EREMA Recycling Machines and B+B Anlagenbau have recently supplied an expansion line for the production of food-grade HDPE at one of the UK’s pioneering recycling facilities.
When Dagenham-based Closed Loop Recycling began producing food-contact grade HDPE from transparent bottle material in 2008, the technical equipment was installed by EREMA and B+B. This collaboration has now been continued through the expansion of the existing plant capacity to a total of 4,800 kg/h.
The processing steps comprise dry cleaning; air classification; hot wash; sink float separation; mechanical drying from B+B and subsequent extrusion with upstream decontamination from EREMA. This process enables Closed Loop to produce rHDPE pellets from HDPE milk bottles for direct food contact in line with EFSA requirements.
The basic principle of B+B's plant concept is to treat the regrind material in a dry state as long as possible while it is in the process. This, it says, means that expensive resources such as water can be saved and no elaborate plant engineering is required for processing.
The core component of the washing facility is the hot wash, which removes any unwanted elements such as stickers or adhesives from the regrind material. This particular application also features the removal of milk residues and the associated odours as a crucial part of the cleaning process. The hot wash system works continuously and is fully automatic to ensure maximum availability and minimum maintenance intervals.
In the subsequent extrusion process, food contact grade HDPE regrind material is made on two Vacurema Advanced 1716 TE systems and is then reused in the production of milk bottles. Closed Loop ordered what is now the third of these systems – each with a capacity of 7,000 t/year – as part of the expansion.
EREMA says its Vacurema technology for the processing of rPET for direct food contact also works in a slightly modified form for the recycling of food contact grade HDPE pellets that require an additional extruder degassing.