The key observations reported in this paper are supported by the body of literature reviewed and cited.
The clearest quantitative multifunctional results are reported in at least two of the cited articles. It is observed that treating wool with 3.5% o.w.f. reactive nonionic softener at 130 °C for 5 min increases surface smoothness by 21.7% and felting-shrinkage resistance by 90%. This treatment retained air permeability and dyeability, and the finish remained durable through washing, although smoothness suffered somewhat after extended laundering. Increasing phosphorus flame retardant to 8 wt% reduced nonwoven fire damage distance by up to 60%, while 3 wt% ZnO reduced bacterial infestation caused by S. aureus and K. pneumoniae by 99.96% and 98.79%, respectively. The most effective weight compositions for treatments involving ZNO and PFR were 3 wt% ZnO and 5 wt% PFR.
The most recurrent gaps, as stated in the literature, are wash durability, scale-up and pre-industrial validation, comfort/softness loss, cost-effectiveness, and end-of-life design for FR textiles. Those gaps were identified by multiple researchers.