The hometown of silk has long mastered the technology of silk dyeing. The book "Works" written by Song, a scientist in Ming Dynasty, recorded the extraction and dyeing methods of plant dyes in detail. In recent decades, China's textile dyeing and finishing industry has made progress. The output of textile fiber and textile printing and dyeing processing clothing has been in the forefront of the world, and dyes and auxiliaries have developed rapidly. The traditional textile dyeing and finishing industry has encountered problems, and the special environmental pressure is becoming more and more serious around the world.
Hardware elements and software elements that support the development of textile dyeing and finishing technology, hardware elements mainly refer to fiber materials, dyeing materials, processing machinery supporting equipment, etc., while software elements mainly refer to information product design, processing technology management technology, etc., which all support the development of textile dyeing and finishing technology.
The modern progress of textile dyeing is directly determined by the development of some factors. This paper mainly analyzes the progress of modern dyeing technology, especially the dyeing of new fiber and group fiber textiles.
1. Modern dyeing technology
Modern textile printing and dyeing began in18th century. With the development of chemical fibers, dyes and equipment, it has gradually established an independent branch.
The main factors that promote the development of modern dyeing technology are:
(1) New fibers and new structural textiles are emerging rapidly;
(2) Application of new dyes and processing equipment;
(3) The promulgation and implementation of new environmental protection regulations;
(4) The global supply of resources and labor is tight, and the processing cost is rising;
(5) Modern dyeing theory goes deep into modern science and technology and is applied to dyeing processing.
The rapid development of dyeing technology for modern important pigments is introduced.
1. 1 new fiber group fiber textile dyeing
With the improvement of quality and the development of modern new materials, new fibers are faster and faster, and the varieties are more and more unique. At present, there are 275 kinds of new synthetic fibers that have been commercialized, including superfine, PLA, PTTPDT-related profiled and differentiated fibers. New regenerated fibers include lyocell fiber and bamboo fiber. Various histochemical fibers include soybean protein, silkworm chrysalis protein and milk protein fiber.
The fabric structure of textile group is different from blended and interwoven composite textiles. At present, there is a gap between China and the advanced level in the world. For example, according to recent statistics, the average fiber group of inner fabric is only 1.3, while the average fiber group of imported outer fabric is 5.6, with 7-8 fibers.
New hair fibers may include all kinds of spinning fibers.
The new textile dyeing of fiber textiles needs new dyeing technology to adapt [3] dyeing characteristics to adapt to new characteristics, and it is necessary to choose new dyes and adopt new processes. For example, polyester superfine fiber dyeing bulk dyes need to be colored. There are new requirements for special auxiliaries for levelness and color fastness, heating process and dyes suitable for dyeing standard fibers and their new fibers. After screening, domestic and foreign dye manufacturers have developed various series of special dyes. The supply characteristics of two adaptive groups enable species to dye colors, and the homochromy between the same adaptive groups should be close to the dyeing process of seed dyeing bath or one bath. For example, loose/acid dye dyeing, loose/acid dye dyeing and loose/cationic dye dyeing are suitable for polyester fiber, cellulose fiber and nylon acrylic fiber. Dyeing technology of cellulose fiber with nylon, wool silk and spandex fiber textiles: two baths, two baths, etc.
Simplifying the process, saving water and energy, some research units of various companies have studied the dyeing process of dyeing seeds with a single dye, including dyeing polyester wool, nylon and silk with a single loose dye; Single dyes are used to dye cellulose fibers such as wool, silk and nylon, including nearly divergent and dispersed cationic dyes such as silkworm chrysalis protein fiber and soybean white fiber, which are suitable for seed group dyeing. My research proves that this special auxiliary-CUN-disperse dye is used for dyeing wool, silk and nylon spandex in bath [45].
When dyeing with two dyes in one bath or with seed groups of two dyes, in order to make the dye groups dye evenly and improve the color fastness of the same color, it is necessary to formulate a new dyeing process, especially to control the temperature rise program to adjust the PH value of the dyeing bath. At present, the supply of additives for controlling PH value has been allowed. Using the temperature rising interval, the PH value is alkaline and acidic, and the dyeing effect of fiber dyes sensitive to PH value is not good, only reducing the damage of fiber dyes and improving the color fastness of the same color and level dyeing. I use this principle to dye cotton/nylon fabric with neutral dyes and acid dyes in one bath, and use it to hydrolyze dyes to dye nylon.
