What are the methods of using knitted fabric dyeing machines?

1. Direct dyes:
Features: It can directly dye cellulose fibers in a neutral dye bath, has a complete color spectrum, is easy to use, and is inexpensive, but has poor washing and light fastness, and often requires color fixation.
How to use:
Generally, it is carried out on an ordinary rope dyeing machine, with a dyeing bath ratio of 1:15 - 30, and the bath ratio of light colors is larger than that of dark colors. For example, when dyeing light-colored knitted fabrics, the bath ratio may be 1:30, while the bath ratio can be 1:15 when dyeing dark colors.
Dyeing temperature usually uses near-boiling point dyeing to obtain good dye transfer, color and fastness. Dyeing can start at room temperature (dark colors can start from 60℃ - 80℃). For example, for some darker knitted fabrics, dyeing can be started at a temperature of 60℃ - 80℃, and then gradually heated to near boiling point.
In direct dyeing, salt or sodium sulfate is often used as a dyeing accelerator, and sodium sulfate can be used to obtain a brighter color. And direct dyes are not resistant to hard water, so soft water dyeing must be used.
After dyeing, cationic dye fixers such as dye fixer Y and dye fixer M can be used for color fixation to improve fastness.
2. Reactive dyes:
Characteristics: Soluble in water, containing active genes in the molecular structure, can covalently bond with the hydroxyl groups on cellulose fibers under certain conditions, with bright color, good wet fastness and friction fastness, good levelness, more uniform color spectrum, convenient application, good light fastness and other advantages.
Usage:
Immersion dyeing method:
One-bath one-step method: dyeing in an alkaline bath and fixing at the same time. This method has a simple process, short dyeing time and convenient operation, but because adsorption and fixation are carried out at the same time, the dye can no longer diffuse after fixing, so the levelness and permeability are poor, and dyeing under alkaline conditions, the dye stability of the dye bath is poor, hydrolysis is more, generally not commonly used.
One-bath two-step method: first dye in a neutral bath, when the dye is close to equilibrium, add an alkali to the dye bath, adjust the pH value to the specified pH value for color fixation (generally 11), at which time the dye and the fiber are covalently bonded to achieve color fixation. This is a relatively reasonable dyeing method in the reactive dye exhaust method, which can not only obtain a higher dyeing rate and color fixation rate, but also has a good leveling effect. This method is often used for dyeing cotton knitted fabrics. For example, first dye the knitted fabric in a neutral dye bath for a period of time, and after the dye is close to equilibrium, add an alkali to make the pH value of the dye bath reach about 11 for color fixation.
Pad dyeing method: The fabric is dipped into the dye solution through a roller, and then treated by steaming or baking to react with the fiber and fix it on the fabric.
3. Sulfur dyes:
Characteristics: cheap, easy to use, suitable for dyeing various products of cellulose fibers, but the color is not bright, the chlorine fastness is poor, the color spectrum is incomplete, it has a brittle effect on the fiber, and the light fastness varies greatly with different varieties.
Usage:
After dyeing, post-treatment is required, including soaping (removing floating color attached to the fiber surface, improving dyeing fastness and enhancing color brightness), Taiko oil treatment (improving the color light of the dyed material, increasing the sulfur blackness, and having a certain anti-brittleness effect), color fixing treatment (using color fixing agent M for color fixing) and anti-brittleness treatment (some sulphur dye dyed materials will produce brittleness after being placed for a long time, which seriously reduces the fiber strength. Urea 0.8-1% plus Taiko oil 5-5.8% can be used for anti-brittleness treatment).
When using knitted fabric dyes, the following matters should also be noted:
1. For knitted fabrics of different materials, such as cotton, linen, silk, wool, chemical fiber, etc., it is necessary to select appropriate dyes and corresponding dyeing processes to ensure dyeing effect and quality.
2. Accurately control various parameters in the dyeing process, such as temperature, time, pH value, bath ratio, etc., and strictly follow the instructions for use of the dye.
3. Before dyeing, the knitted fabric needs to be fully pre-treated, such as cleaning and degreasing, to remove impurities and oil stains to ensure the uniformity and fastness of dyeing.
4. Pay attention to the dissolution and mixing methods of the dye to ensure that the dye is fully dissolved and evenly dissolved to avoid problems such as uneven dyeing or color spots.
5. During the dyeing process, the knitted fabric should be constantly stirred or turned over to promote the uniform adsorption and diffusion of the dye to prevent the occurrence of color flowers and color differences.
6. After dyeing, it is necessary to carry out sufficient water washing and post-treatment to remove unfixed dyes and impurities, and improve the fastness of dyeing and the feel of the fabric.
The above is the use of the knitted fabric dyeing machine. If you have other aspects of the knitted fabric dyeing machine that you want to know, please pay attention to www. chinadyeingmachines.com!