In the case of roofing with HFFR compounds, this solution has always been a drawback, since these quantities of carbon black, despite protecting the polymer, worsen the mechanical properties of a type of compound that, due to its formulation with high percentages of flame retardant fillers, is already at the limit in terms of mechanical properties. However, Delta Tecnic has overcome this obstacle with a masterbatch that incorporates a smaller quantity of carbon black, along with UV filter additives to protect the polymer against the harmful effects of the sun.
This masterbatch is dosed at just 2%, making it a cost-effective and efficient option for cable manufacturers.
Manuel Miret, Area Manager & New Product Developer at Delta Tecnic, states: “We have been offering this innovation for over five years, and the results speak for themselves: excellent acceptance and superior performance compared to standard solutions.”
When a specific carbon black content is required, such as 2.5% in a polymer filler, understanding how to properly dose the masterbatch is essential. If starting with a masterbatch containing 40% carbon black, the dosage must be adjusted to 6.25% to achieve the necessary concentration in the cable jacket. This precise dosing process is critical to ensuring the material's integrity and its ability to effectively resist fire.
The European CPR regulation establishes standards for evaluating the behavior of plastics used in cables when exposed to fire. One of the key requirements is that the cables must not drip when burned, which necessitates incorporating significant quantities of flame retardants into their composition.
By developing a masterbatch with a lower amount of carbon black and UV filter additives, the company achieves an optimal balance between fire resistance and mechanical properties.
