Process, method, products and systems for optimizing the integrated cycle of sublimation printing processes on textiles

Abstract

A product for optimizing the integrated cycle of sublimation printing processes on textiles, which comprises a closed-matrix sublimation paper with final basis weight comprised between 19 and 120 gsm, according to the applications.

Description

[0001] PROCESS, METHOD, PRODUCTS AND SYSTEMS FOR OPTIMIZING THE INTEGRATED CYCLE OF SUBLIMATION PRINTING PROCESSES ON TEXTILES

[0002] The present invention relates to a process, a method, products, and systems for optimizing the integrated cycle of sublimation printing processes on textiles, which are used particularly for running up clothing, both for fashion and for sports, as well as for home decorations and for commercial presentation.

[0003] In the sector of sewing textiles, the use is known of the sublimation printing technique.

[0004] Technology for sublimation printing on textile is a relatively recent method which makes it possible to produce realistic printed designs, at photographic quality, at high resolution (including up to 2400 DPI), on textile substrates.

[0005] Even though normally the sublimation process makes it possible to print on objects and on a wide variety of materials, in the textile sector the possibilities are reduced to synthetic fibers, of which polyester is the most common, but which also include elastane and microfiber.

[0006] For this reason the clothing most suited to be produced and personalized with sublimation printing is clothing for sports, but also everyday (casual) clothing and high-end clothing (evening and ceremonial wear), mainly for women's clothes, as well as commercial and marketing presentations (i.e., signage).

[0007] More specifically, in the digital printing sector, the sublimation process is the conversion that inks undergo when, as they come into contact with heat, they are converted to gases (i.e. they sublimate) and are transferred by bonding stably with the surface of the polyester textile.

[0008] The sublimation is obtained with ink-jet printers or plotters (for large dimensions) with cartridges of sublimating inks, using special sublimation paper. Subsequently, the ink received from the paper is transferred to the receiving surface using a specific dedicated calendering unit or press.

[0009] This technology is widespread, especially for personalizing polyester textiles, pre-treated materials based on polyester and nylon which are used to provide a great many applications for the fashion and fast-fashion sectors, but also for sports clothing and interior decoration, and commercial and marketing presentations (i.e., signage).

[0010] The sublimation occurs when the ink printed on the paper, by way of a dedicated press or a calender press for continuous production processes, is transferred onto the textile and passes directly from the solid state to the gaseous state, instantaneously.

[0011] Usually, in the fashion sector polyester textiles are used which, at 200°C, by loosening their molecular structure, allow the inks to combine with the material permanently, with the characteristics of resisting scratches, stresses, or color fading.

[0012] The end result makes it possible to have a surface or a textile that is perfect and flat, with no protrusion or thickening, which is washable and which preserves - for printing on a textile substrate - the weave of the material.

[0013] The equipment required to execute and manage the sublimation printing process is comprised of a dedicated electronic computer provided with a graphics software and with an RIP (Raster Image Processor), i.e. a software program that can substitute the original driver of the printer, which makes it possible to manage the printing and the sublimation parameters.

[0014] With respect to the original, ordinary printer driver, an RIP offers far more precise control of the print functions, managing color and making it possible to create special calibration (called "linearization") files for each type of paper used.

[0015] Furthermore, the technological equipment consists of: large-format printers that use sublimating inks, calendering units (or vacuum presses), sublimation paper on which to print the graphics, and finally textiles to be printed which are suitable for sublimation (i.e. polyester, for the most part). The equipment and the materials for executing the sublimation printing process for the fashion sector are:

[0016] • A sublimation plotter

[0017] • Sublimating inks

[0018] • A printing RIP

[0019] • Sublimation transfer paper

[0020] • A sublimation heat calendering unit

[0021] In the fashion / sport sector, transfer by static press can also be used. In the production sequence, the first item of equipment necessary for indirect sublimation printing is the sublimation plotter. The sublimation process begins by printing with an inkjet plotter that uses sublimating inks.

[0022] A large-format sublimation plotter is a print plotter that uses special cartridges with sublimating inks. It functions exactly like other large-format plotters, with the difference that it prints exclusively on transfer paper, unlike other plotters which can also print on other materials.

[0023] It is essential that the plotter can print hundreds of meters of defect-free transfer paper, and furthermore the entrainment of the transfer paper must be linear in order to prevent the plotter from jamming during the printing process. Print speed plays an important part in high production rates and the plotter must be capable of handling defect-free printing with no anomalous modifications to the designs which would be visible at the moment of heat transfer onto the textile.

[0024] The print quality must be excellent, especially for applications like fashion, high fashion, and sports clothing, and also to correspond exactly with the designers' creations.

[0025] The ink loading system must allow long printing autonomy, in order to avoid interruption while the plotter is not supervised, for example at night.

[0026] The sublimation plotter can be fed only with sublimating inks: the sublimation ink is deposited by the plotter heads on the transfer paper, and from this moment onward it assumes solid state.

[0027] While the ink-loaded transfer sheet is mated to the textile and subjected to a thermal load with a temperature of approximately 200 °C it passes to the gaseous state, and when the heat transfer is concluded, the ink returns to the solid state in the form of colored pigment trapped in the fibers of the textile.

[0028] Quality sublimating inks must have very precise characteristics:

[0029] • They must not clog the nozzles of the print heads

[0030] • Vivid, bright colors

[0031] • Rapid drying on the transfer paper, to be subsequently rolled up

[0032] • Resistance to washing

[0033] • Ecological certifications or attestations suitable for use.

[0034] In general sublimating inks are water-based, completely non-toxic, and this characteristic is essential for textile printing in the manufacture of clothing.

[0035] A particular characteristic of sublimating inks, and the corresponding configuration of the plotter, are spot colors: in fact in addition to the classic four colors plus light cyan and light magenta, which help improve gradations, it is possible to use spot colors to boost the color range. Furthermore, by using sublimating inks like orange, purple and blue, it is possible to reproduce a wider range of colors.

[0036] Furthermore it is possible to use fluorescent colors like yellow, green and pink, which are useful especially in sports clothing; these fluorescent colors combined with the rest of the inks make it possible to achieve further fluorescent tones.

[0037] In sublimation printing, black ink can have several shades, i.e. it can tend toward a colder black or a warmer black, to be used depending on the market or on the end use.

[0038] The ink configuration can be double four-color or it can also use spot colors: this depends on the specific qualitative / productive requirements. In general with the double four-color configuration, the plotter prints more rapidly but with a reduced color range compared to configurations using spot colors.

