PETpla.net Insider 12 / 2012

MATERIAL / RECYCLING 21 PET planet insider Vol. 13 No. 12/12 www.petpla.net screws of a German manufacturer. The extruder was combined with a melt pump, a filter system and an underwater pelletizing system. Martin Urban, Head of Application’s Technol- ogy at PTP, looks back on the begin- nings: “It was during a visit to a trade fair where we got to know the Austrian extruder manufacturer MAS and its extrusion system with conical co- rotating twin screw extruder. After the start-up phase the process technology had to be improved and we found that there was a lot to optimize. We could not fully use the performance of the parallel twin screw extruder without Mas Project Engineer Gerhard Oss- berger and Martin Urban, Technical Manager at PTP-CZ draw a positive conclusion about the one year period of permanent operation. The end prod- uct of the innovative PTP recycling process offers the same material prop- erties as the primary material and also has all usual test certificates for use in food packaging . PTP Plastic technologies and Products s.r.o. The company PTP - Plastic Technologies and Products s.r.o. is a start-up company which was established in 2006 and oper- ates in the industrial exploitation of research results achieved by the scientists George Javakh- ishvili, Levan Dadiani and Viktor Bulgakov in the area of PET recycling technology. The central principle of the process is the addition of a modifying agent on the basis of silicone compounds which acts as adhesive and wet- ting agent on the short-chain molecules, thereby raising the material properties to or above the level of the starting material without producing decomposition products. Therefore, the recycled material referred to as M-PET has approval for food packaging and can be used alternatively to primary PET in all productions. The special recycling process was registered for patent in 2002. The patent was granted in 2006 and applies in the most important industrial countries. The industrial reference plant was erected in Jίlové near Prague. It is the foun- dation for the granting of produc- tion licences. The headquarters of the PTP group which currently has 80 employees, is located in Amsterdam; a second produc- tion location in California/USA is still to go into operation in 2012. Additional branches are located in Austria, United Kingdom and Cyprus. www.ptpgroup.eu compromising on the high material quality. Measurements showed that this was primarily attributable to the relatively high shearing strain on the melt in the comparatively long and fast turning twin screw extruder. To reduce material damage through shear and the associated molecular disintegration, we had to reduce the extruder speed. As a result, the output performance declined from the maxi- mum possible 1,200 to 750kg/h. Only in this way were we able to keep the melt temperature at the extruder con- stantly below 280°C and at the same time keeping the AA (acetaldehyde) value low.” According to Martin Urban, the PTP has clearly reached industrial scale maturity for the process. Cur- rently between 700 and 1000t/month of M-PET are manufactured in the PTP reference plant. This corre- sponds to some 60% of the PET recy- cling volume in the Czech Republic. PTP is currently commissioning two further recycling systems with MAS extruder technology in their new pro- duction location in California. Further locations in Europe are planned. “All in all we expect great potential from our chemical modificator technology beyond the recycling application. As tests have shown, we can success- fully combine materials which have so far been viewed as incompatible and open up so far unknown potential. The combination of PET and PP for appli- cations in pipeline constructions is a good example here.” www.mas-austria.com The twin screw extruder features a large intake zone which permits the efficient feeding of raw material with low bulk density. Both screws turn in the same direction and provide the best prerequisites for a gentle treatment of the material thanks to the characteristic plastification without high-pressure-peaks. At the heart of the PTP recycling plant technology is a MAS 90 extruder with a discharge performance of up to 1,300kg/h of PET.