Juan Andrés Álvarez defended his doctoratethesis “Development and Characterization of polyethylene multilayer filmscrosslinked by means of electron beam irradiation”, developed under thesupervision of Prof. Ane Urtiaga and Prof. María del Rosario Benavente Castro.The defense took place on December 17th, 2018 at the conference room of theETSIIT of the University of Cantabria. The evaluation committee was formed by Prof.Javier Bilbao (University of Basque Country), Prof. Ángel Irabien (Universityof Cantabria) and María Luisa Cerrada (ICTP-CSIC). This thesis has achieved theIndustrial Doctorate Mention.