Disperse dye washing-free duplex printing energy-saving process for cellulose acetate fiber fabric

Abstract

The invention discloses a disperse dye washing-free duplex printing energy-saving process for acetate fiber fabric. The disperse dye washing-free duplex printing energy-saving process comprises the following steps of S1, pretreatment, S2, printing paste preparation, S3, duplex printing, S4, drying, S5, heat fixation and S6, after-treatment. The invention has the following advantages and effects: through innovative process design, high-water-consumption links such as traditional water washing and soaping are omitted, the direct water-saving rate reaches more than 90%, and great energy conservation is synchronously realized due to reduction of water heating and subsequent drying requirements. And the production process is greatly simplified, and the processing time is shortened, so that the overall production efficiency is improved. Meanwhile, generation and discharge of printing and dyeing wastewater are remarkably reduced from the source, and the environmental governance pressure is effectively relieved.

Description

Technical Field

[0001] This invention belongs to the field of textile printing and dyeing technology, specifically relating to a fabric printing process, and more particularly to an energy-saving double-sided printing process for acetate fiber fabrics that uses disperse dyes to achieve a waterless washing effect. Background Technology

[0002] Acetate fiber is a semi-synthetic fiber derived from natural wood pulp. Due to its elegant luster, smooth hand feel, and good drape, it is often used in the production of high-end fashion, formal wear, and home textiles. The market demand for printed acetate products is growing. Traditional printing on acetate fabrics mostly uses disperse dyes, and its standard process includes: printing → drying → high-temperature color fixing → washing → soaping → reduction cleaning → washing → drying.

[0003] This process has many significant drawbacks, such as the lengthy washing process, which requires a large amount of hot water and steam, resulting in huge energy and water consumption. The washing process also generates colored wastewater containing dyes, auxiliaries, and pastes, leading to high treatment costs and significant environmental impact. Furthermore, repeated washing and mechanical tension can easily damage the delicate feel and luster of acetate fibers, affecting the quality of the finished product.

[0004] In addition, conventional printing is mostly single-sided, which is difficult to meet the modern fashion demand for double-sided printed fabrics. Achieving double-sided printing usually requires more complex processes and stricter cost control.

[0005] Therefore, developing a new printing process for acetate fiber fabrics that can significantly save water and energy, reduce pollution, and achieve high-quality double-sided printing effects has become an urgent technical problem to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an energy-saving, water-free double-sided printing process for disperse dyes on acetate fiber fabrics. This process optimizes the dye and paste system and precisely controls the thermosetting parameters, enabling the dye to almost completely sublimate and fix, and the paste to decompose at high temperatures. This essentially eliminates the need for the water-intensive washing process and simultaneously achieves a uniform double-sided printing effect on both sides.

[0007] The above-mentioned technical objective of this invention is achieved through the following technical solution: an energy-saving process for waterless double-sided printing of disperse dyes on acetate fiber fabric, comprising the following steps: S1: Pretreatment: Pretreatment of the acetate fiber fabric to obtain uniform wettability; S2: Preparation of printing paste: Mixing disperse dyes, paste, dyeing accelerator and auxiliaries in proportion to prepare printing paste, wherein the paste is one of polyacrylic acid paste or modified polyacrylic acid paste; S3: Double-sided printing: Printing on both sides of the fabric treated in S1 using printing equipment to ensure accurate alignment of the front and back patterns; S4: Drying: Drying the printed fabric at a temperature of 80-110℃; S5: Heat curing: Placing the dried fabric in an environment of 180-200℃ for heat melting treatment for 60-120 seconds; S6: Finishing: Stretching and shaping the fabric after color curing, or stretching and shaping after light washing, to obtain the finished product.

[0008] The further configuration is that the disperse dye is a medium-temperature or high-temperature disperse dye.

[0009] The paste is further configured as follows: the paste is a polyacrylate ammonium salt or modified polyacrylate ammonium salt paste, with a solid content ≤5% and a thermal decomposition temperature of 150-220℃.

[0010] The dyeing accelerator is further configured to be urea or thiodiethanol, and its addition amount accounts for 1-3% of the total mass of the printing paste.

[0011] The setting is further configured such that the thermosetting color in S5 is carried out in a hot air circulating hot melt machine, and the hot air speed is uniformly controlled at 5-15m / s.

[0012] The process is further configured such that the S5 thermosetting step employs a segmented heating method, comprising a first stage of treatment at 160-175℃ for 20-40 seconds and a second stage of treatment at 190-200℃ for 40-80 seconds.

