Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Fluorescence tracer technology for material identification: automatic sorting and process control

Plastic industries are currently under pressure from government legislation and environmental lobbies to recover and recycle commodities and components after the end of their useful lives. The ability to rapidly and confidently identify and segregate polymer types and variants is fundamental to achieving an effective recovery operation for plastic materials. Infra-red reflection (absorption) technique has recently been applied to address this challenge only with limited success.

The development of the optical tracer system was based upon the spectral absorption and fluorescence properties of selected tracers. The selection of tracers was, however, restricted by requirements that these are compatible in both polar and non-polar plastics, have good thermal and ultraviolet (UV) stability, low toxicity and migration and are photo-physically non-interacting with the host materials and with each other. A database on the above properties for over 60 different commercial tracer materials has been compiled which will have important application in other industry sectors requiring continuous monitoring for on-line quality/process control such as fabric, pharmaceutical, tannery and in many water-intensive industries where re-use of effluent is required.

Although the project has focused initially on application in the plastic packaging industry, this innovative technology is equally applicable to sorting other plastic types. For example, the plethora of different types and grades of high value 'engineering' plastics used in the automotive, household durables, and electronic industries could be more effectively sorted than have been done hitherto. Industrial trial for sorting tracer doped plastics using the presently developed sensor system has demonstrated that the technology is immensely more superior to manual sorting in terms of efficiency and cost-effectiveness.


Sheikh Rafi AHMAD, (Head of Applied Laseer Spectroscopy)
Tél.: +44-1793-785233
Fax: +44-1793-785774