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USER REPORT Linz-Pucking, July 2012

MAS extruder contributes to the breakthrough in M-PET recycling technology A feature which was made public for the first time in a patent application in 2002 would appear to be incredible at first glance. It is a recycling process for PET bottles, the end product of which is equivalent to primary PET, even better in some respects but without having to use an SSP (Solid State Polymerization) process. The alternative is to add a chemical modification agent on the basis of silicone compounds to the PET flakes in liquid form or as powder directly at the extruder. During plastification it acts as a polymer adhesive primarily on the short-chain decomposition products and recombines them. The M-PET produced in this way represents a high quality alternative to the original material. The modification process results from the fundamental work performed by three chemists in Georgia and Russia who were awarded the patent in 2006. The industrial implementation of this patent is in the hands of the Czech company PTP-Plastic Technologies & Products s.r.o. established in 2006 which operates a reference plant in Jίlové u Prahy. Large-scale technical maturity was achieved with the extrusion system with conical parallel twin screws as central components developed by the Upper Austrian MAS-Maschinen- und Anlagenbau Schulz GmbH.

One of the most surprising plastics recycling innovations of recent years is based on the research work conducted over 30 years ago by Georgian chemists in the former Soviet Union. Research centred on the interactions between different polymer molecules in contact with polyesters. The focus was placed on polysiloxanes (silicone-oxygen polymers), silazanes (silicone-nitrogen polymers) and silanes (silicone-hydrogen polymers). One result of this research work was the discovery that silane compounds, preferably polyhydrosiloxane in combination with a plasticiser such as di-octylphthalate, dinonylphthalate or di-butylsebacate can enter into compounds with polyester molecules. The combination of the active substances acts as a polymer adhesive. In this way the short-chain molecules, as they arise in decomposition products through all kind of processes, are recombined to or even beyond the starting chain lengths. In addition to chain extensions, the modification agent also promotes the creation of cross-linking which counteracts the characteristic tendency of PET to crystallise. In order to achieve these effects, the addition of only 4 to 5 percentage by weight of the modification agent is sufficient. The recyclate thus manufactured is referred to as M-PET. It differs from the

MAS Maschinen- und Anlagenbau Schulz GmbH., A-4055 Pucking Tel.: +43 (0) 7229/78999-11, Fax: -10, E-Mail: info@mas-austria.com – www.mas-austria.com


MAS extruder contributes to the breakthrough in M-PET recycling technology - Page 2 conventionally treated recycled PET primarily in terms of the higher resistance to oxidation and hydrolysis, higher elasticity and tensile strength as well as higher thermal dimensional resistance. The gas permeability which is decisive for use in the production of drinks bottles achieves the level of new PET goods. The production process to modify the starting material is very simple. While originally, i.e. in 2002 at the time of the patent application, the modification agent had to be added to the PET flakes in a reactor mixer and had to be agitated at around 130 °C for between 50 and 100 minutes so as to finely distribute and gel the flakes, the modificator can be added in liquid form or alternatively as granulate directly in the MAS extruder.

From laboratory to industrial production The time between patent application and granting of patent in 2006 was used to obtain the test certificates and approvals for food packaging relevant to the international application and to set up a reference plant for industrial production. The first one is within the responsibility of PTP-Plastic Technologies & Products B.V. in Amsterdam which is at the same time the base of the cooperate holding company. Parallel to this, a reference plant was established at the Czech location of Jίlové u Prahy in which the process technology was transferred from a laboratory scale to industrial volumes and optimized in several evolutionary stages.

Production technology optimized Entry to production on industrial scale was made with plant technology surrounding a 75mm twin screw extruder with co-rotating parallel 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 Technology at PTP, looks back on the beginnings: “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 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

MAS Maschinen- und Anlagenbau Schulz GmbH., A-4055 Pucking Tel.: +43 (0) 7229/78999-11, Fax: -10, E-Mail: info@mas-austria.com – www.mas-austria.com


MAS extruder contributes to the breakthrough in M-PET recycling technology - Page 3 reduce the extruder speed. As a result, the output performance declined from the maximum possible 1,200 to 750 kg/h. Only in this way were we able to keep the melt temperature at the extruder constantly below 280°C and at the same time keep the AA (acetaldehyde) value low.” Martin Urban continues: “Coincidence helped us in the search for possible improvements. It was during a visit to a trade fair where we got to know the Austrian extruder manufacturer MAS and its innovative extrusion system with conical co-rotating twin screw extruder (Fig. 1). From the very beginning we were convinced of its systematic advantages. In contrast to the parallel twin screw extruder, the intake volume of the MAS extruder is distinctly larger that the discharge volume. The large intake and melt zone of the conical extruder produces a high screw filling level and a correspondingly high output performance even at low screw speeds and therefore a lower shearing strain on the material. This is emphasized by the system-related comparatively short design length of the MAS extruder and the correspondingly shorter time the material stays in the barrel (Fig. 2). A further advantage of the conical design is to be found in the ability to connect the degassing system in a cylinder segment with a comparatively larger cross section and therefore with more material contact than with a parallel extruder which is a quite important aspect for improving the quality of recycling material. Another positive side effect of the short extruder length was also that we were able to install an additional plant without costly conversion measures within the limited space resources of our production (Fig. 3). All these advantages were strong arguments for the MAS extruder and the answer to the existing process problems with the parallel twin screw extruder.”

Expectations fully satisfied. Looking back on a year of operational practice the conical co-rotating extruder has fully satisfied the expectations placed on it. According to PTP, existing comparative measurements of AA, b* and IV values have proven the superiority of the MAS extruder with regard to previous experiences.

