Plastic recyclates under the microscope: the surface counts too

A new research project at Germany’s scientific institute SKZ is developing standards for evaluating recycled surfaces during bonding and coating processes to improve quality and confidence in the use of recycled plastics.

Plastic recyclates are increasingly the focus of sustainable manufacturing. But their use brings challenges, especially knowing the range of materials used in the original plastic product, unlike the certainty that virgin materials offer.  The nature of recycled surfaces can negatively affect the quality of downstream finishing processes such as bonding, printing and coating. Many companies are therefore reluctant to treat the surfaces of recycled components.

Standards required

SKZ’s research initiative SurfRec aims to classify the surface quality of recycled plastics. ‘The safe and efficient use of recycled materials in surface-sensitive applications requires standardised evaluation criteria,’ says SKZ scientist David Herbig. With his team, he is developing proposals to supplement existing limited standards with surface-specific aspects. This will lay the foundation for quality-assured surface finishing and bonding processes for recycled materials.

Supporting downstream processes

The core of the two-and-a-half-year project is the development of defined levels of surface data quality that meet the requirements of downstream processing steps. To this end, procedures 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 ‘SurfRec’ project is funded by the German Federal Ministry for Economic Affairs and Energy.