[0039] Another important aspect is the ink feeding system, which can be the conventional bulk feeding with 1 -liter containers, into which the ink is poured, or with sealed packets which are inserted into the body of the plotter.

[0040] The advantage of the packets is that the ink does not come into contact with the air (which oxidizes the ink) and with the inevitable impurities that arise from pouring the ink.

[0041] Furthermore, if the plotter is not used often, the ink can create a sediment at the bottom of the container where it remains trapped and, in the long term, the sediment can reach the print heads, damaging them.

[0042] Packets sealed in a controlled atmosphere ensure superior quality and continuity of production.

[0043] As mentioned previously, the printing RIP is the special software that produces the graphic file during the stage known as “ripping”. The file is created in a “language” which is understood by the plotter and which enables correct printing in terms of layout, speed, deposition and quality.

[0044] The printing RIP for the sublimation printing must be able to manage color spot channels, in order to correctly process the colors of the print file.

[0045] Correct and effective RIP software for sublimation must also have advanced functions such as for example the capacity to create a “pattern” (i.e. a design that can be printed continuously, without interruptions) with a small portion of the total file.

[0046] For example, if the task is to produce a swatch of printed textile 100 meters long, with a particular colored pattern, it is not necessary to create a 100-meter file, but a module of the pattern which the RIP will reproduce in the necessary dimensions, therefore with a function called “step & repeat”, so building a print file in such a manner as to allow a perfect, seamless interlocking between one module and the next.

[0047] An essential factor for correct sublimation printing is printing the exact color, based on the project requirements of the designer / stylist.

[0048] In the clothing sector, printing the color required by the buyer is the essential foundation of successful production. In fact, printed designs that do not conform to the color approved at the quotation stage, or which do not pass the tests of the designer / stylist, are not accepted. Furthermore, the approved color must be reproduced in subsequent print runs as well.

[0049] For example the reissue of a dress in a fashion collection must be the same as other dresses from different and subsequent production runs of that collection. Maintaining this level of equivalence is possible only with professional RIP and with correct color management.

[0050] In this regard, attention is drawn to the automatic creation of color derivations by the RIP, i.e. starting from a single color the RIP automatically generates an array of colors close to the main color: this function is widely used for printing a sample to be submitted to the buyer, also in order to avoid having to execute numerous and excessive print tests.

[0051] Professional RIP makes it possible to print an exact color and to reproduce it in future production runs: the automatic material nesting function serves to optimize the positioning of the printed designs in order to rationalize costs and production. In conclusion, the choice and management of RIP software is essential together with the choice of plotter.

[0052] Sublimation transfer paper is the medium on which the ink printed by the plotter is deposited, and which will be mated to the textile in order to transfer the print.

[0053] Sublimation paper has two sides, one coated and one uncoated.

[0054] The function of the coating is to be receptive to the ink, in order to “trap” it and release it in gaseous form when it is mated to the textile, in the calendering or heat press phase. Sublimation papers differ in basis weight and in the amount of coating.

[0055] Therefore, the quality of the printed end product will be influenced by the type of transfer paper used and, in general, the greater the basis weight, the better the end result will be, as a function of the type of end product.

[0056] A paper with a low basis weight printed with a lot of ink will warp, creating waves at the printing stage, while a paper with a high basis weight will make it possible to have great expanses of ink without problems during printing, especially at high speeds; as a consequence, the types of coating or surface treatment and the rigidity of the paper are determining factors for the correct execution of the print transfer method.

[0057] Nowadays there are sublimation transfer papers on the market made by several paper makers, with an average basis weight of approximately 45 gsm for the fashion sector and clothing, while for the sports clothing sector papers are used with a greater basis weight, with an average of approximately 100 gsm, and even reaching 120 gsm.

[0058] The essential characteristic common to the various types of sublimation paper is to retain the correct quantity of ink, homogeneously and uniformly, and also to enable maximum precision in the transfer to the textiles.

[0059] The calendering unit for sublimation is used in the process of continuously printing the roll of textile. To be suitable for sublimation, the calendering unit for sublimation transfer must meet the following essential requirements:

[0060] • It must have the same pressure over the entire surface of the cylinders,

[0061] • It must have a uniform temperature over the entire surface of the cylinders.

[0062] These conditions of pressure and temperature are indispensable to obtain sublimation-printed textiles without differences in color on the surface. Continuous printing on the roll is used for long print runs on textiles of different composition and weave.

[0063] To begin production, the roll of transfer paper and the roll of textile (and, for some types of production, also calender protection paper) are mounted on the calendering unit and both are made pass under the oil-heated cylinder.

[0064] The parameters of temperature, pressure and contact time (advancement speed) are managed according to the type of textile and the transfer paper used.

[0065] Another roll which is always mounted on the calendering unit is of calender protection paper, known in the jargon as protective paper or sacrificial paper, the function of which is to protect the felt of the calendering unit in the transfer of the print from the sublimation paper to the textile.

[0066] Heat sublimation or heat transfer is a specific technology used for printing on various media, in particular textiles.

[0067] Transfer to textile using sublimation can also be discontinuous, using flat presses (e.g. for the fashion / sport sector), with the same technological criteria as roll calenders.

[0068] The term "sublimation" derives in fact from chemistry, and refers to the change of state of a substance from a solid to a gas, and a specific application of this is heat-printing by sublimation: this indirect printing method is used for the most part in the decoration of the synthetic woven textiles, but also on non-woven textiles (NWF), such as polyester, elastane, microfiber, or nylon and acrylics.

[0069] Using sublimation printing, it is therefore possible to use an effective technique to decorate various types of textile, all white or light-colored and for use in the clothing sector, but also in furnishings.

[0070] The principal characteristic of sublimation printing is that it occurs only on polyester or mixed cotton / polyester textiles, or on nylon. The best color results are obtained on 100% polyester textiles, but it is possible to use textiles with a percentage of cotton which have a minimum content of at least 70% polyester, and the remainder with other fibers.

[0071] The greater the presence of polyester, the more vibrant the colors will be.

[0072] The typical sublimation process on textiles occurs using the indirect sublimation method. With indirect sublimation, the ink printed on a special sublimation transfer paper is subjected to a heat source which causes the change of physical state, the transfer, and the bonding of the ink with the fibers of the textile, which absorb the ink and fix it, firmly and definitively.

[0073] The sequence of steps entails preparing the desired graphic design, which is printed in reverse (a mirror image) with respect to how the graphic image is intended to be applied to the textile, on a sheet which is technically termed a "transfer sheet". Subsequently, the transfer sheet is placed in contact with the textile to be decorated, using a calendering unit or with a hot press, which will enable the paper to adhere to the textile and, using temperatures of approximately 200 °C, will enable printing by sublimation onto the textile.

