DYEING METHODS

There are three method for continous reactive dyeing.

1. pdc


2. pdps


3. w/w

PDC

in pad dry cure process the axuliries used other than dyes are soda ash and sodium bicarbonate,antimigrating agent (FFAM,solidicol n,...) and urea and some time wetting agent also. the fabric first passed through the color then dry at 120 to 130 degree. Then cure at 150 to180 degree tempreture.

this is a good process and is most commonly used in several dying units.

this process is simple but it causes poor light fastness as well as washing festning.

to avoid this dificulty padry pad steam process is used.

PDPS PROCESS

IN this process deyes and axiliries are padded on thermosol , not cured .the axiliries used on thermosol are antimigrating ahent and wetting agent .the dyes are fixed on padsteam , padded with NaOH 6 to 8g/l, and soda ash 20g/l and common salt 250 g/l . then fabric is passed through steamer . 1 min is enough for fixation.

W/W

THIS DIRECT DYING ON PAD STEAM . in this process ,dyes , sodium bicarbonate and antireduction agent are mixed in solution and fabric is padded with this solution and passed through steamer.a mild quantity of urea is also used to enhance solubility.