bIR-Mark

When it comes to distinguishing between different grades of the same polymer, the state of the art of NIR sorting systems for plastic waste reaches its limits. These non-separable fractions include, for example, more than half of the plastics produced globally in the form of different types of PE and PP. Examples include viscosity, mechanical characteristics, or even bio-based raw material sources (so-called drop-in solutions). The recyclates obtained from these sorting fractions then consist of mixtures of the different types with correspondingly undefined properties. To counteract this problem, plastics will be equipped with new polyphenol-based IR-active markers and their processability and recyclability in plastics will be investigated as part of the research project. The project aims to realize a targeted reuse of materials in their original purpose as far as possible and to increase the purity of sorting fractions compared to current possibilities. As this is a sustainable approach, a marker system based on biological sources will be used. An important aspect in the project is the stability and longevity of the new NIR makers. The advantage of the IR technology compared to fluorescent markers, which are also investigated in the research, is the chance to increase the performance of existing NIR sorting systems in a timely manner and to retrofit existing sorting systems at low cost. In addition, another possible application is the targeted identification and return of material from a manufacturer. This prevents uncontrolled mixing and also improves the traceability of licensed material streams. The scientific and technical effort required to investigate new marker molecules is very high and at the same time of great benefit to the companies in the compounding and recycling sectors, which are predominantly made up of SMEs.


Approach

• Increase of thermostability by chemical modification of biobased markers
• Investigation of thermal and material stability as well as NIR signature
• Incorporation and blending of markers into selected plastics
• Production of sorting samples and sorting tests with near-infrared sorter