[0074] The ink printed on the sheet, by virtue of sublimation, changes state to gas, and the image is transferred indelibly and permanently to the synthetic fibers of the textile.

[0075] The products thus obtained remain soft and present printed designs with bright, clear and vivid colors, for a result of unique brilliance but without sacrificing endurance and stability over time.

[0076] Sublimation is the preferred method for printing on textiles used for technical and sports clothing, which are often subjected to heavy use and are at risk of being rapidly worn out, as well as for casual clothing.

[0077] Sublimation printing is particularly indicated for printing on textiles at very high resolution (up to 2400 DPI) extremely rapidly, while ensuring results of excellent quality in short time spans. Textiles printed using this technique can furthermore be folded, reused, machine-washed countless times without ever losing the quality or the extremely vivid colors of the printed image. Sublimation printing is a modern and effective printing method which makes it possible to print personalized images directly on textiles. In fact, by using a chemical process that involves heating and pressure, the color is directly absorbed by and bonded to the fibers of the textile.

[0078] After the transfer to the textile, the weave remains unaltered because the sublimation printing has no thickness, and the color remains trapped within the fibers of the textile and as a result the colors are brilliant.

[0079] Furthermore, the printed designs offer long resistance to washing and the textile remains breathable: for this reason the sublimation printing is the best technique for sports clothing, or for casual summer clothing, in that it allows normal transpiration of the skin, something that would not happen with other methods, for example using laser-printed transfers.

[0080] With sublimation the advantage of digital printing is maintained, i.e. there are no plant costs, unlike with screen printing, and it is also possible to conduct small print runs and samples.

[0081] The chemical process begins with the deposition on the sheet of paper of the color, which is initially in the liquid state and then solidifies by drying. In the step of transfer by heat calendering, the sliding rollers take the textile through a press where the deposited color is heated and changes state to a gas so that it can be absorbed directly by the fibers of the textile, with the heat changing the structure of the weave of the textile, opening up the fibers and enabling the ink in the gaseous state to penetrate them and become firmly and solidly fixed.

[0082] Once absorbed, the cooling process begins, which returns the color to the solid state. This is what differentiates the sublimation technique from other printing techniques: the color is not deposited on the surface, but instead becomes an integral part of the fibers themselves. The entire roll of printed transfer paper is loaded in the calendering unit together with the textile, and in this manner the entire roll of textile will be printed continuously by sublimation.

[0083] The textiles, thus printed, can be folded and reused countless times without ever losing the quality and brilliance of the printed image, the format or the physical characteristics of the textile.

[0084] The textiles can be machine-washed without compromising the quality of the image or the color rendering.

[0085] Direct sublimation printing has an extremely high resolution (up to 2400 DPI) and is a four-color process.

[0086] The printing machines work at very high speeds (up to 500 square meters per hour), therefore the time scales for production and delivery of the finished products are extremely fast. The inks are water-based, and therefore completely ecological.

[0087] Following a meticulous analysis, it has emerged that the chain of production in the textile sublimation printing sector described up to this point is not devoid of drawbacks, among which is the fact that this has always treated the actors across the entire production cycle as independent, with no apparent direct correlation, and therefore their respective close and direct technical and operative correlation has never been either considered or exploited.

[0088] In more detail, the principal actors, i.e. the enterprises and manufacturers operating in the chain of production of the textile sublimation printing sector, are:

[0089] 1.1. PAPER FACTORY

[0090]

[0091] sublimation transfer paper;

[0092] 1.2. PAPER FACTORY protective paper for felt on calenders; 1.3. POLYESTER MANUFACTURERS

[0093]

[0094] polyester for clothing and fashion;

[0095] 1.4. INK MANUFACTURERS inks for sublimation printing;

[0096] 1.5. PRINTER-PLOTTER MANUFACTURERS plotters for sublimation printing;

[0097] 1.6. RIP SOFTWARE COMPANIES

[0098]

[0099] RIP software for sublimation printing;

[0100] 1.7. CONVERTERS

[0101]

[0102] cutting paper into spools for printing, from jumbo rolls produced by paper factories;

[0103] 1.8. MANUFACTURERS OF CALENDERS AND PRESSES makers of heat calenders and presses for transferring prints;

[0104] 1.9. PRINTERS

[0105]

[0106] printers on sublimation transfer paper and transfer to textile (polyester);

[0107] 1.10. PACKAGERS

[0108]

[0109] packagers of items of clothing, from swatches to finished products to be shipped to sales points of clothing companies;

[0110] 1.11. BUYER-END CUSTOMER

[0111]

[0112] clothing maker, designer, fashion brand.

[0113] Furthermore, the macro-sector of fashion and clothing has recently adopted sustainability policies, but these are still limited to:

[0114] 1. The type of inks and their specific technical characteristics, including the requirements of non-toxicity, absence of metals, water-based products, environmental compatibility and sustainability, taking into account that up to 50% of the costs of the finished industrial product, i.e. of the swatches of printed textile, is the cost of inks;

[0115] 2. The type of final medium to be printed on, including polyester, with indication that the polyester used need not be completely virgin, but can also be polyester made partly or entirely from recycled material;

[0116] 3. Policies for end-of-life management of the products packaged, sold, then used or returned.

[0117] In addition, with specific reference to the textile sector, the following factors therefore still remain topical:

[0118] 1. Exclusion of the “worst” products from the market: through environmentally-friendly design regulations (ESPR, Ecodesign for Sustainable Products Regulation) it is possible to implement sustainability good practices, including the Ecolabel label, as a new reference standard in the textile sector;

[0119] 2. Informed disposal of textiles and of items of clothing that are beyond use, in that they are handled like a true “waste colonialism” from Europe to Africa and Asia: European directives aim to ensure that the proceeds of the Extended Producer Responsibility (ERP) schemes can serve to support the communities that handle the disposal and to significantly reform the production chain;

[0120] 3. The proposal to introduce a digital passport for the finished product must be ambitious, so as to make it possible to manage not only the correct disposal, but also all the information relating to safety and sustainability of various textile and clothing products, as well as about the production processes.

[0121] All these impositions of a regulatory and political nature, although well-intentioned, appear to be useful but insufficient, and clearly point to the creation of a technical protocol for a circular economy that makes it possible to reduce waste and reduce costs by making the various actors in the production chain interact. These actors center around the printers (for printed textiles), in that the above principles must be realistically applicable in production cycles for manufacturing textile products and items of clothing, with specific requirements on the part of clothing manufacturers and fashion brands.

