26/11/2020 – Modernisation / Stranding
Fit for future in only 4 days
How does a virtually indestructible basket style stranding machine, Krupp stranding machine “KVR 8x1400” with reverse twist, manage to be upgraded to meet future process requirements with the shortest possible downtime of only a few days? The project team of Acoteq GmbH employees are now able to provide their thoughts here from lessons learned during the upgrade process.
How does a virtually indestructible basket style stranding machine, type Krupp “KVR 8x1400” with reverse twist, manage to be upgraded to meet future process requirements with the shortest possible downtime of only a few days? The project team of Acoteq GmbH employees are now able to provide their thoughts here from lessons learned during the upgrade process.
The first step was to define the required specifications together with the end customer.
The following customer requirements were defined as follows:
– 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
– Machine Stop functionality should the strand tension be outside (too high or too low) of the limit values set for that process
– Ensure consistently high product quality, independent of the machine operator
Integration of the new systems into the existing Krupp stranding machine (reverse twist) as efficiently as possible. This included development of a mechanism to transfer the linear motion of the “RTM X42” brake actuators to the disc brake systems.
Selection of components
For the selection of components, Acoteq chose FMS Force Measuring Systems from Switzerland. For 15 years, FMS has been the only manufacturer capable of offering a complete range of technologies for force measurement, data processing, and radio transmission of signals in stranding machines. The telemetry system RTM X42 offers all technical solutions as required by the customer, and consists of the wire tension measuring system, the control center, and the brake system. The FMS brake actuators used here are powered by rechargeable batteries, and thus do not require expensive 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 2.44GHz band, and therefore the wiring effort on the rotating side of the machine was kept to a minimum.
“Thanks to good preparation, such as the construction of special holders for measuring rollers, on-site assembly could be completed in a time window of four days," explained Willibert Dautzenberg (CEO) and Stefan Krüttgen (project manager) proudly.
The main advantages as a result of 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
– Improved quality and throughput with the constant closed-loop tension regulation of the individual strands
– The ability to record and document all of the production parameters over the course of a complete product run
The German company Acoteq GmbH was founded in Monschau in April 2016 by Gabriela Queins and Willibert Dautzenberg. Together with Stefan Krüttgen, their employees and various key partners from the regional wire and cable supply industry, Acoteq forms an experienced and qualified team with roots in the global wire and cable industry. Acoteq is established in the market as a complete provider of expertise, machinery, ancillary equipment and services for customers in the international wire and cable industry.