Method for laser marking of a textile material, solid-state laser marker and over-pigmentation composition

Abstract

The present disclosure relates to a method for laser marking of a textile material, comprising the steps of providing a textile material dyed with a base pigment, applying an over-pigmentation composition comprising an over-pigment onto at least one predetermined zone of the dyed textile material, thereby defining a stained area, irradiating at least one marking point of the stained area with at least one laser beam from a solid-state fiber laser marker, wherein the laser irradiation partially or totally removes both the over-pigmentation composition and the base pigment to produce a predetermined design pattern on the textile material. The present disclosure further relates to a solid-state laser marker and an over-pigmentation composition.

Description

[0001] 1 OLS-12517-24

[0002] 04.08.2025

[0003] Method for Laser Marking of a Textile Material, Solid-State Laser Marker and Over-Pigmentation Composition

[0004] Field of the Invention

[0005] The invention has application in the textile sector. The present document relates to a method for laser marking of a textile material. Furthermore, the present document relates to a solid-state laser marker of the fiber optic laser type for marking a textile material to modify the appearance of this material by providing different finishes on at least one irradiated zone with respect to other adjacent non-irradiated zones of the textile material. The irradiated zone is where a discoloration of the textile material based on a predetermined design pattern is provided. The present document also relates to an over-pigmentation composition for laser marking of a textile material.

[0006] Background of the Invention

[0007] Currently, developments in the textile industry cover countless fields, from the inclusion of synthetic fibers, smart fabrics, to shortening and making manufacturing processes efficient using increasingly automated machinery, in addition to reducing the environmental impact that it generates today. In addition to these developments, the resulting products must satisfy increasingly diverse consumption trends in terms of shapes, colors, designs, etc.

[0008] Thus, any material made of interlaced fibers can be understood as a textile material. Fibers can come from a variety of sources, including plants (such as cotton or linen), animals (such as wool or silk), minerals (such as glass), and synthetic materials (such as nylon or polyester). In particular, a thread is a long, continuous strand of textile fibers, which can be composed of a single continuous fiber (mono-filament) or of several shorter fibers spun together (multi-filament). A fabric is a flexible material or product composed of a 2 OLS-12517-24

[0009] 04.08.2025 network of natural or synthetic fibers (threads or filaments). These fibers may be spun, woven, braided, or otherwise interwoven to form cloth or fabric.

[0010] When it comes to obtaining the different colors in textiles, a dyeing or pigmentation process is required. Thus, the dyeing or tinting of a textile is the process of applying color to textile materials, such as fibers, threads, fabrics or garments, to change their original color or give it a new color. This process is fundamental in the manufacture of textiles, as it allows the creation of products with a wide variety of colors and patterns. On the other hand, over-dyeing or over-pigmentation is an additional dyeing process that is applied to textile materials, such as fibers, threads, fabrics or garments, after they have already been previously dyed with a base pigment. This process can have several objectives, including modifying the original color, creating special effects or correcting unwanted colors.

[0011] In addition to traditional tinting, laser marking is currently compatible with the vast majority of textile materials, and its working speed and precision make laser machines ideal equipment for the development of new proposals in the textile sector. Finishing with a laser marker reduces environmental impact, processing time and overall processing costs, while maintaining the look and feel of traditional finishing techniques.

[0012] An example of use of this type of laser marker is the use of gaseous state lasers, specifically a CO2 laser. This type of laser provides a predetermined finish to denim garments, obtaining a discolored, worn appearance, washed in a textile type textile dyed in pure indigo, sulfurous indigo or a combination of both pigments. Individually or mixed, they are coloring pigments that resemble each other and can be used in textile laser marking processes at a high wavelength such as that used by a gaseous state laser, around 10,200 and 10,600 nm, which generates an ablation on the irradiated surface of the textile. 3 OLS-12517-24

[0013] 04.08.2025

[0014] In this case, the use of a CO2 gaseous state laser marker for marking implies more expensive acquisition costs, less energy-efficient processes, bulkier, and limited in its maximum permissible power for this textile application, which generates an increase in the cost of production and the space occupied in the plant.

[0015] It is, therefore, necessary to develop solutions that allow an improvement in the processes of treatment of a textile material by laser marking, allowing, among other improvements, the use of a greater number of textiles.

[0016] Summary

[0017] A solid-state laser marker modifies the finish of a textile dyed with a base pigment, wherein the laser marker irradiates with at least one laser beam to at least one marking point or pixel of a predetermined zone of the dyed textile impregnated with an over-pigmentation composition superficially deposited on the base pigment of the textile material, totally or partially removing selected portions of both the over-pigmentation composition and a dyeing base pigment.

[0018] The over-pigmentation composition is applied by spraying on at least one zone of the textile material, by total or partial immersion of the textile material for a predetermined period of time, at a predetermined temperature, at a predetermined pressure or the like.

[0019] The over-pigmentation composition forms a spot, stained area, on the surface of the predetermined area of the dyed fabric, which is homogeneous and covers at least the area of the target fabric wherein a target design pattern will be applied. The over-pigmentation can be chosen to react with the specific wavelength of the employed laser so that the textile material can be marked even if the base pigment does not react to this specific wavelength. Optionally, after the application of the over-pigmentation composition a drying 4 OLS-12517-24

[0020] 04.08.2025 step can be included for a predetermined period of time to remove residual water from the over-pigmentation composition.

[0021] The over-pigment employed in the over-pigmentation composition can be selected from a wide range of organic and inorganic pigments capable of absorbing laser radiation in the respective wavelength range. Preferably, the over-pigment is selected from the group consisting of carbon blacks, phthalocyanine pigments, metal oxide pigments, mixed metal oxide pigments, metal sulfide or sulfite pigments, elemental sulfur, NIR-absorbing oxide pigments, metallic pigments, and combinations thereof.

[0022] Carbon blacks include, for example, furnace black, channel black, lamp black, thermal black, and acetylene black. These carbon-based pigments preferably have an amorphous carbon structure with a typical composition of 95-99% elemental carbon (C) with trace amounts of hydrogen (H), oxygen (O), nitrogen (N), and sulfur (S).

[0023] Phthalocyanine pigments include, for example, copper phthalocyanine blue (C32H16CuN8, Color Index PB15) and its chlorinated derivatives PB15:1 , PB15:3, and PB15:4, as well as copper phthalocyanine green (C32H16CICuN8, Cl PG7) and its brominated variant (C32Br6CI10CuN8, Cl PG36).

[0024] Metal oxide pigments include, for example, iron oxides such as hematite (a- Fe2O3, Cl PR101 ), magnetite (Fe3O4, Cl PBk11 ), goethite (a-FeOOH, Cl PY42), and various hydrated forms. Further examples include chromium oxide green (Cr2O3, Cl PG17), titanium dioxide in both anatase and rutile forms (TiO2, Cl PW6), zinc oxide (ZnO, Cl PW4), cobalt oxide (Co3O4), manganese oxide (Mn02), and cerium oxide (CeO2).

[0025] Mixed metal oxide pigments include, for example, cobalt aluminate blue (CoAI2O4, Cl PB28), chromium iron oxide (Cr2FeO4), copper chromite black 5 OLS-12517-24

[0026] 04.08.2025

[0027] (CuCr2O4, Cl PBk28), nickel titanate yellow (NiTiOS, Cl PY53), cobalt chromite green (CoCr2O4, Cl PG26), iron cobalt black ((Fe,Co)Fe2O4), zinc ferrite (ZnFe2O4), and manganese ferrite (MnFe2O4).

[0028] Metal sulfide or sulfite pigments include, for example, sodium sulfide (Na2S), sodium sulfite (Na2SO3) cadmium sulfide (CdS, Cl PY37), zinc sulfide (ZnS, Cl PW7), molybdenum disulfide (MoS2), lead sulfide (PbS), copper sulfide in various forms including chalcocite (Cu2S) and covellite (CuS), and iron sulfide (FeS2) in pyrite form.

[0029] Elemental sulfur comprises the various allotropic forms of sulfur, particularly the orthorhombic a-form (S8) which appears as bright yellow crystals, the monoclinic [3-form, and amorphous sulfur. Elemental sulfur can be milled to achieve the required particle size and provides yellow coloration with specific absorption characteristics in the near-infrared region.

[0030] NIR-absorbing oxide pigments include, for example, antimony tin oxide (Sb:SnO2 or ATO) with typical antimony doping levels of 5-20%, indium tin oxide (ln:SnO2 or ITO) with indium content typically 90%, cesium tungsten oxide (CsxW03, where x < 1 , typically 0.2-0.33), lanthanum hexaboride (LaB6), vanadium dioxide (VO2), tungsten oxide (W03-x) in various reduced forms, and doped semiconductor oxides such as aluminum -doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), and fluorine-doped tin oxide (FTO). These materials provide selective near-infrared absorption while often maintaining transparency in the visible region.

[0031] Metallic pigments include, for example, aluminum powder or flakes (Al), copper powder (Cu), bronze powder (Cu-Sn alloy typically 90-95% Cu, 5-10% Sn), brass powder (Cu-Zn alloy), zinc dust (Zn), stainless steel powder (Fe- Cr-Ni alloys), silver powder (Ag), gold powder (Au), and various alloy compositions. These metallic pigments can be surface-treated with silica, alumina, 6 OLS-12517-24

[0032] 04.08.2025 organic coatings, or controlled oxidation to modify their optical properties and chemical stability.

