Pigmented inkjet ink dispersion for silk fabric printing

The purpose of this research was to study the effect of pigmented inkjet ink dispersion for silk fabric. The pigmented inkjet inks were formulated using two types of pigment dispersion techniques, surface modification and microencapsulation. Viscosity, surface tension and particle size were studied with results as follows: viscosity 3.5-5 mPa s, surface tension 38-45 mN m⁻¹, and particle size 0.22-0.23µm. The stability of ink was examined for changes in viscosity and particle size distribution. The inks were held in storage at ambient room temperatures for 12 weeks. After storage, the ink viscosity was increased by 20-40% and the particle size distribution by 2-15%. The printed silk fabric was analyzed for optical density, tone reproduction, color gamut, gamut volume, crockfastness, washfastness, lightfastness air permeability and bending stiffness. The surface modified pigmented inks yielded high optical density, good tone reproduction, better color gamut, and gamut volume. The pigmented inkjet inks gave good crockfastness, high lightfastness, greater air permeability and higher bending stiffness. The microencapsulated pigmented inks also rendered good washfastness. This research also investigated the printing quality of the pretreated silk fabric using cationic polymer. It was found that the pretreated silk fabric produced the better image quality, high optical density, and greater color gamut, especially in the case of microencapsulated pigmented ink. Both inks gave high crockfastness and washfastness when they were printed on the pretreated silk fabric. The air permeability and bending stiffness of the printed fabric was more dependent on the pretreatment than the printed ink layers themselves.