[0122] It is evident that even the European Environmental Agency has not fully targeted direct and effective actions in the short term, and should instead focus on operations that can directly manage integrated production cycles, which involve integrated processes of printing on paper and on textile, which are the main users of the resources drawn on by clothing manufacturers, including the big multinational groups in the “sport and fashion mass market” sector (including ZARA, H&M, PRIMARK, NIKE, ADIDAS), as well as the most widely-known brands in international high fashion.

[0123] In conclusion, currently there are considerable limitations, in terms both of vision and of production practice, in the entirety of the integrated production processes for printed textiles in the fashion sector.

[0124] The aim of the present invention consists of providing a new paper product and a new circular and integrated method / production process that makes it possible to directly correlate all the actors in the production chain so as to obtain synergies and optimize the respective interactions, with significant environmental and economic benefits, including for the recovery and reuse of spent paper.

[0125] Within this aim, an object of the present invention consists in providing a process, a method, a procedure, with specific correlated products and systems, that makes it possible to directly correlate all the actors so as to obtain synergies and optimize the respective interactions, with significant environmental and economic benefits.

[0126] This aim and these and other objects which will become more apparent hereinafter are achieved by the products, machinery and method according to, respectively, claims from 1 to 19.

[0127] Further characteristics and advantages of the invention will become more apparent from the detailed description of a preferred, but not exclusive, embodiment of a process, a method, products, and systems for optimizing the integrated cycle of sublimation printing processes on textiles, illustrated by way of non-limiting example with the aid of the accompanying drawings wherein:

[0128] - Figure 1 is a schematic view of the portion of one of the production processes of providing and applying an innovative finish to sublimation paper, by single-side coating in a size-press in order to finish the closed-matrix single-side coated sublimation paper to be used for sublimation printing on textiles, or by means of another method of specific coating deposition, film press, combi-blade, bars or engraved cylinders, for applying the innovative coating, both in-line and off-line, with plants and apparatus with reduced environmental impact and low resource consumption (with carbon-neutral targets, containment of water and energy use);

[0129] - Figure 2 is a set of tables summarizing comparative printing tests, both on sublimation paper and by transfer to polyester using sublimation transfer paper, made by three different paper makers with basis weight comprised between 39 and 45 gsm, using sublimation printing inks, and an approximately 20% lower consumption of ink (TIL) was found for one paper compared to the use of other sublimation papers, obtaining the same result of transferring images onto polyester textile, for the fashion sector;

[0130] - Figure 3 gives the outcomes of the recyclability tests of spent sublimation paper for making sublimation paper according to the present invention.

[0131] Likewise a specific paper base substrate will be provided, with technical characteristics suitable for use in the sublimation printing step, but also for the application of the special coating with an innovative formulation for the efficient transfer and hold of the sublimating inks, for excellent color rendering.

[0132] With reference to Figure 1, the portion of the paper factory production method comprises:

[0133] - a supporting structure from which the sheet of paper emerges after the step of forming and drying the sheet 1 of base paper 2 according to one or more of the claims;

[0134] - a series of tensor cylinders 3 around which the moving base paper 2 is guided;

[0135] - a series of mutually opposing nozzles of the size-press application system 4 for the application of surface additives 5,

[0136] - two heated calendering cylinders 6 through which the base paper 2 passes in order to allow impregnation,

[0137] - two collection trays 7 for collecting the excess surface additives in order to reuse them in the feeding cycle,

[0138] - an infrared drying system 8 for completing the drying and fixing of the surface additives;

[0139] - a final support for collecting the finished paper sheet 9 in a final roll 10, in order to be then cut to suitable formats for sale for printing.

[0140] In more detail, the product for optimizing the integrated cycle of sublimation printing processes on textiles for the fashion sector is characterized in that it comprises a closed-matrix, single-side coated sublimation paper, with a recycling quota to the extent of from 5% to 30%, with low final basis weight comprised between 19 and 50 gsm and preferably comprised between 20 and 38 gsm, and also aims to reduce transport costs determined by weight, as well as of reducing the costs of drying the paper sheet (in terms of energy and other resources) in the continuous machine for producing paper.

[0141] Similarly to what is said above, for the fashion / sport sector, the product is characterized by a closed-matrix sublimation paper with final basis weight comprised between 70 and 120 gsm.

[0142] By "closed matrix" what is meant is a fibrous structure of the sheet, characterized by a compact, homogenous distribution of the cellulose fibers, with low porosity and tighter inter-fiber micro-bonds than in an “open” matrix.

[0143] This configuration offers a lower passage of air and ink, a higher surface density, and excellent control of the capillarity of the sheet.

[0144] The closed matrix is obtained through a balanced combination of beating, sheet formation, and calendering, aimed at reducing the permeability and improving the regularity of the surface for a more stable heat transfer during the sublimation printing.

[0145] In the method according to the present invention, the formation of the closed matrix:

[0146] - determines superior dimensional stability and mechanical strength of the sheet;

[0147] - optimizes the controlled release of the sublimation ink, so reducing bleeding and feathering;

[0148] - produces an average contact angle comprised between 95° and 108°, which indicates a low-absorbency surface with controlled hydrophobic behavior;

[0149] - reaches Gurley air resistance values comprised between 35 and 55 seconds (TAPPI T460 om-02), significantly higher than standard sublimation papers (typically 10-25 seconds), confirming the reduced permeability and the tighter closure of the matrix;

[0150] - enables ink savings of 15-20% by virtue of lower fiber penetration and superior color transfer.

[0151] These characteristics do not derive from a simple increase in the weight or in the basis weight, but from a controlled modification of the fibrous structure and of the production method, verified by SEM analysis of porosity, Gurley measurements, and static contact angle tests.

[0152] The closed matrix represents a measurable and reproducible technical parameter, which characterizes the functional behavior of the paper according to the invention and distinguishes its performance in sublimation transfer.

[0153] Therefore it constitutes an innovative element of the production method, aimed at obtaining an optimal equilibrium between controlled permeability, dimensional stability and transfer efficiency, in line with the principles of sustainability and reduction of consumption which characterize the invention.

[0154] The use of a quota of spent sublimation paper remaining after the textile transfer method as raw material is a particular requirement of the present invention, as technical recyclability tests have shown that in the initial phase of the process to produce new sublimation paper (the step of pulping cellulose fibers and the step of preparing the mixture of products for the paper), it is possible to obtain a homogeneous mixing of the paper pulp, so as to prevent any residues or residual ink impurities from being “reactivated” in the new paper produced, when used in the sublimation process.

