Effect of selective pretreatments and subsequent mixed enzyme treatment on properties of jute-cotton union fabric

451-467<span style="font-size: 16.0pt;font-family:Fd1490491-Identity-H;mso-bidi-font-family:Fd1490491-Identity-H">Jute-cotton (75:25) union furnishing fabric has been treated with varying dose of mixed enzyme (cellulase, xylanase and pectinase) system with or without selective pretreatments and the consequent changes in important textile-related properties of the fabric evaluated. For untreated jute-cotton union fabric, 4% (owf) mixed enzyme treatment at 55°C for 2 h using pH 4.8-5.0 is found to be optimum. Between cotton (warp) and jute (weft), enzyme action is found to be more pronounced in cotton than in jute. However, the degree of enzymatic hydrolysis and associated weight loss for jute are found to increase if the mixed enzyme treatment is done after selective pretreatments. 1 % NaOH pretreatment at 30°C for 30 min offers some unique advantages, except browning of surface colour, when subsequently treated with 4% (owf) mixed enzyme. Steaming of wetted jute-cotton union fabric at 130°C for 5 min shows almost negligible weight loss and marginal or no strength loss, although the reduction in stiffness in jute is poor and inadequate. Conventional scouring followed by 2% H2O2 bleaching with stabilizer A WNI instead of sodium metasilicate makes the fabric most suited for subsequent 4% mixed enzyme treatment. The use of 5 steel balls in the rotating beaker of the launder-O-meter during the enzyme treatment is found to be very useful for the removal of surface fuzz. Changes in functional group pattern and chemical composition of jute have also been analyzed after the treatments. Scanning electron microscopic and X-ray crystallographic studies respectively reveal the changes in the surface morphological features and fine structure of differently treated jute component of jutecotton union fabric. There is apparent increase or decrease in X-ray crystallinity due to associated mass loss from noncrystalline <span style="font-size: 16.0pt;font-family:Fd1490491-Identity-H;mso-bidi-font-family:Fd1490491-Identity-H">zone/crystalli ne interface for different pretreatments and subsequent enzymatic hydrolysis.