Intermeshing twin-screw extruders have been recently identified as useful in special application niches such as the extrusion of PVC dry blends, (counter-rotating machines) and compounding operations (co-rotating machines). Thus, it is of interest to study the mechanical and/or chemical effects that occur along the screw axis of the extruding, they will dictate the characteristics and performance of the final material. This work aims at illustrating the usefulness of a simple experimental tool recently developed for the study of the physical, chemical and morphological evolution along, the extruder of polymer based systems, data being presented and discussed for a number of composites and blends.