1.2 new dyes and auxiliary equipment
To meet the needs of dyeing, new dyeing auxiliaries are constantly emerging [7]. The development of new dyeing auxiliaries mainly meets some requirements:
(1) instead of banned dye auxiliaries, develop environment-friendly dye auxiliaries;
(2) Adapting to the dyeing needs of new fiber group textiles;
(3) meet the needs of new technology and new equipment processing;
(4) meet the needs of efficient, water-saving and energy-saving processing.
Although various dye auxiliaries have developed rapidly obviously, it is important to keep loose dyes and related auxiliaries [7-8].
Sex dyes include new chromophores, sex groups and their combinations, and linking groups mixed with dyes. The main performances of processing commercial dyes to improve the performance of new dyes are as follows:
(1) High color intensity and high direct fixation;
(2) High fastness includes fastness to sunlight, fastness to rubbing, fastness to perspiration and fastness to soaping.
(3) Low salt, low alkali or sex dyeing fixation;
(4) Environmental friends contain substances such as formaldehyde, which is harmful to aromatic amines;
(5) Compatibility of levelness and reproducibility
However, special dyes suitable for dyeing or new printing technology promotion are excluded, such as special dyeing dyes for inkjet printing bath.
It must be emphasized that some improved hair bases include dyes with the same anisotropic base, and only amphoteric base dyes are approved. Tri-basic or tetra-basic dyes can improve the fixation rate and wet fastness of the improved dyes. The high directness of acid dyes in the matrix structure makes the linear structure of sex dyes enhance the planarity of a few aromatic rings. Some dyes have higher directness.
Hair reducing dyes other than cellulose fiber dyes
Some new fiber groups, such as silkworm chrysalis protein fiber, bamboo fiber, etc., have been pointed out earlier. Not suitable for dyeing with dyes. My technicians screen to make sex dyes more effective.
The recent development focus of bulk dyes is that there are few new varieties with new special heterocyclic structures. The improvement of chromophore dosage form makes bulk dyes have high dye uptake, deep dyeing or high fastness, including washing fastness, rubbing fastness and thermal migration fastness.
Similarly, the new disperse dyes are friendly to the environment and contain harmful aromatic amines, heavy metals and other substances, so as to adapt to alkaline dyeing or batch dyeing with disperse dyes with strong alkali resistance.
Suitable for dyeing superfine polyester, PLA and PTTPDT new fibers. The new loose dyes are suitable for dyeing superfine polyester. The color rendering of loose dyes needs to be improved. All companies should provide a series of dyes suitable for dyeing PLA fibers. In addition to improving the dye uptake, they also have lower dyeing temperature and special requirements for light fastness and wet fastness. Dyes suitable for PTTPDT fiber dyeing are suitable for dyeing spandex-containing textiles with supercritical CO2 fluid.
In addition to new bulk dyes, fiber textiles or new processes are used to dye and dye seed fiber composite dyes, such as bulk dyes, bulk dyes, cationic dyes, etc., which have not been industrialized in energy production and application at present.
The new dyeing equipment mainly shows as follows: the bath reduction ratio between dyeing rooms is reduced by 3: 1 or even lower, the consumption of chemicals, water and energy is increased, the degree of automation is sought, the labor is reduced, and even full automatic control is realized. Jet dyeing machine only reduces water consumption, improves energy conversion and reduces turbulent friction of fabric. The new equipment has automatic control of surface height, such as feeding, heating and on-line monitoring, which makes the production error and control accurate dyeing. Controlled dyeing [9]
New dyeing process of 1.3
In recent years, with the development of fiber and dyeing auxiliaries, equipment and computers, the progress of dyeing technology is especially manifested in some new technologies, such as firm processing, environmental protection products, improving processing efficiency, reducing energy consumption, saving dyes and improving environmental conditions.
An important new dyeing process uses disperse dyes, which belong to two kinds of dyes, and their dyes include original sulfide dyes.
Dye with 1.3. 1
Sex dyes are only used for dyeing cellulose fibers and textiles, and for some synthetic fibers such as protein fibers. Nylon is used for grouping fibers and their textiles, and silkworm pupa protein soybean protein fibers are blended and interwoven.
1.3. 1. 1 controlled dyeing
In recent years, dye manufacturers have produced dyes with benign compatibility, and the dyeing properties of each dye are expressed by dyeing characteristic values. The important dyeing characteristic values S, E, M 1 or LDF, T50 or RF selected by the supplier respectively represent the deviation or levelness of the first and second dye uptake and fixation rate. Some characteristic values reflect the properties such as directness, shift value, fixation rate, and fixation preparation silk. Cotton fibers with similar characteristic values are dyed by the recommended dyeing process through the determination of dyeing conditions and the change of process. Good compatibility or compatibility RCM (reactive dye compatibility matrix).
