The first months of the project were allocated to the careful choice of the different component of the first devulcanization unit. 27mm twin-screw extruder has been chosen to be the core of the prototype. The different parts of the prototype have been assembled and installed inside Phenix facilities and this first unit has been led to proper functioning over these months of work. This devulcanisation unit is now able to run different kind of rubber; going from natural rubber (polyisoprene) to EPDM or GTR (Ground Tyre Rubber). Physico-chemical behavior of the recycled rubber.
During the second part of the project, our work was particularly focused on the TPV line. We ordered it in mid-2016 and we received it at the beginning of the year 2017. The TPV extruder have been installed inside Phénix facilities and we had to make some arrangements inside our warehouse. First TPV trials were conducted in this new line and led us to good products according to the mechanical properties we obtained.
In parallel, we took advantage of the extruder to study the devulcanisation process at higher rates. In fact, the TPV study subcontracted by Inspiralia is having delays and we need this study to begin the TPV study at semi-industrial scale. The extruder was available, that is the reason we had the opportunity to proceed to the devulc process scaling-up. To prepare this study we made some modifications on the new extruder: we changed the screw configuration and we worked without the die and scCO2. This study led us to good results for the devulc products quality. Unfortunately, we had to face some issues concerning the security and the products packaging. However, this study was investigated in order to prevent a part of the troubles we could meet when we will work on the industrial pilot extruder, in view to save time when we will scale up at industrial dimension. We understood then that the devulcanisation at bigger scale needs to be more secured to protect from hazardous gas emission and smelling. Additionally, we found a solution to be able to pack the rubber continuously after the devulcanisation process in order to save space on the packaging, leading us to save money on transports.
During the third period of the project, we used the 40 mm partly to study the correlation between the TPeV made at lab scale by Inspiralia and the TPeV made with the extruder at industrial scale ; and partly to study the scale-up of our devulc process and to solve several problems arising from potential customers. We can finely calendar a product made out of 100% devulcanized ground tire rubber (thickness = 1,3 mm) ; recycle EPDM to make sealing with a good surface state ; maintain the viscosity of the Devulc product with time.
At the end of the period, the pilot plant was mounted and tested with good quality of the final products. The system is ready to work at industrial scale (more than 1200 t/year). Several contracts are signed or about to be. The H2020 programme allowed us to make a very important step forwards in this project and was certainly a condition for moving in three years at an industrial scale.