[0013] The method is further configured such that: between the S5 heat-curing step and the S6 finishing step, there is an S5.5 negative pressure purification step, which includes passing the heat-cured fabric through a closed negative pressure chamber, while simultaneously using circulating cold air to remove trace amounts of gaseous products and dye dust generated on the fabric surface due to thermal decomposition.

[0014] The further configuration is as follows: the light water wash in S6 is soaking in warm water at 25-40℃ or washing flat for 5-10 minutes.

[0015] The further configuration is as follows: the printing equipment in the S3 double-sided printing step is a rotary screen printing machine or a flat screen printing machine, and double-sided printing is achieved by using synchronous or sequential precise alignment printing technology with double screens.

[0016] In summary, this invention offers the following advantages: Through innovative process design, it eliminates water-intensive steps such as traditional washing and soaping, achieving a direct water saving rate of over 90%. Furthermore, it significantly reduces water heating and subsequent drying requirements, resulting in substantial energy savings. The production process is greatly simplified, processing time is shortened, and overall production efficiency is improved. Simultaneously, it significantly reduces the generation and discharge of dyeing and printing wastewater at the source, effectively alleviating environmental governance pressures. Detailed Implementation

[0018] An energy-saving process for disperse dye double-sided printing on acetate fiber fabric without water washing includes the following steps: S1 pretreatment step includes pretreatment of the acetate fiber fabric to obtain uniform wettability.

[0019] The S2 printing paste preparation steps involve mixing disperse dyes, paste, dyeing accelerators, and auxiliaries in a certain proportion to prepare a printing paste. The paste is one of polyacrylic acid pastes or modified polyacrylic acid pastes.

[0020] The disperse dyes are medium-temperature disperse dyes, such as disperse yellow brown SE-3RL, disperse bright yellow SE-6GFL, disperse red 153 (disperse scarlet GS), disperse brown 27, etc., or high-temperature disperse dyes, such as disperse scarlet SR, disperse yellow SF-6G, CI disperse blue 367, etc., which are suitable for the acetate fibers of this application.

[0021] The paste is specifically a polyacrylate ammonium salt or modified polyacrylate ammonium salt paste, with a solid content ≤5% and a thermal decomposition temperature of 150-220℃. Using a polyacrylate paste ensures that during the baking process of acetate fiber fabric at 180-200℃, the paste can almost completely decompose into gaseous volatilization, physically eliminating the root cause of traditional paste residue leading to fabric stiffness and the need for washing. This specific paste, precisely matched with the thermal properties of acetate fiber and the sublimation temperature of disperse dyes, achieves water and energy savings.

[0022] The dyeing accelerator is urea or thiodiethanol, and its addition amount accounts for 1-3% of the total mass of the printing paste.

[0023] The S3 double-sided printing step uses a rotary screen printer or a flat screen printer to print double-sided patterns on the fabric treated in the S1 step using a synchronous or sequential precise alignment printing technique with double screens, ensuring accurate alignment of the front and back patterns.

[0024] The S4 drying step involves drying the printed fabric at a temperature of 80-110℃. In the S5 heat-curing step, the dried fabric is placed in an environment of 180-200℃ for heat-melting treatment for 60-120 seconds. This step is carried out in a hot air circulating heat-melting machine, with the hot air speed uniformly controlled at 5-15m / s.

[0025] Preferably, the fabric is heated in stages, including a first stage of treatment at 160-175℃ for 20-40 seconds and a second stage of treatment at 190-200℃ for 40-80 seconds, with the total time for the two steps controlled between 60-120 seconds.

[0026] The S5.5 negative pressure purification step involves passing the heat-cured fabric through a sealed negative pressure chamber, while simultaneously using circulating cold air to remove trace amounts of gaseous products and dye dust generated on the fabric surface due to thermal decomposition.

[0027] The S6 finishing step involves stretching and shaping the fabric after color fixing to obtain the finished product. Alternatively, the fabric can be stretched and shaped after a light wash. The light wash process involves soaking or washing the fabric flat in warm water at 25-40℃ for 5-10 minutes, after which no soaping is required to obtain the finished product.

[0028] Specifically, taking a 19 momme cellulose acetate fabric as an example for double-sided printing, the pretreatment steps include: refining the fabric in a flat width to remove spinning oil and ensure that the wicking effect is uniform at 8cm / 30min or more.

