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Tape casting is a suitable process for large-scale production of biodegradable films. This study presents a comparison of three drying procedures of starch-cellulose films: i) conduction drying, ii) infrared drying (42.3 W m−2, higher infrared heating power damaged the films), and iii) conduction-infrared drying. All the drying procedures were performed at approximately 60°C. Drying times from the second and third methods were close to 1 h, half the time observed for conduction drying. Films from the second and third methods showed similar hygroscopicity (0.15 g. g−1, RH 43%), tensile strength (31.3 MPa, RH 58%), and glass transition temperature (−12.13°C, RH 43%). [ABSTRACT FROM AUTHOR]

Highlights: [•] It was possible to produce large films from starch–fiber–glycerol by tape-casting. [•] Wetting of Myllar® film is sufficient to assure the suspension spreading. [•] The shear-thinning suspensions is suitable to use the tape-casting technique. [•] The composite-films were transparent, easy to handle, continuous and uniform. [•] Tensile strength was influenced by addition of fibers and conditioning RH. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to investigate the water transfer properties of starch films using steady-state and transient methods and to evaluate the influence of air relative humidity on the film roughness using atomic force microscopy (AFM). Films were prepared with 3% starch and 0.3g glycerol/g dry starch. Composite-films were prepared with the addition of 0.3g cellulose/g dry starch. Water transfer through the films exhibited a dependence on the relative humidity RH. Using AFM, film roughness was observed to increase from a few nanometers to 45nm over 1.5h when the films were exposed to high RH. Results indicated that the equilibrium conditions at the film surface were not reliable boundary conditions and that the diffusion coefficients determined by both transient and steady-state methods may be different because they were determined at different conditions. Further studies of water permeability, assisted by AFM, could be performed for a better understanding of film barrier properties. [Copyright &y& Elsevier]