[0155] Furthermore, the sublimation paper, with its recycled quota, for the closed-matrix fashion sector has, indicatively:

[0156] - a surface water absorption index measured by way of COBB 60 (according to the ISO 535 standard) with a target of approximately 15 gsm;

[0157] - a sufficient wettability characteristic, with corresponding contact angle, for the respective surface tension for optimal reception of printing ink;

[0158] - a low BENDTSEN porosity (according to the ISO 5636 standard) with a target comprised between 100-250 ml / min or a low BEKK porosity (according to the ISO 5627 standard);

[0159] - a tensile strength comprised between 8000 and 14000 1 / q (according to the ISO 1924 standard) and a burst strength (according to the ISO 2758 standard) equal to 100 kPa, in order to allow the easy printing and subsequent transfer of images without the creation of lines or creases;

[0160] - a high barrier effect with specific constituent products of the paper substrate, with a suitable mixture of cellulose for both the paper substrate and the final paper recipe, including: inorganic pigments (kaolin and silicates), polyvinyl alcohol (PVA), starch, and carboxymethylcellulose (CMC), or new, latest-generation specific barrier components, amphoteric in nature (therefore non-cationic and non-anionic), applied in the range substantially equal to 3-10 gsm, the particle sizes, geometries, and rheology of which are to be better established, as well as organic compounds (including lactic compounds) in order to maintain the deposited ink in optimal condition and over time in order to favor the sublimation process at the transfer temperature and pressure onto the textile;

[0161] - surface coating treatments (by direct coating, in-line or off-line, film press, size press, combi-blade, bars, engraved cylinders) in order to allow the precise deposition of the inks and fast drying so as to obtain an exact, clear and vivid print of the images or of the motifs with photographic-level resolution and transfer;

[0162] - lower thickness of the paper for fashion use, approximately half that of the average basis weights present on the market, i.e. comprised between 23 and 45 pm to reduce penetration of the ink and to reduce environmental impact in terms of carbon / water production footprint, of transport and of volumes, in that the type of paper in use on the market currently has an average basis weight of 45 gsm and an average thickness of approximately 55 pm.

[0163] The combination of these requirements of sublimation paper with a low basis weight comprised in the range 19 and 50 gsm, preferably comprised between 20 and 38 gsm, together with the specific characteristics of the sublimating inks, enable the innovative, unique, and never-beforeachieved provision of a new integrated method of production, by also factoring into the sublimation paper recipe the reuse by recycling of “spent” sublimation paper, i.e. paper deriving from printing after the transfer by sublimation of the images on the rolls of textile, in that currently, after transfer such spent paper is classified as waste, but with this new recovery method it will become a source of fibers to be reused for making new printing paper and new calender protection paper.

[0164] This new sublimation paper, in the various basis weights required for transfer printing, is made with a special application of coating with either one or two passes (pre-coating + top coating), with a subsequent super calender processing pass, in which a mirror-symmetrical, homogeneous surface is created and the fibrous paper substrate and the coating layers are “welded” together, so as to provide a closed but sensitive, special receptive matrix, capable of fixing and then releasing the deposited inks in the best way. Following technical tests it has been established that this surface coating treatment is applied by preparing an innovative coating obtained by mixing pigments (for example, kaolin or calcium carbonate), binders (such as resins or adhesives) and other additives to improve the properties of the coating, in particular using a specific and advanced CMC (carboxymethylcellulose) which makes the characteristic properties of the final product possible. The mixture of the new coating is made by availing of: binders like modified starch and resins to improve the strength and adhesion of the ink pigments; aqueous solvents to improve the thickening and binding capacity of the CMC; mixtures with overall slightly alkaline or neutral pH to increase the effectiveness of the CMC; and taking care to avoid contaminants and loosening agents for the coating mixture (including: excess metal ions and mineral ions; acidic environment and high temperature).

[0165] Furthermore, the new integrated cycle of the production method entails reusing the used expendable paper (spent calender protection paper), but also the spent printed sublimation paper for reuse in the production recipe for the new calender protection paper, so as to self-supply at least part of the production of the paper, to the extent of from 5% to 100%.

[0166] Sublimation paper does not require a high degree of whiteness, therefore in the recipe for producing new sublimation paper there can be a reuse of “spent” paper, even if prepared by a de-inking process, while calender protection paper has a tan color and therefore it is even easier to reuse spent calendering unit protection paper, or even spent sublimation paper itself.

[0167] Sublimation paper for transfer printing is therefore a “transit medium” which must ensure superior anchoring of the inks deposited by the printer, fast and uniform drying, faithful and high-resolution reproduction of the images to be printed on the paper, reduced use of inks, sufficient sublimation of the inks during the step of calendering with faithful and high- resolution transfer of the images to be transferred onto the rolls of textile, in close combination with the characteristics of the inks.

[0168] Furthermore, using a specific closed-matrix paper and a reduced basis weight also makes it possible to reduce the amount of water contained, in that, with reference to an average relative humidity of paper of 5%, there is as a consequence a lower amount of water in the finished sublimation paper product, for a product with a low basis weight (for example: 5% humidity in a 35 gsm paper is a lower value of the absolute fraction of water contained than 5% humidity in a 45 gsm paper), therefore adding in the ecological and use advantages correlated to weight and volumes for transport and use.

[0169] The technical achievements outlined for the integrated production method therefore have analogies both for the high / casual fashion sector, ad for the fashion / sport sector.

[0170] The technological combination of ink and paper means that a paper with higher humidity offers superior yield in printing, in order to prevent the critical impact of the amount of water contained in the inks, while in the transfer step a drier paper has a better yield; in fact the water in the paper, referred to as relative percentage (%) humidity, does not influence the printing method, since it evaporates at 100°C.

[0171] For the fashion sector, the advantage of paper with a low basis weight (e.g. in the range 20-38 gsm) is that the ink tends to remain more on the surface, since the print substrate is less thick and therefore the ink will not penetrate through the full thickness of the paper sheet.

[0172] The method for optimizing the integrated cycle of sublimation printing processes on textiles is therefore characterized in that it uses a sublimation paper like the one just described in combination with a special sublimation ink having a composition with a high intensity of dispersed dyes and high fluidity with fast drying.

[0173] The special sublimating inks for the current application are composed of dispersed dyes which, after the printing on sublimation paper, enable the subsequent solid and definitive transfer of the images onto the polyester textile; the mixture of the inks also comprises glycols and dispersants, which are vehicles for enabling only the dyes to be transferred to the polyester. These inks have ECO PASSPORT certification from OEKO-TEX, which attests that these products can be used in sustainable textile production.