[0029] The printing paste preparation involves using 6% disperse dye (high temperature type, bright red), 5% polyacrylic paste, 60% urea (dyeing accelerator), 2% defoamer, and finally adding 0.5% deionized water to make up to 100%, and stirring at high speed for 30 minutes to ensure that the dye is fully dispersed.

[0030] Double-sided printing uses an eight-color rotary screen printing machine. The front side is printed first, and then the back side is printed on the same precisely aligned machine. The screen mesh is 125 mesh, and the amount of ink applied is controlled.

[0031] In the drying step, dry in a hot air dryer at 100℃ for 3 minutes.

[0032] The heat-setting step is carried out in a hot air circulating hot melt machine at 190℃ for 90 seconds, with the hot air speed controlled at 10m / s.

[0033] In the post-processing steps, the fabric is tested after baking, achieving a dry rubbing fastness of grade 4 and a wet rubbing fastness of grade 3-4. To obtain the best hand feel, it undergoes a 5-minute flat-width warm water wash at 35℃, followed by a softening and stretching shaping at 130℃. The final finished fabric has vibrant and uniform colors on both sides, precise pattern alignment, a smooth hand feel, and all color fastness indicators meet national standards. Furthermore, the water consumption during production is reduced by approximately 92% compared to traditional processes, achieving water and energy conservation.

[0034] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. An energy-saving process for waterless double-sided printing of disperse dyes on acetate fiber fabrics, characterized in that... Includes the following steps: S1: Pretreatment: Pretreatment of the cellulose acetate fabric to obtain uniform wettability; S2: Printing paste preparation: Disperse dye, paste, dyeing accelerator and auxiliaries are mixed in proportion to prepare printing paste, wherein the paste is one of polyacrylic acid paste or modified polyacrylic acid paste; S3: Double-sided printing: Printing equipment is used to print on both sides of the fabric after S1 treatment, ensuring accurate alignment of the patterns on both sides; S4: Drying: Dry the printed fabric at a temperature of 80-110℃; S5: Thermosetting: Place the dried fabric in an environment of 180-200℃ for heat melting treatment for 60-120 seconds. S6: Finishing: Stretching and shaping the fabric after color fixing, or stretching and shaping after light washing, to obtain the finished product.

2. The energy-saving process for disperse dye waterless double-sided printing of acetate fiber fabric according to claim 1, characterized in that: The disperse dye is a medium-temperature or high-temperature disperse dye.

3. The energy-saving process for disperse dye waterless double-sided printing of acetate fiber fabric according to claim 1, characterized in that: The paste is a polyacrylate ammonium salt or modified polyacrylate ammonium salt paste, with a solid content ≤5% and a thermal decomposition temperature of 150-220℃.

4. The energy-saving process for disperse dye waterless double-sided printing of acetate fiber fabric according to claim 1, characterized in that: The dyeing accelerator is urea or thiodiethanol, and its addition amount accounts for 1-3% of the total mass of the printing paste.

5. The energy-saving process for disperse dye waterless double-sided printing of acetate fiber fabric according to claim 1, characterized in that: The heat-setting process in S5 is carried out in a hot air circulating hot melt machine, with the hot air speed uniformly controlled at 5-15m / s.

6. The energy-saving process for disperse dye waterless double-sided printing on acetate fiber fabric according to claim 5, characterized in that: The S5 thermosetting step employs a segmented heating process, comprising a first stage of treatment at 160-175℃ for 20-40 seconds and a second stage of treatment at 190-200℃ for 40-80 seconds.

7. The energy-saving process for disperse dye waterless double-sided printing of acetate fiber fabric according to claim 1, characterized in that: Between the S5 heat-curing step and the S6 finishing step, there is an S5.5 negative pressure purification step, which involves passing the heat-cured fabric through a closed negative pressure chamber, while simultaneously using circulating cold air to remove trace amounts of gaseous products and dye dust generated on the fabric surface due to thermal decomposition.

8. The energy-saving process for disperse dye waterless double-sided printing of acetate fiber fabric according to claim 1, characterized in that: The light water wash in S6 is soaking in warm water at 25-40℃ or washing flat for 5-10 minutes.

9. The energy-saving process for disperse dye waterless double-sided printing of acetate fiber fabric according to claim 1, characterized in that: The printing equipment in the S3 double-sided printing step is a rotary screen printing machine or a flat screen printing machine, and double-sided printing is achieved by using synchronous or sequential precise alignment printing technology with double screens.