[0033] Other organic pigments suitable as over-pigments include various synthetic organic colorant classes:

[0034] Quinacridone pigments include, for example, quinacridone red (C20H12N2O2, Cl PR122), quinacridone violet (C20H12N2O2, Cl PV19), quinacridone magenta (Cl PR202), and quinacridone gold (Cl PO49).

[0035] Perylene pigments include, for example, perylene maroon (C32H16N2O4, Cl PR179), perylene red (C32H22N2O4, Cl PR149), perylene scarlet (C26H14N2O4, Cl PR224), and perylene black (C46H28N2O4, Cl PBk31 ).

[0036] Azo pigments include, for example, a large class of synthetic organic colorants containing one or more azo groups (-N=N-), such as pigment yellow 12 (C32H26CI2N6O4), pigment yellow 13 (C36H34CI2N6O4), pigment red 57:1 (C18H15CIN2O6S Ca), pigment red 48:2 (C18H15CIN2O6S Ca), pigment orange 34 (C34H28CI2N6O4), and pigment orange 13 (C32H24CI2N8O2).

[0037] Dioxazine pigments include, for example, dioxazine purple (C34H22CI2N4O2, Cl PV23), carbazole violet (C34H22CI2N4O2, Cl PV23:1 ), and related derivatives.

[0038] Other inorganic pigments include ultramarine pigments based on the sodalite structure with the general formula Na8[AI6Si6O24]Sn (where n = 2-4), including ultramarine blue (Cl PB29), ultramarine violet (Cl PV15), and ultramarine pink. The color arises from sulfur radical anions trapped within the aluminosilicate framework. Graphite, in its various forms including natural flake graphite, synthetic graphite, and expanded graphite, provides black to gray coloration with excellent chemical inertness. 7 OLS-12517-24

[0039] 04.08.2025

[0040] Special effect pigments include interference pigments based on mica (KAI2(AISi3O10)(OH)2) coated with titanium dioxide or iron oxide in controlled thicknesses, synthetic pearl pigments based on alumina (AI2O3) or silica (SiO2) platelets with metal oxide coatings, glass flakes coated with metal oxides, bismuth oxychloride (BiOCI) platelets, and liquid crystal pigments. These materials produce angle-dependent color effects through thin-film interference.

[0041] Fluorescent pigments include daylight fluorescent pigments based on rhodamine, fluorescein, or coumarin derivatives encapsulated in polymer matrices, and phosphorescent pigments such as strontium aluminate doped with europium and dysprosium (SrAI2O4:Eu,Dy) or zinc sulfide doped with copper (ZnS:Cu).

[0042] The over-pigment may also be composed of a combination of the abovelisted pigments.

[0043] The location of the stained area on the dyed fabric is in accordance with an objective design pattern. The over-pigmentation composition comprises a reactive over-pigment, preferably dark, such as carbon black or an ecological mineral pigment. The base pigment is initially a non-reactive pigment such as pure indigo, thus the dyed fabric exhibits an indigo color.

[0044] The laser marker is of the high-power optical fiber laser type that emits at least one laser beam in the range of infrared radiation of the continuous wave, CW, near infrared radiation type of modulable optical power cycle and amplitude, therefore, it is characterized by the absence of power intensity peaks significantly higher than the nominal power of the laser used, common in pulsed laser generators.

[0045] A deflection system redirects the emitted laser beam along the stained dyed textile material. The original design pattern is reproduced pixel by pixel or 8 OLS-12517-24

[0046] 04.08.2025 vector by vector by radiating the stained area until the design pattern is completed on the dyed textile material.

[0047] Those pixels that are within the stained area that are necessary to reproduce the target design pattern are successively irradiated. The rest of the pixels that are inside and outside the stained area, which correspond to the background of the pattern to be reproduced, are not irradiated because they are not necessary to reproduce the design pattern.

[0048] The fiber optic laser marker radiates wavelengths within the range of 1 ,060 to 1 ,090 nm, preferably wavelengths of 1 ,070 nm.

[0049] In other embodiments, the fiber optic laser marker radiates wavelengths within the range of 750 to 1 ,060 nm. Alternatively, the laser marker radiates visible wavelengths of the green type in the range 570 to 590 nm, violet-blue in the range 380 to 495 nm.

[0050] In another embodiment, the laser marker irradiates wavelengths in the ultraviolet UV range of the near UV type, IIV-A in the range between 315 to 400 nm, medium UV, UV-B in the range 280 to 315 nm, far UV-C in the range 100 to 280 nm, in the latter case more common for disinfection and sterilization tasks due to the ability to destroy micro-organisms.

[0051] Employing a low wavelength, for example, visible or near infrared length, allows reducing the cost of the textile marking operation, significantly increasing the quality (definition and repeatability) of the final finish on the textile, significantly increasing the durability of the textiles processed using this method, and therefore releasing a smaller amount of fibers in each wash of the garment during the garment finishing process, as well as throughout its useful life. 9 OLS-12517-24

[0052] 04.08.2025

[0053] The fiber optic laser marker irradiates laser beams to reproduce the target design pattern on stained areas of the dyed fabric. The design is reproduced with precision and high repetitiveness.

[0054] The dyed textile material is of the type, a textile fiber, yam based on a twist of several fibers, knitted or woven fabric, composed of several yams, a textile garment, a denim garment, a textile complement such as bag, wallet, belt, backpack, shoe, slipper, handkerchief, gloves, one, that some of the yams or fibers that compose it for example have a cross section where the dyeing base pigmentation is deposited superficially forming an outer ring on the inner core of the yam, usually in the warp thread, of the textile material.

[0055] A warp, denim cloth or cowboy-style cloth, where the warp yams are those that are dyed, usually with an indigo color. The yams are for example dyed in a process known as ring dyeing. The surface of the yams is dyed blue, leaving the core white. With the use and washing of the indigo-dyed fabric, the dye fades away, gradually revealing the white core of the yams that gives the denim fabric a worn appearance.

[0056] Therefore, the dyed textile material for example comprises ring dyed yams. The outer ring of the textile material has the color of the base pigment, while the inner core of the textile material has a color equal to or different from that of the base pigment.

[0057] The white or off-white color of the inner core of the fabric is related to a denim garment such as a pair of jeans. Therefore, the base pigment does for example not penetrate into the inner core of the textile material.

[0058] A weft made of denim fabric has weft threads, which are generally not dyed and are white or natural in color. These yams pass over and under the warp yams, creating the structure of the denim fabric. The combination of the dyed warp and the undyed weft is what gives the denim its characteristic 10 OLS-12517-24

[0059] 04.08.2025 appearance, with the outer side of the fabric predominantly showing the colour indigo and the inner side predominantly showing the colour white.

[0060] The over-pigmentation composition and the base pigment form a particle having a size suitable to react to the radiation of the optical fiber laser marker, therefore, the fiber laser marker discolours the pure indigo of the stained area. During an exposure time of the stained area exposed to the deflection system of laser beams, both the over-pigmentation composition and the base pigment are totally or partially removed without the textile material supporting great thermal impact. Thus, the fiber laser marker discolors the ring-dyed yams of the indigo-dyed fabric.

[0061] The fiber laser marker provides a discoloration to the dyed fabric that is located within the irradiated stained area. However, the indigo base pigment deposited on the fabric outside this irradiated stained area does not discolor or evaporate if it receives the laser beam emitted from the fiber optic laser marker.

[0062] Pure indigo reacts to the fiber optic laser marker if pure indigo dyed textile material is impregnated with the over-pigmentation composition. Sulfurous indigo such as sulfur bottom, sulfur top reacts to the fiber optic laser marker without requiring the over-pigmentation composition.

[0063] The fiber optic laser marker modifies the appearance of the dyed fabric by removing in whole or in part selected portions of both the over-pigmentation composition and the dyeing base pigment disposed superficially on the outer surface of the inner core of the fabric. The degree of removal is a function of the exposure time of a predetermined marking position to the laser beam, as well as the optical power density of the laser beam, and the concentration of the over-pigmentation composition applied on the dyed textile material. 11 OLS-12517-24

[0064] 04.08.2025

[0065] The modulated continuous wave, near infrared fiber optic laser marker emits continuous CW laser radiation, with an operating cycle that can be variable, and of optical power that is temporarily constant, variable within the exposure time range of the laser beam.

[0066] The irradiation exposure time of a marking position comprises an optical pulse rise time of less than or equal to 5 ps, a marking time of variable duration depending on the pixel hue of the target design pattern to be reproduced, and an optical pulse fall time of less than or equal to 5 ps. The exposure time presents a geometric shape of the type of a scalene triangle, an acute-angle scalene triangle, a rectangle, a scalene trapezoid.

[0067] The fiber optic laser marker directs and moves the laser radiation at a speed of movement of the laser beam between two contiguous marking points, equivalent to or less than the speed resulting from the calculation of the distance between the centers of both pixels, "pitch” distance, divided by the exposure time of one pixel, and different from the marking speed reached during the exposure time.

[0068] The fiber optic laser marker has an operating cycle in the range of 0% to 100%. The fiber optic laser marker exhibits an optical pulse repetition rate equal to or lower than 100,000 pulses per second at a frequency equal to or lower than 100 kHz. It is not impossible to exceed 100 kHz in the near future.

[0069] The optical pulse repetition rate is a function of the optical power of the fiber optic laser marker, the optical power being in the range of 0.5 kW to 10 kW, preferably 2 kW to 8 kW and preferably 6 kW.

