Chemical Reaction
Polymer network formation strengthens pigment prints by linking binder chains together during thermal curing. This process of binder crosslinking occurs when functional groups on the polymer react with multi-functional crosslinking agents to form three-dimensional covalent bonds. The resulting network traps the pigment particles firmly on the fibre surface.
It prevents the print from washing out.
Curing Condition
Temperature control in the stenter decides the density of the polymer network. High temperatures are required to trigger the chemical reaction between the binder chains. If the oven temperature is too low, the crosslinking remains incomplete and the pigment prints will detach during standard home laundering.
The dwell time must balance complete reaction against fabric yellowing.
Rubbing Durability
Mechanical abrasion during wear can rupture a weak binder film and cause color transfer. Efficient binder crosslinking ensures that the printed surface resist rubbing when wet or dry. This is because the crosslinked film remains elastic and tough.
Testing Checkpoint
Laboratory testing verifies print stability through standardized wash and crocking cycles. A poorly crosslinked pigment print will show color loss after a single wash. The technician measures the change in shade using a greyscale.
The batch is approved only when the crosslinking is complete.
