New Formulations for PVC Cables
Since 1950s, electric cables made from PVC have been satisfactorily produced on the market and used in a wide range of applications. Each application has specific requirements which lead the manufacturer to produce cables with specific characteristics related to what they have to transmit, and where they are used. Today, cables are also made by combining different polymers to optimize their required performance. As far as the use of PVC is concerned, at least three specific and different uses can be identified:
- External sheath
- Internal cable fi lling
- Single conductor insulation
Each of these three uses involves a dedicated and detailed formulation. Preparing a compound to suit the end use is neither easy nor simple, and therefore a formulation dedicated to a sheath, a filler or an insulation is composed on average of about a dozen substances that are introduced to satisfy the ease of production, the performance that the end user is looking for and the characteristics that the normative references impose. In building and construction, for example, the primary objective is to define the ideal behavior of the materials for a correct choice of components, and certainly fire safety characteristics are of paramount importance.