The concept of dyeing and finishing
Dyeing and finishing processing, together with spinning and weaving processing, form the entire process of textile production.
Dyeing and finishing is a physical or chemical treatment process for textile trees and their products, with chemical treatment being the mainstay. Its purpose is to give textiles color effects (coloring or color removal), morphological effects (appearance, surface properties), and practical effects (such as anti-shrinkage, easy-iron, flame retardant, etc.).
The dyeing and finishing process can be summarized into four categories: pretreatment, dyeing, printing and finishing.
Pretreatment
Use chemical methods to remove impurities on the fabric that hinder subsequent processing (such as Fiber symbiosis, slurry, pollutants, etc.), thereby making the surface of the fabric clean and moist, showing the natural luster of the fabric.
Dyeing
Use dye bath (dye + auxiliary + solvent) to process textiles. Through the chemical or physical chemical combination of dyes and fibers, the dyes in the dye bath are transferred to the fibers to generate insoluble colored substances, making the fabrics uniform in color and good in dye fastness.
Printing
Configure the dye into color paste (dye + paste + chemical agent), and The fabric is dyed according to a preset pattern and has a certain color intensity.
Finishing
Improving the appearance of fabrics through physical, chemical or a combination of both methods , feel and intrinsic quality, improve the wearing performance of fabrics and give fabrics some special practical effects.
Route classification of dyeing and finishing processes
Due to different textile products , their fiber raw material characteristics, fabric structure, specifications, finished product uses and quality requirements are different, and their dyeing and finishing process routes are also different. The traditional process routes of cotton, wool and silk fabrics are as follows:
Basic requirements for dyeing and finishing machinery and equipment in the dyeing and finishing process
(1) Strong process adaptability:
Process parameters such as temperature, pressure, speed, and processing time must be met.
(2) High degree of automation:
Process parameters should be automatically detected, automatically adjusted and accurately controlled as much as possible.
(3) Equipment has good corrosion resistance:
The dyeing and finishing process has many pressure-resistant and corrosion-resistant containers and equipment, and high-strength, corrosion-resistant metal materials must be used; some high-temperature drying and steaming equipment require heat conduction, heat radiation and thermal stability. Good materials, and use materials with good thermal insulation properties as insulation layers, etc.
(4) The combination machine has good synchronous transmission performance and wide speed regulation range:
Ensure that the operating tension of the fabric is as small as possible to avoid fabric elongation or wrinkles. There must also be a certain speed range.
(5) Equipment has low energy consumption and less pollution:
Improve the sealing performance, thermal efficiency and thermal insulation effect of the structure to save energy; the equipment should be equipped with necessary chemical recovery devices and waste heat recovery devices to reduce environmental pollution.
Characteristics of dyeing and finishing machinery
(1) The machine size is relatively large
In order to meet the needs of the width of the processing object, process action time and production speed, the unit machine must have a certain fabric capacity.
(2) There are many types of equipment, pressure vessels and high-temperature equipment
Since there are many dyeing and finishing processing objects (fibers, yarns, fabrics and garments, etc.), different processing objects require a variety of processes (intermittent, semi-continuous, continuous; open-width processing and rope processing, etc. ), so there are many types of equipment.
(3) The unit machine has strong versatility and high degree of serialization
In order to reduce the types of unit machines, it must be designed as a universal unit machine that can be used with a variety of connected machines. The series of dyeing and finishing machines are designed according to the width of the fabric. The nominal width of the machine is 200mm greater than the width of the fabric. The current nominal width is 1200 to 4000mm, with every 200mm as a series.
(4) Combined machine multi-unit synchronous transmission requires high requirements and wide speed adjustment range
The AC variable frequency synchronous speed regulation system has been applied, and the speed regulation range has reached 1:10.
(5) The degree of automation is gradually improved
Applying electronics and microcomputers Control technology improves equipment automation and process reproducibility.
Basic components of dyeing and finishing machinery
General devices
1. Open-width fabric feeding device
Its function is to ensure that the fabric enters the unit machine from the central position without wrinkles under a certain tension. Hold points for continuous runs.
Open width cloth feeding device
<img width=100% height=auto data-preview-srIt is composed of a frame, safety protection device and automatic control system. The liquid rolling truck also includes a liquid rolling tank.
There are many types of rolling mills, which can be divided into two-rollers and three-rollers according to the number of rolls; according to their arrangement It can be divided into discrete type, horizontal type, tilt type, etc.; it can be divided into light and heavy type according to the pressure level; it can be divided into hydraulic type (oil cylinder pressure) and pneumatic type (film cylinder, air bag, cylinder directly or through Lever pressure); according to the rolling groove type, there are single groove, double groove, fixed type, lifting type, central sleeve type, etc.; according to the roll structure, there are ordinary rolling cars (including medium and high roller rolling cars, medium solid roller rolling cars , Chinese roller rolling car), adjustable deflection rolling car (including top bending moment rolling car, air-controlled medium-solid roller rolling car, hydraulic internal support uniform rolling car, air bag internal control uniform rolling car) and axial moving curve Roller truck, etc.