Some dyes with the same or similar dyeing characteristics produced by various dye companies include ProcionH-EXL, Procion XL Remazol RR, IntracronCDXSumifix HF, etc.
Dye and computer technology are combined to establish a strict dyeing monitoring system, and the quality control repair system is used to control dyeing, so as to improve dyeing ability (RFT), reduce cost, improve efficiency, reduce sewage and save energy for dyeing materials [8].
1.3. 1.2 wet short steam dyeing
The pad dyeing process of sex dyes can be seen as pad drying and steaming process, which has the advantages of less urea consumption, environmental protection, low fixation rate, high energy consumption and great impact. According to this process, the dyeing and fixation of dyes are closely related to the humidity and water content of fabrics. Especially, the phenomenon that the fabric enters the steamer after being pad-dried and rapidly heats up (that is, the steam temperature is over) slows down the dyeing speed of dyes, reduces the dye fixation rate, and has high through dyeing levelness.
Even if the dry fabric is saturated with steam, it should enter the steamer, that is, preheating, heating, cooling and balancing with steam temperature. In the first stage, preheating, heating, cooking and heat exchange reach the steam temperature (100℃). Just because of the heat release of water and cellulose (hydrogen bond), fabric heat reduces the swelling of fibers, dissolves dyes, and accelerates the dyeing and fixation of dyes. It is very beneficial that wet cloth enters the steamer only to delay the heating rate, keep the fiber moisture and prevent the heating phenomenon.
Although the equipment of wet short steaming process is strictly and accurately controlled by computer, so it can adapt to the fixation speed of temperature dyes, the example of MonfortsBASF combined with Econtrol pad dyeing wet steaming machine is only suitable for similar equipment of wet short steaming dyeing of woven fabrics and knitted fabrics, and the dyeing process is studied.
The application of this process has the advantages of short process flow, high fixation rate, energy saving of products, reduction of pollution, leveling and permeability by using urea. Because this process requires accurate adjustment of temperature and humidity, the two parameters are related and directly affect the fixation speed of dyes. The equipment requires high dyeing depth (dye concentration increase) for dyes (active diffusion rate) and fibers (hygroscopicity, microstructure). It is said that the dyeing conditions are the same as urea, and the auxiliaries work. Appropriate auxiliaries can improve the fixation rate or lower the fixation temperature and reduce the amount of alkali. The fixation temperature of dicyandiamide, an auxiliary agent for NF dyeing bath developed by myself, is 200-265,438+00℃. Some devices are suitable for wet short steam dyeing. Because the fixation temperature of wet short steaming process is higher than that of low fabric (25-30%)
1.3. 1.3 cross-linking dyeing
Crosslinked dyes are mainly used to combine dyes with valence bonds on some functional fibers. For example, direct dyes are crosslinked with fiber dyeing process through crosslinking agent.
Research on improving dye fastness: I have done some research on crosslinking dyeing process with less crosslinking agent. In fact, the cross-linking dyeing process uses cross-linking agent to hydrolyze dyes to cross-link and fix fiber dyes. The dosage of hydrolyzed dyes is as high as 30-40%, which only reduces the utilization rate of dyes, reduces the dyeing fastness and increases pollution. The crosslinking agent used for fully dyeing and adsorbing fibers with hydroxyl groups is used for completely fixing light-colored dyes of fiber color. The crosslinking agent used to dye the structure is actually used to approximate the application process of some chromogenic dyes and amphoteric functional dyes.
Using cross-linking agent to hydrolyze dyes to fix fibers, the wet rubbing fastness is improved by about 1 level. I will introduce the dyeing process of a new dye in detail in another article.
1.3.2 dyed with its dyes
The latest progress of dye dyeing, especially electrochemical dyeing, has attracted people's attention. Traditional raw dyes or sulfide dyes are dyed with chemical dyes. The original case used the industrial output of insurance powder, and the output of wastewater was broken. Earlier, it was assumed that charging would make the dye directly electrode obtain charged leuco for dyeing. The problem of dye pollution is caused by the original reagent. In the early 1960s, I used a molten metal machine as an electrode to roll the original soluble leuco and molten metal of the original dye matrix into the fabric to prevent air oxidation from dyeing fibers. Experiments show that it is necessary to dye light color with sodium hydrosulfite. The padding time of NaOH suspension of the original dye is shorter by tens of seconds, but because it can dye dark color, the experiment is not continued. With regard to 1960, Australia issued a patent for electrochemical primary dyeing of raw dyes, and the dyeing processes and equipment that have appeared one after another by BASF Company have attracted much attention because of their good environmental protection [7 13].