[0070] In another embodiment, the optical pulse has a rise time in the range of 1 to 3 ps and a fall time in the range of 1 to 3 ps. 12 OLS-12517-24

[0071] 04.08.2025

[0072] In a preferred embodiment of the present invention, the solid-state fiber laser marker employs a direct fiber oscillator configuration, preferably with a single pump laser. Unlike pulsed fiber lasers or fiber laser systems that utilize a separate seed laser followed by fiber amplifiers (MOPA - Master Oscillator Power Amplifier configuration), the direct fiber oscillator generates laser radiation directly within the doped optical fiber itself, without requiring any external seed source or master oscillator.

[0073] The direct fiber oscillator preferably with a single pump laser comprises a continuous length of active optical fiber, typically doped with rare-earth ions such as ytterbium (Yb3+). The entire laser cavity is formed within the fiber structure, preferably creating a monolithic, all-fiber architecture. This configuration eliminates free-space optical components, resulting in exceptional mechanical stability and reliability.

[0074] The advantages of the direct fiber oscillator configuration include a simplified architecture with fewer components, higher electrical-to-optical efficiency, and lower manufacturing costs due to the elimination of seed laser components.

[0075] In a particularly preferred embodiment, the direct fiber oscillator incorporates fiber Bragg gratings (FBGs) to form the laser resonator cavity. The fiber Bragg gratings are periodic refractive index modulations inscribed directly into the core of the optical fiber using for example ultraviolet light exposure or femtosecond laser writing techniques.

[0076] The fiber Bragg grating configuration typically comprises a high-reflectivity FBG (>99% reflectivity) at one end of the active fiber serving as the rear cavity mirror and a partial-reflectivity FBG (typically 10-50% reflectivity) at the output end serving as the output coupler. The gratings are designed with a specific period to reflect a desired laser wavelength while being transparent to the pump wavelength. 13 OLS-12517-24

[0077] 04.08.2025

[0078] The described fiber laser is of small size and weight, therefore, it has a compact structure, has a high energy efficiency that allows operation without a high input electrical power requirement, which reduces the environmental footprint and is of interest in environments where manufacturing space is scarce. Furthermore, the described fiber laser allows for lighter weight marking heads without the need to carry the whole laser generator. For example, the fiber laser can be split into a cabinet containing all electronics, pump laser and optical amplifier, and a delivery fiber that can be connected to the deflection unit being of small size and weight. In this configuration, the marking head is easier to move and generally more flexible.

[0079] The described fiber optic laser marker is currently cheaper, price per watt of optical power, compared to any other medium and high power laser and increases the quality, definition and repeatability, of the final finish of the dyed textile material, and increases the durability of the processed textile materials.

[0080] The fiber optic laser marker provides differentiated finishing effects of an irradiated stained area with respect to other irradiated stained areas, also, based on the target design pattern applied, therefore, the dyed textile material has different finishes.

[0081] After laser irradiation, the textile material can for example be washed to remove the over-pigmentation composition.

[0082] The present solution discloses an over-pigmentation composition wherein the composition is a solution comprising, per kilo of composition:

[0083] - 300 - 550 grams of water,

[0084] - 100 - 200 grams of over-pigment,

[0085] - 250 - 350 grams of dispersing agent, 14 OLS-12517-24

[0086] 04.08.2025

[0087] 50 - 150 grams of glycol, and 5 - 15 grams of wetting agent.

[0088] Over-pigment is a pigment capable of absorbing radiation from a laser in the range of 400 and 1 ,800 nm. In addition, for a correct arrangement on the surface of the textile material, the over-pigment must have a particle size of less than 10 micrometers.

[0089] The use of a solution from this over-pigmentation composition on a textile material generates a stained zone in the material, wherein said zone is reactive, including the base pigment of a dyed textile, to radiation from a laser marker in the wavelength range between 400 and 1 ,800 nm.

[0090] In a further embodiment of the solution, the invention relates to a method of obtaining the previously disclosed over-pigmentation composition. The method of obtaining the over-pigmentation composition comprises a step of mixing the elements and a subsequent grinding.

[0091] Specifically, mixing is done by introducing into a mixer, per kilogram of composition: 100 - 200 grams of over-pigment, 250 - 350 grams of dispersing agent, 50 - 150 grams of glycol, and 5 - 15 grams of a wetting agent in 400 - 550 grams of water. The result of mixing the elements is a uniform viscous mixture of all the elements of the composition. For its part, the milling of the uniform viscous mixture resulting from the above mixture gives rise to a composition comprising a particle size of less than 10 micrometers. This particle size allows a suitable arrangement in the subsequent over-pigmentation, or dyeing, of the textile material. Thus, the product resulting from this method is a concentrated viscous composition that can be operated by a user for marketing.

[0092] In yet another embodiment, an over-pigmentation method is disclosed. The over-pigmentation method comprises: applying a dilution of the over- 15 OLS-12517-24

[0093] 04.08.2025 pigmentation composition on a region, defining a stained area, of a textile material and applying laser radiation on at least one marking point of the stained area where the dilution has been applied, partially or totally removing both the over-pigmentation component and the base pigment, and obtaining a marked textile material. The marking point is that point of interest established according to a predetermined design pattern of the user.

[0094] Specifically, the dilution to be applied for obtaining a marked textile material comprises a concentration in the range of 2.5 - 10 grams of over-pigmentation composition per kilogram of dilution. During this method, the initial fiber of the textile material is not affected or altered by laser radiation.

[0095] In a further embodiment, disclosed is a textile product comprising a textile material marked according to the method described above, i.e., over-pig- mented. Thus, the textile product comprises a user-defined design pattern.

[0096] Therefore, the development of the present solution allows the laser marking of non-reactive textiles initially, having been dyed or not, by means of a laser radiation between 400 and 1 ,800 nm, including the radiation of a solid fiber optic laser - 1 ,070 nm -, alternatively to other current solutions where other reactive dyes or another laser marker are used, such as the CO2 gaseous state laser.

[0097] In an alternative embodiment of the present invention, the over-pigmentation composition may comprise a sulfur dye in its reduced, soluble leuco form.

[0098] The sulfur-based over-pigmentation composition comprises, per liter of sprayable solution:

[0099] - 2 to 5 grams of sulfur dye powder as the over-pigment,

[0100] - 1 to 2 grams of sodium sulfite (Na2SO3) as a reducing agent to solubilize the dye,

[0101] - optionally 0.1 to 0.2 grams of sodium hydroxide (NaOH) to create a slightly alkaline environment, 16 OLS-12517-24

[0102] 04.08.2025

[0103] - optionally 0.1 to 0.3% of a non-ionic surfactant to improve sprayability and distribution, and

[0104] - Deionized water to make up to 1000 ml.

[0105] The preparation process may involve dissolving the sodium sulfite in warm deionized water at 40 to 60°C, optionally adding sodium hydroxide to create a slightly alkaline environment. Preferably, the sulfur dye powder is then gradually added under continuous agitation, whereby the dye is reduced to its leuco (soluble) form. The resulting solution may be filtered to remove any undissolved particles before spray application.

[0106] A critical aspect of this sulfur-based formulation is the deliberate avoidance of any oxidation step that would convert the dye back to its insoluble form and cause permanent fixation. Common oxidizing agents such as hydrogen peroxide (H2O2), sodium hypochlorite (NaCIO), atmospheric oxygen combined with heat, or potassium dichromate (K2Cr2O7) must be excluded from the formulation and application process. This ensures that the sulfur dye remains in its temporary, removable state throughout the laser marking process.

[0107] The sulfur-based over-pigmentation composition is applied to the textile material by spraying, creating a stained area similar to the previously described over-pigmentation compositions. Once dried, the dye remains non-fixed on the textile surface, allowing it to interact with laser radiation to facilitate marking while maintaining easy removability after the marking process.

[0108] Following laser marking, the sulfur-based over-pigmentation can be completely removed using warm water, mild detergent, and optionally a small amount of sodium hypochlorite (household bleach). This removal process eliminates any unfixed dye without damaging the underlying textile material or affecting the laser-marked pattern. 17 OLS-12517-24

[0109] 04.08.2025

[0110] The sulfur dye particles in this formulation, when maintained in their reduced state, exhibit particle sizes compatible with the requirements of the present invention (less than 10 micrometers) and provide effective absorption of laser radiation in the specified wavelength range of 400 to 1 ,800 nm.

[0111] Brief description of the figures

[0112] A more detailed explanation of the invention in accordance with the embodiments thereof is given in the description below, based on the attached figures wherein:

[0113] Figure 1 shows in a graph the low repeatability of pulse-to-pulse energy, green colour, product of the rise and fall time of each laser pulse, in blue, of a CO2 gas state laser marker,

[0114] Figure 2 shows the generation of the same pulse train of figure 1 with a near infrared, NIR, fiber optic laser marker, with high energy repeatability, in green, product of reduced response times of an optical pulse, in blue, for pulses of a predetermined target energy, orange,

[0115] Figure 3A shows a Gaussian distribution of the near infrared, NIR, fiber optic laser marker of the single mode SM type,

[0116] Figure 3B shows a distribution of the near infrared, NIR, fiber optic laser marker of the multi-mode MM type,

[0117] Figure 3C shows a distribution of the near infrared, NIR, fiber optic laser marker of the ring distribution type,

[0118] Figure 4 shows in an oval cross section of the laser beam of a CO2 gas state laser marker, if the oval laser beam is displaced perpendicularly to the wide diameter direction of the oval cross section, the resulting trace is thickened away from the target cross section, by about 1.2:1 , if the oval laser beam is 18 OLS-12517-24

[0119] 04.08.2025 displaced perpendicularly to the short diameter direction of the oval cross section, the resulting trace approaches the target cross section, the cross section of the near infrared, NIR, fiber optic laser marker is always a circle, therefore the trace always has the same size in either of the two XY directions of an orthogonal reference system where the laser beam is displaced, without a variation in the quality of the marked pixel in relation to the marking direction, and

[0120] Figures 5A, 5B show in a cross-section the textile material, e.g.: plain weave, section of 8 threads B, dyed with a ring base pigment C, an over-pigmentation composition D being superficially deposited, e.g. by spraying, a near-infrared fiber optic laser marker, NIR, irradiates with a laser beam A an area stained with the over-pigmentation composition D, the laser beam A is displaced in the direction E of the dyed textile material, to remove both the overpigmentation composition D and the base pigment C without affecting the threads B of the textile material, based on an applied target design pattern.

