Due to increased requirements on polymer materials, various methods of physical and chemical modification of polymers are used in order to fulfill the property level for different applications. In several applications, the reactive extrusion is used since this approach combines the possibility to modify the polymer in a physical and chemical way. In the state of the art reactive extrusion, the chemical reaction is induced by temperature-sensitive initiator decay, whereby it is difficult to precisely control the desired chemical reaction and to handle the resulting viscosity change. Polymer modification using high energy electrons (EB) can apply for branching, crosslinking, curing, degrading, grafting, and polymerization of polymeric materials. In contrast to the conventional reactive melt extrusion, the EB technology is able to induce polymer chemical reaction by a spatial and temporal precise input of electron energy. Based on these advantages, the electron-induced reactive processing (EIReP) was developed in order to overcome the disadvantages of the state of the art reactive processing. This novel temperature-sensitive melt processing method was successfully tested for different polymer blends and composites. The results proof that EIReP offers a novel approach for preparing various high-performance polymeric materials without using temperature-sensitive initiator or chemical additives. In this study, the scale up to a continuous working in-line demonstrator using a 300 keV electron emitter is shown for the first time. Additionally, the main requirements on demonstrator design and first results of testing are presented.