Electrochromic dyeing directly and indirectly causes the dye to be directly cathodically electrochromic and dissolved in alkaline solution, indirectly, the medium reacts with the electrode first, and then the original medium dyes the colorless dyed fiber. Because the dye matrix is difficult to dissolve in water, the general indirect efficiency is extremely high.
As dielectric compounds, organic compounds, organic compounds, two kinds of organic compounds, and some metal complex salts, especially Fe2+ complexes, allow ligands, especially alkaline solutions, to stabilize the complexes, which are easy for Fe3+ protoFe2+(the redox potential of alkaline solutions is at least lower than -600mv, lower than-1000 mv), so that protochromes include indigo and other protochromes.
Indirect electrochemical mechanism (such as Fe2+ triethanolamine complex);
Step 3, a primary cathode of a primary -Fe3+ composite cathode;
Fe3+L+e= Fe2+L(L triethanolamine ligand)
The prototype complex electrode diffuses into the dye matrix and is reduced.
Dye colorless oxidized insoluble dye matrix to fix fiber;
The carbonylation reaction of raw dyes with complex structure is more complicated, so we should choose the same dyes and adopt the same electrochemical conditions. The specific process needs to be improved. Because it is easier to control the value with or without original dyes, it is especially suitable for products with stable dyeing with single dyes. For example, indigo dyed denim is said to have been used abroad. In addition, my batik products are suitable for products with low requirements for single-stage dyeing, and the external stabilization process is adopted to reduce the dosage of sodium hydrosulfite.
There are few new dyeing processes, including disperse dyes and acid dyes. This paper introduces that the repeatability of this product is developing in the direction of high efficiency, rapidity and cleanness.
1.4 dyeing and washing technology
The fixation of sex dyes requires water injection, especially for dark products, which only affects the color fastness of products. The on-off key is used to accelerate the dyeing of the product and make the color of the product stable. In addition to soaping fastness, wet rubbing fastness is often closely related to important technical indicators of products.
On the one hand, the research on the washing amount of near dyeing improves the fastness of products, on the other hand, it saves water, reduces sewage and improves washing efficiency. Firstly, the evaluation standard of washing principle is deeply studied, the theoretical relationship of intermittent continuous water exchange is put forward, and the technical parameters of the same stage washing are designed according to the material removal characteristics of the same stage washing. Washing mainly consists of three steps:
(1) In the dilution exchange stage, water is mainly used to dilute some fiber direct substances such as salt floating color.
(2) In the internal diffusion stage of hydrolyzed dye fiber, the temperature must be raised to near boiling (soaping) to speed up the diffusion.
(3) firstly, diluting and exchanging diffusion hydrolysis dyes with hot water and cold water.
The notorious washing process is designed according to the washing process, and the key development points of improving the washing equipment are as follows:
(1) The dyeing process is changed from cold water washing to hot water washing (60-70℃), and intermittent water change is changed to continuous water change, which reduces the precise control of water flow;
(2) the bath ratio washing is changed to bath ratio or super bath ratio washing;
(3) Slow running water washing is changed to fast liquid-liquid washing.
(4) changing the experience control water washing into the control water washing;
And (5) washing with a conventional washing aid and a high-efficiency chelating agent.
In particular, the controlled water washing process is adopted to shorten water consumption, reduce sewage, reduce treatment cost and improve efficiency. All new bath ratio dyeing machines are controlled by water washing.
1.5 environmental pressure in dyeing process
At present, the pressure of dyeing process mainly includes replacing the banned dyes containing carcinogenic aromatic amine heavy metals (hexavalent chromium, etc.). By strictly selecting various chemicals to control the three wastes, save water and energy, and monitor the national standards of products. In order to solve the problems existing in the dyeing process
The national dyeing system project should first reasonably select raw materials, including fibers, dyes and auxiliaries. Establish state-run production, reduce the consumption of dyes, auxiliaries, water and energy, and effectively control the three wastes. Products that meet the sewage discharge standards should be strictly monitored to produce safe and healthy products.
Textile products should meet the Eco-Tex Standard 100 environmental protection standard, that is, there are six requirements: containing carcinogenic aromatic amines or cracking and releasing carcinogenic aromatic amines, containing sensitive dyes, additives exceeding the standard, containing heavy metals exceeding the standard, containing formaldehyde, absorbing halides, easily polluting the environment or meeting the three wastes treatment standards. Now the requirements are more stringent.
