Improved method for the fabric printing process

Abstract

An improved method for a digital printing process for fabrics using reactive dyes and acids, comprising a first step including a series of operations defined by preparing the fabric using a chemical bath that does not contain urea, printing the fabric, and subsequently drying the printed fabric, a second step including an operation for fixing the dye transferred in the first step of printing, and a third washing step, wherein the first step is prepared in a single machine consisting of a digital printing press.

Description

[Technical Field]

[0001] (Related Applications) This application claims priority to Italian patent application 102022000021420, filed October 18, 2022, which is incorporated herein by reference in its entirety.

[0002] Various embodiments disclosed herein relate to improved methods for fabric printing processes. [Background technology]

[0003] Known digital printing consists of printing systems that are substantially based on sending a digital file from a personal computer or similar device to a printer that reproduces the contents of the particular file on fabric by inkjet or laser printing systems, ultraviolet light (UV printing), or other known techniques.

[0004] Fabrics for digital printing must be prepared to remove any impurities that could impair the quality of the print and, consequently, the quality of the finished product.

[0005] Fabric preparation prior to digital printing includes the functions of fixing the dye ink to the fabric, preventing the ink from spreading or spreading on the fabric, improving print clarity, and facilitating ink absorption on the fabric, thereby simplifying fabric drying and facilitating dye penetration into the fabric.

[0006] Fabric preparation before digital printing typically involves chemical baths containing urea, a hygroscopic and hydrotropic substance that allows dye diffusion and promotes steam condensation on the fabric surface during steaming, limiting fabric temperature rise and optimizing fabric humidity to a value corresponding to maximum fiber expansion.

[0007] Fabrics treated in chemical baths containing urea must then undergo a drying step, generally at temperatures not exceeding 110°C, to prevent stiffening (or "binding") of the fabric due to decomposition of the urea (which is subsequently removed by washing), and to prevent loss of urea and loss of color fidelity of some inks used in printing.

[0008] The chemical bathing process and subsequent drying of the fabric must be carried out in a stenter machine, an oven used in the textile industry to dry and heat-treat fabrics after wet processing. The prepared fabric is then stored in a warehouse until it is printed on a digital printing press using reactive dyes and acids.

[0009] The above-mentioned aspects illustrate the drawbacks associated with conventional methods of preparing fabrics for digital printing.

[0010] These drawbacks result in further drawbacks in terms of increased production time and relative costs, in addition to increased warehousing costs for fabrics that are treated with chemical baths containing urea and subsequently dried.

[0011] A further drawback is that urea-treated fabrics cannot be stored for long periods due to the decomposition of urea and exposure to light and temperature changes, which can cause complications and difficulties in managing the production cycle.

[0012] A further drawback is the fact that all products used in the chemical baths for fabric preparation have to be removed by washing the fabric at the end of the printing process, and this procedure of removing chemical bath residues involves considerable disposal costs, in addition to the time required for the washing operations and environmental problems such as pollution, etc.

[0013] A further drawback is the fact that after treatment in the chemical bath and before printing, the fabric needs to be dried, which requires significant space in the factory layout and is also costly in terms of energy consumption.

[0014] A known solution for digital printing and finishing of fabrics comprises a preparation step before digital printing and includes a fabric preparation station arranged between the fabric supply station and the printing station, said preparation station comprising a tank containing an aqueous solution in which the fabric is immersed and a squeezing roller designed to squeeze the fabric emerging from the tank to remove excess aqueous solution. However, this solution has the drawbacks mentioned above and further drawbacks related to the dimensions of the printing plant and its layout.

[0015] It would be advantageous to remedy the above deficiencies. Summary of the Invention

[0016] Embodiments of the present invention provide an improved method for a fabric printing process.

[0017] More specifically, embodiments of the present invention provide a method of printing fabrics obtained by digital printing techniques using reactive dyes and acids.

[0018] More specifically, embodiments of the present invention provide an improved method of printing fabrics that does not require preparation of the fabric for printing on a particular machine prior to running the printing process on the printing press, reducing the associated costs.

[0019] Additionally, embodiments of the present invention provide an improved method for the fabric printing process that eliminates or reduces the need to warehouse prepared fabrics prior to printing, and the associated costs.

[0020] Furthermore, embodiments of the present invention do not require urea, thus avoiding the problems associated with drying impregnated fabrics prior to digital printing, providing a method with reduced energy consumption and associated costs.

[0021] Furthermore, embodiments of the present invention provide a method for reducing the disposal costs of post-printing fabric washing residues, thus reducing the environmental impact.

[0022] Furthermore, embodiments of the present invention provide users with an improved method for digitally printing fabrics that is easy to implement and economically advantageous.

[0023] According to the present invention, an improved method is provided for a textile printing process, more particularly for digital printing of textiles, comprising a series of main operational steps defined by a first step, a second step and a third step, the first step being prepared on a single machine comprising a digital printing press. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 shows a block diagram of an improved method for a digital fabric printing process according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The construction and functional characteristics of the improved method for a fabric printing process of the present invention will be better understood from the following detailed description, which refers to the accompanying drawings, which illustrate embodiments provided by way of non-limiting example only, and in which Figure 1 shows a block diagram of the improved method for a fabric digital printing process of the present invention.

