Original article Vegetable oils in textile finishing applications: the action mode of wrinkle- reduction sprays and means for analyzing their performance Bojan Stefanovic 1 , Mirjana Kostic 2 , Markus Bacher 1 , Thomas Rosenau 1 and Antje Potthast 1 Abstract The effect of different aqueous emulsions of vegetable oils on the wrinkle recovery properties of 100% cotton fabric was investigated. Six vegetable oils (rapeseed oil, olive oil, coconut oil, safflower oil, linseed oil and modified sunflower oil) with different fatty acid profiles were used. The results prove that the fatty acid profile is an important factor affecting the wrinkle recovery properties of treated cotton fabrics. In general, higher concentrations of the active agent (vegetable oil) provide better wrinkle properties for treated cotton fabrics. The results suggest that better recovery from wrinkle deformation is due to the formation of a micro-film around the fibers and yarns that reduces the friction coefficient. For analysis that better monitors the complex process of fiber relaxation after deformation, an optical wrinkle tester based on grazing light analysis was developed. The technique allows more precise scanning of textile surfaces and measuring of small increments of wrinkle recovery after a spray treatment, for example. The optical wrinkle tester offers the possibility of time-dependent measurements to follow the kinetics of wrinkle relaxation and, for the first time, gives access to kinetic profiles of fiber relaxation. Keywords cotton, vegetable oil, fatty acids, wrinkle recovery angle, optical wrinkle tester, fiber relaxation Cotton is a well-known cellulosic fiber with a utilization history dating back to ancient times. Cotton is still the most important natural textile fiber, because of its numerous advantages, such as being hypoallergenic, having good air permeability, having a good ability to absorb body moisture and being generally comfortable to wear. In processing, cotton is easy to dye and blend with other fibers. Those positive characteristics are why the apparel industry is predominantly cotton based, with cotton accounting for about 40% of the global textile fiber consumption. In addition to those many advantages, there are also less positive issues; one is that cotton fabrics are barely wrinkle-resistant. Wrinkles form easily, and they strongly – and in most cases negatively – influence the garment’s aesthetical appearance. Untreated cotton fabric has poor wrinkle recovery mainly due to attractive forces between fibers, such as van der Waals force and hydrogen bonds. Since these forces are relatively weak, they can be easily broken and rearranged by moisture and external stress. Once the stabilizing bonds are broken, the polymer chains are free to move, and slippage occurs between them. New attractive forces form at a new location and tend to maintain the fiber in the shifted – bent or 1 Christian-Doppler-Laboratory, Department of Chemistry, University of Natural Resources and Life Sciences, Austria 2 Department of Textile Engineering, Faculty of Technology and Metallurgy, University of Belgrade, Serbia Corresponding author: Potthast Antje, Christian-Doppler-Laboratory, Department of Chemistry, University of Natural Resources and Life Sciences, Konrad-Lorenz- Strasse 24, 3430 Tulln an der Donau, Austria. Email: antje.potthast@boku.ac.at Textile Research Journal 2014, Vol. 84(5) 449–460 ! The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0040517513495946 trj.sagepub.com