Innovative PVC recycling technology

Polyvinyl chloride (PVC) and aluminum play a major role as composite materials for the packaging of medical products. They are easy to process, inexpensive and, as composites in blister packaging, protect tablets and capsules from dirt and moisture. This makes them indispensable in the medical field.

The production of primary aluminum with no recyclate fraction is, however, very energy-intensive. In contrast, the production of secondary aluminum requires about 95% less energy. Rising energy costs, dwindling resources and the quantities of waste generated are increasing the demand for efficient and environmentally friendly recycling technologies. Across Europe, only about 50% of waste aluminum-containing packaging is currently recycled. This is mainly due to the use of aluminum in disposable products, such as blister packaging, in this industry.  

Currently, these materials are recycled via fine grinding to mechanically separate the laminated materials. The resulting aluminum can contain up to 10% residual PVC and can hence not be used directly as a recyclate. Thermal post-treatment of such recycled aluminum requires expensive waste gas scrubbing to remove HCl that arises from the PVC fraction. The result is that commercial aluminum recyclates have much poorer quality than primary aluminum. Furthermore, PVC that is still contaminated with foreign materials and plasticizers cannot be reused for high-quality product packaging.

A solvent-based process is used to separate PVC from aluminum

As part of industry- and publicly funded research projects, the Fraunhofer IVV developed and tested processes for recovering high-quality secondary aluminum and PVC recyclates from blister packaging. The process must be commercially viable. The German market for PVC-aluminum laminates alone is currently several thousand metric tons annually. This highlights the enormous potential of the new technology.

The technological approach being used for the innovative separation of the components involves an extractive, solvent-based recycling process. The latter was developed at the Fraunhofer IVV to recycle polystyrene. The aim is total removal of the PVC using selective Green Solvents (non-hazardous, non-VOC). The objective is to produce high-purity secondary aluminum and a PVC recyclate that can be used by the plastics industry.

Possible applications for the PVC recyclate include use in window profiles, check cards and, above all, film applications (including blister packaging) . At the same time, the PVC-free aluminum recyclate is suitable for established material recycling processes, since any residual PVC has been completely removed. 

The process was already tested on blister packaging 10 years ago (SMEs innovative project "Refined aluminum - High-quality secondary aluminum from packaging waste from the pharmaceutical industry") and was recently optimized in an industry project (in collaboration with the PVC industry's sustainability program, VinylPlus). The implementation was successfully demonstrated on a small scale (5 kg/d).

Today, the large-scale pilot plant, with a throughput of up to 20 kg/h for solvent-based plastic recycling, is available at the Fraunhofer IVV to evaluate the process on a technical scale and to produce sample quantities for external application tests.

Project samples