Digital printing process for high-color-fastness cotton fabric

Abstract

The invention provides a digital printing process for a high-color-fastness cotton fabric, and relates to the technical field of textile printing and dyeing, and according to the digital printing process for the high-color-fastness cotton fabric, the color fastness of digital printing of the cotton fabric is remarkably improved by accurately controlling parameters such as temperature, time and concentration of each stage; according to the method, the color shedding and fading phenomena in the use and washing process are reduced, the service life of the fabric is prolonged, the optimized pretreatment step can effectively remove the sizing agent on the cotton fabric, a good foundation is provided for subsequent sizing and printing, the uniformity and definition of printing are ensured, and the printing quality is improved. The adhesive force of printing ink on the cotton fabric is enhanced through reasonable sizing treatment, so that printed patterns are brighter and finer, meanwhile, the hand feeling and air permeability of the fabric are improved, digital printing parameters are accurately controlled, it is ensured that the printing ink permeates and is evenly distributed, the color is bright and saturated, and the pattern precision is high; and the requirements of consumers on high-quality printing are met.

Description

Technical Field

[0001] The invention belongs to the technical field of textile printing and dyeing, and more specifically, particularly relates to a digital printing process for cotton fabrics with high color fastness. Background Art

[0002] In the modern textile printing and dyeing industry, cotton fabrics are favored by consumers due to their good air permeability, moisture absorption and comfort. However, in the printing process of cotton fabrics, achieving high color fastness has always been a technical problem.

[0003] Traditional cotton fabric printing technology has many shortcomings. First, common printing methods such as direct printing and reactive printing often fail to achieve satisfactory results in terms of color fastness, especially after repeated washing and friction, which are prone to fading and discoloration, affecting the beauty and service life of the fabric.

[0004] Secondly, the traditional process also has certain limitations in terms of printing accuracy and clarity, and it is difficult to meet consumers' demand for high-quality and refined printing patterns. Moreover, the traditional process is relatively complicated and consumes a lot of water resources and chemical reagents, which not only increases production costs, but also puts great pressure on the environment.

[0005] In addition, traditional processes are not precise enough in parameter control, making it difficult to ensure the consistency and stability of each batch of products, thus affecting product quality and market competitiveness.

[0006] In order to overcome these problems, the industry has been exploring new cotton fabric printing technologies and processes. As an emerging printing technology, digital printing has many advantages, but it still needs to be further improved and optimized in terms of high color fastness.

[0007] Therefore, developing a digital printing process for cotton fabrics with high color fastness is of great significance for improving the quality and performance of cotton fabric printing products, meeting market demand, and promoting the development of the textile printing and dyeing industry. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a digital printing process for cotton fabrics with high color fastness to solve the above problems.

[0009] A digital printing process for cotton fabric with high color fastness comprises the following steps:

[0010] Step 1: pretreatment, placing the cotton fabric in a desizing solution at a temperature of T1°C for desizing treatment, the treatment time is t1 minutes, the pH value of the desizing solution is PH1, and T1 = a1 × PH1 + b1, where a1 is 0.5, b1 is 40, t1 = c1 × T1 + d1, where c1 is 0.1, and d1 is 10;

[0011] Step 2: sizing, the pretreated cotton fabric is sizing at a temperature of T2°C, a sizing agent concentration of C1 g / L, and a bath ratio of B1, the sizing time is t2 minutes, and T2 = a2 × C1 + b2, where a2 is 0.2, b2 is 30, t2 = c2 × B1 + d2, where c2 is 0.8, and d2 is 8;

[0012] Step 3: Digital printing: Print the cotton fabric with a digital printing device at a temperature of T3°C and a printing ink concentration of C2 g / L. The printing time is t3 minutes, and T3 = a3 × C2 + b3, where a3 is 0.1, b3 is 25, t3 = c3 × T3 + d3, where c3 is 0.08, and d3 is 7;

[0013] Step 4: Fixation: The printed cotton fabric is fixed at a temperature of T4°C and a fixing agent concentration of C3 g / L. The fixing time is t4 minutes, and T4=a4×C3+b4, where a4 is 0.3, b4 is 60, and t4=c4×T4+d4, where c4 is 0.1, and d4 is 15.

[0014] Preferably, in the pretreatment step, the desizing solution is an alkaline solution, and the pH1 value is 10.

