Cables used in buildings, automotive public transportation and power networks are required to have strong fire resistance and low smoke generation. Halogen Free Flame Retardant (HFFR*) compounds are made of polyethylene, Lotryl®/Evatane® copolymers, high mineral fillers loading (ATH or MDH) and Orevac®/Lotader® coupling agents. Coupling agents facilitate compounding with high filler content, as well as improve flame retardancy and mechanical properties (before and after ageing).
* Also called: Low smoke non halogen (LSNH) / Low smoke 0-halogen (LS0H, LSZH) / Eco-product (In Japan)
HFFR (Halogen Free Flame Retardants) compounds are replacing PVC in more and more transportation, construction and military applications. Their formulations are based on polyolefins blends including Lotryl® or Evatane® copolymers, polyethylene, high mineral fillers loading (ATH or MDH) and coupling agents to optimize flame retardancy, mechanical properties and cost.
● Flexible and polar copolymers such as Evatane or Lotryl ensure the base polymeric resins can accept a high loading of mineral fillers;
● Orevac or Lotader coupling agents are necessary to improve the mechanical performance of the highly filled compounds.
The recommended grades are:
- Evatane® with 28% vinyl acetate content
- Lotryl® with 24% or more methyl acrylate content
- Lotader® 3210 coupling agent
- Orevac® 18343 coupling agent