WCA September 2020

Technology news

Polypropylene power insulation

that the polypropylene compound cable can have better current-carrying capacity and transmission capacity, and lower electrical losses at 90°C, and that the cable can also be run at 110°C, if necessary. This was also the case in auxiliary tests when a similar MV XLPE cable was compared to an MV PPC cable. Rosendahl extensively tested RoSET MV PPC in its laboratory and also with complete production runs on an installed line. Over the past 18 months the company has had a dedicated extrusion setting for the RoSET insulation system compounds with high and stable performance. During the real cable runs, it also found that it had to advise cable producers to take care of cross contamination when changing from one material to another, and to be particularly careful when handling the materials in general. On this basis, a special material-handling system has been developed. Rosendahl recommends a dedicated horizontal MV PPC insulation line to avoid problems and to ensure successful test and production runs.

electrical properties and higher operating temperature. Rosendahl conducted both internal and test institute tests, which revealed the electrical performance at both the AC breakdown and impulse tests. The successfully passed full electrical type test also showed low loss factor (tan delta) values, even when compared to the reference peroxide XLPE grade. The new RoSET insulation system is tailored to MV cable production, and should therefore be compared to similar kinds of grades. Quite often these are water-tree retardant XLPE compounds with

RoSET is the name of Rosendahl’s next-generation power cable insulation technology for MV cable production with polypropylene-based compounds. A number of cable makers, along with major utilities worldwide, are already producing and testing polypro- pylene-based insulation systems (PPC) for MV and HV applications, both in AC and DC. PPC systems are characterised by a lower carbon footprint, no need for degassing and no by-products, as well as being recyclable, and having equal or better

different properties to HV/ EHV XLPE grades. The thermal conductivity of pure polypropylene is lower than that of polyethylene. With polypropylene copolymers, however, the difference is not as great. Together with development partner HV Cable Solutions, Rosendahl carried out ampacity calculations with different XLPE and PPC grades for a single 20 kV cable. The results showed

Rosendahl Nextrom GmbH www.rosendahlnextrom.com

❍ Rosendahl’s next-generation power cable insulation technology

Mixer SpA offers solutions based on proprietary technologies, invented and refined over two decades. Its Ekopren ® brand is a portfolio of compounds for insulation, sheathing and bedding. For shipboard and offshore applications, Mixer offers grades meeting the IEC 60092-360 and NEK 606 specifications. Ekopren 3SH821 and Ekopren 3SH831 halogen-free and flame-retardant sheathings were developed with a high oil resistance, to pass the SHF 2 and MUD requirements. For rolling stock cables according to EN 50264, Mixer has set up a full solution. To ensure high electrical insulation, Ekopren 3IS75L is implemented as inner insulation, coupled with Ekopren 3IS771 for outer insulation, suitable as EI 101 to EI 104 insulation. Alternatively, Ekopren 3IS801 can be used as EI 106 to EI 110 insulation. Finally, Ekopren 3SH821 acts as the EM 101 to EM 104 sheathing. The Ekopren range also includes low voltage insulation compounds that meet standards for automotive cables. Ekopren 3IS941 is intended for battery cables according to ISO 6722 and SAE J1127. Special compounds for special cables

For primary cables, Ekopren 3IS911 adheres to SAE J1128 only, and Ekopren 3IS931 can be used for both SAE J1128 and ISO 6722. Ekopren 3IS951 is an option for ISO 6722 thin wall applications. In addition to product development, Mixer is committed to scientific research, with the aim of offering innovation to customers and to the cable industry. In 2016, Mixer presented a paper introducing the TPV technology: Galanti A, Dossi S, Magri A, Cardelli C, TPV based insulation for medium voltage applications. The company then studied the relationship between the ultimate properties of these compounds and the microscopic structure. The results of this investigation are reported in the latest published paper: Ciardelli F, Dossi S, Galanti A, Magri A, Riolo S, Molecular evolution during dynamic vulcanisation of polyolefin mixtures for lead-free thermoplastic vulcanised. The complete Ekopren portfolio will be on display in Düsseldorf, Germany, during wire 2020, on stand E74 in hall 12. Mixer SpA https://mixercompounds.com


Wire & Cable ASIA – September/October 2020


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