[0174] Special sublimating inks are differentiated for specific printing technologies of greater or lesser speed: if e.g. fabric is printed at a speed of 70 m / min, then the combination of special inks plus sublimation paper means that there is a surface coating that makes it possible to keep the ink on the surface of the paper, so making it possible to set a lower ink-limit if a special paper with a reduced basis weight is used, with less use of ink, while also taking advantage of the benefit of dedicated processing of the print file.

[0175] The inks envisaged for optimal combination with sublimation paper with a low basis weight and for best print performance and subsequent transfer comprise a special mixture of the chromophore portion (i.e. of the dispersed dyes) and of the additives portion, with the aim of boosting the color rendering without creating technical problems on the application head of the printing machine, following current and new advances in printing machines, which have heads that are used for printing at ever-increasing speeds. The dye is not soluble and is prepared by specific grinding to different levels of fineness, with finer particle sizes than those for normal and conventional use, and then dispersed in special, calibrated mixtures.

[0176] In the sublimation transfer calendering unit, the best and most effective transfer occurs by balancing temperature and pressure, so that the sublimation process with transfer from paper is correctly activated, triggering a sufficient dilation of the polyester fibers and, in the subsequent cooling step, the fibers return to their original dimensions, so encapsulating the inks and concluding the transfer of the images.

[0177] Furthermore, as mentioned previously, the sublimation paper is made using a quota of the same type of spent sublimation paper, since sublimation paper does not require a high degree of whiteness.

[0178] Furthermore, a type of calender protection paper is used which is tan in color, and so in the production recipe for new calender protection paper it is possible to reuse used expendable paper (spent calender protection paper), but also spent printed sublimation paper, so as to self-supply production of the abovementioned paper, as technical recyclability tests have shown that in the initial phase of the production process (the step of pulping cellulose fibers and the step of preparing the mixture of products for the paper), it is possible to obtain a homogeneous mixing, so as to prevent any residues or residual ink impurities from being “reactivated” in the new paper produced, when used in the sublimation process.

[0179] Therefore the new integrated method uses an optimal unique and specific combination for the type of sublimation paper of: RIP printing, ICC (International Color Consortium) profile for color data transfer, printing plotter setup with color cartridge metering management, printer resolution, ink dispensing limit (ink-limit), printer / plotter calibration and linearization, to obtain photographic-resolution printing both on paper and on textile, with validation of the printing results with measurements of the color intensity response with spectrophotometry both on paper and on textile.

[0180] In practice it has been found that the process, the method, the product and the systems according to the invention achieve the set aim and objects.

[0181] In fact, in the textile sector a method / production process has never been devised and developed that makes it possible to directly correlate all the actors so as to obtain synergies and optimize the respective interactions, with significant environmental and economic benefits, as in the schedule ?elow:

[0182] ACTOR IN THE Product / process in the production PRODUCTION CHAIN chain

[0183] 1 PAPER FACTORY Sublimation transfer paper

[0184]

[0185] 2 PAPER FACTORY protective paper for felt on calenders 3 POLYESTER polyester for clothing and fashion MANUFACTURERS

[0186] 4 INK MANUFACTURERS inks for sublimation printing

[0187] 5 PRINTER-PLOTTER plotters for sublimation printing MANUFACTURERS

[0188] 6 RIP SOFTWARE COMPANIES RIP software for sublimation printing 7 CONVERTERS cutting paper into format spools for printing, from jumbo rolls produced by paper factories

[0189] 8 MANUFACTURERS OF makers of heat calenders for CALENDERS transferring prints

[0190] 9 PRINTERS printers on sublimation transfer paper and transfer to textile (polyester), production of swatches

[0191] 10 PACKAGERS packagers of items of clothing, from swatches to finished products to be shipped to sales points of clothing companies

[0192] 11 BUYERS / END CLIENTS clothing manufacturers, fashion brands, sportswear brands

[0193]

[0194] Furthermore, after careful examination of the steps of the entire production method and of the correlated evidence of weak points or of considerable margins for improvement over the entire production cycle, various considerations were formulated relating to the entire production cycle, which at the moment appears to have been ignored overall, taken as a whole. Comparative printing tests were conducted, both on sublimation paper and by transfer to polyester using sublimation transfer paper, made by three different paper makers with basis weight comprised between 39 and 45 gsm (as can be seen from Figure 2 with the results of the comparative tests), using sublimation printing inks, and an approximately 20% lower consumption of ink (TIL) was found for one paper compared to the use of other sublimation papers, obtaining the same result of transferring images onto polyester textile, for the fashion sector.

[0195] Recyclability tests were conducted on the spent paper, the results of which are given in Figure 3.

[0196] At the production site of a printer, the setup parameters of the machinery executing the sublimation printing method for the fashion sector were examined, assessed and optimized, and in particular an optimal combination of the following was identified: RIP printing, ICC (International Color Consortium) profile for color data transfer, complete printing plotter setup with color cartridge metering management, resolution of the printer, ink dispensing limit (total ink limit), printer / plotter calibration and linearization, and measurement of the printing results with spectrophotometry both on paper and on textile.

[0197] It was also considered that the depositing of ink on the sublimation paper has a physiological amount limit, as on sublimation papers with a lower basis weight, as low as 30-38 gsm for the fashion sector, the amounts of the inks that are deposited on the surface of the paper sheet in the step of printing must be custom-dosed, specifically by calibrating the RIP and the settings of the printers, with the associated software for managing the images and the speed / quantity / distribution on the sheet of the roll of sublimation paper.

[0198] Actions on these technical parameters have made it possible to obtain particular configurations, achieving correct performance in terms of: structural surface of the print transferred to the textile, opacity and brilliance of the transferred print, image transfer time, faithfulness of the dimensions of the motifs of the image transferred to polyester.

[0199] Analysis and market research have found that, in European Union countries, only recently have European initiatives aimed at sustainability begun to affect the textile sector, which is the fourth most critical sector in Europe in terms of environmental impact.

[0200] The European Commission has adopted a special resolution for a new strategy on sustainability textile products, with the aim of encouraging countries in the European Union to adopt measures to bring an end to the phenomenon of "fast fashion", i.e.: decarbonizing production, facilitating the collection, reuse and circularity of items of clothing, starting from the design stage, with some operating recommendations, including increased transparency and traceability of production; however, a long time is required to effectively implement these undoubtedly good policies, which will need to be translated into concrete, new production protocols.

