WCA March 2021

Technology news

❍ Niehoff has already delivered thirteen D 1252 double-twist stranders

❍ Detail of the D 1252 model

Manufacturing larger dimensioned strands for power cables

Maschinenfabrik Niehoff’s latest de- velopments in stranding technology include three types of double-twist stranding machines for spool sizes up to 2,000mm. The new models – D 1252, D 1602 and D 2002 – are designed for the manufacture of conductors with a uniform lay direction (“unilay”) and a strand cross-section of 6 to 500mm 2 . However, cable producers also have the option to manufacture other products such as flexible control, connection and motor cables on the new double- twist stranders. The D 1252 model is a further development of Niehoff’s D 1251, and is fully equipped with a new Siemens control and HMI. Niehoff has already delivered thirteen D 1252 type stranders to the wire and cable industry. The D 1602 strander is designed for 19- wire Class 2 conductors and Class 5 conductors of up to 150mm 2 , while the D 2002, being combined with a PTD 1000 external rotating capstan, can be used for larger constructions, such as

those with up to 61 wires and a maxi - mum cross-section of 500mm 2 when manufacturing aluminium conductors, and 400mm 2 for copper conductors. The new stranders enable the conductors to be compacted by means of a compacting die with interval lubrication, making a compacting degree of up to 13 per cent possible. To ensure proper laying, all three models are equipped with a laser-controlled flange detection system (NBAT). In designing the machines, Niehoff put emphasis on optimising the conductor path: all rollers and capstans have large diameters, while a straight path from the second pulley to the capstan contributes to conductor quality. Ergonomic criteria also played an important role in the design, making the operator’s work easier, since the machines’ working height is 1,300mm. In common with the other machines of the Niehoff D series, the new models feature an energy-saving one-bow design. The double-twist stranders also include an energy efficiency class

IE3 rotor drive and a controllable fan drive in the soundproof cabin. Niehoff has increased production safety and simplified maintenance for the D series by using wireless telemetry for all signals. The machines are operated via a network-compatible interface with a colour touchscreen monitor – the NMI (Niehoff Machine Interface). Information, instructions, maintenance advice, stored recipes and system status messages are displayed on the screen in the operator’s language. Sensors monitor quality throughout the stranding process, such as the temperature of the rotor bearings and the vibration of the rotor. The sensors enable production parameters to be recorded, documented and evaluated in accordance with Industry 4.0, allowing continuous proof of quality. Maschinenfabrik Niehoff GmbH & Co KG www.niehoff.de Niehoff Endex North America Inc www.niehoffendex.com

Graphics bigstockphoto.com Artist Olechowski

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Wire & Cable ASIA – March 2021 021

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