Layered silicates have attracted research and industry interest over the last years. The main advantage of nano-scaled fillers in comparison to conventionally used micro-scaled fillers is the significant higher specific surface area and subsequently smaller amount of filler needed to reach or exceed the same property profile. The most commonly used layered silicates are montmorillonites. Due to their excellent intrinsic barrier properties also aluminum particles have promising properties to increase the barrier properties of polymer-based composites also at low concentrations. In this research work the influence of processing conditions as well as filler content on the barrier properties against diffusion of oxygen of PVC (nano-) composites containing layered silicates or aluminum platelets were investigated. Thereby the morphology of the samples was investigated by scanning electron microscope to examine relationships between barrier properties and final morphology of an extruded profile. The concentration of the layered silicate respectively the aluminum platelets were altered in steps from 1 wt.%, 3 wt.% to 5 wt.%. Two different routes of processing were chosen. On the one route the dryblend was mixed directly with a pre-produced masterbatch containing 25 % of either layered silicates or aluminum. The other route comprised of an additional compounding step where the masterbatch-dryblend was added during processing on a co-rotating twin-screw extruder for pre-exfoliation and homogenization of the particles in the polymer matrix. These materials were processed on a conical counter-rotating twin-screw extruder into rectangular shaped profiles for further investigation of barrier properties and morphology. Especially the pre-compounded products lead to well homogeneous dispersed particles inside the polymeric matrix, which also has positive influence on the final barrier properties.