[0121] Figure 6 shows a photograph of the results obtained by laser marking a denim-type textile after the application of a laser marker and subsequent washing to the laser marking of an anionic over-pigmentation composition comprising an organic carbon black over-pigment.

[0122] Figure 7 shows a photograph of the results obtained by laser marking a denim-type textile after the application of a laser marker and subsequent washing to the laser marking of an anionic over-pigmentation composition comprising a mineral over-pigment.

[0123] Figure 8 shows a photograph of the results obtained by laser marking a black dyed non-denim textile after application of a laser marker and subsequent washing to laser marking of an anionic over-pigmentation composition. 19 OLS-12517-24

[0124] 04.08.2025

[0125] Figure 9 shows a photograph of the results obtained by laser marking a green dyed non-denim textile after application of a laser marker and subsequent washing to laser marking of an anionic over-pigmentation composition.

[0126] Figure 10 shows a photograph of the results obtained by laser marking a blue-tinted non-denim textile after application of a laser marker and subsequent washing to laser marking of an anionic over-pigmentation composition.

[0127] Figure 11 shows a set of photographs (a, b, c and d) of the results obtained by laser marking a non-denim textile dyed navy blue after the application of a laser marker and subsequent washing to the laser marking of an anionic over-pigmentation composition.

[0128] Figure 12 shows a set of photographs of the results obtained by laser marking a tencel fabric: a) after washing a textile dyed with indigo pigment, b) fixing the color after application of the laser marker.

[0129] Detailed description

[0130] Referring to figures 2 to 5, one embodiment of a solid-state laser marker is used to modify the finish of a textile material B dyed with a non-reactive base pigment C. The solid-state laser marker irradiates a beam of laser beams A towards a marking point or pixel of a predetermined zone of the dyed textile material C previously impregnated with an over-pigmentation composition D which is superficially deposited on the base pigment C of the dyed textile material B.

[0131] The over-pigmentation composition D forms a spot, stained area, on the surface of the predetermined area of the dyed fabric. The location of the stained area on the dyed fabric is in accordance with an objective digital design pattern. OLS-12517-24

[0132] 04.08.2025

[0133] The laser marker is a fiber optic laser that emits beams of laser beams A in the range of infrared radiation, preferably, near infrared radiation, NIR, modulated continuous wave, CW, and constant optical power.

[0134] The near-infrared, NIR, fiber optic laser marker irradiates beams of laser beams A with wavelengths within the range 1 ,060 to 1 ,090 nm, preferably wavelengths of 1 ,070 nm.

[0135] The laser beam A irradiated by the near infrared fiber optic laser marker, NIR, has a configurable beam spot diameter, between 0.5 and 1.5 mm, preferably 0.7 mm wherein the optical embodiment is designed for a useful working area of 1 .5 x 1 .5 meters, placing the entire textile material or folded in half and therefore allowing to increase the resolution of the images in the range of 40 to 50 dpi. The diameter of the laser beam spot A is located at a distance of in the range of 1 to 2 m from the NIR fiber laser marker.

[0136] The size of the spot, laser beam A at the focal point, is calculated according to the following formula

[0137] For NIR 1 ,070 nm near infrared fiber optic laser marker, area 1 ,500 x 1 ,500 mm:

[0138] Beam diameter: 30 mm

[0139] Laser Beam Parameter (M2): 7 21 OLS-12517-24

[0140] 04.08.2025

[0141] Wavelength: 1 ,070 nm

[0142] Lens Focal Length: 2,000 mm

[0143] Spot Size: 634 pm, equivalent to 0.63 mm

[0144] Referring to figure 4, the 1 ,070 nm NIR near-infrared fiber optic laser marker, the spot size is substantially reduced, equivalent to a smaller "brush size" for drawing in greater detail, allowing to improve the resolution of the images to be transferred to the dyed textile material.

[0145] There is also another parameter that has an effect, called M2, M squared, which in the case of the multi-mode 1 ,070 nm NIR near-infrared fiber optic laser marker is higher than 5 to 7, which proportionally penalizes the size of the spot.

[0146] An electronic controller is connected to the NIR fiber optic laser marker and to an information data repository that stores at least one target digital design pattern.

[0147] The electronic controller transmits control instructions to the NIR fiber optic laser marker based on the stored target digital design pattern. The NIR fiber optic laser marker controls the laser radiation to modulate it and direct the laser beam A to impinge on marking positions of stained areas of the dyed textile material to mark the recovered target digital design pattern.

[0148] Referring now to figs. 5A and 5B, the laser beam A by impinging on a marking position of the stained area of the textile material B, dyed fabric C, partially or totally removes both the over-pigmentation component D and the base pigment C by decolorizing the dyed fabric, providing different discoloration shades of the base dye, without affecting the dyed fabric. 22 OLS-12517-24

[0149] 04.08.2025

[0150] The electronic controller is a computer that instructs the NIR fiber laser marker to irradiate optical pulses of CW continuous laser radiation, of modu- lable operating cycle, and of constant, variable power amplitude, combined within the application time range of the laser beam.

[0151] The electronic controller transmits control instructions to supply the laser radiation wavelength, power, intensity, operating cycle, duration, shape and repetition rate of the laser radiation for each pixel point or vector forming the target digital design pattern to be transferred to the dyed textile material.

[0152] The set of transmitted control instructions includes information for following a marking path related to the target digital design pattern, positioning the NIR fiber optic laser marker over a predetermined position to be marked from a predetermined stained area of the dyed fabric to be irradiated, exposure time to the laser beam A of the laser marker, including the rise time, exposure or marking time and fall time of the optical pulse, instructions for positioning the laser beam A markers over the next position to be marked that could belong to a different stained area of the dyed fabric.

[0153] The number of control instructions issued is related to the digital design pattern to be applied on the dyed textile material.

[0154] The exposure time of a predetermined laser beam A is based on the target design pattern to be applied. Therefore, the laser beams A require different or similar exposure times according to the target design pattern to be reproduced, however, the rise time and the fall time of each emitted optical pulse are the same or approximately the same.

[0155] The irradiated optical pulse of the laser beam A shows a rise time, marking time, wherein the optical power remains constant, in a scenario where the amplitude of the optical power during the pulse is not modulated and a fall 23 OLS-12517-24

[0156] 04.08.2025 time, which have a shape of the type of scalene triangle, of acute scalene triangle with sides of different length and angles of different amplitude, each of the three angles has an amplitude less than 90°, of scalene trapezium that has four unequal sides, their interior angles being also different from each other, the sum of the four angles is equal to 360°.

[0157] The electronic controller transmits control instructions for directing the laser beam toward the marking point of the stained area to be irradiated based on the digital design pattern to be reproduced on the dyed fabric.

[0158] The NIR fiber optic laser marker exhibits a displacement rate of the laser beam A during the marking process lower than the displacement rate of the laser marker between stained areas, without radiating with the laser beam A, because neither the over-pigmentation composition D nor the base pigment C is removed from the dyed textile material.

[0159] The NIR infrared fiber laser marker provides different degrees of discoloration of the dyed textile material, within the same marking line, according to the following combinations:

[0160] - Varying the exposure time, keeping the working power of the laser marker at a constant level, keeping the size and energy distribution of the focal point constant, but varying the speed of movement between adjacent marking positions, therefore, only the time of exposure to the laser beam on each of the marking points is varied to make it correspond to the target digital design pattern.

[0161] - Maintaining the exposure time, keeping the speed of movement between adjacent marking positions constant, keeping the size and energy distribution of the focal point constant, but varying the working power of the laser marker, therefore, only the optical power amplitude of the laser beam on each of the marking points is varied to make it correspond to the target digital design pattern. 24 OLS-12517-24

[0162] 04.08.2025

[0163] - Maintaining the exposure time, keeping the speed of movement between adjacent marking positions constant, keeping the working power of the laser marker constant, keeping the size and energy distribution of the focal point constant, but varying the temporal modulation, operating cycle, of the laser beam, therefore, only the operating cycle of the laser beam on each of the marking points is varied to make it correspond to the target digital design pattern.

[0164] - Maintaining the exposure time, keeping the speed of travel between adjacent marking positions constant, keeping the working power of the laser marker constant, keeping the temporal modulation, operating cycle, of the laser beam constant, but varying the size or energy distribution of the focal point and therefore varying the power density of the laser beam on each of the marking points to make it correspond to the target digital design pattern.

[0165] - Any combination of the above.

