The most thermoplastic material for metal plating is a terpolymer of acryl nitril, butadiene and styrene.By etching with chromosulfuric acid the butadiene domaines are selectivley dissolved. By this, the surface is partly oxidised. The use of Cr(VI) compounds is restricted since 2017 in the EU. Therefore we investigated a way to modifiy surfaces for plating that can be applied to a broader range of polymers. Polycarbonate is a transparent polymer that can be used for half-trasparent coatings. Polyether ether ketone is a high performance thermoplastic material with high modulus, high chemical stability, and high thermal stability. It is certified for aviation, space flight, and medicine. However, it lacks a stability against radiation and has to be protected by coatings. Coatings with metal layers are desired for electromagnetic shieldings and for design aspects. Due to the low surface polarity, its surface has to be chemically modified. Both polymers cannot be plated with chromosulfuric acid. Most alternativ processes use plasma-based approaches to render the surface composition. Etching methods are also in use. All the methods used for surface modification of thermoplastics are realized in a separate processing step. Our approach is based on grafting of a reactive polymer anto the part surface, which is done already during moulding. A thin layer of this polymer is applied to the mould surface prior to injection of the melt. On contact between melt and polymer a reactive coupling is initiated. The physical, chemical and technological conditions for this reaction are considered in the contribution. The surface properties of the produced PEEK parts are investigated. The potential of our approach is demonstrated on chemical plating which does not need any further etching or swelling.