[0015] Preferably, in the sizing step, the sizing agent is a polyacrylate sizing agent, the value of C1 is 25 g / L, and the value of B1 is 1:6.

[0016] Preferably, in the digital printing step, the nozzle resolution of the printing equipment is 1200 dpi, the viscosity of the printing ink is η1 centipoise, and η1=a5×C2+b5, wherein a5 is 2, and b5 is 10.

[0017] Preferably, in the color fixing step, the color fixing agent is a formaldehyde-free color fixing agent, and the C3 value is 45 g / L.

[0018] Preferably, after the digital printing step, the printed cotton fabric is dried, the drying temperature is T5°C, the drying time is t5 minutes, and T5=a6×t3+b6, where a6 is 0.8, b6 is 45, t5=c5×T5+d5, where c5 is 0.05, and d5 is 4.

[0019] Preferably, after the color fixing treatment, the cotton fabric is washed with water, the washing temperature is T6°C, the washing time is t6 minutes, and T6=a7×T4+b7, where a7 is 0.6, b7 is 30, t6=c6×T6+d6, where c6 is 0.07, and d6 is 3.

[0020] Preferably, after washing, the cotton fabric is subjected to a stretching and setting treatment, the setting temperature is T7°C, the setting time is t7 minutes, and T7=a8×T6+b8, where a8 is 1.5, b8 is 90, t7=c7×T7+d7, where c7 is 0.03, and d7 is 2.

[0021] Preferably, during the entire process, the running speed of the cotton fabric is controlled to be V m / min, and V=a9×T7+b9, wherein a9 is 0.05, and b9 is 8.

[0022] Preferably, before the digital printing step, the cotton fabric is preheated, the preheating temperature is T8°C, the preheating time is t8 minutes, and T8=a10×C2+b10, wherein a10 is 0.08, b10 is 20, t8=c8×T8+d8, wherein c8 is 0.04, and d8 is 2.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. This high color fastness digital printing process for cotton fabrics significantly improves the color fastness of digital printing on cotton fabrics by precisely controlling parameters such as temperature, time, concentration, etc. at each stage, reduces color shedding and fading during use and washing, and extends the service life of the fabric.

[0025] 2. The optimized pretreatment steps can effectively remove the sizing on cotton fabrics, provide a good foundation for subsequent sizing and printing, and ensure the uniformity and clarity of printing.

[0026] 3. Reasonable sizing treatment enhances the adhesion of printing ink on cotton fabric, making the printed pattern more vivid and delicate, while improving the feel and air permeability of the fabric.

[0027] 4. Precisely controlled digital printing parameters ensure uniform penetration and distribution of printing ink, bright and saturated colors, and high pattern precision, meeting consumers' demand for high-quality printing.

[0028] 5. Effective color fixing treatment promotes the reaction between the fixing agent and the dye, forming a stable chemical bond, further improving the color fastness, and enabling the printed cotton fabric to maintain good color in various environments.

[0029] 6. The optimization of the overall process reduces the waste of raw materials, reduces production costs, improves production efficiency, and has good economic benefits.

[0030] 7. This process reduces energy consumption, reduces environmental impact, and meets green and environmentally friendly production requirements.

[0031] 8. The adjustability of process parameters makes this process applicable to cotton fabrics of different specifications and requirements, and has wide applicability and scalability.

[0032] 9. Digital printing products on cotton fabrics with high color fastness are more competitive in the market, can meet consumers' demand for high-quality, personalized textiles, and help companies expand their markets. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0034] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0035] The present invention relates to a digital printing process for cotton fabrics with high color fastness, and aims to improve the color fastness and overall quality of digital printing of cotton fabrics by accurately controlling process parameters and optimizing process flow. The implementation process and effect of the process will be described in detail below through specific embodiments.

[0036] Embodiment 1:

[0037] Pretreatment: desizing temperature T1 = 0.5 × 10 + 40 = 45 ° C, desizing time t1 = 0.1 × 45 + 10 = 14.5 minutes, desizing solution pH value is 9;

[0038] Sizing: sizing temperature T2 = 0.2 × 20 + 30 = 34 ° C, sizing time t2 = 0.8 × 6 + 8 = 12.8 minutes, sizing agent concentration C1 is 20 g / L, bath ratio B1 is 1:5;

[0039] Digital printing: printing temperature T3 = 0.1 × 30 + 25 = 28 ° C, printing time t3 = 0.08 × 28 + 7 = 9.24 minutes, printing ink concentration C2 is 30 g / L;

[0040] Fixing: Fixing temperature T4 = 0.3 × 40 + 60 = 72°C, fixing time t4 = 0.1 × 72 + 15 = 22.2 minutes, fixing agent concentration C3 is 40 g / L.

