Burn protective materials
View Patent ↗A method is described for reducing the afterflame of a flammable, meltable material. A textile composite is described comprising an outer textile comprising a flammable, meltable material, and a heat reactive material comprising a polymer resin-expandable graphite mixture.
1. A method of reducing the percent burn of a garment in a 4-second Garment Flammability Test (4-second Pyroman exposure) by at least 10% comprising:
a) providing a textile composite comprising:
a meltable outer textile comprising meltable material;
a thermally stable convective barrier comprising expanded polytetrafluoroethylene or polytetrafluoroethylene; and
a heat reactive material between the meltable outer textile and the thermally stable convective barrier, wherein the heat reactive material comprises a polyurethane-expandable graphite mixture;
b) constructing a garment with an outer surface of said garment comprising said outer textile; and
c) with the outer surface of the outer textile oriented toward a flame, subjecting the garment to a 4-second Pyroman exposure test,
wherein the percent body burn is decreased by at least 10 percentage points in the 4-second Pyroman exposure test compared to a garment constructed without the heat reactive material between the meltable outer textile and the thermally stable convective barrier.
2. The method of claim 1 , wherein the polyurethane-expandable graphite mixture is applied as discrete dots that cover an area of less than 50%.
3. The method of claim 1 , wherein the polyurethane-expandable graphite mixture bonds the meltable outer textile and the thermally stable convective barrier.
4. The method of claim 1 , wherein the polyurethane-expandable graphite mixture comprises less than 50 wt % of the expandable graphite.
5. The method of claim 1 , wherein upon exposing the meltable outer textile to heat sufficient to melt said meltable outer textile, the heat reactive material expands and absorbs the melt of said meltable outer textile, forming a composite of said meltable outer textile and said expanded heat reactive material.
6. The method of claim 1 , wherein said expandable graphite has an expansion of at least 900 μm upon heating to about 280° C.
7. The method of claim 1 , wherein an outer surface of said meltable outer textile has an afterflame time of less than 15 seconds.
8. The method of claim 1 , wherein the textile composite has a break-open time that is at least 20 seconds greater than the break-open time of the meltable outer textile without a heat reactive material.
9. The method of claim 1 , wherein said meltable outer textile consists of said meltable material.