At present, the main problems faced by textile dyeing and finishing engineering are water saving, energy saving and reducing sewage discharge.
The water consumption and sewage discharge of dyeing process only increase with the increase of water price, which is serious all over the world, including China. The stricter the discharge standard of sewage treatment is, the shorter the dyeing process is. Bath washing is more efficient than dyeing, saving water and reducing emissions, realizing recycling water and improving sewage treatment efficiency. At present, there are three main ways to recycle water:
(1) membrane filtration;
(2) using an adsorbent to remove the dye;
(3) chemical or high-energy ray (ozone ultraviolet treatment) decolorization;
Treating sewage is as difficult as dyeing, and it needs some treatment before it can be used. It is more practical to use the treated water in the same place.
It is reported that indigo is collected and reused.
The more attention is paid to the detection and control of national standards of products in the production process, the higher the requirements, and the important indicators of product quality.
2. Prediction of dyeing technology
The undyed processing needs to be cleaned first, and textiles only need to be cold-proof, warm and beautified. High-performance products, especially undyed products, should be developed first.
2. 1 dyeing
For undyed processing, establish a safer and more perfect production and processing chain, which will affect the environmental damage of fiber materials and dyed products; Safe production and processing, destroying resources and polluting the environment; Efficient and highly adaptive; Product safety, health function and the whole production chain are strictly monitored. The establishment of clean dyeing chain needs raw materials, product design, processing and application. * * * Work together to establish a clean dyeing production system.
2.2 Dyeing of new fibers and new structural textiles
With the rapid development of science and technology, the structure, performance and processing of textiles are becoming more and more complicated, including dyeing. At present, there are 5-6 kinds of fibers in the outer layer of textile fabrics. The more kinds of fibers our textile products contain, the more suitable the dyeing process is. The rapid development of dyeing and the in-depth study of the same color dyeing theory.
At present, some new dyeing technologies are gradually maturing, such as high-efficiency short-flow dyeing, beam ultraviolet fixation, ink-jet printing, electro-phase printing and so on.
2.3 Non-water saving dyeing
At present, water is still dyed without medium, and water-saving dyeing of sewage discharged from water includes continuous dyeing with various bath ratios and low liquid ratio, and the development of purifying and reusing water from external circulating water treatment solution [10].
Non-aqueous dyeing is a hot research topic in supercritical CO2 fluid dyeing. Although it is hoped to completely replace water as the dyeing medium, some special dyeing systems hope to apply another non-aqueous dyeing medium, that is, a dye medium that can explode from liquid. Because of the vapor pressure, the dyeing equipment is simple. By adjusting the hydrophobic groups of the liquid, it can be used as a dyeing medium similar to dyes. My experiment proves that only direct dyes, acid dyes and neutral dyes have the same soluble dye uptake, while nonionic dyes have the same dye uptake.
Non-aqueous medium dyeing * * * The same problem is to improve the recycling rate of some media and reduce costs, except for some new non-aqueous medium dyeing.
2.4 High information network with high self-staining
Non-highly informationized network reflects dyeing processing.
To meet the needs of establishing the communication market efficiently and quickly, we will supply raw materials, design products, order delivery and technical information analysis, and establish information networks in all aspects of production, processing and connection management.
Dye-free automation is high, which reduces labor and improves processing efficiency and quality. All processing is automatic, and equipment control is used to improve the production environment. The more common workshops are.
2.5 Imitation coloring
Because of the boundary, the structure of various material groups is reasonable and the function efficiency is high, including the colors produced by various objects.
Objects and special objects are rich in color and colorful, and the ways to produce color are also rich and colorful. The two kinds of pigments have the same structure, and each has its own special function. For example, although chlorophyll is the main function of green plants, it can convert light energy into electric energy, and the structural color of chemical energy can be scattered by light. Examples of colors produced by interference and diffraction: The beautiful colors and structural colors of butterflies are closely related to the combination of object colors, pigments and structural colors. At present, structured color fiber membrane is polluted by chemicals, and structured color special textiles are paid attention to. In addition, the new imitation color products are more like colored textiles. Functional products only have beautiful colors, such as antibacterial, moisturizing and ultraviolet protection, and have photothermal and photoelectric conversion functions [1 1- 12].
The faster the undyed technology develops, the more predictable it is at present.
Conclusion:
With the development of modern science and technology, the quality of traditional ancient dyeing is improved, and the progressive class lacks processing technology.
What we are doing now is textile dyeing and finishing. We should follow the progress of the next generation, strengthen science and technology, and develop special original technology, so that we can become the world's leading textile dyeing and finishing company as soon as possible.