This is made possible by the intelligent combination of VACUREMA® technology and vacuum-assisted Solid State Polycondensation (SSP) to create a process in which all thermal process steps are performed in a nitrogen and/or vacuum atmosphere. VACUNITE® is the answer to the challenges facing PET recycling, because in order to be approved for contact with food, recycled PET plastics must meet increasingly stringent quality criteria. At the same time, the demand for high-quality recycled pellets is increasing because legal requirements and voluntary commitments of leading brand manufacturers demand a higher use of recycled material in the end products. Although this development increases the overall collection rate, it also reduces the quality of the material to be recycled, as the collected material inevitably has a higher proportion of inhomogeneous components. "Recycling plants have to therefore produce better output material despite a reduction in input quality," says Christoph Woess, Business Development Manager for the Bottle Division at EREMA.
The best technologies in one plant
The VACUNITE® process is based on the combination of VACUREMA® technology - which has been proven over the past 20 years and has been further developed for this application - together with newly patented vacuum-assisted Solid State Polycondensation (SSP), which Polymetrix developed for EREMA especially for this demanding application. What makes this combination so special is that all thermal process stages take place in nitrogen and/or vacuum atmosphere, largely eliminating undesirable flake and pellet discoloration and reliably removing additives which could lead to unfavourable reactions in the melt. Another benefit of VACUNITE®: the nitrogen used in the SSP is cleaned and can be fed back into the previous processing stage so that nitrogen consumption is reduced as a result. To increase the transparency of the preforms, the pellets are dedusted again before filling.
