Study on carrier dyeing for high strength high modulus PVA fiber

Abstract

High strength high modulus PVA fiber or PVA high-fiber has excellent performances, such as high strength, high modulus, heat resistance, corrosion resistance, UV resistance, excellent impact resistance and adhesion. With the expansion of the application range of PVA high-fiber and the demand for color, it is pressing to study on the dyeing of PVA high-fiber. In this paper, dyeing process on PVA high-fiber had been deeply researched. PVA high-fiber has compact structure and high crystallinity, so carrier dyeing was selected here. Meanwhile, the types of dyes (Direct dyes, Reactive dyes, Cationic dyes, Disperse dyes) and carriers (type: anion, amphoteric ion, non-ion), the carrier concentration, the dyeing temperature and dyeing holding time were all selected and optimized. In the end, the most suitable dye, the most suitable carrier and the most optimal dyeing process were all identified. It was found that Direct dyes were the most suitable for PVA high-fiber dyeing, and non-ionic carrier had the most obvious dyeing effect. Under Direct dye and carrier N-25 conditions, the dye uptake was higher up to 68.6%, and wash fastness could reach grade 4. In addition, the optimal pretreatment time and power of low temperature plasma was identified. However, it was found that the pretreatment was little effective to promote PVA fiber dyeing. Considering that the carrier may reduce PVA high-fiber performance, x-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), single fiber strength test were used. Finally it was concluded that the break strength of the dyed PVA high-fiber was slightly decreased and the crystal structure was barely changed.