Wire and Cable India: Cable manufacturers today produce an increasingly diverse range of products using different polymers, performance requirements and production speeds. Which developments are placing the greatest demands on modern extrusion systems, and why?
Vivek Kohli: The biggest change we see is that cable manufacturers are no longer looking for machines designed around one product or one material. They increasingly want flexible platforms capable of handling a wider range of materials, cable constructions, diameters and production speeds without compromising consistency.
The growth of renewable energy, EVs, automotive, data communication and higher-performance power cables is bringing more demanding materials and tighter dimensional requirements. At the same time, manufacturers expect higher output and faster changeovers.
This places greater demands on the complete extrusion system—not just the extruder. Screw and barrel design, temperature control, cross-head flow distribution, tooling, cooling, line tension and online measurement all have to work as one integrated system.
At Supermac, we therefore see process stability and flexibility as equally important as maximum line speed. Our lines are designed with configurable single, dual and triple extrusion arrangements, depending on the product and customer requirement.
WCI: Compared with five years ago, which aspects of the extrusion process have become technically more difficult to control consistently? How have machinery design and process engineering evolved to address these challenges?
VK: The principal challenge is maintaining consistent product quality at increasingly higher speeds and with increasingly narrow tolerances.
Melt temperature stability, pressure variation, wall-thickness consistency, eccentricity, cooling conditions, line tension, and synchronization between different sections of the line become more critical as speed increases.
The industry has therefore moved from machines that were primarily mechanically controlled to integrated electromechanical and digital process systems.
Modern extrusion lines increasingly incorporate recipe-based operation, online diameter measurement, automatic process adjustments, improved communication between machines and remote diagnostics. Supermac’s systems incorporate Industry 4.0/IoT capabilities and online remote service, while our machine-upgrade programs can also bring newer control and drive technologies to existing equipment.
The objective is not simply automation for its own sake. The objective is to make the process less dependent on operator intervention and more repeatable from one production run to another.
One common misconception is that a higher machine speed automatically means higher productivity. In reality, productivity is determined by the amount of conforming products produced efficiently and consistently.
WCI: Modern cable compounds such as HFFR, LSZH, XLPE, specialised elastomers and engineering polymers each present unique processing characteristics. Which material-related challenges are driving the most significant innovations in extrusion equipment today?
VK: Material technology is probably one of the strongest drivers of extrusion-machine development. Materials such as HFFR and LSZH can have very different flow, thermal and shear characteristics compared with conventional PVC compounds. XLPE and silane-based systems introduce their own processing and curing requirements, while specialised elastomers and engineering polymers can demand precise temperature and residence-time control.
The challenge is therefore to achieve homogeneous melting and mixing without excessive shear, degradation or temperature variation.
This is driving improvements in screw and barrel geometry, temperature-control systems, melt-flow distribution and cross-head design. Tooling has become particularly important because the melt has to be distributed uniformly around the conductor while maintaining very tight wall-thickness tolerances.
Supermac’s triple-extrusion technology for silane-XLPE, for example, uses a dedicated cross-head and melt distributors matched to the different insulation and semiconductive layers.
Going forward, we expect material-specific process engineering rather than one-size-fits-all extrusion design to become increasingly important.
WCI: Customers increasingly expect higher line speeds together with tighter quality tolerances. In practice, where do machinery builders encounter the greatest trade-offs between productivity, process stability and product quality, and how are these being addressed?
VK: The fundamental issue is that speed alone does not represent productivity. Increasing line speed can reduce production time, but if it creates higher scrap, dimensional variation, frequent stops or difficult changeovers, the real productivity gain can disappear.
The most important engineering challenge is therefore to increase speed while maintaining stable melt conditions, precise wall thickness and eccentricity, consistent cooling, stable cable tension, reliable take-up and pay-off, accurate synchronization between line components, and fast response to process disturbances.
Modern systems address this through better screw and cross-head design, improved drives, closed-loop measurement, online diameter control and better coordination between the different sections of the line.
Our philosophy is to optimise output per hour of good-quality cable, rather than simply maximising nominal machine speed. Supermac’s equipment incorporates online diameter control and precision pay-off/take-up systems for this reason.
WCI: Energy efficiency, automation, digital monitoring and process control are widely discussed across the industry. Which of these developments are delivering the greatest measurable operational benefits today, and where do you still see a noticeable gap between industry expectations and practical implementation?
VK: The greatest measurable benefits are currently coming from a combination of efficient drives, process optimisation, automation and reduced downtime.
Energy efficiency is important, but manufacturers should look beyond the electrical consumption of the extruder alone. A more efficient machine is one that also reduces start-up waste, improves changeover time, reduces rejected cable and minimizes unplanned downtime.
Digital monitoring and remote diagnostics are also becoming increasingly valuable. They allow manufacturers and machinery suppliers to identify problems faster and reduce the time required for troubleshooting.
Supermac already incorporates IoT-enabled systems, Industry 4.0-compatible controls and online remote service capabilities.
The gap we still see is between what digital technology can technically deliver and what plants are operationally prepared to use. Installing sensors is relatively easy; converting the data into useful process decisions, predictive maintenance and measurable product
Source: wirecable