[0201] The combination of these requirements of new closed-matrix sublimation paper, with a low basis weight in the range comprised between 19 and 50 gsm, and preferably comprised between 20 and 38 gsm, with the specific characteristics of the sublimating inks, enable the innovative, unique, and never-before-achieved (in the fashion sector) provision of a new integrated method of production, by also factoring reuse into the sublimation paper recipe by reusing “spent” paper, i.e. paper deriving from printing after the transfer by sublimation of the images on the rolls of textile. Furthermore, the new integrated cycle of the production method entails reusing the used expendable paper (spent calender protection paper), but also the spent printed sublimation paper for reuse in the production recipe for the new calender protection paper, so as to self-supply the production of the paper.

[0202] It has been noted that sublimation paper does not require a high degree of whiteness; therefore in the recipe for producing new sublimation paper there can be a reuse of “spent” paper, even when prepared by a de-inking process, while calender protection paper has a tan color and therefore it is even easier to reuse spent calendering unit protection paper, or even “spent” sublimation paper itself.

[0203] Sublimation paper for transfer printing is therefore a “transit medium” which must ensure superior anchoring of the inks deposited by the printer, fast and uniform drying, faithful and high-resolution reproduction of the images to be printed on the paper, reduced use of inks, sufficient sublimation of the inks during the step of calendering with faithful and high-resolution transfer of the images to be transferred onto the rolls of textile, in close combination with the characteristics of the inks.

[0204] Furthermore, using a specific closed-matrix paper and a reduced basis weight also makes it possible to reduce the amount of water contained, in that, with reference to an average relative humidity of paper of 5%, there is as a consequence a lower amount of water in the finished sublimation paper product, for a product with a low basis weight (for example: 5% humidity in a 35 gsm paper is a lower value of the absolute fraction of water contained than 5% humidity in a 45 gsm paper), therefore adding in the ecological and use advantages correlated to weight and volumes for transport and use.

[0205] The technological combination of ink and paper means that a paper with higher humidity offers superior yield in printing, in order to prevent the critical impact of the amount of water contained in the inks, while in the transfer step a drier paper has a better yield; in fact the water in the paper, referred to as relative percentage (%) humidity, does not influence the printing method, since it evaporates at 100°C.

[0206] The advantage of paper with a low basis weight (e.g. in the range 20-38 gsm) and with a barrier effect is that the ink tends to remain more on the surface, since the print substrate is less thick and therefore the ink will not penetrate through the full thickness of the paper sheet.

[0207] The major innovations achieved form the central core of the new method / process with its corresponding products, according to the present invention, together with the creation of an innovative integrated production protocol called “SUBLINOVATON”, to be applied and to be followed, so providing a single, flexible and effective system, for reducing the use of resources, with qualification and characterization in terms of carbon / water footprint, as well as of economic savings.

[0208] The technical achievements outlined for the integrated production method therefore have analogies both for the high / casual fashion sector, and for the fashion / sport sector.

[0209] Therefore, the optimization of the integrated cycle of the sublimation printing processes on textiles for the fashion sector is characterized in that it comprises a closed-matrix sublimation paper with low final basis weight comprised between 20 and 38 gsm, while for the fashion / sport sector, it is characterized by a closed-matrix sublimation paper with final basis weight comprised between 70 and 120 gsm.

[0210] After having analyzed the cycle of the overall production method, taking account of the possible and real-world innovation opportunities, creating a close technical / productive correlation, the following advantages have been identified:

[0211] 1. Reduction in consumption of inks in the step of printing the sublimation transfer paper, but for the absolutely same final result (color rendering, brilliance and solidity) on the textile, as the cost of the inks counts for approximately 50% of the cost of the end product;

[0212] 2. Optimization of print yield performance and the associated brilliance and hold of the colors printed with indirect sublimation, to achieve a measurable reduction in use of the inks;

[0213] 3. Utilization of a specific and innovative type of sublimation paper, with reduced basis weight compared to the current products available on the market (which nowadays, for the fashion sector, are papers with a basis weight in the range 35-50 gsm), with finalization of the use of a new sublimation paper with a target basis weight in the range 20-38 gsm for the fashion sector and with a basis weight in the range 70-120 gsm for the sport sector;

[0214] 4. Finalization, development and identification on the market of a type of sublimation paper, with a barrier effect, low basis weight, with a specific new composition of additives, mixtures, cellulose and a new method of applying the coating, which makes it possible to obtain a saving on printing inks;

[0215] 5. Performance of a comparison between various types of sublimation transfer paper used by printers, in order to attest that the new type of sublimation paper with low basis weight in fact enables an effective and overriding saving on ink use in printing;

[0216] 6. Achievement of a new product / method environmental certification protocol to be applied to actors in the production chain, which comprises a product / method environmental declaration that includes the carbon / water / energy footprint, and observes the requirements of the ISO 14020 and ISO 14021 environmental standards, with LCA analysis of the cycle of the integrated production method, with the cooperation of international certification bodies;

[0217] 7. Creation and implementation of a system for recovering “spent” transfer paper, i.e. what is left after the transfer step of the sublimation printing, given that nowadays it is classified as refuse, as well as for recovering the protective paper for felt on calenders, as the new production system has never been run using all, or a quota, of “spent” product; therefore including the reuse of the spent paper (both for sublimation and for calender protection), with recycling of discards / scraps for the production of “tan” calendering unit protection paper;

[0218] 8. Involvement and creation of a sector production chain with the principal companies that operate in the sector of sublimation printing, taking into consideration the pattern of the main actors, with the ultimate aim of making the packaged end product unique and innovative for the clothing manufacturer or fashion brand, which recognizes the uniqueness and innovative sustainability of the entire cycle of production processes, applying the new environmental protocol as a mark of distinction on the market;

[0219] 9. Recycling of any production discards of polyester, both printed and to be printed, for the new manufacture of new fibers with recycled content, within the integrated production system;

[0220] 10. Creation of a “smart” integrated logistics system for the recovery and reuse of discarded material and of spent papers, in order to set up a virtuous system with the principal printers and with qualified and accredited packagers;

[0221] 11. Development and improvement of the performance of current types of sublimation transfer paper for the fashion sector, as the basis weights are lighter than current papers, with an average basis weight of 45 gsm, which can be substituted by new papers that are even lighter with a basis weight located in the band 20-38 gsm, since less energy is needed for the transfer method, working according to the simple principle of “less mass-less temperature”, therefore with transfer process temperatures of 180°-190°C, instead of 200°C and similarly for the fashion / sport sector;

[0222] 12. Development of the sublimation transfer paper product with low basis weight, by studying and optimizing the recipe of the product, in terms of recipe and rheology of the coating, types of mineral fillers in the paper pulp, dimensions and particle sizes of the kaolin (flat or splintered), latex in the paper pulp, dosage of CMC (carboxymethylcellulose) and PVA (polyvinyl alcohol) and / or new, latest-generation specific barrier components, amphoteric in nature (therefore non-cationic and non-anionic), applied in the range substantially equal to 3-10 gsm, the particle sizes, geometries, and rheology of which are to be better established;

[0223] 13. Development of the best combination of paper and inks, with definition of the maximum “capture” performance on paper and of stable transfer onto the polyester textile;

[0224] 14. Attestation of the economic and environmental advantages of logistics, since for the same volumes transported, the new paper is lighter, thus achieving a significant increase in the surfaces usable for printing, for the same motor vehicle loaded and dispatched.