[0166] In an alternative embodiment, the laser beam has a Gaussian distribution, M2 or M squared = 1 .0, or a multi-mode laser beam, M2 greater than 3, or a laser beam with a ring distribution, or any combination thereof.

[0167] The over-pigmentation composition D and the base pigment C of a predetermined marking position are decolorized together to a greater or lesser extent by varying the intensity or concentration of the laser beam A radiated on the marking point according to any of the modes described above, varying the speed of travel, varying the amplitude of optical power, varying the operating cycle, varying the size or density of the optical power of the focal point or its energy distribution, or any combination of the above parameters.

[0168] The NIR fiber optic laser marker irradiates optical pulses with an optical pulse rise time equal to or less than 5 ps, preferably 1 ps. 25 OLS-12517-24

[0169] 04.08.2025

[0170] Changing the relative position of the irradiated laser beam A to the surface of the dyed fabric, in some scenarios, involves moving the dyed fabric relative to the laser beam A radiated by the NIR fiber laser marker.

[0171] The electronic controller transmits control instructions to guides of the laser beam of the NIR fiber laser marker that change the direction of the radiation of the laser beam A on the marking position of the stained area. The guides of the laser beam A to spatially modulate it by means of at least one of the following deflection systems:

[0172] - rotating polygonal mirror,

[0173] - piezoelectric scanner,

[0174] - high resolution acousto-optic, or electro-optic deflector

[0175] - linear guide,

[0176] - or, preferably, a set of two mirrors placed in XY galvanometric scanners,

[0177] - or any combination of the above which is capable of deflating, guiding the laser beam A temporarily modulated, or modulated in optical power amplitude, or modulated in size or energy distribution of the laser beam, or modulated by its operating cycle, or modulated by any combination of the above, at high angular speed on the 1 D scan line along a vector or sequence of points, or of a 2D scan plane of the textile material, preferably at scan line repetition frequencies of up to 100,000 Hz or even higher, and which is controlled through the electrical or optical signal, digital or analogue, coming from the information processing unit that manages the system.

[0178] In another embodiment, the electronic controller is connected to a movable platform on which the dyed textile material to be radiated is arranged. The movable platform moves relative to the beam of laser beams that is radiated 26 OLS-12517-24

[0179] 04.08.2025 over the marking position of the stained area of the dyed textile material and arranged on the platform.

[0180] If the digital design pattern comprises marking positions with different degree of partial discoloration, the electronic controller transmits control instructions regarding the exposure time, that the laser beam will irradiate each marking position. The discoloration of the marking position of the irradiated stained area is achieved by controlling parameters such as the exposure time of the marking position to the irradiated laser beam, the modulation of the operating cycle, or of the optical power amplitude, of the operating cycle, of the size and / or energy distribution of the laser beam, or of any combination of the above.

[0181] According to the exposure time or density, it is possible to provide different finishes of dyed textile material, producing wear and discoloration of the dyed textile material without burning the dyed textile material. If the set of the above parameters is varied, the textile material can also be burned, either totally or partially.

[0182] The NIR fiber optic laser marker has an operating cycle in the range of 0% to 100%. The fiber optic laser marker has an optical pulse repetition rate less than, equal to, or greater than 100,000 pulses per second at a frequency less than, equal to, or greater than 100 kHz.

[0183] The optical pulse repetition rate is chosen based on the optical power of the near infrared fiber optic laser marker NIR, the output optical power being in the range of 0.5 kW to 20 kW, preferably 2 kW to 12 kW and preferably 6 kW.

[0184] In another embodiment, the optical pulse has a rise time in the range of 1 to 3 ps and a fall time in the range of 1 to 3 ps. 27 OLS-12517-24

[0185] 04.08.2025

[0186] Once the laser beam of the NIR fiber optic laser marker has finished modifying the finish of the related dyed fabric, the rest of the over-pigmentation composition D of the non-irradiated stained area, remains deposited on the base pigment C of the dyed fabric, being removed from the dyed fabric by a washing type removal process, in an aqueous medium such as water, water with peroxide, or washing in a gaseous medium such as ozone, supercritical CO2, or nitrogen.

[0187] Referring to figure 4, the NIR fiber laser marker is small in size and weight, therefore, it has a compact structure, has a high energy efficiency that allows operation without a high input electrical power requirement, which reduces the environmental footprint and is of interest in environments where manufacturing space is scarce. In addition, and having no optical elements exposed to the environment, it does not require any optical maintenance, thus reducing maintenance costs.

[0188] The fiber optic laser marker provides differentiated finishing effects of an irradiated stained area with respect to other irradiated stained areas, also, based on the target design pattern applied, therefore, the dyed textile material has different finishes.

[0189] The present solution discloses an over-pigmentation composition. The overpigmentation composition is an aqueous solution comprising an over-pigment, a dispersing agent, a glycol and a wetting agent.

[0190] In particular, to obtain a kilo of the over-pigmentation composition, the following is used:

[0191] - 300 - 550 grams of water,

[0192] - 100 - 200 grams of over-pigment,

[0193] - 250 - 350 grams of dispersing agent,

[0194] - 50 - 150 grams of glycol, and 28 OLS-12517-24

[0195] 04.08.2025

[0196] 5 - 15 grams of wetting agent.

[0197] The over-pigment is at least a pigment capable of absorbing radiation from a laser at a predetermined wavelength. Additionally, the over-pigment has a particle size of less than 10 micrometers. This particle size allows a correct arrangement during its application on the textile to be marked, achieving a good surface dispersion of the over-pigment on the textile.

[0198] The over-pigment is, particularly, a pigment capable of absorbing low wavelength radiation, in the visible or near infrared range, in a wavelength range of 400 nm to 1 ,800 nm. This absorbed radiation can be used for the partial or total removal of the pigments present in the textile material, both the overpigment and the base pigment.

[0199] In a particular embodiment, the wavelength range is from 600 nm to 1 ,600 nm. In another more particular embodiment, the range is from 700 nm to 1 ,400 nm, and more particularly between 800 nm and 1 ,200 nm. In a preferred embodiment, the wavelength range is from 1 ,060 nm to 1 ,090 nm, and more specifically from 1 ,060 nm to 1 ,070 nm. This particular wavelength range allows a solid-state laser, preferably a fiber optic laser, to be employed instead of a CO2 gaseous state laser as presently employed, as a laser marker. This type of laser marker enables reducing the cost of the textile marking operation, significantly increasing the quality (definition and repeatability) of the final finish in the textile, significantly increasing the durability of the textiles processed using this method, and therefore releasing a smaller amount of fibers in each wash of the garment during the finishing process of the garment, as well as throughout its useful life.

[0200] Additionally, the over-pigment of the composition is a dark-colored pigment. More specifically, the over-pigment may be a black, grey, blue, green, red, orange pigment or variations thereof. 29 OLS-12517-24

[0201] 04.08.2025

[0202] The use of a dark over-pigment allows for a better contrast in the final product obtained. That is, a textile that has as its base a white color (original of cotton), or with an initial dyeing in light colors, when treated with a dark pigment and subsequently marked with laser, gives rise to a product with a greater contrast in the marked pattern. For a light over-pigment embodiment, laser marking can also be performed, but the contrast is much lower and, in some cases, practically negligible in case of employing a textile with a light base color, e.g. white, as natural cotton is. This method would therefore be feasible in some embodiments, although it would be advisable to present a dark color as a base color to achieve an acceptable contrast with an overpigment in a light shade.

[0203] In another particular embodiment, the over-pigment may be an organic pigment, for example, carbon black, or inorganic, for example, a mineral pigment. The choice of an over-pigment or another can have a direct impact on the sustainability of the textile dyeing process.

[0204] In a particular embodiment, the over-pigment is carbon black. This pigment has a strong coloring power. A small amount can produce an intense and deep black color, which is very effective for achieving dark tones. In addition, it has a very small particle size and a large surface area, which contributes to its strong color properties and its ability to cover surfaces evenly. It provides excellent opacity and coverage, which is useful in textile applications where full coverage and a deep and uniform color are desired. Carbon black is chemically stable and resistant to environmental factors such as light, heat and chemicals, which ensures that dyed textiles retain their color during the coverage time. On the other hand, it can impart electrical conductivity to textiles, which can be beneficial for producing antistatic or conductive fabrics.

[0205] Carbon black is compatible with various types of textile fibers, including natural fibers (such as cotton and wool) and synthetic fibers (such as polyester and nylon). In this way, the use of this type of pigment in textile dyeing provides an intense dark color, difficult to achieve with other pigments. Due to its 30 OLS-12517-24

[0206] 04.08.2025 strong dyeing power, the use of a small amount of pigment is required which translates into an economically competitive option. In addition, it has excellent durability and uniformity, giving rise to textiles resistant to washing, sun exposure and abrasion, with a consistent color throughout the textile. Additionally, carbon black requires the use of dispersion and stabilizer processes due to its tendency to agglomerate.

[0207] On the other hand, a mineral pigment with a high concentration of calcium carbonate can also be used for dyeing textiles. This type of mineral material has a high surface area. This feature provides a high number of active points for the adherence of dye molecules. This results in a significant improvement in the absorption and fixation of the dye in the textile, which generates more vibrant and durable colors. The material exhibits strong interactions with various dye molecules, improving the affinity between the dye and textile fibers. This ensures better absorption and retention of the dye. Textiles dyed with mineral pigment show improved color fastness properties. This means that the colors are less likely to fade over time or with washing, keeping the appearance of the fabric for longer. This material is compatible with a wide range of dyes, including natural and synthetic dyes. This versatility allows it to be used in various dyeing applications and for different types of fibers, which, together with its own environmentally friendly design, contributes to obtaining more sustainable textile products. In short, mineral pigment offers numerous advantages for textile dyeing, including improved dye affinity, enhanced color fastness, environmental friendliness, and cost-effectiveness. Its characteristics make it a valuable material for achieving sustainable and high-quality dyeing results in the textile industry.

