Use of a carbon dioxide laser for environmentally beneficial generation of distressed/faded effects on indigo dyed denim fabric: Evaluation of colour change, fibre morphology, degradation and textile properties

Denim garments are particularly popular with the younger population of adults. Distressed or worn out effects have been and will continue to be popular with this market sector. These faded or worn effects have been achieved using a range of physical, chemical and mechanical finishes. Both wet and dry finishing of denim fabrics and garments pose severe environmental and health risks. Recently, environmentally beneficial decolourisation/ablation methods for denim fabrics have been investigated. Such methods have included plasma, laser, and ozone treatments. Researchers in this field have highlighted the potential of CO2 laser treatment of 100% cotton denim, however the textile performance post-treatment has not been properly investigated. In this study, light, medium and heavy weight indigo dyed 100% cotton denim fabrics were exposed to a CO2 laser at a range of power and intensity levels. Colour change was investigated using a Spectrophotometer, morphological structural analysis was carried using Scanning Electron Microscopy, and attenuated total reflectance Fourier transform Infrared spectroscopy (ATR-FTIR) was used to monitor the loss of indigo dye and degradation of the cellulose fibres. The thermal-oxidative degradation behaviour of fabrics was also studied using differential scanning calorimetry to obtain oxidation onset temperature. In addition, several fabric performance assessments were carried to evaluate tensile strength, colour fastness, air permeability and thickness. Findings reveal that the grayscale rating, which is the tone density and hence laser power affected the colour change and as the grayscale increased, the colour fading was higher and affected the fabric performance across all fabric weights. Based on this, the research recommends an optimum set of laser processing parameters to produce stressed or faded denim effects without compromising the fabric performance. This research demonstrates that faded effects on denim can be produced with low environmental and health risks

Incorporation of lipid nanosystems containing omega‑3 fatty acids and resveratrol in textile substrates for wound healing and anti‑inflammatory applications

In the present work, lipid nanosystems containing omega-3 fatty acid (nanostructured lipid carriers, NLCs) or omega-3 fatty acid and resveratrol (liposomes) were developed to improve cotton textile substrates as dressings with anti-inflammatory properties for wound healing applications. Lipid nanosystems were incorporated into woven, non-woven and knitted cotton substrates by exhaustion and impregnation. Based on physical–chemical characterization of the textile substrates, the textile structure and type of lipid nanosystems dictated the adsorption efficiency. In the case of NLCs, the woven substrate functionalized by exhaustion had a higher omega-3 release being the most promising for wound dressing application. Whereas for liposomes, the most adequate textile was the cationized knitted fabric functionalized by impregnation, that showed a more prolonged release profile of resveratrol.This work is financed by Project UID/CTM/00264/2019 of 2C2T - Centro de Ciencia e Tecnologia Textil, funded by National Founds through FCT/MCTES. The authors also acknowledge the Portuguese Foundation for Science and Technology (FCT) for financial support in the framework of the Strategic Funding UID/Multi/04546/2013 and UID/FIS/04650/2019 in the ambit of the project POCI-01-0145-FEDER-032651, co-financed by the European Regional Development Fund (ERDF), through COMPETE 2020, under Portugal 2020

Wax removal for accelerated cotton scouring with alkaline pectinase

A rational approach has been applied to design a new environmentally acceptable and industrially viable enzymatic scouring process. Owing to the substrate specificity, the selection of enzymes depends on the structure and composition of the substrate, i.e. cotton fibre. The structure and composition of the outer layers of cotton fibre has been established on the basis of thorough literature study, which identifies wax and pectin removal to be the key steps for successful scouring process. Three main issues are discussed here, i.e. benchmarking of the existing alkaline scouring process, an evaluation of several selected acidic and alkaline pectinases for scouring, and the effect of wax removal treatment on pectinase performance. It has been found that the pectinolytic capability of alkaline pectinases on cotton pectin is nearly 75% higher than that of acidic pectinases. It is concluded that an efficient wax removal prior to pectinase treatment indeed results in improved performance in terms of hydrophilicity and pectin removal. To evaluate the hydrophilicity, the structural contact angle () was measured using an auto-porosimeter