Extrusion International 3-2019

35 Extrusion International 3/2019 Further, multiple product layers are measurable as well as foam pipes and equally thick-walled pipes. We offer a real 100 % measurement and a vari- ety of systems with 1 to 38 measuring spots. Clear and simple user guidance is offered and the consistent imple- mentation of the Industry 4.0 protocol OPC UA. This makes our THz-systems plug & play systems which are very easy to implement into any extrusion process. THz technology is not only suitable for pipe extrusion, but also for numerous other applications, e.g. blow moulding or the production of sheets and profiles. When did iNOEX start this technical development? And what is the state of the art today? Klose: We started this development in 2011 as a research project. We cooper- atedwith Fraunhofer-InstituteHHI and the Kunststoffzentrum in Würzburg (SKZ). At the time the THz community was able to provide a technical solu- tion but no product application. There was still a long way to go until we suc- ceeded in making the technology us- able for the industry and together with our partners we learned a lot on this path. A technology which was created in the lab now has become an indus- trially usable measuring technology. Our systems are field-proven and have been used by leading pipe producers for some years now. The good coop- eration with our customers and their feedback have continuously led to the implementation of improving design features. Todaywe can say that we cur- rently work on the next generation of THz systems. Most significantly however is the fact that the iNOEX THz systemQUANTUM features the latest THz femtosecond la- ser technology which permits the mea- suring of layer thicknesses starting at 25 µmand ameasurement rate of 1600 Hz. The systemWARP consists of an in- telligent sensor technology based on FMCW-microchips, frequencies are be- tween 60 – 170 GHz (depending on the application). All systems are CE compli- ant, have been certified in accordance with RED and FCC-compliant. What is important in this context is the variety of patents/patent applications developed in our R&D department and generated together with our coopera- tion partners which are integrated into iNOEX GmbH. For the past 8 years you have done in- tense research and development in the Terahertz field. Where do you pres- ently see the greatest challenges and what is your view on the future devel- opment of this technology? Klose: THz technology becomes more and more intelligent and complex and will be used increasingly in other appli- cations, too, such as e.g. layer thickness measurement and process engineer- ing.Weareworking full steamon these technical projects and on other specific applications and we do this together with our cooperation partners. In this context we also decided to invest into a new THz testing and assembly center inMelle which will cover a total surface of approx. 1.400 square metres. Mr. Klose, you mentioned two dif- ferent Terahertz measuring systems. What is thedifferencebetweenQUAN- TUMandWARP? Klose: The essential difference be- tween the two systems is how the THz wave is technically generated and the number of sensors which is used for the system’s performance. QUANTUM is based on the optical laser generation of Terahertz waves. This technology offers very high fre- quencies and a large bandwidth. Therefore, QUANTUM is mainly used for measuring thin layers or multiple layers. WARP, on the other hand, is operated in the lower Terahertz fre- quency range. Terahertz waves are generated electronically by an iNOEX microchip. Thus, the system is suit- able for large and medium-size wall thicknesses of 5 mm or higher. Thin- ner wall thickness sizes larger than 3,5mmwill bemeasurable in the fore- seeable future. As mentioned, there is a difference in the number of sensors The alignment of WARP sensors ensures that measuring spots overlap. This permits close monitoring also in extrusion direction.