[0208] The choice of the size and shape of the over-pigments depends on several factors, such as the desired color intensity, coverage, texture, and method of application. In general, different structures of these over-pigments can be listed: 31 OLS-12517-24

[0209] 04.08.2025

[0210] - Nano-particles: extremely small particles with diameters typically from 10 to 100 nanometers as a single unit. Its density is between 1.8 to 2.1 g / cm3Nano-particles provide excellent color intensity and dispersion properties.

[0211] - Micro-particles: these are slightly larger particles with diameters ranging from 100 nanometers to a few micrometers. They offer good coverage and color opacity.

[0212] Regarding the shapes of these over-pigments, they can also be differentiated between:

[0213] - Spherical: spherical particles provide good color intensity and coverage. They are often preferred to achieve an even distribution of color.

[0214] - Aggregates: aggregate particles are formed by small groups of primary particles. They offer enhanced color intensity and can provide unique textural effects on textiles.

[0215] - Nodular: nodular particles have irregular shapes that resemble small nodules. They can contribute to a matte finish and improve color depth in textiles.

[0216] The over-pigment employed in the over-pigmentation composition can be selected from a wide range of organic and inorganic pigments capable of absorbing laser radiation in the respective wavelength range. Preferably, the over-pigment is selected from the group consisting of carbon blacks, phthalocyanine pigments, metal oxide pigments, mixed metal oxide pigments, metal sulfide or sulfite pigments, elemental sulfur, NIR-absorbing oxide pigments, metallic pigments, and combinations thereof (see above).

[0217] In a particular embodiment, the over-pigment of the composition comprises a particle size of less than 10 micrometers, preferably between 5 and 8 micrometers. In addition, the over-pigment has a nodular shape. 32 OLS-12517-24

[0218] 04.08.2025

[0219] For its part, the dispersing agent is an element used to achieve a uniform distribution of the pigment particles in an aqueous medium. The dispersing agent prevents agglomeration by preventing the over-pigment particles from clumping together or forming agglomerates. By keeping the over-pigment particles apart, the dispersing agent helps stabilize the suspension. The dispersing agent improves the efficiency of the production process by reducing the viscosity of the mixture, facilitating handling. Therefore, production is faster and more efficient. Obtaining a good dispersion of the over-pigmentation composition ensures a much more uniform application on the textile to be marked.

[0220] Dispersing agents can be classified into different categories according to their chemical nature and their mechanism of action. Among the best-known dispersants, anionic, cationic (amines and quaternary ammonium salts, such as benzalkonium chloride), non-ionic (ethers, polyethers, alcohols), amphoteric (betaines and sulfobetaines) and polymeric (acrylic and polymethacrylic polymers, polyurethanes and peptide and protein polymers) dispersants can be highlighted. Additionally, new dispersants have been developed, such as nano-dispersants that use nano-particles to stabilize the dispersion, or reactive dispersants, which are covalently attached to the surface of the pigment, providing additional stability.

[0221] In a particular embodiment of the invention, anionic dispersants are employed that comprise negative charges that repel the particles of the over-pigment from each other, preventing agglomeration. This type of anionic dispersants includes carboxylic acid salts (fatty acid soaps), sulfates and sulfonates (alkyl sulfates and alkylbenzene sulfonates) and phosphates and phospho- nates (phosphoric and phosphonic acid salts). In a particular embodiment, the dispersing agent is a sulfate. Specifically, in a particular embodiment is alkyl sulfate. 33 OLS-12517-24

[0222] 04.08.2025

[0223] The wetting agent is an element participating in the improvement in the dispersion and adhesion of over-pigments, adjusting the viscosity and compatibility with other components. Additionally, they accelerate the drying of the composition once applied to the textile. These benefits result in high-quality textile products with vibrant and durable colors. In particular, the wetting agent reduces the surface tension between two phases, such as the solid (over-pigment) and the liquid (carrier), improving the dispersion and adhesion of the over-pigment. It participates in the improvement of the dispersion of the over-pigment in the mixture of the composition, ensuring an even distribution of said over-pigment. On the other hand, it succeeds in increasing the adhesion of the over-pigment to the surface of the textile where it is applied, which is essential to obtain a uniform and durable coverage. In addition, it prevents agglomeration of the over-pigment particles, which can improve the color quality and consistency of the final product.

[0224] Among the wetting agents may be ethoxylated fatty alcohols (ethoxylated lauryl ether) or ethers, for example, of propylene and ethylene. These compounds are effective in reducing the surface tension of the solution, improving the wetting of the over-pigments. They are also known for their low foaming, which is beneficial in industrial processes. In addition, they can offer adjustable solubility and wetting properties, which makes them versatile for different pigment formulations. There are also derivatives of fatty acids and glycerine that offer good properties as a wetting agent and, additionally, are biodegradable, which makes them attractive from an environmental point of view. In contrast, there are compounds such as alkylphenol ethoxylates (nonylphenol ethoxylate) whose use may be restricted due to environmental concerns. On the other hand, there are silicones (modified siloxanes) that can be used as a wetting agent, providing excellent wetting properties and can improve the softness and finish of textiles, in addition to reducing the surface tension of the formulations. In a particular embodiment, the wetting agent employed is ethylene oxide. 34 OLS-12517-24

[0225] 04.08.2025

[0226] On the other hand, the glycol comprised in the over-pigmentation composition plays a complementary role to the dispersing agent and the wetting agent. Glycol is a chemical compound belonging to the family of alcohols, examples being ethylene glycol and propylene glycol. Glycol is employed as a solvent to disperse and dissolve other components in the formulation of the over-pigmentation composition. In addition, it helps to adjust the viscosity of the mixture to make it easier to handle and apply and to improve the stability of the pigment, preventing sedimentation and increasing the uniformity of the dispersion of the particles in the resulting composition. In a particular embodiment, the glycol employed is ethylene glycol.

[0227] Thus, the glycol of the over-pigmentation composition acts primarily as a solvent and viscosity modifier, while the wetting agent focuses on improving the interaction between the over-pigment and the medium, facilitating more effective dispersion and adhesion. That is, while the glycol is designed to affect the physical properties of the mixture (such as viscosity and stability), the wetting and dispersing agent affect the chemical-physical properties of the interaction between the components, such as surface tension and dispersion. The presence of the glycol provides an adequate and stable environment for the over-pigment, in addition to the performance of the wetting and dispersing agent, which ensure that the over-pigment is evenly dispersed in the mixture and subsequently adheres adequately to the surface of the textile. In summary, the combined use of these compounds is essential to obtain a high-quality final product with desirable application, stability and performance properties.

[0228] Therefore, thanks to the presence of these elements, the over-pigmentation composition can be applied on a textile formed from cotton, raw cotton, polyester, spandex, bamboo fabric, tencel fabric or a combination of these, so that the resulting textile is reactive to radiation irradiated by a laser marker in the wavelength range between 400 - 1 ,800 nm and can be marked by a laser marker. 35 OLS-12517-24

[0229] 04.08.2025

[0230] However, regardless of the over-pigment used, the characteristics that initially generated advantages in the dye can be translated into disadvantages in the case of requiring the removal of this compound when it acts as an over-pigment.

[0231] In a particular embodiment of dyeing, the over-pigmentation composition further comprises a fixing agent. The fixing agent is in a formulation of 5 - 25 grams per kilogram of composition. The fixing agent is used to fix the dye and ensure that the color remains vibrant and resistant to multiple washes. Among the fixing agents that may be employed in the composition are mordants and binders.

[0232] Mordants are chemicals that help to fix pigments to textile fibers. In a particular embodiment, the mordant employed is a metal salt. In a more particular embodiment, the mordant is selected from the group consisting of aluminium sulfate, aluminium acetate and iron sulfate — these mordants form bonds with the fibers and pigments of the textile, improving the adhesion and colour fastness. On the other hand, binders are substances that are mixed with the pigments to create an adherent layer on the textile fibers. These products can be incorporated for those compositions that do not chemically react with fibers. Among the fixing agents of the binder type, acrylic resins may be employed. These resins are used in pigment dyes and help form a film on the fiber that traps the over-pigment. On the other hand, polymers, such as polyvinyl alcohol, could also be used to create a network on the fiber, which increases the resistance to washing.

[0233] Additionally, fiber conditioners may be employed. Fiber conditioners are applied before or after the dyeing process to prepare the fiber or improve color fixation: There are cationic conditioners, such as quaternary ammonium chlorides, which increase the positive charge in the fiber, facilitating the adhesion of anionic dyes. On the other hand, silicones and softeners can improve color 36 OLS-12517-24

[0234] 04.08.2025 absorption and fabric softness, reducing friction during washing and prolonging color life.

[0235] There are also color fixing agents that can be applied after dyeing to increase the color fastness: examples of this type are formaldehyde and its derivatives. Although less and less used for environmental and health reasons, these compounds can significantly improve wash resistance. Acetic acid and vinegar are also used in natural tinctures as they help to close the cuticles of the fiber, trapping the color inside. Finally, reactive fixing agents that form covalent bonds between the pigment and the fiber can be used, improving the resistance to washing and light.

