A pigment has no affinity to fiber. It is insoluble in
water. It needs binder for fixation onto fiber. A binder is a prepolymer available in the form
of aqueous emulsion. Chemically it is copolymer of UTYLACRYLATE-N-METHYLOL
ACRYL AMIDE. Mechanism of binding
involves the following sequence: PRINT > DRY >CURE. During curing, the
binder polymerises and forms a strong film.
The film embeds pigment color and also strongly adheres to the fiber. Curing
is done at 150 degrees for 4-5 minutes. When curing is not proper the poor wash
fastness and poor colorfastness will result. Assuming sufficient binder was
added to the color paste, these problems are usually resolved by repeating the
heat exposure ( Re curing)
