NOPR Collection:

Garment dyeing

2005-12-01T00:00:00Z

Title: Garment dyeing Authors: Chakraborty, J N; Pal, Rudrajit; Megha, P R Abstract: Garments are either prepared directly from processed fabric or the grey fabric is converted into garment followed by processing. Out of these two, the latter has gained undue importance to tack le present day scenario more effectively. This paper reviews the reasons behind this new challenge a s well a s other technical aspects related to dyeing of garments. Page(s): 468-476

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

2005-12-01T00:00:00Z

Title: Effect of selective pretreatments and subsequent mixed enzyme treatment on properties of jute-cotton union fabric Authors: Samanta, A K; Singhee, Deepali; Basu, Gautam; Mahalanabis, K K Abstract: 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 zone/crystalli ne interface for different pretreatments and subsequent enzymatic hydrolysis. Page(s): 451-467

Simultaneous dyeing and finishing of cotton fabric using reactive dyes and citric acid

2005-12-01T00:00:00Z

Title: Simultaneous dyeing and finishing of cotton fabric using reactive dyes and citric acid Authors: Malik, S K; Kumar, Sushil Abstract: The efficacy of concurrent dyeing and finishing of cotton fabric with reactive dyes and citric acid has been studied. Factors affecting the process, such as alkali concentration and catalysts, were examined in two different process routes, i.e. simultaneous alkali addition and after development with alkali, for two dyes concentrations. Control samples were prepared by conventional two-step method. Evaluation of the simultaneously dyed and finished (SDF) fabrics was made with respect to colour strength (K/S), crease recovery angle (CRA), tensile strength and fastness properties, and the findings were compared with control samples. It is observed that the SDF fabric gives better K/S, CRA, tensile strength as well as fastness properties as compared to control samples; K/S and CRA increase with the increase in alkali concentration, whereas tensile strength decreases. Catalyst sodium hydrosulphite is found to give better overall results than sodium dihydrogen phosphate in case of SDF method as well as in control samples. Page(s): 444-450

Factors affecting radiation grafting of N-vinylpyrrolidone onto nylon-6 fabric

2005-12-01T00:00:00Z

Title: Factors affecting radiation grafting of N-vinylpyrrolidone onto nylon-6 fabric Authors: EI-Gendy, E H; El-Shanshoury, I A Abstract: The effect of monomer concentration, exposure time, dose rate fabric-to-liquor ratio and irradiation temperature on the kinetic parameters of grafting N-vinylpyrrolidone (NVP) onto nylon-6 fabric has been studied. Induction period is observed before the start of grafting process, especially at low dose rates and low NVP concentrations. Electron spin resonance study indicates that the oxygen still remaining in the grafting solution is possibly responsible for the existence of induction period via peroxide formation with free radicals. The order of the grafting process is found to decrease linearly with the increase in dose rate at 0.766 per increase in dose rate by 1 Gy/s. It decreases from a second order to a first order kinetics as the dose rate increases from 0.37 Gy/s to 1.81 Gy/s. The grafting rate constant increases with the increase in dose rate to the power of 2.9. The increase in fabric-to-liquor ratio from 1:7.5 to 1:1 5 increases the reaction order and decreases the grafting rate constant. The increase in the grafting temperature decreases the grafting rate and rate constant. The calculated activation energy 23.6 kJ/mole is attributed to the homopolymerization of NVP and the existence of unidentified transfer process. Page(s): 437-443