Serge Bourbigot, Centrale Lille / UMET France, indicated an increase in the number of publications addressing intumescents for fire safety of around 4x from 2000 to 2020*. He summarised tests using different amounts of expandable graphite (EG) and conventional intumescent PIN FR in polypropylene (IFR). The conventional intumescent was a combination of ammonium polyphosphate and a char former. Lab scale results showed that at 10% total intumescent loading, fire performance was similar best for 10% EG, and also good for 5% EG – 5% IFR or 10% IFR, whereas fire performance was not good for 1% EG – 9% IFR. This was probably because low levels of EG generated faults (“worms”) in the intumescent foam layer. Intumescent PIN-FR was also successfully tested in zero-gravity, for the first time. He also presented results of trials to develop a small-scale test of jet-fire resistance, showing initially good coherence with full-scale jet-fire tests (ISO 22899-1).
* pinfa note: this increase is in in fact similar to the inflation of the total number of scientific papers published annually worldwide, which has also increased by nearly 4x since 2000. “Over-optimization of academic publishing metrics; Observing Goodhart’s Law in action”, M. Fire, C. Guestrin, 2019 http://dx.doi.org/10.1093/gigascience/giz053