Jute - pretreatment
Singeing and desizing of Jute fabric: To make the fabric surface smooth and uniform, jute fabric would be subjected to flame singeing followed by enzymatic desizing. In the desizing diastase enzyme 1 gpl and a wetting agent like Lissopol N 0.1 gpl is used at 55-65 deg celcius on a winch or beck for 45 minutes. This would be followed by a hot and cold wash.
Scouring: The desinged fabric is subjected to scouring in bath containing 3 gpl soda ash (sodium carbonate) and 0.5 gpl Lissopol N at 85 -90 deg celcius for an hour (MLR 1:20). Then hot washed and cold washed.
Liquid Ammonia Mercerization: The scoured and dried fabric is treated with liquid Ammonia at -33 deg celcius for 10 minutes followed by neutalization with 1 gpl Sulphuric acid.
Caustic Mercerization: Alternately Jute fabric can also be mercerized by a treatment with 17.5 W/V caustic Soda at room temperature for 10 minutes followed by a neutralization with Sulpuric acid 10 gpl. The acid should be thorughly washed with overflow water and dried in air.
Bleaching with Hydrogen Peroxide: The pretreated fabric as above is then bleached in a bath containing 10 gpl (50%) Hydrogen Peroxide, 6 gpl Sodium Silicate, ).5 gpl Lissopol N, 1 gpl sodium carbonate (Soda ash) in 1:20 MLR at 80-85 deg celcius for 1 hour. The fabric afterwards should be thoroughly washed, neutralized and air dried.