As polymers progressively meet more stringent requirements in terms of processing and performance, it is often necessary to developed complex material systems while minimizing costs and time-to-market. Thus, it seems useful to make available fast response characterization tools that although using small amounts of sample, are still capable of conveying adequate data on the correlations between rheological response, process-induced material structure and product properties. For this purpose, a prototype small-scale single / twin-screw extrusion system of modular construction, with outputs in the range 30-300 g/h, was coupled to a rheo-optical slit die designed to be able to measure shear viscosity and normal-stress differences, as well as performing rheo-optical experiments, namely small angle light scattering (SALS) and polarized optical microscopy (POM). The extruder is equipped with ports that allow sample collection, in order to subsequently evaluate the evolution of melting and mixing, morphology, or chemical conversion, whichever relevant. Also, downstream equipment is available, so that the engineering properties of the extrudate can be evaluated. As an example, processing of a PS/PMMA industrial blend and the properties of extruded sheets will be studied. The morphological evolution along the extruder, the flow-induced structures developed and the corresponding rheological characteristics are presented, together with the mechanical and structural characteristics of the sheets.