WCA September 2021

Technology news

Upgrading a 1970s stranding machine The project team of Acoteq GmbH has carried out the upgrading of a basket- style stranding machine, to meet future process requirements, with a downtime of only a few days. The Krupp KVR 8x1400 stranding machine with reverse twist was originally constructed in 1977. The identified customer requirements were: • Machine Stop functionality should the strand tension be outside the limit values set for that process • Ensure consistently high product quality, independent of the machine operator The project also involved the development of a mechanism to transfer the linear motion of the RTM X42 brake actuators to the disc brake systems.

tube. It offers high-resolution and real-time surface defect detection with 200,000 images per second. Scratches, die marks or defects such as impurities, bubbles or particles on the insulation are displayed on PC software for analysis and characterisation. The system works like a “ring camera” around the circumference of the cylin - drical object. The image is analysed in real time by algorithms in order to pro- vide defect information such as length, width, surface and location. It allows the operator to identify and isolate the causes, and generates alarms accord - ing to the customer’s parameters. SQM was developed to focus on very fine dimensions: wire diameter from 2,000μm down to 20μm. The technology is suited to detecting and characterising defects on metal wires with a reflective surface (such as steel, copper, gold and silver); drawn products and certain extruded products; and enamelled wires, plated wires and some insulated wires. Cersa-MCI www.cersa-mci.com The main advantages resulting from the modernisation are the measurement and display of an actual tension value for each individual strand; reduced set- up time, and reproduction of critical process parameters, during product changeovers through the use of recipes; and improved quality and throughput with the constant closed-loop tension regulation of the individual strands. All of the production parameters over the course of a complete product run can be recorded and documented. FMS Force Measuring Systems AG www.fms-technology.com Acoteq GmbH www.acoteq.com and maintenance-intensive slip rings to provide the required torque at each individual spool. Data transmission is handled by radio (also with a rechargeable battery/no slip rings) in the 2.44 GHz band, so the wiring on the rotating side of the machine was kept to a minimum.

• Measurement of the current strand tensions prior to the stranding point • Automatic tension control, from full to empty spools, during production runs • Simplification and reduction of operator settings and changeover times through a recipe system • Recording and documentation of production parameters • Replacement of the pneumatically operated spool brakes, which can only adjust the braking forces equally for all of the spools in a given cage • Installation of a disc brake system for precise torque control of each individual spool

For the selection of components, Acoteq chose FMS (Force Measuring Systems) from Switzerland. For 15 years, FMS has been capable of offering a complete range of technologies for force measurement, data processing and radio transmission of signals in stranding machines. The RTM X42 telemetry system consists of the wire tension measuring system, the control centre and the brake system. The FMS brake actuators used are powered by rechargeable batteries, and do not require expensive

Wire and cable surface defect detection Measuring devices based on non- contact laser measurement for geo- metric monitoring of wire and cable have been available for many years. The measurement of the outer diameter, the calculation of the ovality, and the detection of shape defects such as lumps and necks are part of the classical measurements. The inspection of the surface appearance and detection of surface defects on cylindrical products during production present an even greater technical challenge. Measuring tech- niques and equipment do exist, but they are often either dedicated to offline measurement of samples, or for in- line measurement at diameters of several millimetres or even centimetres, and at low speeds.

As diameters become smaller and speeds increase, many devices are limited in performance by their technology.

There has previously been a lack of equipment capable of detecting

defects that may appear on the surface of wire, cable or tube during the drawing or extrusion process, particularly for products with very small diameters and at high speeds. Demand from manufacturers for zero-defect production and minimal scrap has led Cersa to fill this gap by developing a new measuring device. The SQM is a patented instrument developed to meet the need for continuous monitoring of the surface quality of fine wire, cable or

❍ Cersa’s SQM surface defect detection instrument

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Wire & Cable ASIA – September 2021

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