fixing the reproduced patterns Q thereonto.
[0084] In other words, the reproduced three-dimensional patterns Q solidified and fixed to the surface S2 of the section T are obtained by the layer comprising the adhesive 12 and the polyurethane mixture.
[0085] Advantageously, the mechanical compression sub-step e1) may be obtained by calandering and/or pressing using a substantially flat press subsequently to the sub-step d4) of depositing the adhesive 12.
[0086] Specifically, with reference to FIG. 13, after depositing the adhesive 12, the cast 7 and the flexible laminar material P are firstly calendered using a cylinder 14, or preferably a pair of opposite cylinders, afterward they are pressed by a substantially flat press and subsequently treated in a furnace at about 100°C to promote the full evaporation of the water or solvent-based adhesive 12.
[0087] However, there may be used plants provided with cylinders alone or with presses alone without departing from the scope of protection of the invention.
[0088] Whether one uses calandering or the press, the laminar material P is detached from the first cast 7 and filed, eliminating any surplus adhesive 12, and then refined using techniques known in the industry.
[0089] However, it is known that the three-dimensional printing, induces deformations in a pattern, generally due to the fact that during the fixing the UV ink takes a pyramid-like shape which therefore causes a narrowing of the profile of the printed pattern with respect to the dimensions contained in the data received by the printer.
[0090] Therefore, the relief patterns M made on the outer surface S1 of the first sample 1 by means of a three-dimensional printing using UV ink take a substantially pyramid-like final shape with different deviations Δ in shape and size with respect to the original patterns N.
[0091] Therefore, when the first cast 7 is made, the negative patterns O may no longer reflect the original patterns N.
[0092] Furthermore, as described above, the negative patterns O will be transferred onto the flexible laminar material P by mechanical compression, which will induce further substantial deformations.
[0093] Hence, the reproduced three-dimensional patterns Q on the laminar material P could substantially differ from the original patterns N, therefore leading to obtaining a product that does not correspond to customer's request.
[0094] According to a peculiar aspect of the method, in order to overcome such technical problem, there is provided a step f) of modifying the reproduced patterns Q obtained on the first product 13 so as to compensate the deviations Δ induced during the step c) of forming the first cast 7 and during the compression step e).
[0095] Suitably, this modification step f) provides a sub-step f1) of detecting the shape and size of the reproduced patterns Q on the first laminar product 13 to detect the deviations Δ as shown in FIG. 14.
[0096] Such step f1) of detecting the shape and size of the patterns Q on the first laminar product 13 to compare them with the original patterns N can be carried out by an operator or using optical means.
[0097] Subsequently, in the sub-step f2) the first digital data 3 are modified to eliminate the detected deviations Δ so as to obtain second digital data 16 to be used to obtain a second sample 1', 1",..., a second cast 7', 7",..., a second printing plate 11', 11",..., and subsequently to obtain a second modified laminar product 13', 13",....
[0098] Given that the digital data 3 consist of vector files, the dimensional values of the patterns N to be printed can be modified without losing in terms of definition.
[0099] As a matter of fact, the vector files consist of unitary elements each positioned in a virtual space in predetermined coordinates so as to form the image of the requested pattern N.
[0100] Hence, modifying the coordinates of the single elements and/or adding new ones allows to modify the pattern N therefore obtaining the second data 16.
[0101] Advantageously, the step f) of modifying the first digital data 3 provides a dedicated processing programme for automatically modifying the vector files.
[0102] Obviously, the second sample 1', 1",..., the second cast 7', 7",..., the second printing plate 11', 11",..., and the second modified laminar product 13', 13",..., are obtained through the steps b)-e) of the method, as described above.
[0103] Specifically, the second sample 1', 1",..., is obtained following the procedure of step b), the second cast 7', 7",..., according to step c), the second printing plate 11', 11",..., according to step d) and the second laminar product 13', 13",..., according to step e).
[0104] Therefore, as visible in FIG. 15, the second laminar product 13', 13",..., will have modified patterns V with respect to the first printed laminar product 13.
[0105] Possibly, should the modified patterns V on the second laminar product 13', 13",..., still deviate from the original ones N, a possible sub-step f3) of repeating this sampling cycle, that is steps b)-e) or b)-f), will be carried out up to obtaining a final laminar product 17 with the patterns V the closest possible to the original ones N requested by a customer.
[0106] Upon obtaining a final laminar product 17 there can be obtained a plurality of printing plates 11', 11",..., starting from the suitable sample 1', 1",..., so as to be able to start a mass production.
[0107] Given that the sub-step e1) of transferring the negative patterns O on the laminar material P is carried out by compressing, a mass production of final products 17 with modified patterns V will therefore be quick and cost-effective with respect to the extensive use of 3D printing.
[0108] The method allows to achieve a final laminar product 17 quickly, therefore reducing the cost and production times thereof.
[0109] The final laminar product 17 with the relief patterns V will therefore be used to obtain a leather article which can be used in the footwear, automotive, clothing, furnishing industries and the like.
[0110] In the light of the above, it is clear that the method for reproducing relief patterns on a visible surface of flexible laminar materials, such as natural and synthetic leather, regenerated leather, microfibres, synthetic coated and layered products according to the invention achieves the pre-established objects and in particular it allows to reproduce, on the surface of a flexible laminar material, even complex relief patterns in a quick and cost-effective manner without deformations with respect to the original project requested by a customer.
[0111] This method allows to avoid having to use the 3D printing for all the products (a technique that would generally require 2 hours to obtain patterns on 1 m2), starting from a single initial sample there can be obtained a plurality of products in a short time (250 m2 per hour of treated flexible laminar material).
