New melting process gets FDA approval

Germany – German plastics technology specialist Gneuss Kunststofftechnik has received unrestricted approval from the US Food and Drug Administration (FDA) for its PET recycling system.

The company had already received a non-objection letter last year and its MRS (Multi Rotation Extruder) extrusion process is now cleared to produce all types of food packaging products, in classes C-G.

FDA approval means that the MRS extruder, its devolatilising system and its rotary melt filtration system are permitted to process up to 100% unwashed PET bottle flakes for food contact containers. This is achieved without the need for any treatment of the material, such as drying or crystallising, before or after it is processed on the extruder.

Stephan Gneuss, Managing Director of the company, explains: ‘Approval to process up to 100% PET bottle flakes using only an extruder, without any pre- or post-extrusion treatment, is a unique selling point. For us, it is the best proof that MRS is a genuine innovation.’

The result is achieved by creating an extremely large polymer melt surface area in the multiple rotation section of the extruder, together with rapid melt exchange and optimised venting.

Trials under production conditions show that devolatilisation is possible while treating the material gently and with a very low IV drop. Gneuss claims this permits the production of high quality food-grade products with high flexibi¬lity, low energy costs, little requirement for manual intervention and minimal maintenance.