NGR debuts innovative PET improvement equipment at NPE2015

NGR - Next Generation Recyclingmaschinen GmbH - will premiere its new P:REACT equipment at next month’s NPE2015. Based on the principles of LSP (Liquid State Polycondensation), a process that considerably enhances the material properties of PET, the P:REACT is a good choice for PET converters seeking to re-use production scrap, as well as for end-of-life PET recyclers. According to NGR, the P:REACT process enables production waste such as fibers, fabrics, wovens and non-wovens, preforms, strapping tapes and films to be re-processed into virgin quality resin.

Last fall, NGR received the Upper Austrian Innovation Award for the development of the new LSP process. The process has the advantage of working within minutes; by contrast, using conventional PET upgrading technologies, which are generally based on Solid State Polycondensation, enhancement of the material properties usually takes hours.

Liquid State Polycondensation takes advantage of the inherent capability of PET to undergo postcondensation in the molten phase under vacuum. This postcondensation causes the intrinsic viscosity value to rise. Decontamination of the material occurs during the liquid phase of the PET. The high performance vacuum effectively eliminates all harmful chemicals from the material, even removing spin oil from the fibers. The result exceeds the limits set by recognized food safety standards, making it safe for food contact applications. The process received 100% approval for these applications from the FDA in November 2013.

How does it work?
First, the PET needs to be melted in order to be recycled. As the molten PET enters the vertical part of the P:REACT, strands are formed to create a suitable surface-to-volume ratio. The material is then collected in a horizontal drum and slowly pushed forward. Postcondensation starts immediately when the strands are formed and continues until the PET has exited the P:REACT. The P:REACT uses the melt energy for postcondensing PET. The reactor itself only maintains the heat level. P:REACT is therefore highly energy-efficient, which results in low operating costs.

The rise in intrinsic viscosity is controlled by the residue time of the molten PET inside the reactor, hence the machine parameters automatically adjusted to achieve the desired IV at a consistent level, within a small tolerance band. This results in IV increase rates of some 0,01 dl/g per minute. Faster reaction leads to faster results and a more profitable operation.

The continuous operation of P:REACT yields recycled pellets within a narrow IV-range, suitable for usage in such high-end applications as fiber spinning or sheet extrusion. Batch related IV-fluctuations are simply designed out, said NGR.