[0225] All these achievements make it possible to optimize and orient both the new product sublimation paper toward lower basis weights than those currently on the market, and the sublimating inks to be better tuned to the combination with lighter papers, and these combinations are entered in the method according to the invention so as to involve the entire production chain, starting from the fashion brand which can therefore manage the production chain and can “impose” this environmental sustainability on all the actors in the production chain.

[0226] The process, the method, the products and the systems, thus conceived, are 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.

[0227] 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.

[0228] The disclosures in Italian Patent Application No. 102024000025560 from which this application claims priority are incorporated herein by reference.

[0229] Where the technical features mentioned in any claim are followed by reference numerals and / or signs, those reference numerals and / or signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference numerals and / or signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference numerals and / or signs.

Claims

CLAIMS1. A product for optimizing the integrated cycle of sublimation printing processes on textiles, characterized in that it comprises a closed-matrix sublimation paper with final basis weight comprised between 19 and 120 gsm.

2. The product according to claim 1, characterized in that said closed-matrix sublimation paper has a final basis weight comprised between 19 and 50 gsm.

3. The product according to claim 1 or 2, characterized in that said closed-matrix sublimation paper has a final basis weight comprised between 20 and 38 gsm for the fashion sector.

4. The product according to claim 1, characterized in that said closed-matrix sublimation paper has a final basis weight comprised between 70 and 120 gsm for the fashion / sport sector.

5. The product according to one or more of claims 1 to 4, characterized in that said closed-matrix sublimation paper has a surface water absorption index equal to COBB 60 with a target of 15 gsm.

6. The product according to one or more of claims 1 to 5, characterized in that said closed-matrix sublimation paper has a low BENDTSEN porosity with a target comprised between 100-250 ml / min.

7. The product according to one or more of claims 1 to 5, characterized in that said closed-matrix sublimation paper has a low BEKK porosity.

8. The product according to one or more of claims 1 to 7, characterized in that said closed-matrix sublimation paper for the fashion sector has a tensile strength comprised between 8000 and 14000 1 / q and burst strength of 100 kPa, so as to allow easy printing and subsequent transfer of images without the creation of lines or creases.

9. The product according to one or more of claims 1 to 8, characterized in that said closed-matrix sublimation paper has an effect withspecific constituent products of the paper substrate, with a suitable mixture of cellulose for both the paper substrate and the final paper recipe, including: inorganic pigments (kaolin and silicates), polyvinyl alcohol (PVA), starch, and carboxymethylcellulose (CMC) applied in the range of 3 to 10 gsm, the particle sizes, geometries, and rheology of which are to be better established.

10. The product according to one or more of claims 1 to 9, characterized in that said closed-matrix sublimation paper has surface coating treatments, with methods of applying the coating, by means of a coating system, size press, film press or combi-blade, etched bars and cylinders, as a function of the best technologies.

11. The product according to one or more of claims 1 to 7, characterized in that said closed-matrix sublimation paper for the fashion sector has a thickness comprised between 23 and 45 pm.

12. A method for optimizing the integrated cycle of sublimation printing processes on textiles, characterized in that a sublimation paper according to one or more of claims 1 to 11 is used in combination with a sublimation ink having a composition with a high intensity of dispersed dyes and high fluidity with fast drying.

13. The method according to claim 12, characterized in that said sublimation paper is made by employing a recycling quota of the same type of spent sublimation paper in the amount of from 5% to 30%.

14. The method according to claim 12 or 13, characterized by the production of a specific paper base substrate with technical characteristics suitable for use in the sublimation printing stage, but also for the application of the special coating with an innovative formulation for the efficient transfer and setting of sublimation inks, for optimal color rendering, with an innovative finish of the sublimation paper, by single-side coating in a sizepress in order to finish the single-side coated sublimation paper, or by means of another method of specific coating deposition, film press, combi-blade, bars or engraved cylinders, for coating application, both in-line and off-line,with plants and apparatus with reduced environmental impact and low resource consumption (with carbon-neutral targets, containment of water and energy use).

15. The method according to one or more of claims 12-14, wherein in the initial step of the production process of said sublimation paper a homogeneous mixing of the paper pulp is obtained, such as to prevent any residues or impurities of residual ink from being “reactivated” in the new paper produced, upon use in the sublimation process.

16. The method according to one or more of claims 12-15, wherein said sublimation paper is made with a coating application with either one or two passes (pre-coating + top coating), with a subsequent super calender processing pass, in which a mirror-symmetrical, homogeneous surface is created and the fibrous paper substrate and the coating layers are “welded” together, so as to provide a closed but sensitive, receptive matrix, capable of fixing and then releasing the deposited inks in the best way.

17. The method according to one or more of claims 12-16, wherein said surface coating treatment is applied by preparing a coating obtained by mixing pigments (for example, kaolin or calcium carbonate), binders (such as resins or adhesives) and other additives to improve the properties of the coating, in particular by using a carboxymethylcellulose, the mixture of said coating being provided by means of binders such as modified starch and resins to improve the strength and adhesion of the pigments of the inks; aqueous solvents to improve the thickening and binding capacity of the carboxymethylcellulose; mixtures with overall slightly alkaline or neutral pH to increase the effectiveness of the carboxymethylcellulose.

18. The method according to one or more of claims 12 to 17, characterized in that a type of calender protection paper with a tan color is used with the possibility of reusing in the production recipe in the new calender protection paper, the used expendable paper (spent calender protection paper), but also the spent printed sublimation paper, so as to self-supply at least part of the production of said paper, to the extent of from 5% to 100%.

19. The method according to one or more of claims 12 to 15, characterized in that it uses a specific combination for the type of sublimation paper of: RIP printing, ICC (International Color Consortium) profile for color data transfer, printing plotter setup with color cartridge metering management, printer resolution, ink dispensing limit (ink-limit), printer / plotter calibration and linearization, to obtain photographicresolution printing both on paper and on textile, with validation of the printing results of color intensity response with spectrophotometer measurements both on paper and on textile.

Images