Pla.to Technology has developed the first industrial technology solution for the bottle-to-bottle recycling of HDPE detergent bottles, the company said.
At its technical facility in Görlitz, the company worked with clients Beiersdorf and the Fraunhofer Institute for Process Engineering and Packaging on the development of an upcycling solution for used shampoo and shower gel bottles at the end of life.
Due to its high stability and tensile strength, HDPE is commonly used In the detergent industry. The bottles are typically manufactured by extrusion blow moulding, are labelled and feature caps from PP.
Pla.to has now successfully created a water-saving process for a closed HDPE cycle – without the addition of virgin granulate necessary in other processes.
The rHDPE granulate derived from bimodal high-density polyethylene could be reintroduced into the production cycle to produce new detergent bottles from 100% recycled granulate. The new bottles fully met the quality standards of new products.
“Our solution is a sustainable and water-saving method to fully recycle HDPE in large quantities,” explained Pla.to managing director Heinz R. Schnettler.
Pla.to reprocessed the used bottles at its in-house demonstration centre. Before recycling, the bottles were first sorted by colour with the caps and then granulated. Dry cleaning technology was then used to remove residual ingredients inside the bottles without any wastewater. Stubborn contaminants were first soaked and then removed from the plastic using friction and hot water. The label adhesive was then eliminated and the material was dried, both mechanically and thermally. Finally, a zig-zag separator was used to separate the bottles and caps from the label particles according to their bulk density. In order to separate the HDPE from the other components for reuse at the end, the polypropylene was separated out using near-infrared spectroscopy . After compounding, this was regranulated into rHDPE and could be directly reused to produce new bottles.
