Extrusion International 2-2018

36 Extrusion International 2/2018 MEASUREMENT TECHNOLOGY temperature stability and a proven lifetime of more than 50 years. These pipes are permanently durable for high (+95° C) and lower (-60° C) temperatures and they are extremely pressure-resistant. Inline monitoring of the process A combined vacuum and cooling technology is part of the complete concept and ensures that a good pipe ge- ometry is produced and an excellent cooling efficiency is achieved. The unique PEXLINK inline crosslinking degree measurement which operates at an accuracy of ± 2 % provides instant information on the pipe quality. Con- trasting to this technique is the traditional and complex wet chemical method which supplies results only after ap- prox. 12 hours. The inline inspection provides crosslinking data immediately, including the information whether the minimum crosslinking degree of 70% which is stipulated in DIN 16892 for PEXa-plastic pipes is adhered to. Best performance Additional function layers are added to the pipe at the co- extrusion station: an oxygen barrier layer (EVOH), an exte- rior protective layer (polyethylene) and the adhesive bond- ing agent layers. These layers ensure that the pipe becomes oxygen-impermeable, corrosion-proof and encrustation- free. Optionally, a preheater may be implemented into the extrusion line before the co-extrusion station. This device will preheat the pipe by infrared technology and will dry the material. The gravimetric dosing process is optimally adapted to the process and is carried out by SAVEOMAT mono-weighers or dosing stations and the SAVEOMAT SATELLITE conveyance technology made by iNOEX. An- other particular feature is the revolutionary control unit: not the extruder speed and mass throughput rates can be set for each co-extruded layer, but the layer thickness as stipulated in the factory standards is entered directly. In ac- cordance with set values, the output of the co-extruders is adjusted depending on line speed. This means that the control unit calculates and controls independently all ma- chinery parameters for the current line speed and adapts these parameters if necessary. This is a fully automated process for line speeds up to 200 kg/h and it does not affect either the crosslinking quality or the pipe quality. Proven measuring technique The iNOEX Terahertz-wall thickness measuring system QUANTUM Tube and/or the iNOEX ultrasonic wall thick- ness measuring system AUREX MK 32 are able to pre- cisely measure wall thickness sizes and diameters. The static measuring system QUANTUM Tube offers a 4-point measurement of the total wall thickness based on the in- novative Terahertz sensor system and it is perfectly suit- able for small pipes and tubes from 10 to 32 mm. The temperature-independent direct measurement is carried out without a coupling medium such as e.g. water. The AUREX MK 32 is installed inside a tank extension. The process-adapted measuring chamber supplies highly pre- cise measuring results for pipe dimensions between 0,5 to 32 mm. Ultrasonic technology permits the measurement of wall thickness, ovalness and eccentricity, starting at 0,02 mm. Both systems log all measuring data and thus provide comprehensive quality evidence. A proven solution for an optical 360° inspection of pipe surfaces on dots, dents, scratches, foreign bodies and glossy stripes is the AUREX OBF. Even minor surface flaws of up to 0,27 mm² are reliably detected at line speeds of up to 48 m/min. Turnkey solution iBA underlines its market position as a full-range supplier by offering not only comprehensive consultancy, process and parameter setting know-how, but also all other ex- trusion line components. This includes a fully automated coiler which is optionally available with an accumulator. The accumulator is specifically designed for high-perfor- mance lines or also in order to buffer make-ready times iBA’s extrusion lines are run at a speed of up to 35 m/min, outputs reach up to 200 kg/h 4-strand-conveyor oven with specific deflection rollers ensuring careful pipe handling. Higher speeds and higher outputs become possible based on longer dwell times for different pipe dimensions