Recyclates under the Microscope

A new SKZ research project is developing standards for evaluating recycled surfaces for adhesive bonding and coating processes. The aim is to improve quality assurance and confidence in the use of recycled plastics. Plastic recyclates are increasingly becoming the focus of sustainable manufacturing – but their use brings challenges. Particularly problematic are the highly variable and often inadequately documented material properties compared to virgin material. The nature of recycled surfaces in particular has a significant influence on the quality of downstream finishing processes such as bonding, printing and coating. Many companies are therefore reluctant to treat the surfaces of recycled components.

The SKZ Plastics Centre wants to change this. With the new IGF research project SurfRec, the project team aims to thoroughly characterise and classify the surface quality of recycled plastics. "The safe and efficient use of recycled materials in surface-sensitive applications requires standardised evaluation criteria," explains David Herbig, scientist at SKZ. Together with his team, he is developing proposals to supplement existing standards with surface-specific aspects. This will lay the foundation for quality-assured surface finishing and bonding processes for recycled materials.

The core of the two-and-a-half-year project is the development of defined surface data quality levels (DQLs) that meet the requirements of downstream processing steps. To this end, suitable test methods – such as wetting tests or chemical analyses – are identified, validated and optimised in terms of their informative value. In addition, investigations are being carried out to determine whether artificially accelerated ageing tests can improve surface evaluation.

The IGF project SurfRec of the research association FSKZ e.V. is funded by the Federal Ministry for Economic Affairs and Energy (BMWE) as part of the programme for the promotion of industrial joint research (IGF) based on a resolution of the German Bundestag (FKZ: 01IF23716N).

(Source: FSKZ e. V.)