WCA January 2013

Cable sheathing, armouring & taping

Manufacturing complex data and special cables

The BMV braiders and the DSI machines with their ancillary equipment are part of the modular Niehoff machinery programme which covers all operational steps from rod wire drawing to fine wire drawing and to data and special cables manufacturing.

As cables must meet ever more demanding tasks, cable design is continually becoming more complex. In order to keep pace with this development, cable manufacturers need manufacturing lines which are technically mature, operate economically and can be used to produce reliably and efficiently today’s as well as tomorrow’s cables. The machines and lines built by Maschinenfabrik Niehoff meet these requirements, for example the DSI double twist stranding machines and the lever arm rotary braiding machines of the BMV series with their taping devices. About ten years ago, Niehoff began to develop both the data and special cable stranding machines of the DSI series with ancillary equipment and the BMV type braiding machines. The DSI stranding concept is based on the successful design of Niehoff’s D series double-twist bunching machines, which represents a well-established experience in the design of wire bunching and cable stranding machines dating back to the early 1970s. Similarly the BMV type braiding system has been developed by specialists with a long-standing experience in building this type of machinery. The field proven double twist stranding machines of the DSI series, DSI 631 and DSI 1001, are designed to manufacture insulated conductors into pairs or quads or to strand conductor pairs into special cables with or without foils. With diverse components the DSI machines can be configured into complete lines, perfectly adapted to the requirements of the users. Depending on the configuration, a DSI stranding line can apply up to three foils inline on a cable under controlled foil tension in the multi taping process. One of the several DSI application examples is the manufacturing of instrumentation cables for the petrochemical industry. During the stranding process, the inner part of the cable has to be covered with three film layers. All elements of the cable are assembled in one process on a stranding line which is composed by three tangential pay-offs type ATP 630, three longitudinal tape pay-offs type ALB 600, a pre-twister type VVD 180, and a DSI 631 type double twist stranding machine. The 12, 16 and 24-carrier lever arm rotary braiding machines of the BMV series are mainly designed to apply an EMC shielding onto cables. With an integrated central taping device, the braiding and the subsequent taping processes are completed in one step under constant and uniform haul-off tension. In this case, considerable cost savings result from eliminating intermediate rewinding and WIP storage, from requiring less shop floor space and from a higher product quality. The applications of the BMV machines include the manufacture of data, control and coaxial cables, hollow braids for battery cables, stranded braids, and mechanical reinforcements for pressure hoses and medical catheters.

❍ ❍ BMV 16 type lever arm rotary braiding machine

By means of several quality control systems BMV braiders can work for a long time unattended and without operator intervention. With DSI lines all types of the above-mentioned cables – and even cables of future categories – can be manufactured with high speeds and the utmost precision and quality. Another advantage for the users of Niehoff systems is that Niehoff supports customers with comprehensive process knowledge, reliable technical assistance and a worldwide customer service, which is always ready for action. The users of Niehoff technology therefore have the ideal tools at hand to benefit from the further development in the cable sector. Maschinenfabrik Niehoff GmbH & Co KG – Germany Website : www.niehoff.de

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Wire & Cable ASIA – January/February 2013