Novel sodium carboxymethyl cellulose-g-poly (sodium acrylate)/Ferric chloride (CMC-g-PNaA/FeCl3) nanoporous hydrogel beads were prepared based on the ionic cross-linking between CMC-g-PNaA and FeCl3. The structure of CMC and CMC-g-PNaA were elucidated by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, and the elemental composition was analyzed by energy dispersive X-ray analysis (EDX). The physicochemical properties of the CMC-g-PNaA/FeCl3 hydrogel beads were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). The swelling percentage of hydrogel beads was studied at different time periods. The obtained CMC-g-PNaA/FeCl3 hydrogel beads exhibited a higher nanoporous morphology than those of CMC-g-PNaA and CMC beads. Furthermore, an AFM image of the CMC-g-PNaA/FeCl3 beads shows granule type topology. Compared to the CMC-g-PNaA (189 °C), CMC-g-PNaA/FeCl3 hydrogel beads exhibited improvement in thermal stability (199 °C). Furthermore, CMC-g-PNaA/FeCl3 hydrogel beads depicted a higher swelling percentage capacity of around 1452%, as compared to CMC-g-PNaA (1096%). Moreover, this strategy with preliminary results could be useful for the development of polysaccharide-based hybrid hydrogel beads for various potential applications.
Rotogravure printing cylinders are engraved by electro-mechanical engraving (EME) process in India used for printing purpose. But this process has drawbacks of the emissions of hazardous gases, solid and water pollution. EME cylinders are better in cell size, depth and needed higher copper and chrome plating thickness. By laser engraving (LE) copper and chromium thickness were reduced by 75 µm and 5 µm in a cylinder by laser engraving with also a reduction in power consumption and plating time. The carbon footprints were also reduced by 227 g per cylinder with a cost-effective solution for rotogravure printing process.
6 October 2022 in Clean Technologies and Environmental Policy
Organic solvents have been frequently and excessively used in the printing process for a long time. The use of organic solvents in solvent-based ink is responsible for fire hazards, volatile organic compounds emission, and high manufacturing cost during printing. The present study aimed at replacing solvent based ink with water-based ink for reducing the volatile organic compounds emissions and carbon footprints in gravure printing without affecting overall printing quality. The PET film was printed with a water-based ink laser engraved cylinder having reduced cell depth and it resulted in the transfer of a low volume of inks on printing substrate. The cost of printing one kg of polyester film with water-based ink was reduced by US$ 1.95 compared to solvent-based ink. The volatile organic compounds emissions for water-based ink were measured at 2478 ppm against 3373 ppm for solvent-based ink. The water-based ink reduced the carbon footprint by 3.04 kg, which was equivalent to CO2 during printing of one kg polyester film used for making flexible pouches compared to solvent-based ink. The outcome of this study may be the benchmark to authorities for green manufacturing systems in gravure printing applications for the betterment of the environment and humanity.