Discharging is the process
of removing dye (by destroying or altering the dye "chromophores") with
various chemicals or bleach, often by stamping, stenciling or block
printing. Discharging can be incorporated into more complex designs with
over-dyeing other colors or combined with painting, printing or
stenciling with opaque Fabric Paints. Discharging is one more way to
make your own incredible unique fabrics for quilting or clothing.Fabrics
discharge with different chemicals depending on the type of fabric and
what it was dyed with. Some dyes won't discharge at all, Also,
discharging rarely returns fabric to its original color or white. Some
blacks, for example, will only discharge to a nice reddish brown color,
while others will go to a very pale tan. The moral of the story is test
test test!Discharge paste is a reducing agent for safely removing color
from natural fibers, and is even safe on silk. It removes most fiber
reactive dyes, direct dyes, and acid dyes. It is thick enough to block
print, brush it on, screen it on, stencil it on, etc. You can apply the
paste to your fabric, let it dry and steam it with a steam iron or steam
in a steamer for 5 minutes or so, until it stops discharging. Then wash
your fabric in water.Discharge Paste does not always remove all of the
color, it depends on the dye and the color to which it is applied.
Always best to test.Here we mainly use it to discharge jeans by screen
printing.
Technological Process:
1,Mix the discharge paste and discharge
powder in the weight ratio during 5:1 to 4:1.
2,Screen printing the jeans.The printing times depends on the thickness
of jeans,for thin garment,3-5 times work well,for thick garment,2-3
times work well,all in all,it is the best to just print through the
fibre.
3,Heat press the printing area 15-25 seconds with the temperature 150℃(302℉),lift
the heating plate,then repress 5 seconds,or you may use flash fryer to
dry 3-4 minutes with the temperature 150℃(302℉)
,after heating,the white paste will become light yellow from the white.
4,Wash the jeans,hand-launder the printing area with water, discharge
effect appears.
Notice:
The mixture of discharge paste and powder must be used in eight hours.
