Because rayon/nylon filament / modified polyester filament / Lycra do not contain natural impurities, they have better whiteness in itself, so they can be dyed directly without pretreatment.

A. dyeing rayon process
To dye dark green / Rosiness/ Pink rayon as an example. dyed green rayon.
Rayon dyeing process, prescription, and condition
Prescription and condition (bath ratio 1:10):
Reactive yellow HE4R 0.121%
Reactive Blue H-EGN 0.205%
Na2S04 50 g/L
Na2C03 15 g/L
Softener PA 1 g/L
Penetrant JFC l.0 g/L
The heating rate  1.O℃/min
The holding time   80℃×30 min

B. Dyeing of nylon filament / modified polyester filament
Dye the nylon filament rose color and the modified polyester filament pink.
Dyeing process of nylon filament / modified polyester filament
Prescription and condition (bath ratio 1:10):
Acid red RLS 0.0585%
Acid yellow PA-1 0.0103%
Acid blue PA-1 0.014%
Cationic (red) GRL 200% 0.0012%
Cationic (yellow) GL EC 400% 0.0083%
Cationic (blue) GRL 300% 0.0052%
Water absorbing agent TM 2 g/L
(NH4) 2S04 2 g/L
Acid leveling agent AD 0.60 g/L
Anion retarding agent M 1%
Anti settling agent S 1%
Acid HAc/NaAc  l/0.5
The temperature holding time  98℃×30 min

Softener CN role is to reduce the friction coefficient of material and equipment, thereby reducing the fabric wrinkle and scratches, Adding water absorbing agent TM into dye, the water absorbing agent will help in the fabric’s water absorbing and perspiration function.

C. post-treatment conditions
Prescription and condition of soaping:
Soaping Agent DM l.0%
The temperature holding time   55℃×10min
Prescription and condition of fixation:
Acetic acid 1.30 g/L
Fixing agent NT 3 g/L
The temperature holding  time    70℃×30 min

D. Shape setting

The shape setting is an important process in the whole fabric dyeing and finishing process, it will make the fabric cloth size further stability, and eliminate the wrinkle in the dyeing process
As a result of the predetermined type, the fabric width, size, gram quality and other physical indicators is basically stable. In the process of shape setting, we can add a certain amount of deodorant, anti-mildew agent, fixing agent, softening agent and hydrophilic agent into the shaping setting slurry according to customer requirements across the material fastness. Which will make the fabric softer, moisture easy absorption and comfort. But we need to pay more attention to the ionic nature of the setting agent so as to avoid slurry contamination.

The sizing agent recipe:
Biocontrol agent DA 35 g/L
FT deodorant 15 g/L
Soft water oil N 20 g/L
Citric acid 0.3 g/L
Setting conditions: 150℃×10s,machine speed 30m/min.

Shape setting temperature: because the cationic dye discoloration critical temperature is 140～150℃, and both higher or lower temperature will make the fabric has a bad performance, and Leica fiber is very sensitive to temperature and time. If it is at high temperature in a long time the elasticity of the fabric will reduce. Therefore, on the safe side, the setting temperature is chosen to be about 150 degrees Celsius, and the machine can not be stopped in the process of shape setting, so as not to produce paragraph discoloration caused by uneven setting time.