RESUMEN
Cellulosic fabrics were surface modified using Brewer's yeast filtrate and cellulase enzymes (Valumax A828, Valumax A356) to enhance its affinity to ink jet printing. The effect of enzymes on the surface structure and morphology of the cellulosic fabrics used has been illustrated using scanning electron microscope. Related test as tensile strength have been measured. The bio-treated cellulosic fabrics were digitally printed and the colour strength (K/S) and % increase in K/S were measured. Effect of different conditions (enzyme concentration, temperature and time) was investigated to obtain the optimum condition of each enzyme for each fabric that or which was indicated by higher colour strength. Results show a noticeable increase in the K/S especially for cellulosic linen and its blend compared to the standard samples. The optimum conditions to obtain the higher K/S by using Brewer's yeast filtrate and the other two cellulase enzymes in the pre-treatment of ink jet samples were obtained.
Asunto(s)
Celulasa/metabolismo , Poliésteres/química , ImpresiónRESUMEN
A novel utilization of chitosan as a cationic biopolymer in the chemical resist printing of linen fabrics and its polyester blend using reactive dyes. The effects of ratio and concentration of various resist-printing agents and processing conditions are observed and discussed. The concentration of chitosan, type of resist agent, and the ratio of chitosan to resist agent were varied to determine their effects on the efficiency of resist-printing. Regardless of the type of fabric, the resist effect on printed fabrics expressed as % decrease in K/S was obtained at optimal chitosan concentration of 1% with a mixture of chitosan/maleic acid as a resist salt at a ratio of 25:75. Thus, chitosan can be used pure or in admixture with different resist salts successfully in chemical resist printing.
RESUMEN
Carboxymethyl cellulose samples of different D.S. values were prepared from rice straw via pulping followed by etherification with monochloroacetic acid under the catalytic action of sodium hydroxide. The prepared derivatives were assessed for D.S., rheological properties as well as suitability as thickening agents in different printing styles. It was found that carboxymethyl cellulose derived from rice straw is characterized by a non-Newtonian pseudoplastic behavior and its apparent viscosity at any specific rate of shear depends on the D.S. All the prepared derivatives could be used successfully as thickening agents in discharge and/or discharge/resist printing of cotton fabrics. Furthermore, they could be used also as thickening agent for burn-out printing style of wool/polyester blended fabrics using sodium hydroxide. Attractive samples could be obtained via using these techniques.