The effect of O2 plasma treatment and PA 6 coating on digital ink-jet printing of PET non-woven fabric

In the absence of pre-processing, polyethylene terephthalate (PET) non-woven have strong hydrophobicity. Therefore, patterns printed with pigment ink-jet printing have poor color yield and low resolution. In this study, the surface properties of PET non-woven fabric were modified by plasma treatment, and a coating solution made by waste polyamide 6 (PA 6) filament, methanol, and CaCl2 to prepare 3.5% and 6.8% PA 6 concentration. After that, plasma-treated sample, coated sample, and plasma treatment plus PA 6 coated sample results on pigment ink-jet printing were investigated to prepare good printing PET non-woven packaging fabric. Scanning electron microscopic image indicated that plasma makes etching on the fabric surface, hence increase the hydrophilic property of the fabric, which helps slight increase in the color yield and resolution. The contact angle shows PA 6 coating also achieved hydrophilic on the surface of PET non-woven fabric and facilitated the ink absorption in pigment ink-jet printing, which helped the printed fabric have higher color yield and clear resolution. However, for significant results it was very important to increase the absorption of coating solution. Plasma makes it easier for the fabric to absorb more coating solution containing dissolved waste PA 6 filament in both concentrations from 11.97% to 19.92% and 5.68% to 10.50%. This ultimately provides the capacities for the fabric to capture more ink and penetration of more colorant particles into the fabric. Therefore, plasma treatment first plus PA 6 coating can help prepare better-patterned PET non-woven fabric packing through pigment ink-jet printing, even though the plasma treatment and coating caused a little negative influence in whiteness and handle.