| Para-aramid fiber is a high performance fiber with excellent insulation properties.But it’s sensitive to ultraviolet light and has a light discoloration problem. It’s necessary to develop the dyeing method of para-aramid fiber.Based on comparison of dye uptake and K/S value, homemade carrier-2 is chosen as the carrier and Cationic Red RL, Cationic Blue 5G, Cationic Golden Yellow X-EC,Disperse blue ER, Disperse Yellow SRL are chosen as the dyes.The optimum carrier dyeing process of para-aramid fabric is obtained by dye uptake,K/S value and the actual production conditions. The optimum technological conditions of Cationic Red RL are obtained, the dye concentration, carrier concentration, dosage of inorganic salt, dyeing temperature, dyeing time, p H value and liquor ratio are 3%(o.w.f),30g/L, 20g/L, 140 ℃, 60 min, 3~4 and 1:10 respectively. The optimum technological conditions of Cationic Blue 5G and Cationic Golden Yellow X-EC are obtained, the dye concentration, carrier concentration, dosage of inorganic salt, dyeing temperature, dyeing time, p H value and liquor ratio are 2%(o.w.f), 30g/L, 20g/L, 140℃, 60 min, 5~6 and 1:10respectively. The optimum technological conditions of Disperse blue ER and Disperse Yellow SRL are obtained, the dye concentration, carrier concentration, dyeing temperature, dyeing time, p H value and liquor ratio are 2%(o.w.f), 30g/L, 140℃, 60 min,3~4 and 1:10 respectively. The soaping fastness already reach to 4 grade or more. The rubbing fastness already reach to 3 grade or more.Para-aramid fiber is modified by acid or alkali. When the modified para-aramid fiber is dyed, the dyeing rate and K/S value don’t change. The dyeability of para-aramid fiber don’t improve. The modified para-aramid fiber has very low breaking strength and elongation at break. The application of para aramid is limited by acid or alkali modification, the method cannot be applied in practical production.Para-aramid fiber is treated through the low-temperature plasma technology. The results show that the fiber surface has not been etched. When the modified para-aramid fiber was dyed by cationic dye, the dyeing rate and K/S value don’t change. The dyeability of para-aramid fiber don’t improve. |