[0026] Referring to Figure 1, the improved method of digital printing of fabrics of the present invention, generally designated by the numeral 10, comprises three main steps defined as a first step 12, a second step 14, and a third step 16, which are followed by a step 18 of discharging and / or storing the fabrics that have been subjected to the method of the present invention.

[0027] The first step 12 comprises a series of operations defined by preparing the fabric, printing the fabric, and then drying the printed fabric, all carried out on the same machine.

[0028] The second step 14 comprises fixing the color on the fabric treated (prepared and printed) in the first step 12 .

[0029] The third step 16 comprises washing and drying the fabrics coming from the second step.

[0030] Fabric preparation according to the first step 12 is carried out on a digital printing press without using a chemical bath containing urea and comprises a fabric "wet" operation in which the fabric entering the press is blade coated with an aqueous product comprising an anti-migration agent, an anti-reducing agent, and water, in a fabric preparation section located between the entrance section of the press and the printing units of the press.

[0031] Blade coating of the fabric may be carried out by means of an application device such as a doctor blade, a screen printing tile frame or a roll, or any other device suitable for the purpose.

[0032] Optionally, the first step 12 can comprise a pre-drying step which is carried out after the wetting operation and is preferably carried out by a blade blower.

[0033] After the fabric preparation operation, a digital printing operation is performed, followed by drying of the printed fabric.

[0034] The fabric preparation operations (including optional pre-drying), printing, and drying are all performed on the same machine (i.e., the printing press). The fabric emerges from the reel onto the press conveyor belt and is advanced toward the fabric preparation section, located between the press entry section and the press itself. In the fabric preparation section, the fabric is wetted as described above.

[0035] The fabric is wetted and advanced through the preparation section at a variable speed depending on the printing speed.

[0036] After the operation in the first station 12, the fabric passes to a second station 14 where it undergoes an operation to fix the color transferred by printing. This fixation operation is carried out by treatment in the steam chamber of a fixing device.

[0037] The third step 16 comprises washing the fabric as it leaves the press, followed by drying. Washing serves to remove substances from the aqueous solution used to treat the fabric in the first step 12.

[0038] In a third step 16, once the printed fabric has dried, it is ready for storage and / or further manipulation and may, for example, be wound onto a reel and stored for subsequent manipulation or transport, etc.

[0039] As can be seen from the above, the advantages provided by the improved method of fabric printing of the present invention are clear.

[0040] The improved method of fabric printing of the present invention includes a pre-printing fabric preparation step that is performed on the same digital printing press, rather than on a separate dedicated machine as in conventional methods, thus resulting in savings in machine setup, size limitations, optimized management of plant layout, and energy and related economic savings.

[0041] A further advantage is that the method of the present invention eliminates or reduces the cost of warehousing prepared fabrics prior to the digital printing process.

[0042] A further advantage is that the method of the present invention does not require the use of urea in the fabric preparation stage before digital printing, thereby avoiding the problems associated with drying impregnated fabrics before digital printing, and therefore the problems of factory layout management, increased warehouse costs, and energy consumption.

[0043] A further advantage is represented by the fact that the method of the present invention reduces the disposal costs of fabric washing residues after printing, thereby reducing the environmental impact.

[0044] While the present invention has been described above with particular reference to embodiments thereof, which are provided by way of non-limiting example only, numerous modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention includes all such modifications and variations that fall within the scope of the following claims.

Claims

1. 1. A method for a digital printing process of textiles using reactive dyes and acids, comprising: a first step comprising a series of operations defined by preparing a fabric using a chemical bath comprising an aqueous solution of an anti-migration agent, an anti-reducing agent and water and not containing urea, printing the fabric, and subsequently drying the printed fabric, the first step being carried out on a single machine comprising a digital printing press; a second step comprising an operation for fixing the dye transferred by the printing in the first step; and a third step comprising washing and subsequently drying the fabric emerging from the printing press; A series of operation steps are provided. method.

2. The method of claim 1 , wherein the fabric preparation comprises a blade coating operation during feeding of the same fabric into the printing press.

3. 3. The method of claim 2, wherein the blade coating operation of the fabric is carried out using a product in an aqueous solution comprising an anti-migration agent, an anti-reducing agent, and water.

4. The method of claim 3 , wherein blade coating the fabric comprises application of a doctor blade, a screen printing tile frame, or a roll-type device.

5. 4. The method of claim 3, wherein blade coating is performed in a fabric preparation section located between an entrance section of the printing press and a printing unit of the same printing press.

6. 6. The method of claim 5, wherein the fabric advances through the preparation section at a speed that is variable and that is a function of the printing speed.

7. 3. The method of claim 2, wherein said preparation of said fabric comprises a pre-drying operation following said blade coating operation and preferably carried out by a blade blower.

8. 2. The method of claim 1, wherein the second step comprises fixing the dye transferred by printing, carried out by treatment in a steam chamber of a fixing device.

9. 10. The method of claim 1, wherein the third step comprises washing the fabric after it leaves the fixator, followed by drying.

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