Grey NHF-S

Industry knowledge

How to dye with Grey NHF-S Dye?

The dyeing process with Grey NHF-S Dye involves multiple steps and the control of key parameters. It is mainly used for dyeing protein fibers (such as wool, silk) and their blends. This type of dye is an acid dye and usually needs to be dyed under acidic conditions, and factors such as temperature, dye concentration, and pH value should be considered.

1. Preparation
Before starting dyeing, you need to prepare the required dyeing equipment and dye solution.
1.1 Materials and Equipment
Dyeing Fibers: Protein fibers such as wool, silk, or their blends.
Grey NHF-S Dye: Dye required according to the amount of dyeing.
Acidic auxiliaries: Such as acetic acid, sulfuric acid, etc., used to adjust the acidity in the dye bath.
Dyeing tank/dyeing machine: used for uniform dyeing.
Temperature control equipment: Control the temperature during the dyeing process to ensure stable dyeing effect.
Water: Used to dissolve the dye and dilute the dye solution.
1.2 Prepare the dye solution
Prepare a certain amount of Grey NHF-S Dye according to the required dye concentration. Generally, the concentration of dye used is related to the desired color depth, fiber type and area to be treated. The specific amount can be adjusted according to actual conditions or production processes. Generally, the recommended dye concentration range is 1% to 4% (based on fiber weight). Dissolve the dye in warm water (40-50°C) and ensure complete dissolution to avoid lumps.

2. Dyeing process
2.1 Prepare the dye bath
Pour the prepared dye solution into the dyeing tank and add an appropriate amount of acidic auxiliary (such as acetic acid) to adjust the pH value of the dye bath to a suitable range. Generally, the optimal pH range for acid dyes is 4.5 to 5.5. This pH value helps the dye molecules to bind to the amino groups on the fiber, thereby improving the fastness of the dye.

2.2 Heat the dye bath
Heat the dye bath to a suitable temperature, usually 60°C to 90°C. For Grey NHF-S Dye, higher temperatures help the dye penetrate better into the fiber. Too low a temperature may result in uneven dyeing, while too high a temperature may damage the fiber quality, so strict control is required.

2.3 Put the fiber into the dye bath
Put the pretreated fiber or fabric evenly into the dye bath to ensure that it is evenly distributed in the dye bath. Constant stirring is required during the dyeing process to prevent the fibers from entangled or piled up, thereby ensuring uniform dyeing.

2.4 Dyeing time control
The length of dyeing time is determined according to the desired color depth and fiber type. Generally, the dyeing time is 30 to 60 minutes, but it needs to be adjusted according to the actual dye concentration and the adsorption capacity of the fiber. During the dyeing process, check the dyeing effect regularly and adjust the dyeing time in time according to the depth of the color.

2.5 Gradually increase the temperature
At the beginning of dyeing, it is recommended to use a lower temperature (such as 60°C) and gradually increase the temperature to 80°C or 90°C over time to ensure uniform adsorption and reaction of the dye.

3. Post-treatment
After dyeing is completed, a series of post-treatment steps are required to ensure the stability of dyeing and the quality of the fiber.

3.1 Cooling and rinsing
Take the dyed fabric out of the dyeing tank and rinse it with cold water first to remove the residual free dye and chemicals. A small amount of detergent can be used during the rinsing process to ensure that the dye residue is completely removed. The washing water gradually becomes clear, indicating that the residual dye has been basically removed.

3.2 Fixation treatment
After dyeing, fixation treatment can be carried out to further enhance the color fastness and prevent the dye from fading. Commonly used fixatives include metal salts such as chromium salts and aluminum salts, which can bind to dye molecules to enhance the stability of color.

3.3 Drying and finishing
The dyed fabric can be dried as needed. Dry gradually at low temperature to prevent heat damage or deformation. After drying, finishing can be carried out, such as softening treatment, anti-wrinkle treatment, etc., to improve the feel and performance of the fabric.

4. Precautions and tips
pH value control: In the dyeing process, pH value is a key factor affecting the dyeing effect. Too high or too low pH will affect the adsorption of dyes. The best range is between 4.5-5.5.
Temperature control: The temperature needs to be gradually increased during the dyeing process to avoid fiber damage caused by sudden temperature changes.
Dye dissolution: Make sure the dye is completely dissolved before use to avoid caking, which leads to uneven dyeing.
Adjustment of dyeing time: Different fabrics and dye concentrations require different dyeing times, and dark tones usually take longer.

5. Dyeing effect and quality inspection
After dyeing is completed, the dyeing effect can be checked in the following ways:

Color fastness test: Perform light fastness, washing fastness and other tests to ensure dyeing quality.
Visual inspection: Visually check the uniformity of color and whether there are color differences or uneven dyeing marks.