[0236] In contrast, the over-pigmentation composition may also comprise 10 - 50 grams of an anionic active tensor per kilogram of composition. The presence of an anionic active tensor generates a modification in the characteristics of the composition. Specifically, it interacts with the over-pigment of the composition, giving rise to an anionic over-pigment. In this way, the embodiment of the over-pigmentation composition comprising an anionic active tensor has no or very low chemical affinity with the textile on which it is applied. The chemical affinity can be measured by the number of chemical bridges that are generated between the composition and the textile.

[0237] In this sense, in a preferred embodiment, the rest of the elements of the overpigmentation composition (dispersing agent, wetting agent) are selected to favor the negative charge of the over-pigmentation composition. In this sense, as indicated above, the use of an anionic dispersing agent is preferred when obtaining an anionic composition since it collaborates in the formation of the negative charge of the composition.

[0238] The over-pigmentation composition according to this particular embodiment, comprising an anionic active tensor, has a negative charge. The negative charge of this composition allows it to interact specifically with other positively 37 OLS-12517-24

[0239] 04.08.2025 charged compounds and surfaces. Being negatively charged generates an opposite effect by not being compatible with textile fibers that have negatively charged functional groups, avoiding an ionic bond with the pigment. Anionic pigments are water-soluble or dispersible, which facilitates their uniform application in aqueous solutions during the dyeing and printing processes. The water solubility obtained in the over-pigmentation composition also facilitates the cleaning and handling of the pigments during the production process.

[0240] Well-fixed anionic pigments also have good wash resistance, which ensures that the color remains vibrant and does not fade easily. In this particular embodiment, by having a low affinity, we are able to reverse said wash resistance and this allows us to easily remove excess pigment remaining in the garment.

[0241] Thus, the over-pigmentation composition according to this embodiment can be used in printing and dyeing processes due to its ability to provide bright and long-lasting colors. The combined use with other agents such as wetting agents, dispersants and fixatives improves its performance. Additionally, anionic pigments are available in a wide range of colors, allowing great versatility in textile design, providing vivid and saturated colors, which is highly desired in textile applications. Another important factor is environmental improvement. The anionic composition according to the present embodiment may be designed to be more environmentally friendly, being biodegradable or less toxic elements compared to other types of pigments.

[0242] Thanks to the presence of this anionic active tensor, the over-pigmentation composition is able to interact with a base pigment previously present in a textile, activating said pigment in the presence of laser radiation, and to be easily removed once the laser marking has been carried out on an initially non-reactive textile, for example on a denim fabric dyed in pure indigo. In this sense, it is understood to be an easy separation, for example, to washing after laser marking. 38 OLS-12517-24

[0243] 04.08.2025

[0244] That is, the over-pigment can generate a temporary interaction with the initially non-reactive textile to laser radiation, and be easily removed or separated from the textile on which it is applied once the laser marking is finished.

[0245] In other words, thanks to this chemical affinity contributed by the anionic composition, the application of an anionic over-pigmentation composition as described above on a textile, initially non-reactive, enables performing a laser marking of the textile, and once the marking is finished, to easily remove or eliminate the over-pigmentation composition by washing the textile.

[0246] In a particular embodiment, the anionic active tensile is an alkylbenzene sulfonate, for example, sodium dodecylbenzene sulfonate.

[0247] In a further embodiment, a method of obtaining the over-pigmentation composition is disclosed. This method comprises the following steps:

[0248] - Mixing 100 - 200 grams of over-pigment, 250 - 350 grams of dispersing agent, 50 - 150 grams of glycol and 5 - 15 grams of a wetting agent in 300 - 550 grams of water, until a uniform viscous mixture is obtained,

[0249] - Milling the uniform viscous mixture resulting in a composition comprising a particle size of less than 10 micrometers.

[0250] The result of this milling is an over-pigmentation composition capable of activating a textile that is non-reactive to laser radiation in the wavelength range between 400 - 1 ,800 nm, with a good surface dispersibility on the textile. The resulting over-pigmentation composition is a composition useful for the pigmentation and subsequent marking of a textile material by the application of laser radiation.

[0251] According to the present disclosure, the uniform viscous mixture is the result of the mixture between the over-pigment and the rest of the components. In a 39 OLS-12517-24

[0252] 04.08.2025 particular embodiment, the uniform mixing of the elements can be carried out by introducing the elements into a mixer for at least two hours. For its part, the milling can be carried out in a mill for at least 5 hours. In a particular embodiment, the milling is carried out so that the particle size is reduced to a size between 5 and 8 micrometers. The milling of the particles present in the over-pigmentation composition gives a good surface deposit on the textile material.

[0253] Additionally, in a particular embodiment, the method of obtaining the overpigmentation composition may have the step of incorporating an anionic active tensor into the composition. In a particular embodiment, the incorporation is carried out once the milling of the viscous solution has been carried out. The incorporation of the anionic active tensor is carried out as a last step, with a duration of 15 minutes. In this way, it is possible to vary the electrical charge of the composition and pass the mixture from an ionic state (positive charge) to an anionic state (negative charge). The result of this incorporation is the functionalization or modification of the over-pigment molecule, resulting in an anionic over-pigmentation composition. Obtaining an anionic over-pig- mentation composition as disclosed enables the composition to have a low affinity with the textile, so that, once the laser marking has been carried out, the composition is easily removable.

[0254] In the same way, the method of obtaining over-pigmentation may have a step of incorporating a fixing agent. Specifically, the method may further comprise incorporating, per kilogram of composition, 5 - 25 grams of a color fixing agent into the over-pigmentation composition, such that the color may be fixed to the fabric.

[0255] In yet another embodiment, a method of making a laser-marked textile is disclosed. The method comprises the following steps: 40 OLS-12517-24

[0256] 04.08.2025

[0257] - Applying a dilution of the over-pigmentation composition on a region of a textile, either in a localized area or in the entire piece to be treated, defining a stained area and

[0258] - Applying laser radiation on the stained area where the over-pigmentation composition has been applied.

[0259] The laser beam, by impinging on at least one marking point of the stained area of the dyed textile material, partially or totally removes both the over-pig- mentation component and the base pigment by decolorizing the dyed textile material, providing different discoloration shades of the base dyeing. The discoloration process does not affect the fiber of the textile material.

[0260] The concentration of the dilution employed for obtaining a textile material with laser marking is in the range 2.5 - 10 grams of over-pigmentation composition according to the present invention per kilogram of dilution used in the method. That is, the composition comprises a dilution factor in the range between 400 and 100, this factor being measured as the mass of diluted composition divided by mass of concentrated composition.

[0261] Dilution factor Mass of the diluted composition

[0262] Mass of the concentrated com-position

[0263] Additionally, the method of obtaining the textile material may further comprise the step of removing the over-pigmentation composition remaining in the stained area of the textile by obtaining a textile marked according to the initial color of the textile material. In a particular embodiment, the removal of the over-pigmentation composition is carried out by means of a wash. Washing is a simple separation process, which can be carried out through a multitude of processes. These processes include:

[0264] - Traditional washing: washing that includes the use of water together with a chemical agent. This type of washing is usually carried out in a washing machine, preferably industrial. 41 OLS-12517-24

[0265] 04.08.2025

[0266] - Ozone: Through ozone generators, the textiles are deposited in a special drum where ozone is injected at different concentrations, to achieve a general discoloration of the fabric or simply a removal of excess dye. In addition, the ozone process can be wet as it accelerates the discoloration process.

[0267] - Nano-bubbles: in this process a system of spraying or spraying a wa- ter / chemical agent mixture in a washing machine is required. It is a system where nozzles are mounted in the washing drum and instead of filling the washing machine with water and adding the chemical agent, it is sprayed directly. This system manages to save on water, chemical agent and not have any type of liquid discard since the ratio is very low and everything is absorbed by the garments.

[0268] - Foam: in more current solutions, a system can be used to further reduce the consumption of chemical agent and water, through the use of foam. To do this, the textiles are introduced into a drum and with a specific system the water is mixed with a chemical agent that typically carries a very concentrated foamer and the drum is filled through a hose.

[0269] The result of this process may be a textile product comprising a textile material with a design pattern obtained by the method described previously.

[0270] This test was performed with an over-pigmentation composition that includes a black organic pigment, subsequently made anionic with the addition of an anionic active tensile, specifically 20 grams of sodium dodecylbenzene sulfonate.

[0271] In particular, the remainder of the base over-pigmentation composition was as follows: 42 OLS-12517-24

[0272] 04.08.2025

[0273] - 460 grams of water,

[0274] - 140 grams of organic over-pigment carbon black,

[0275] - 95 grams of ethylene glycol

[0276] - 275 grams of tridecyl sodium sulfate (TDS) as a dispersing agent, and

[0277] - 10 grams of ethylene oxide as a wetting agent.

[0278] The result of the mixing and subsequent milling of this composition is an over-pigmentation composition capable of activating a textile material to be reactive to a radiation of a laser marker.

[0279] Depending on the purpose of the laser marking used, the composition may comprise an anionic active tensioner, enabling separation by washing, or a fixing agent, achieving a good result in the color of the textile material.

[0280] The concentrated composition of the above-described over-pigmentation composition should not be applied directly onto the fabric. That is, dilution of the composition is necessary. To do this, 5 grams of the concentrated composition were taken and diluted with distilled water to obtain a kilogram of composition, equivalent to a dilution factor of 200, of diluted over-pigmentation suitable, now, for application on a textile material.

