Research On Fixing Method Of Liquid Ammonia Dyeing And Liquid Ammonia Washing Performance

Liquid ammonia dyeing is a technology that uses liquid ammonia instead of water dyeing medium,which not produces any pollution problems as water dyeing process with the recycling use of liquid ammonia and dye stuff.Liquid ammonia dyeing is not good at exhaustive dyeing rate and fixation rate,while cationic modification of fiber is an effective way to improve the exhaustion and fixation rate.In order to raise ammonia dyeing fixation rate,three ammonotelic fixation methods,25 ?room temperature,100 ?drying and steaming,are studied separately and immediately,after ramie fiber was dyed in liquid ammonia with five kind reactive dyes,which have different reactive structures.In view of the problem of a large number of floating dye in dyeing material,the possibility of washing the floating dye through soaking dyed fabric in liquefied ammonia is studied,by changing the soaking time.And also comparative study on fixation rates of dyed fabric,which is being dyeing in liquid ammonia or water,after liquid ammonia washing and water washing.In addition,the study of liquid ammonia treatment of dyed fabric color fastness,including: rubbing fastness,wash fastness and light fastness fastness,is done after fabric,which were soaking treated in liquid ammonia indifferent time before or after dyeing,were dyeing in water with different concentration of the dye stuff.In addition,cotton fabric which dyeing with Direct Red 4BS or Reative Blue 19,was treated in liqiud ammonia before or after dyeing,or both before and after dyeing.The color fastness that including rubbing fastness,washing fastness and sunlight fastness was studied with a series of dye concentration and different ammonia treatment and time.Experimental results show that the dyed fabric after washing of water or liquid ammonia,drying obtain better fixation rate than other two methods,and steaming cause more dye hydrolysis,reduce wet rubbing fastness and washing fastness.Cationic modification has a definite influence on wet rubbing fastness.Ammonia washing can effectively wash out the floating color,but easily transfer the hydrolyzed dyes into the fiber.The different ammonia treatments and time do not have obvious effect on different color fastness while cotton was dyeing with the series of dye concentration of Reactive Blue 19.But not for the Direct Red 4BS.The dry rubbing fastness is decreseed.While wet rubbing fastness,washing fastness and sunlight fastness are improved with the help of liquid ammonia treatments and the best result show around 30 s of liquid ammonia treatment.And cotton fabric treated in liquid ammonia after dyeing can obtain the best result of different color fastness in these three ammonia treatments.In addition to the sunlight fastness,the high direct dye concentration will lower the color fastness.