[0041] Embodiment 2:

[0042] Pretreatment: desizing temperature T1 = 0.5 × 11 + 40 = 45.5 ° C, desizing time t1 = 0.1 × 45.5 + 10 = 14.55 minutes, desizing solution pH value is 10;

[0043] Sizing: sizing temperature T2 = 0.2 × 25 + 30 = 35 ° C, sizing time t2 = 0.8 × 7 + 8 = 13.6 minutes, sizing agent concentration C1 is 25 g / L, bath ratio B1 is 1:6;

[0044] Digital printing: printing temperature T3 = 0.1 × 35 + 25 = 28.5 ° C, printing time t3 = 0.08 × 28.5 + 7 = 9.28 minutes, printing ink concentration C2 is 35 g / L;

[0045] Fixing: Fixing temperature T4 = 0.3 × 45 + 60 = 73.5 ° C, fixing time t4 = 0.1 × 73.5 + 15 = 22.35 minutes, fixing agent concentration C3 is 45 g / liter.

[0046] Embodiment 3:

[0047] Pretreatment: desizing temperature T1 = 0.5 × 12 + 40 = 46 ° C, desizing time t1 = 0.1 × 46 + 10 = 14.6 minutes, desizing solution pH value is 11;

[0048] Sizing: sizing temperature T2 = 0.2 × 30 + 30 = 36 ° C, sizing time t2 = 0.8 × 8 + 8 = 14.4 minutes, sizing agent concentration C1 is 30 g / L, bath ratio B1 is 1:7;

[0049] Digital printing: printing temperature T3 = 0.1 × 40 + 25 = 29 ° C, printing time t3 = 0.08 × 29 + 7 = 9.32 minutes, printing ink concentration C2 is 40 g / liter;

[0050] Fixing: Fixing temperature T4 = 0.3 × 50 + 60 = 75 ° C, fixing time t4 = 0.1 × 75 + 15 = 22.5 minutes, fixing agent concentration C3 is 50 g / liter.

[0051] Embodiment 4:

[0052] Pretreatment: desizing temperature T1 = 0.5 × 13 + 40 = 46.5 ° C, desizing time t1 = 0.1 × 46.5 + 10 = 14.65 minutes, desizing solution pH value is 12;

[0053] Sizing: sizing temperature T2 = 0.2 × 35 + 30 = 37 ° C, sizing time t2 = 0.8 × 9 + 8 = 15.2 minutes, sizing agent concentration C1 is 35 g / L, bath ratio B1 is 1:8;

[0054] Digital printing: printing temperature T3 = 0.1 × 45 + 25 = 29.5 ° C, printing time t3 = 0.08 × 29.5 + 7 = 9.36 minutes, printing ink concentration C2 is 45 g / L;

[0055] Fixing: Fixing temperature T4 = 0.3 × 55 + 60 = 76.5 ° C, fixing time t4 = 0.1 × 76.5 + 15 = 22.65 minutes, fixing agent concentration C3 is 55 g / liter.

[0056] The cotton fabrics treated in the above four embodiments were subjected to color fastness tests, including color fastness to washing, color fastness to rubbing, etc. At the same time, the fabric's hand feel, air permeability, and other properties were evaluated.

[0057] By comparing and analyzing the test results of Examples 1-4, it is found that Example 3 has the best comprehensive performance in terms of color fastness, hand feel, and air permeability. The specific data are as follows:

[0058]

[0059] Taking all performance indicators into consideration, the process parameters adopted in Example 3 are the optimal parameters, namely:

[0060] Pretreatment: desizing temperature 46 °C, desizing time 14.6 minutes, desizing solution pH 11;

[0061] Sizing: sizing temperature 36°C, sizing time 14.4 minutes, sizing agent concentration 30 g / L, bath ratio 1:7;

[0062] Digital printing: printing temperature 29°C, printing time 9.32 minutes, printing ink concentration 40 g / L;

[0063] Fixing: Fixing temperature 75℃, fixing time 22.5 minutes, fixing agent concentration 50 g / L.

