New solution for separating single-layer PET trays from PET bottles

TOMRA has made it possible to separate single-layer PET trays from PET bottles, enhancing the previous capability of its AUTOSORT machine to separate multi-layer trays. This breakthrough is commercially significant because small but critical differences in the chemical properties of PET food trays and PET bottles mean that they have to be separated for equivalent-product recycling. 

The key to this breakthrough is TOMRA's FLYING BEAM® technology, the well known sensor technology. As the first near-infrared (NIR) scan system with point-scanning (and no need for external lamps), this focuses only on the area of the conveyor belt being scanned. Allowing a wide range of calibration possibilities, this can distinguish even the finest molecular differences in materials flowing down the recycling line.

The step-by-step process which concludes with the separation of single-layer PET trays and PET bottles is seamless and flexible. During the preparation for sorting mixed plastics into different polymers, packaging material collected or pre-sorted from municipal solid waste (MSW) first runs through a mechanical treatment process which reduces voluminous materials, mainly soft items such as plastic, film, and non-plastic products. To then separate mixed PET into different polymers, AUTOSORT functions as a combined system, detecting material and colour in combination with grain size. Even with a very mixed material input, this process achieves an impressive sorting efficiency of 95% or greater.

TOMRA expects this new capability to be welcomed by PET regeneration centres and collection/sorting plants. It arrives at a time when the growing international adoption of 'on-the-go' lifestyles is pushing-up the demand for plastic drink bottles and plastic trays used for fruit, vegetables and other foodstuffs. More than a million plastic bottles are bought around the world every minute and within the next five years this number is expected to increase by a further 20%. In response, EU regulations are tightening and organisations such as Plastics Recyclers Europe are instigating recycling guidelines for PET trays. This will encourage separate sorting streams to enable PET tray recycling and to develop markets for this packaging product.