2. Flat washing machine
Uses washing liquid as the medium. Wash away the slurry, impurities, acids, alkali, fixing dyes, printing paste and auxiliaries remaining on the fabric. It includes two categories: water washing machine (the fabric is only affected by the washing liquid) and steaming machine (the fabric is affected by steam and washing liquid alternately).
Measures to improve the washing efficiency of flat washing machines are:
(1) Increase the washing temperature and use alternating water and steam treatment.
(2) Extend the action time of the lotion on the fabric, such as using the form of zigzag threading.
(3) Increase the number of padding times and add a small pressure roller on the upper row of guide rollers.
(4) Enhance the relative movement of the lotion to the fabric, such as using vibration devices, powerful jets, rotary screen suction washing machines, etc.
3. Steamer
The function of the steamer is to allow the fabric to complete the penetration, reaction and fixation of dyes and chemicals into the fiber under different temperature and humidity conditions.
The steamer box is composed of a box body, a cloth guide roller, a cloth guide roller transmission device, a steam pipe, and a cloth inlet and outlet seal. .
Steam is used as the working medium in the steamer. Steam serves as both a heat carrier and a moisture source. The temperature, humidity and pressure inside are its main process parameters.
According to the dyeing process, it can be divided into two types: reduction steamer and color steamer:
● The reduction steamer is used for steaming cotton and its blended fabrics after dyeing with vat dyes. The inlet of the steamer is sealed with both steam and liquid, and the outlet is sealed with liquid;
● The color development steamer is used for color development and steaming of cotton fabrics after pad dyeing with insoluble azo dyes. The inlet and outlet of the steamer are steam sealed.
4. Dryer
Relies on thermal energy or electromagnetic energy, Evaporate the water in the wet fabric and turn it into a dry fabric.
(1) Cylinder dryer:
make the fabric It directly contacts the high-temperature metal surface to transfer heat, and the moisture evaporates from the free surface to complete the drying process. It is mainly composed of drying cylinder, drying cylinder bearing, steam sealing device (rotary joint), drainage device, frame and insulating door panel. The highest drying efficiency.
(2) Hot air dryer:
Using the principle of convection heat transfer, the hot air transfers heat to the fabric to evaporate the moisture in the fabric. The drying process is relatively gentle, the hand feels soft after drying, and there is no aurora on the surface. It is mainly composed of fabric conveying device, air heating device, hot air circulation system, exhaust device, cloth in and out device, frame and insulating door panel.
(3) Thermal radiation drying machine:
It is mainly used for non-contact pre-drying of fabrics after pad dyeing to prevent dyes from migrating on the fabric and causing uneven dyeing. Because infrared rays can penetrate wet fabrics when irradiating them, the radiant energy is converted into heat energy from inside the fibers. When the temperature increases rapidly, the water molecules in the fabric move strongly and diffuse and evaporate rapidly, so that the inner and outer layers of the fabric can be simultaneously Drying purposes.
Qi whole machinery must meet
the requirements of high quality, high efficiency and short delivery time. Process, multi-function, deep processing, low consumption and environmental protection are developed to meet the requirements of modern rack-mounted production such as multiple varieties, small batches and fast delivery, improve the reliability and stability of the machine, and ultimately achieve the optimization of various process parameters. Online detection and full process automatic control.
1. Improve the technical performance of general units and general devices of dyeing and finishing machinery, and develop towards high efficiency, high speed and miniaturization , the relevant unit machines are developing towards modular modularization, which makes it easier for printing and dyeing enterprises to choose the combined machine model they need.
2. Develop dyeing and finishing machinery suitable for small batches, multiple varieties, and high-quality intermittent processing (such as large rolls) equipment, high temperature and high pressure jigger dyeing machine, microcomputer controlled liquid flow rope dyeing machine, etc.).
3. In conjunction with efficient short-process technology, develop small-batch continuous processing equipment (such as small-batch continuous dyeing machines, short-process Continuous bleaching machine, etc.).
4. Adopt AC variable frequency speed regulation and microcomputer control to achieve synchronization between machines, from edge to wide adjustment. The speed ratio range (above 1:10) keeps the fabric running in loose, semi-loose and low-tension conditions.
5. Develop multi-purpose and multi-functional equipment, such as a long ring steamer that can also be used for baking processes , high-temperature technical width setting machines, multi-function calenders, etc. suitable for tenter technology and heat setting technology:
6 ． Improve the level of online detection technology and automatic control technology, and promote the application of new technologies such as electronic color matching, laser engraving, and microcomputer color matching systems.
Dyeing and finishing technology and equipment
Printing technology and equipment
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Dyeing and finishing technology and equipment
Printing technology and equipment
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