[0064] On the basis of determining the optimal process parameters, the influence mechanism of each process parameter on the digital printing performance of cotton fabrics was further explored in order to more comprehensively understand and optimize this process:

[0065] Effect of desizing temperature and time on printing effect: Reasonable setting of desizing temperature and time directly affects the surface cleanliness of cotton fabrics and the accessibility of fibers. Low desizing temperature and insufficient time may cause sizing residue, affecting the uniformity of subsequent sizing and printing; while excessive temperature and excessive time may damage cotton fibers and reduce the strength and feel of the fabric. In the above embodiments, the desizing temperature of 46°C and the desizing time of 14.6 minutes adopted in Example 3 effectively removed the sizing, providing a good foundation for subsequent processes;

[0066] Effects of sizing agent concentration and bath ratio: The concentration and bath ratio of sizing agent determine the thickness and uniformity of sizing. Properly increasing the concentration of sizing agent and a reasonable bath ratio can help enhance the adhesion of printing ink on the fabric surface and improve the clarity and color fastness of printing. The sizing agent concentration of 30 g / L and the bath ratio of 1:7 selected in Example 3 ensure the sizing effect while avoiding the hardening of the fabric feel and the decrease in air permeability caused by excessive sizing;

[0067] The relationship between printing temperature, time and ink concentration: Printing temperature, time and ink concentration are interrelated and jointly affect the quality of printing. Low printing temperature and too short printing time may lead to insufficient ink penetration and unsaturated colors; while too high temperature and too long time may cause ink diffusion and affect the accuracy of the pattern. The appropriate ink concentration can ensure the vividness and saturation of the color. The printing parameter combination in Example 3 achieves accurate color reproduction and fine presentation of the pattern;

[0068] Importance of fixation temperature, time and fixative concentration: The fixation process is crucial to improving the color fastness of printed prints. A higher fixation temperature, sufficient time and appropriate fixative concentration can promote the reaction between the fixative and the dye to form a stable chemical bond, thereby improving color fastness. The 75°C fixation temperature, 22.5 minutes fixation time and 50 g / L fixative concentration in Example 3 effectively enhance the color stability, allowing it to maintain good color after multiple washings and rubbing.

[0069] This process has certain scalability based on the determination of the optimal parameters, and can be applied to cotton fabrics of different specifications, such as yarn count, fabric thickness, etc. By fine-tuning some process parameters, such as appropriately adjusting the desizing and fixing time according to the thickness of the fabric, high color fastness digital printing can be achieved on diversified cotton fabrics while ensuring the printing quality.

[0070] As consumers' demands for textile quality and personalization continue to increase, digitally printed cotton fabrics with high color fastness have broad application prospects in the fields of clothing, home decoration, etc. This process can not only meet the market demand for cotton fabric products with bright colors, exquisite patterns, and washability and wear resistance, but also help improve the production efficiency and competitiveness of enterprises, and promote the development of the textile industry towards digitalization, intelligence, and green environmental protection.

[0071] This digital printing process can be combined with traditional printing and dyeing technology, such as pre-dyeing before digital printing or overprinting after digital printing, to create more diverse colors and patterns. In addition, the coordinated application with functional finishing technology (such as waterproof, antibacterial, etc.) can further expand the functions and application areas of cotton fabrics.

[0072] This high color fastness cotton fabric digital printing process significantly improves the color fastness of cotton fabric digital printing by accurately controlling parameters such as temperature, time, concentration, etc. at each stage, reduces color shedding and fading during use and washing, and extends the service life of the fabric. The optimized pretreatment step can effectively remove the sizing on the cotton fabric, providing a good foundation for subsequent sizing and printing, ensuring the uniformity and clarity of the printing. Reasonable sizing treatment enhances the adhesion of the printing ink on the cotton fabric, making the printed pattern more vivid and delicate, while improving the feel and air permeability of the fabric. The precisely controlled digital printing parameters ensure the penetration and uniform distribution of the printing ink, the bright and saturated colors, and the high pattern accuracy, satisfying consumers' demand for high-quality printing. The effective color fixing treatment promotes the reaction between the fixing agent and the dye, forms a stable chemical bond, further improves the color fastness, and enables the printed cotton fabric to maintain a good color in various environments. The overall process optimization reduces the waste of raw materials, reduces production costs, improves production efficiency, and has good economic benefits. The process reduces energy consumption and reduces the impact on the environment, and meets the requirements of green and environmentally friendly production. The adjustability of process parameters makes this process applicable to cotton fabrics of different specifications and requirements, and has wide applicability and scalability. Cotton fabric digital printing products with high color fastness are more competitive in the market, can meet consumers' demand for high-quality and personalized textiles, and help companies to expand the market.

