Dyeing of acrylic yarn
1. Dyeing water
Since the cationic dyes are dyed with strong acid groups, acrylic fibers are easily affected by metal ions such as calcium ions in water. Furthermore, some cationic dyes are also susceptible to metal ions. If the water quality is not suitable for dyeing, it must be treated accordingly to reduce the adverse effects of water on dyeing.
In addition, if the tap water contains active chlorine, it must be deactivated before it can be used.
2. Refining
Simple scouring is carried out as needed to remove the spinning oil on the acrylic fiber, the pulp on the previous process and various contaminations, so that the subsequent processes such as dyeing and finishing can be carried out smoothly.
The following simple scouring treatment can be performed on acrylic fibers:
Nonionic surfactant 0.5～1.0g/L
Processing temperature 60℃
Processing time 20～40min.
There are many varieties of scouring aids used for scouring, which can be selected from many products produced by many manufacturers.
3. Bleaching and whitening
The whiteness of acrylic fibers is already quite high. If higher whiteness is also required, fluorescent whitening treatment is required or combined with chemical bleaching.
The use of fluorescent whitening agents for whitening treatment is simple and widely used. There are two types of fluorescent whitening agents: cationic fluorescent whitening agents and dispersion fluorescent whitening agents. According to the dyeing method of cationic dyes or disperse dyes, whitening treatment is carried out respectively. Due to the better levelness when using a dispersion type fluorescent whitening agent, a dispersion type fluorescent whitening agent is often used.