[0112] Although the method been described with particular reference to the attached figures, the reference numerals used in the description and in the claims are meant for improving the intelligibility of the invention and they do not limit the claimed scope of protection in any manner whatsoever.
[0113] The same reference numerals in different figures identify identical or similar elements and the attached drawings are not necessarily to scale.
[0114] Furthermore, the particular characteristics, structures or elements may be combined in any appropriate fashion in one or more embodiments.
Industrial applicability
1. A method for the serial reproduction of relief patterns on flexible laminar materials
(P), such as natural and synthetic leather, regenerated leather, microfibres, synthetic
coated and layered products, which method provides the steps of a) providing first digital data (3) of original patterns (N) to be printed having predetermined shape and size, b) three-dimensional reproducing said original patterns (N) on the outer surface (S1) of a first sample (1) so as to obtain relief patterns (M), c) forming a first negative three-dimensional cast (7) of said first sample (1) made of polymeric material, d) anchoring said first cast (7) to a plate (10) made of rigid material to define a first printing plate (11) to stabilise said first cast (7), e) compressing said first printing plate (11) against a visible surface (S2) of a flexible laminar material (P) to transfer the negative patterns (O) of said first cast (7) thereon to obtain a first laminar product (13) with reproduced three-dimensional patterns (Q), characterised in that said relief patterns (M) are made on the outer surface (S1) of said first sample (1) by means of a three-dimensional printing with UV ink so as to take a substantially
pyramid-like final shape with different deviations (Δ) in shape and size with respect to said original patterns (N), a step being provided of f) modifying said reproduced patterns (Q) obtained on said first product (13) so as to compensate said deviations (Δ) induced during the step c) of forming said first cast (7) and during the compression step e), wherein said modification step f) provides a sub-step f1) for detecting the shape and size of the reproduced patterns (Q) on said first laminar product (13) to detect said deviations (Δ), a sub-step f2) of modifying said first digital data (3) to eliminate said deviations (Δ) and obtain second digital data (16) to obtain a second sample (1', 1",...), a second cast (7', 7",...), a second printing plate (11', 11",...) and to obtain a second modified laminar product (13', 13",...), and a possible sub-step f3) of repeating the sampling cycle (b)-e); b)-f)) up to obtaining a final laminar product (17) with patterns (V) the closest possible to the original ones (N).
2. Method as claimed in claim 1, wherein said original patterns (N) consist of vector files obtained with algorithms and mathematical equations defining
said first digital data (3).
3. Method as claimed in claim 2, wherein said first digital data (3) are uploaded on a storage unit of a microprocessor device connected to a three-dimensional
printing equipment of the plotter type or 3D printer.
4. Method as claimed in claim 1, wherein said step f) of modifying said first digital data (3) provides for a dedicated computer program
for automatically modifying said vector files.
5. Method as claimed in claim 1, wherein after said step b) of three-dimensional reproduction of said original patterns (N), said first and second sample (1, 1', 1",...) are subjected to the following sub-steps:
b1) anchoring them to a support plain (4) made of substantially rigid material;
b2) delimiting the peripheral edge of said samples (1, 1', 1",...) with a frame (5) for forming a confinement compartment (6) above it.
6. Method as claimed in claim 1, wherein said step d) of anchoring said first cast (7) to a plate (10) made of rigid material is carried out by interposition of a cloth.
7. Method as claimed in claim 1, wherein said first and second cast (7, 7', 7",...) are obtained through the following sub-steps:
c1) pouring a polymeric resin mixture (8) in liquid state into said confinement compartment (6);
c2) levelling the polymeric resin mixture (8) using a doctor blade (9) so as to completely cover said confinement compartment (6);
c3) cross-linking and detaching said casts (7, 7', 7",...) from said compartment (6).
8. Method as claimed in claim 1, wherein after said step d) of anchoring said first and second printing plate (11, 11', 11",...), they are subjected to the following sub-steps:
d1) heating said plate (11, 11', 11",...) to a first predetermined forming temperature by keeping the cast (7, 7', 7",...) facing upwards;
d2) spraying a water-based polyurethane mixture on the plate (11, 11', 11",...);
d3) optional repetition of the steps d1) and d2), and cooling said plate (11, 11', 11",...) to a second predetermined temperature lower than the first predetermined temperature;
d4) depositing a section (T) made of flexible laminar material (P) on said cast (7, 7', 7",...) by interposing an adhesive (12) in liquid state;
9. Method as claimed in claim 1, wherein said compression step e) provides for the following sub-steps:
e1) mechanical compression of said section (T) made of flexible laminar material (P) against said plate (11, 11', 11",...) so as to transfer the negative patterns (O) on said section (T);
e2) full evaporation of said adhesive (12) and detachment from the plate (11, 11', 11",...) of the section (T) made of flexible laminar material (P) with the patterns (Q) reproduced in relief on the surface (S2) facing said cast (7, 7', 7",...) to obtain a printed laminar product (13, 13', 13",...),
10. Method as claimed in claim 1, wherein said relief patterns (M) are made on the outer surface (S1) of said first sample (1) with a maximum thickness of 200 µm.
11. Method as claimed in claim 7, wherein said polymeric resin mixture (8) comprises at least two silicone compounds.
12. Method as claimed in claim 8, wherein said first temperature is proximate to 100°C.
13. Method as claimed in claim 8, wherein said second temperature is proximate to 25°C.
14. Method as claimed in claim 9, wherein said mechanical compression sub-step e1) is carried out by calandering and/or pressing using a substantially flat pressing
machine after said sub-step d4) of depositing said adhesive (12).
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.
Patent documents cited in the description