[0281] The textile material on which the over-pigmentation composition was applied has the following properties

[0282] - Textile to be marked: 100 % cotton denim fabric

[0283] - Original dye: indigo

[0284] In this way, the diluted over-pigmentation composition was applied to the fabric by immersing the fabric in the composition described above, either with water at room temperature, or preheated, without significantly varying the final result. Similar results can also be obtained by spraying the over- 43 OLS-12517-24

[0285] 04.08.2025 pigmentation composition on at least one region, the stained area, of the textile material to be marked.

[0286] For laser marking, a fiber laser was used emitting at a wavelength of 1 ,070 nm, with a laser energy between 10 and 80 millijoules (mJ), achieved by means of an exposure time between 2 and 60 ps with a laser generator with a power between 0.5 kW and 2 kW of optical power. Specifically, a laser at different energy levels (10, 20, 30, 40, 50, 60, 70 and 80 mJ) was used to mark the textile with laser, resulting in a variety of contrasts that can be achieved by this solution. As already described, figure 5b shows the discolouration process. Specifically, it is shown how a laser radiation (A), with a displacement (E), is directed on an area stained with the over-pigmentation composition (D). The result of this irradiation is the removal of said composition (D) and the base pigment (C) from the textile material, so that the textile fiber (B) is not affected or damaged, as can occur when using a CO2 laser.

[0287] Having employed 20 grams of sodium dodecylbenzene sulfonate as the anionic active tensor, the excess over-pigmentation composition could be removed by carrying out a standard household wash, i.e. a wash in a conventional washing machine with tap water + detergent, removing the remaining over-pigmentation composition from the textile after marking.

[0288] As shown in figure 6, the result is fully satisfactory. The over-pigmentation composition used helps to remove the original dye (indigo) with the laser energy applied to it, obtaining a good contrast in the final result.

[0289] In a second example, similar to the first example disclosed previously, 140 grams of an inorganic mineral over-pigment was employed in place of the carbon black pigment. This composition was applied again on a denim textile dyed in pure indigo using an anionic over-pigmentation composition. 44 OLS-12517-24 04.08.2025

[0290] As shown in figure 7, the result after washing is totally satisfactory. Again, the over-pigmentation composition helps to remove the original dye (indigo) with the laser energy applied on it, obtaining a good contrast in the final result. of over-pigmentation composition on a non-denim textile

[0291] In addition, additional tests were carried out on non-denim textiles. The overpigmentation composition comprised 5 grams of the previously disclosed concentrated pigmentation composition, per 1 kilogram of composition diluted in distilled water.

[0292] In this case, the fabric was dyed by dipping it with an over-pigment and marking it with a laser marker at different energy levels achieved with exposure times and optical power similar to that disclosed in the previous example, to see the variety of contrasts that can be achieved.

[0293] Specifically, figure 8 shows the results obtained by laser marking a non- denim fabric dyed in indigo with the following properties:

[0294] - Textile to be marked: 100 % cotton fabric

[0295] - Original dye: raw

[0296] - Base pigment: black organic pigment.

[0297] - Power applied by the laser: 20, 30, 40 mJ.

[0298] Figure 9 shows the results obtained by laser marking a dyed non-denim fabric with the following properties:

[0299] - Textile to be marked: 100 % cotton fabric

[0300] - Original dye: raw

[0301] - Base pigment: green organic pigment.

[0302] - Laser power: 20 (Dali), 30 (degraded), 40 mJ (trainers). 45 OLS-12517-24 04.08.2025

[0303] Figure 10 shows the results obtained by laser marking a dyed non-denim fabric with the following properties:

[0304] - Textile to be marked: 100 % cotton fabric

[0305] - Original dye: raw

[0306] - Base pigment: blue organic pigment.

[0307] - Energy applied by the laser: 20, 30, 40 mJ.

[0308] Figure 11 shows a set of photographs of the results obtained by laser marking a dyed non-denim fabric with the following properties:

[0309] - Textile to be marked: 100 % cotton fabric

[0310] - Original dye: raw

[0311] - Base pigment: dark blue organic pigment

[0312] - Laser repetition rate: 80 kHz

[0313] As shown in these Figures, the results are totally satisfactory. The composition helps to remove the original dye with the laser energy applied on it and obtain a good contrast in the textile material. of an over-pi

[0314] Finally, Figure 12 shows a set of photographs of the results obtained by laser marking a tencel textile material.

[0315] Figure 12a shows the result of using an anionic over-pigmentation composition applied on a textile dyed with indigo pigment. When an anionic over-pig- mentation composition is applied, it is possible to remove the excess composition used, achieving a good contrast in the pattern drawn on the textile material. For its part, Figure 12b shows the result of using an over-pigmentation composition. On this occasion, the purpose of over-pigmentation is the OLS-12517-24 04.08.2025 coloration of a designed pattern. To achieve an improvement in the coloration performed, a fixing agent was applied subsequently to the laser marking so that a good fixation of the color obtained is obtained.

Claims

1 OLS-12517-2404.08.2025C l a i m s1 . A method for laser marking of a textile material, comprising the steps of:- providing a textile material dyed with a base pigment,- applying an over-pigmentation composition comprising an over-pigment onto at least one predetermined zone of the dyed textile material, thereby defining a stained area,- irradiating at least one marking point of the stained area with at least one laser beam from a solid-state fiber laser marker, wherein the laser irradiation partially or totally removes both the overpigmentation composition and the base pigment to produce a predetermined design pattern on the textile material.

2. The method according to the preceding claim, wherein the solid-state fiber laser marker emits wavelengths in the range of 100 to 1 ,090 nm.

3. The method according to any one of the preceding claims, wherein the over-pigment is selected from the group consisting of carbon blacks, phthalocyanine pigments, metal oxide pigments, mixed metal oxide pigments, metal sulfide or sulfite pigments, elemental sulfur, NIR-ab- sorbing oxide pigments, metallic pigments, and combinations thereof.

4. A solid-state laser marker for modifying the finish of a textile material dyed with a base pigment , characterized in that the laser marker is adapted to irradiate at least one laser beam (A) to at least one marking point of a predetermined zone of the dyed textile material impregnated with an over-pigmentation composition , following a predetermined target design pattern, with at least one laser beam being adapted to totally or partially remove both the over-pigmentation composition and the base pigment of the textile material , wherein the2 OLS-12517-2404.08.2025 solid state laser marker is a fiber optic laser marker adapted to emit wavelengths in the range of 100 to 1 ,090 nm.

5. Laser marker according to the preceding claim, wherein the fiber optic laser marker is of continuous wave infrared with a variable exposure time, with a percentage of the modulable operating cycle, with a variable optical power, with a focal point on the dyed textile with a variable diameter size, with an energy distribution of the modulable laser beam either Gaussian, or ring, or of a combination of both, in the latter case with variable power distribution between both distributions, any combination of the above, which irradiates the laser beam towards the predetermined zone of the dyed textile during an exposure time.

6. Laser marker according to claim 4 or 5, wherein the exposure time comprises an optical pulse rise time of less than or equal to 5 ps, preferably 1 to 3 ps the marking time and an optical pulse fall time of less than or equal to 5 ps, preferably 1 to 3 ps.

7. Laser marker according to any one of claims 4 to 6, wherein the exposure time comprising the rise time, a marking time and the fall time, has a geometric shape of the type of a scalene triangle, an acute scalene triangle, a rectangle, a scalene trapezium.

8. Laser marker according to any one of claims 4 to 7, wherein the laser marker comprises a direct fiber oscillator preferably with a single pump laser.

9. Laser marker according to the preceding claim, wherein the direct fiber oscillator comprises a fiber Bragg grating.

10. An over-pigmentation composition of a textile material characterized in that the composition is a solution comprising, per kilogram of3 OLS-12517-2404.08.2025 composition:- 300 - 550 grams of water,- 100 - 200 grams of over-pigment,- 250 - 350 grams of dispersing agent,- 50 - 150 grams of glycol, and- 5 - 15 grams of wetting agent; wherein the over-pigment is a pigment configured to absorb laser radiation in the range of 400 to 1 ,800 nm and has a particle size of less than 10 micrometers.11 . The over-pigmentation composition according to the preceding claim, wherein the composition further comprises 10 - 50 grams of anionic active tensor.

12. The over-pigmentation composition according to claim 10 or 11 , wherein the composition further comprises 5 - 25 grams of a color-fixing agent.

13. The over-pigmentation composition according to any one of claims 10 to 12, wherein the over-pigment is configured to absorb radiation of wavelength in the range from 600 nm to 1 ,600 nm, preferably from 700 nm to 1 ,400 nm, more preferably from 800 nm to 1 ,200 nm, more preferably from 1 ,060 nm to 1 ,090 nm, and more preferably still from 1 ,060 nm to 1 ,070 nm.

14. The over-pigmentation composition according to any one of claims 10 to 13, wherein the over-pigment is an organic pigment or an inorganic pigment, preferably a mineral pigment.

15. The over-pigmentation composition according to any one of claims 10 to 14, wherein the over pigment is selected from the group consisting of carbon blacks, phthalocyanine pigments, metal oxide pigments,OLS-12517-24 04.08.2025 mixed metal oxide pigments, metal sulfide or sulfite pigments, elemental sulfur, NIR-absorbing oxide pigments, metallic pigments, and combinations thereof.

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