Water and Oil Repellent Finishing of Textiles by UV Curing: Evaluation of the Influence of Scaled-Up Process Parameters
In this work, various textile fabrics were coated with silicone and fluorocarbon-based resins by photo-curing using ultraviolet irradiation. A great number of large fabric samples were impregnated by padding with commercial finishing agents and then irradiated in air with a high power, semi-industrial UV source. The add-on of various finishing agents was kept low to reduce the treatment cost. White and dyed samples of different textile composition were treated and evaluated in terms of conferred repellency, yellowing, or color changes. Most relevant process parameters were investigated, utilizing the thermal process normally adopted at industrial level as reference. The results were statistically evaluated by ANOVA using Minitab 16 software, in order to identify the most influential parameters and to evaluate the real possibility of replacing the thermal treatment with UV curing.
Water repellent treatment for cotton fabrics with long-chain fluoropolymer and its short-chain eco-friendly alternative
Abstract As the long-chain fluorochemical molecules used to obtain water and stain repellent textiles persist in the environment, chemical suppliers are trying to develop new products in order to find ecological alternatives. The current most developed substituents are based on molecules with shorter fluorine-carbon chains. In the current work, a long-chain fluoropolymer and its short-chain homologue were applied on cotton fabrics at different finishing conditions. Textile properties such as wettability, air permeability, mechanical properties and handle properties, for untreated and treated cotton samples were investigated. Laundering test was also performed to predict the durability of the finishing. The obtained results demonstrated that cotton samples treated with short-chain fluoropolymer show good water repellency and good washing durability. The use of short-chain fluoropolymers, as nontoxic and eco-friendly finishing chemicals, has allowed obtaining comparable performances to those produced with long chain fluoropolymer.
Bevel RIE application to reduce defectivity in copper BEOL processing
Bevel etch used during wafer fabrication for semiconductor devices is discussed. In this case, the bevel etch process was utilized in middle of the line processing (MOL) to reduce back end of line (BEOL) defectivity. Tungsten and titanium nitride films, from the formation of contacts to the transistors, extend into the bevel region of the wafer and have been shown to initiate arcing. This can spread foreign material defects on the front side of the wafer in various BEOL post processing steps including subsequent reactive ion etching, SEM metrology and film depositions. The bevel etch tool confines a plasma etch to the outer edge of the front side of the wafer (which can be individually adjusted) and can remove dielectric, organic and Ti/TiN/W films using a fluorine based chemistry.