MAS Maschinen- und Anlagenbau Schulz GmbH., A-4055 Pucking Tel.: +43 (0) 7229/78999-11, Fax: -10, E-Mail: info@mas-austria.com – www.mas-austria.com


MAS extruder contributes to the breakthrough in M-PET recycling technology - Page 4 Currently between 700 and 1000 tons M-PET are manufactured per month in the PTP reference plant on the basis of the MAS extrusion technology, corresponding to some 60 percent of the recycling PET volume in the Czech Republic. Great potential

Talking to the MAS Sales Engineer Gerhard Ossberger, Martin Urban summarizes as follows (Fig. 4): “Using the MAS extruder as a central component of our plant technology, we are not just in position to confirm the laboratory values of the material characteristics and therefore offer a competitive alternative to primary PET, but now also at a comparatively high level of efficiency, i.e. with greater output and distinctly decreased energy consumption. We have therefore clearly reached industrial scale maturity for the process. We are currently commissioning two further recycling systems with MAS extruder technology in our new production 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 successfully combine materials which have so far been viewed as incompatible and open up so far unknown potential. The combination of PET and PP for applications in pipeline constructions is a good example here.” ■■■ Contact:

Geof Pile Koga Recyclingtech – Australasian Agent for MAS. Email – geofp@koga.com.au Mob - +61419558600 Or Stefan Lehner – Sales Manager of MAS GmbH E-mail: lehner@mas-austria.com Website: www.mas-austria.com Author: Reinhard Bauer - TECHNOKOMM E-Mail: office@technokomm.at  

MAS Maschinen- und Anlagenbau Schulz GmbH., A-4055 Pucking Tel.: +43 (0) 7229/78999-11, Fax: -10, E-Mail: info@mas-austria.com – www.mas-austria.com


MAS extruder contributes to the breakthrough in M-PET recycling technology - Page 5 about MAS Maschinen- und Anlagenbau Schulz GmbH

MAS was founded in 2006 by Helmut Schulz who has over 40 years of experience in building machines for the plastics industry and numerous patents in this field. The core competences of MAS are as follows: > the world’s first conical co-rotating twin screw extruder based on New Conical Technology (NCT) for the processing of plastics and composite plastics. > systems for the dry treatment of used plastics using the DRD system (Double Rotor Disc). 20 patents prove the innovative capacity of the company which generates a turnover of some EUR 8.0 Mio (2011) with 35 employees. Address: Hobelweg 1 A 4055 Pucking www.mas-austria.com

about 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 operates in the industrial exploitation of research results in the area of PET recycling technology. The central principle is the addition of a modifying agent on the basis of silicone compounds which acts as adhesive and wetting 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 all the most important industrial countries. The industrial reference plant was erected in Jίlové near Prague. It is the foundation for the granting of production licences. The headquarters of the PTP group which currently has 80 employees, is located in Amsterdam; a second production location in California/USA is still to go into operation in 2012. Additional branches are located in Austria, United Kingdom and Cyprus. Address of PTP-Cz: V Laznich 395, CZ-254 01 Jίlové u Prahy Contact: Miroslav Fojt - Manager Tel.: +420 731 181 785 E-Mail: miroslav.fojt@ptpgroup.eu Internet: www.ptpgroup.eu

MAS Maschinen- und Anlagenbau Schulz GmbH., A-4055 Pucking Tel.: +43 (0) 7229/78999-11, Fax: -10, E-Mail: info@mas-austria.com – www.mas-austria.com


MAS extruder contributes to the breakthrough in M-PET recycling technology - Page 6 Figures:

Photo: MAS – Maschinen- und Anlagenbau Schulz GmbH / Pucking

Fig.1: The MAS (New Conical Technology) extruder from MAS has a modular design and is available in six sizes for discharge performances from 200 to 1800 kg/h

MAS Maschinen- und Anlagenbau Schulz GmbH., A-4055 Pucking Tel.: +43 (0) 7229/78999-11, Fax: -10, E-Mail: info@mas-austria.com – www.mas-austria.com


MAS extruder contributes to the breakthrough in M-PET recycling technology - Page 7

Artwork: MAS – Maschinen- und Anlagenbau Schulz GmbH / Pucking

Fig.2: The MAS extruder offers the system-specific advantage of a twin screw extruder in the form of 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.

MAS Maschinen- und Anlagenbau Schulz GmbH., A-4055 Pucking Tel.: +43 (0) 7229/78999-11, Fax: -10, E-Mail: info@mas-austria.com – www.mas-austria.com


MAS extruder contributes to the breakthrough in M-PET recycling technology - Page 8

Photo: MAS – Maschinen- und Anlagenbau Schulz GmbH / Pucking

Fig.3: Central plant components of the PTP recycling plant technology is a MAS 90 extruder with a discharge performance of up to 1,300 kg PET / hour.

MAS Maschinen- und Anlagenbau Schulz GmbH., A-4055 Pucking Tel.: +43 (0) 7229/78999-11, Fax: -10, E-Mail: info@mas-austria.com – www.mas-austria.com


MAS extruder contributes to the breakthrough in M-PET recycling technology - Page 9

Photo: MAS – Maschinen- und Anlagenbau Schulz GmbH / Pucking

Fig.4: MAS Project Engineer Gerhard Ossberger and Martin Urban, Technical Manager at PTP-CZ draw a positive conclusion about the 1 year period of permanent operation. The end product of the innovative PTP recycling process offers the same material properties as the primary material and also has all usual test certificates for use in food packaging.

MAS Maschinen- und Anlagenbau Schulz GmbH., A-4055 Pucking Tel.: +43 (0) 7229/78999-11, Fax: -10, E-Mail: info@mas-austria.com – www.mas-austria.com


MAS extruder contributes to the breakthrough in M-PET recycling technology