Conductive drying of starch-fiber films prepared by tape casting: Drying rates and film properties

- Starch-cellulose-based films were prepared by tape-casting.
- Influence of suspension thickness on drying rates and film properties was investigated.
- Tape-casting is a suitable technique to prepare such films in short times.
- Suspension thickness of 3 mm is the most appropriate for films preparation.

Tape casting has been reported as a suitable method for the preparation of ceramic layers on supports for the manufacture of electronics. This technique can also be used to prepare biodegradable films. The spreading of the film forming suspension can be performed on large supports or on continuous carrier tapes on which the resulting film is dried. The aim of this study was to evaluate the influences of both the starch-fiber suspension thickness and the drying temperature on the conductive drying rate and the properties of the resulting films. The results showed that both the suspension thickness and the drying temperature significantly influenced the drying rate as well as the film properties. The suspensions should be spread with doctor blade gaps of 3-4 mm to obtain homogeneous films. The maximum drying temperature for films with satisfactory properties is 60 °C. Under these conditions, 3-mm-thick suspensions can be dried in 2.3 h, which is much shorter than the drying times reported in the literature for films prepared via classical casting. The results reported in the present work will be very useful to researchers and engineers interested in scaling up film production, mainly with respect to the drying conditions.