Microwave assisted henna organic dyeing of polyester fabric: a green, economical and energy proficient substitute.

The proposed work, aims to provide a "green" and cutting-edge technique for the mordanting and dyeing of polyester fabric with natural henna dye using the advanced technology of micro waves. For providing a complete "green" and ecofriendly dyeing process, lemon was used as a natural bio mordant with micro waves and results were compared with conventional mordanting method followed by the natural henna dyeing of polyester fabric with microwave. Color properties were analyzed in detail. Scanning electron microscope (SEM), WIDE ANGLE X-RAY DIFFRACTION (WAXD) and Fourier transform infrared spectrometer (ATR-FTIR) studies provide the details of surface and structural changes induced by microwave lemon mordanting and henna dyeing of polyester. Microwave technique clearly reduced the mordanting and dyeing time upto 60-65% with improved fixation and color characteristics.

Performance evaluation of conventional and hybrid woven fabrics for the development of sustainable personal protective clothing.

This study examines the performance level of hybrid woven protective clothing (HWPC), manufactured from Kevlar® (K) and Ramie (R) yarns. The weave structures (plain, twill 1/3) and variables fiber ratios were used to produce HWPC. The performance level of HWPC was measured according to EN 388:2016. We came to the conclusion that blade cut resistance of plain and twill structure sustained protection level up to increase of KR 80:20 and KR 70:30, respectively; puncture resistance of K100% and HWPC remained in the same level of protection for plain and twill weaves; Abrasion resistance of K100% and HWPC of plain and twill weaves samples presented abrasive performance of same protection level, but the average number of cycles sustained for twill weave samples was slightly higher than plain weave. However, comparing the plain and twill weaves sample for tear resistance, twill weave samples have higher tear resistance than plain weave. A gray relational analysis and Taguchi method was performed to optimize the performance of two structures with variable fiber ratios. It was established that the article produced with K&R yarns with KR 80:20 ratio and twill weave presented the best performance against all test runs. The main objective of this study is to reduce plastic pollution by reducing the amount of synthetic fiber proportion in personal protective clothing and thereby reducing the dependence on nonrenewable sources for synthetic fiber. The 41 g/m2 reduction of Kevlar® fiber has been made in a conventional PC with ramie fiber, without compromising the protection level. This will enhance the sustainability of HWPC.

Exhaust reactive dyeing of lyocell fabric with ultrasonic energy.

Successful dyeing of lyocell, a biodegradable regenerated cellulose fiber, in fabric form is a challenging job. This article reports the successful reactive dyeing of lyocell fabrics with assistance of ultrasonic (US) energy via exhaust process, and compares the results with conventional (CN) exhaust dyeing process. Two commercial reactive dyes CI Reactive Red 195 and CI Reactive Blue 250 were used. Factors affecting dyeing such as fixation time, temperature and dyeing auxiliaries were compared for both processes. Under identical dyeing conditions, US dyed samples offered significantly much higher dyeing performance (i.e. color yield (>40%), dye fixation (>17%)) compared to CN process. Additionally, US exhaust process resulted in significant savings in terms of thermal energy (10 °C), capital (20 g/L NaCl and 2 g/L Na2CO3), and offered 33% higher production rate with yet improved dyeing performance (color yield up to ~7%, dye fixation up to ~5%) when compared under recommended conditions for two processes. Moreover, US dyeing poses considerably lower pollution (chemical oxygen demand 15-18% and total dissolved solids 32-36%) to the effluent in comparison to CN exhaust dyeing process. Furthermore, nearly identical colorfastness results and fiber surface morphology endorse use of US energy as a better, cost effective and relatively environment friendly technique for successful reactive dyeing of lyocell.

Pad ultrasonic batch dyeing of causticized lyocell fabric with reactive dyes.

Conventionally, cellulosic fabric dyed with reactive dyes requires significant amount of salt. However, the dyeing of a solvent spun regenerated cellulosic fiber is a critical process. This paper presents the dyeing results of lyocell fabrics dyed with conventional pad batch (CPB) and pad ultrasonic batch (PUB) processes. The dyeing of lyocell fabrics was carried out with two commercial dyes namely Drimarine Blue CL-BR and Ramazol Blue RGB. Dyeing parameters including concentration of sodium hydroxide, sodium carbonate and dwell time were compared for the two processes. The outcomes show that PUB dyed samples offered reasonably higher color yield and dye fixation than CPB dyed samples. A remarkable reduction of 12h in batching time, 18ml/l in NaOH and 05g/l in Na2CO3 quantity was observed for PUB processed samples producing similar results compared to CPB process, making PUB a more economical, productive and an environment friendly process. Color fastness examination witnessed identical results for both PUB and CPB methods. No significant change in surface morphology of PUB processed samples was observed through scanning electron microscope (SEM) analysis.