Section snippets
Experimental procedure
120 ± 5 gsm para-aramid was used as base fabric and coated with four barrier chemicals viz; NR, PU, Neoprene and Hypalon to make 300 and 500 gsm (±5 %) weight coated fabrics and coating was carried out on both sides using Doctor Blade method [5]. All eight samples were tested by UL-94 V [6] and NFPA-701 methods [7] and results were compared with base fabric.
UL-94 V test
[8] UL-94 vertical test is one of the important FR tests routinely carried out to assess the self-extinguishing time of vertically suspended materials. Cotton wad (or surgical cotton) is placed below burning sample to observe dripping. The substrates are rated (Table 1) based on following observations;
V-0 - Dripping is not observed and flame extinguishes within 10 s.
V-1 - Dripping is not observed and flame extinguishes within 30 s.
V-2 - Dripping is observed but flame extinguishes within 30 s.
Conclusions
In this research, inherently flame-retardant base fabric viz, para-aramid (or Kevlar or Twaron) was coated with four barrier chemicals. Out of four barrier chemicals, two chemicals burned readily and two offered flame resistance due to presence of chlorine atom in their polymeric chain. In our experiments the coated fabrics were taken in increasing coating thickness (and hence weight) viz; 300 and 500 gsm. The coated fabrics were subjected to UL-94 V and NFPA-701 tests to know the best FR
CRediT authorship contribution statement
RG Revaiah: Methodology, Validation, Writing – original draft. TM Kotresh: Conceptualization. Balasubramanian Kandasubramanian: Supervision, Writing – review & editing.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgement
The authors thank Director General Life sciences and Vice Chancellor, DIAT, Pune for constant encouragement.
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