VDE 0295 Class 5 cable

To understand why the ÖLFLEX HEAT 180 EWKF cable uses silicone and why generic silicone cannot match specialized EWKF performance, let me start with a fundamental question about material chemistry that many engineers never consciously consider: what is the difference between silicone and the polyurethane, polyvinyl chloride, and other organic polymers we discussed in previous technical guides? The answer lies in the fundamental backbone structure of the polymer chain itself. Most common cable insulation materials—polyurethane (PUR), polyvinyl chloride (PVC), thermoplastic elastomer (TPE)—are organic polymers built from long chains of carbon atoms bonded together. Carbon is chemically very stable and provides the flexibility and electrical properties these cables need. However, carbon-based polymers have a critical limitation: at elevated temperatures, the carbon bonds begin breaking down through a process called thermal degradation. As temperature increases, thermal energy causes the chemical bonds holding the polymer chain together to vibrate more intensely. Eventually, if temperature gets high enough, the vibration becomes so vigorous that bonds actually rupture. Once bonds break, the polymer chain fragments into smaller pieces, losing all the properties that made it useful as an insulation material. This thermal breakdown becomes severe around 150°C for most organic polymers. Silicone, by contrast, is built from a fundamentally different backbone: alternating silicon and oxygen atoms (Si-O-Si-O-Si-O…). Silicon-oxygen bonds are significantly more thermally stable than carbon-carbon bonds. The silicon-oxygen bond is stronger and vibrates less readily at high temperatures. As a result, silicone polymers can tolerate sustained temperatures of 180°C, 200°C, or even higher without the carbon-carbon bonds breaking down. This is the fundamental reason silicone is essential for cables used in industrial furnaces, steel mills, and other extreme thermal environments where organic polymers would literally fall apart. Now here is the critical insight for this guide: not all silicone formulations are created equal. Generic silicone, while thermally more stable than organic polymers, still includes various additives and plasticizers that are organic (carbon-based) compounds. These additives can themselves degrade at high temperature, leaching out of the silicone matrix or chemically breaking down and causing the silicone’s properties to deteriorate. Specialized EWKF silicone addresses this problem by engineering the entire formulation—not just the silicone backbone but also all the additives, plasticizers, and crosslinking chemistry—to maintain stability at extreme temperatures. This is why EWKF silicone achieves 180°C continuous operation while generic silicone degrades progressively and fails prematurely.