Optimization of polyethylene/binder/polyamide extrusion blow‐molded films. III. Slippability improvement with fatty acid amides

Abstract

The slippability of packaging films has to be controlled to facilitate confectionary operations and guarantee an easy opening for filling. In the case of singlelayer polyethylene (PE) films, the addition of slip agents made of fatty acid amides such as erucamide or oleamide usually allows the tailoring of the coefficient of friction (COF) in the film to match industrial targets, which depend on the final application. The coupling of Fourier transform infrared spectroscopy and atomic force microscopy analysis showed that this method has a limited efficiency and may even be detrimental in the case of multilayer PE þ ethylene vinyl acetate (EVA)/maleic anhydride grafted polyethylene (PEgMAH) þ EVA/polyamide films. The reason is that the migration of the slip additives toward the outermost surface of the PE layer, which leads to a reduction in the COF, are strongly affected by both the existence of the adjacent layers and the presence of EVA in the PE and PEgMAH layers. Nevertheless, a proper knowledge of the effect of this perturbation allows one to reach a slippability level that is required for some confectionary operations and/or for an easy opening for filling without the degradation of the heat sealability.

Cracking the chemical code: European common lizards (Zootoca vivipara) respond to an hexane soluble predator kairomone

“…Wax esters (Pappas 2009) and amides (Getachew et al 2016) probably protect the skin against fouling; fatty alcohols tend to have emollient properties (Fillet and Adrio 2016). Notably, the two amides (oleamide and erucamide) that we found in a subset of the adder skin washes, are used in the packaging industry as slip agents on films that guarantee an easy opening (Poisson et al 2010). For snakes, a high slippability seems a desirable trait during locomotion, so it would be interesting to test whether these amides serve similar purposes in adders.…”