Concentrated Solar Power, Getting to the heart of energy - LEONI

14 Products & Solutionswww.leoni-communication-infrastructure.comCable plasticsCables and plastics are inseparable nowadays, but this has notalways been the case. The first-ever copper conductors were laidin wooden channels in the 17 th century, but it was soon discoveredthat natural rubber in vulkanized (cross-linked) form is anexcellent insulator. Gutta-percha, a close relative of rubber, verysoon took over this task when the extruder we know today wasinvented in a basic form in 1846.Rigid PVC was used as a replacement for horn until it was plasticizedfor the first time in 1935, after which PVC went from strengthto strength. In 1948, PVC was the most-produced plastic in theworld, and it has remained so until this day. Then, when even recordswere made of PVC, which ultimately replaced shellac, everychild knew what it was. This is why the classical record is stillknown as “vinyl” today.Like so many other things in life, PVC can be a blessing and acurse. The advantage of rigid PVC as a very stable chemical compound– and the resulting durability – is also its biggest disadvantage.PVC does not rot. Sunlight does not decompose thesurface and the mechanical properties are not impaired. Seawaterand air have virtually no effect on rigid PVC. For this reasonand as a result of the reasonable costs for raw materials, rigid PVCis still the principal material used for products with a long servicelife such as window-frames or drainpipes.Catastrophic fires in the 1980s and 1990s led to a rethink of theuse of PVC as the material of choice for cables of all types. Chlorinereleased during a fire can react with water or atmospherichumidity to become hydrochloric acid, releasing highly poisonous,corrosive combustion gases in the process. For this reason,the European countries have banned PVC cables from high-risk,high-investment buildings (airports, shopping centres, hospitalsetc.). Polyethylene was out of the question as a replacement – incontrast to PVC, PE is not flame-retardant and has a very highthermal load.