Durethan BKV 15, new pellets and Durethan BKV 15 recycled material
Measuring cell: DSC20
Pan: Aluminum standard 40 μl, pierced lid
Sample preparation: Disk cut from center part of pellet
DSC measurement: Heating from 100 to 300 C at 10 K/min, cooling to 100 C at 10 K/min (to eliminate thermal history). Actual measurement: Heating from 100 to 300 C at 10 K/min
Atmosphere: Nitrogen, 50 cm3 / min
The DSC curves from the second heating runs are practically identical. This shows that both are PA6.
The heat of fusion of the recycled material is higher. The degree of crystallinity of recycled material is in fact often higher than that of new material. This is due to the presence of small amounts of impurities that act as nucleation points. Since the degree of crystallinity influences mechanical properties, the company was advised not to add more than 10% of recycled material and to shorten the injection molding cooling cycle.
PA6, New Versus Recycled Material | Thermal Analysis Handbook No.HB226 | Application published in METTLER TOLEDO TA Application Handbook Thermoplastics