In this news article, a new kind of in-reactor alloying process (Chinese multi-catalyst reactor granule technology, CMRGT) is introduced. It provides the possibility to produce series of new polyolefin materials that can be used in automotive and appliances parts by the substitution of some traditional engineering plastics. A characteristic ‘fractal (self-similar) growth and pore-filling mechanism’ for the CMRGT-produced alloy particles is found. It reveals the fundamental scientific principles that govern the chemistry and physics in the formation mechanism of such novel olefinic alloys. This mechanism allows a detailed control of the dispersion and structure of these polyolefin alloys from a nanometer to micrometer size range, and possesses great potential to fulfil the requirements for a new generation of recyclable automotive materials.