[0073] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A digital printing process for cotton fabrics with high color fastness, characterized in that: The following steps are involved: Step 1: pretreatment, placing the cotton fabric in a desizing solution at a temperature of T1°C for desizing treatment, the treatment time is t1 minutes, the pH value of the desizing solution is PH1, and T1 = a1 × PH1 + b1, where a1 is 0.5, b1 is 40, t1 = c1 × T1 + d1, where c1 is 0.1, and d1 is 10; Step 2: sizing, the pretreated cotton fabric is sizing at a temperature of T2°C, a sizing agent concentration of C1 g / L, and a bath ratio of B1, the sizing time is t2 minutes, and T2 = a2 × C1 + b2, where a2 is 0.2, b2 is 30, t2 = c2 × B1 + d2, where c2 is 0.8, and d2 is 8; Step 3: Digital printing: Print the cotton fabric with a digital printing device at a temperature of T3°C and a printing ink concentration of C2 g / L. The printing time is t3 minutes, and T3 = a3 × C2 + b3, where a3 is 0.1, b3 is 25, t3 = c3 × T3 + d3, where c3 is 0.08, and d3 is 7; Step 4: Fixation: The printed cotton fabric is fixed at a temperature of T4°C and a fixing agent concentration of C3 g / L. The fixing time is t4 minutes, and T4=a4×C3+b4, where a4 is 0.3, b4 is 60, and t4=c4×T4+d4, where c4 is 0.1, and d4 is 15.

2. A high color fastness cotton fabric digital printing process as claimed in claim 1, characterized in that: In the pretreatment step, the desizing solution is an alkaline solution, and the pH1 value is 10.

3. The high color fastness cotton fabric digital printing process according to claim 1, characterized in that: In the sizing step, the sizing agent is a polyacrylate sizing agent, the C1 value is 25 g / L, and the B1 value is 1:

6.

4. The high color fastness digital printing process for cotton fabrics according to claim 1, characterized in that: In the digital printing step, the nozzle resolution of the printing equipment is 1200dpi, the viscosity of the printing ink is η1 centipoise, and η1=a5×C2+b5, where a5 is 2 and b5 is 10.

5. The high color fastness cotton fabric digital printing process according to claim 1, characterized in that: In the color fixing step, the color fixing agent is a formaldehyde-free color fixing agent, and the C3 value is 45 g / L.

6. The high color fastness digital printing process for cotton fabrics according to claim 1, characterized in that: After the digital printing step, the printed cotton fabric is dried at a drying temperature of T5°C and a drying time of t5 minutes, and T5=a6×t3+b6, where a6 is 0.8, b6 is 45, and t5=c5×T5+d5, where c5 is 0.05 and d5 is 4.

7. The high color fastness digital printing process for cotton fabrics according to claim 1, characterized in that: After the color fixing treatment, the cotton fabric is washed with water at a temperature of T6°C and a washing time of t6 minutes, and T6=a7×T4+b7, where a7 is 0.6, b7 is 30, and t6=c6×T6+d6, where c6 is 0.07 and d6 is 3.

8. The high color fastness digital printing process for cotton fabrics according to claim 1, characterized in that: After washing, the cotton fabric is subjected to a stretching and setting treatment, the setting temperature is T7°C, the setting time is t7 minutes, and T7=a8×T6+b8, where a8 is 1.5, b8 is 90, t7=c7×T7+d7, where c7 is 0.03, and d7 is 2.

9. The high color fastness digital printing process for cotton fabrics according to claim 1, characterized in that: During the whole process, the running speed of the cotton fabric is controlled to be V m / min, and V=a9×T7+b9, wherein a9 is 0.05, and b9 is 8.

10. A high color fastness cotton fabric digital printing process according to any one of claims 1 to 9, characterized in that: Before the digital printing step, the cotton fabric is preheated at a temperature of T8°C for a preheating time of t8 minutes, and T8=a10×C2+b10, where a10 is 0.08, b10 is 20, and t8=c8×T8+d8, where c8 is 0.04, and d8 is 2.

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