Low-cost, zero halogen optical cable jacket to meet MIL-C-85045 and Ul-910 standards

摘要

The U.S. Navy has identified the need to develop zero halogen, fire-resistant optical cable jackets (OCJs) that meet both UL 910 and MIL-PRF-85045 fire safety standards. In this Phase I SBIR program, a series of zero halogen, intumescent optical cable jacket (IOCJ) compounds were produced by blending intumescent fire retardant additives (IFRAs) into polyethylene copolymer in the presence of polymeric coupling agent (PCA). Candidate IFRAs included a commercial blend of ammonium polyphosphate/pentaerithritol/melamine (Antiblaze NP), exfoliated clay nanoparticles and Aluminum Trihydrate (ATH) at loadings higher than 65 wt%. Vertical Burn tests indicated that selected IOCJ test specimens self-extinguished within less than 5 seconds with no flaming drips, little smoke and no halogen-containing acid gases. In contrast, commercial OCJ samples flamed for 85 to 185 seconds and smoldered for 140 seconds after self-extinguishment. Selected IOCJ test specimens were also hand-creasable without cracking. E-beam crosslinking improved IOCJ fire performance by eliminating flaming drips. Cone Calorimeter testing (70 kW/cm{sup}2) indicated that IOCJ test specimens exhibited longer time to sustained flame and lower average mass loss rate, smoke generation, average heat release rates and peak heat release rates than commercial OCJ samples. Results of our effort to date will be discussed.