Pigment Dyeing

2.  Pigments are finely-dispersed insoluble colourants
and applied as insoluble particles on fibre
 Mainly used for printing rather than dyeing
 They do not have any affinity for the fibre
 They do not penetrate inside the fibre but remain on
the surface of the fibre; hence it is a surface dyeing
 They are held mechanically to the fabric by binders,
which are then cured at higher temperature

3.  For commercial application pigments should have very good
 heat resistance,
 dispersability,
 light & weather fastness,
 physiological harmless and
 should be available at affordable price
(Heat resistance is required due to the usually high
processing temperature)

4. • Pigments are finely dispersed colourants insoluble in water
• They do not have any affinity towards the fibre
– Binders are require which binds both the fibre and pigments
together
• Pigments have excellent light fastness property and weather
fastness property
• The wash fastness and the rubbing fastness depends on the
binder efficiency
• The rubbing fastness is however is not so good
(Binders are very important during pigment dyeing)

5. • It should bond very effectively to the pigment
• It should have adhere well to the textile fibre
• It should form a clear colourless film on the layer
of pigment particles
• It must have abrasion resistance, wash fastness
and must be capable of being dry-cleaned
• It should display minimum tackiness of film
…… cont

6. • It should not give a harsh handle
• It must not ‘ yellow’ on storage
• It should be resistant to mechanical and chemical
agencies
• It must be compatible with other textile auxiliaries

7.  Pigments can be used for dyeing of any fibres
 It consists of the following process
 Padding or application of the dye paste uniformly on the
fabric
 Drying
 Curing (Done at around 1500C with hot air or steamed air
at higher atmospheric pressure)
 Please note that no after treatment is required in case of
pigment dyeing

8. Padding with
Pigment Dye
Drying
Curing

9. Pigment x g/l (depending upon the depth of shade)
Binder 80 – 100 g/l
Migration inhibitor 10 – 20 g/l
Acid liberating catalyst 60 – 70%

10. Dilute required quantity
of binder + 5 times its
weight of water +
required quantity of 30%
acetic acid
Weight the pigment
emulsion, paste with
little water and dilute
with 10 times its weight
of water
Add the pigment
emulsion to the acidified
binder emulsion with
stirring
Add required quantity of
ammonium chloride to it
Filter the dispersion
through a fine cloth
before padding
Pad the fabric through
this liquor using a
padding mangle
Dry the fabric in a hot
drier and cure it at 1500C
for 4 minutes

11. • The most reliable method to test the pigment dyeing is by the
microscopic test
• A fibre cross-section is viewed at a magnification of around 250
• The evaluation is done on the basis of distribution of colour
across the cross-section of the fibre
– If the colouration is evenly distributed over the total cross-
section, the fibre has been dyed with a standard dye and not
pigment dyed
– If only the fabric surface (i.e. the outermost layer in the fibre
cross-section) shows deposition of pigment particles, the fibre
is pigment dyed