Protective fabric resistant to molten metal splash
Flame resistant fabrics are provided that exhibit improved protection from molten metal spills, metal splatter, electric arc, and related thermal hazards illustratively including open flame and radiant heat. The flame resistant fabrics are made from a combination of cellulosic fibers and thermoplastic fibers, where the flame resistant fabric forms a char layer that does not become brittle when contacted by molten metal, metal splatter, electric arc, and related thermal hazards. By not becoming brittle the likelihood of break out of the fabric is minimized, thereby improving the level of protection to the user. As a result, the flame resistant fabric retains the desirable properties of fibers formed of organic materials in terms of comfort, weight, and durability.
1 . A protective fabric resistant to molten metal splash, the fabric comprising: a combination of cellulosic fibers and thermoplastic fibers in a yarn that include both the cellulosic fibers and the thermoplastic fibers in both the warp and fill directions where upon contact with a molten metal, the cellulose fibers are configured to char with kinetic rapidity relative to the thermoplastic fibers to generate a flexible, non-brittle and adherent char layer that deposits on proximal thermoplastic fibers to protect the thermoplastic fibers, the adherent char layer adapted to alter the surface energy of the fabric to minimize contact time with the molten metal to shed the molten metal wherein the thermoplastic fibers are present from more than 30 to 50 volume percent.
2 . The fabric of claim 1 wherein the thermoplastic fiber and the cellulosic fiber are in direct contact between adjacent fibers thereof or the thermoplastic fiber and the cellulosic fiber are separated by a distance of 1 to 3 fiber diameters therebetween.
3 . The fabric of claim 1 wherein the thermoplastic fiber and the cellulosic fiber are spun together to form a yarn woven into the form of the fabric.
4 . The fabric of claim 1 wherein the fabric is devoid of wool.
5 . The fabric of claim 1 wherein the cellulosic fibers are formed of at least one of cotton, linen, rayon, bamboo, hemp, sisal, jute, or a cellulose ether reaction product of any of the aforementioned.
6 . The fabric of claim 5 wherein the cellulose ether reaction product is one of methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, or carboxymethylcellulose (CMC).
7 . The fabric of claim 1 wherein the thermoplastic fiber and the cellulosic fiber are present in adjacent layers.
8 . The fabric of claim 7 wherein the cellulosic fiber is in an outer layer of the adjacent layers as measured by being the layer first contacted by the molten metal.
9 . The fabric of claim 1 wherein the thermoplastic fiber and the cellulosic fiber independently have fiber diameters of 1.5 denier.
10 . The fabric of claim 1 wherein a number average fiber diameter ratio of the thermoplastic fiber to the cellulosic fiber is between 0.8:1 to 1.2:1.
11 . A process of protecting a volume from a melt comprising:
forming an article from a fabric of claim 1 ; and
exposing the article to a melt, an electric arc, or a combination thereof to form an adherent char on an outer surface of the article.
12 . The process of claim 11 wherein the volume defines equipment and the article is a shield or cover.
13 . The process of claim 11 wherein the outer surface is enriched in cellulosics relative to an inner surface.
14 . The process of claim 11 wherein the melt is molten glass or molten rock.
15 . The process of claim 11 further comprising inverting the article to form an inverted article and then exposing the inverted article to a melt, an electric arc, or a combination thereof.
16 . The process of claim 11 wherein the article is one of an apron, a cape, a sleeve, a bib, a chap, a coat, a coverall, a glove, a hood, a neck guard, pants, a sleeve, or spats.
17 . The process of claim 11 wherein the article has an arc rating of at least 8.5 cal/cm 2 and an arc flash personal protection equipment category rating of 2 per standard NFPA70E Edition 2015 Table 130.7(C)(16).
18 . The process of claim 11 wherein the melt is molten metal.
19 . The process of claim 18 wherein the molten metal is iron or aluminum.