Reactive dyes have good dyeing fastness, complete chromatography and bright color. They are widely applied in cotton knitted fabrics. The dyeing color difference is closely related to the quality of cloth surface and treating process.
The purpose of pretreatment is to improve the capillary effect and whiteness of fabric, so as to make the dyes to dye the fiber evenly and quickly.
Dyes
The analysis of compatibility between dyes is of great significance to reduce color difference. The compatibility of dyes with similar dye-uptake is better.
Feeding and Heating Curve
The dyeing process of reactive dye includes three stages: absorbing, dispersing and fixing.
Dyeing Equipment
The dyeing of cotton knitted fabrics is mostly used the overflow jet rope dyeing machine, which can be adjusted the flow, pressure and speed of feeding fabric according to the structural features of different fabrics (such as thin and thick, tight and loose and the long and short of each fabric) to achieve the best dyeing condition.
Dyeing Auxiliaries
1.Leveling agent
When dyeing light color, it is necessary to add a certain amount of leveling agent to achieve uniform dyeing. But when dyeing dark color, it is unnecessary. The leveling agent has affinity for reactive dyes. It has certain wetting performance, retarding performance and leveling performance.
2.Dispersing agent
Dispersing agent is mainly used to evenly disperse the dye molecules in the dyeing bath so as to make a balanced dyeing bath.
3.Anti-creasing agent and fiber protective agent
Because knitted fabrics are by rope dyeing, during the pretreatment and dyeing process, the fabrics will inevitably crease. Adding anti-creasing agent or fiber protective agent will help to improve the hand feeling and appearance of fabrics.
Post time: May-28-2024