Crystallized meta-aramid blends for flash fire and arc protection having improved comfort
View Patent ↗A yarn, fabric, and garment suitable for use in arc and flame protection and having improved flash fire protection consisting essentially of from (a) 50 to 80 weight percent meta-aramid fiber having a degree of crystallinity of at least 20%, (b) 10 to 30 weight percent flame-retardant rayon fiber, (c) 10 to 20 weight percent modacrylic fiber, (d) 0 to 5 weight percent para-aramid fiber, and (e) 0 to 3 weight percent antistatic fiber based on the total weight of components (a), (b), (c), (d), and (e). In one embodiment, garments made from the yarn provide thermal protection such that a wearer would experience less than a 65 percent predicted body burn when exposed to a flash fire exposure of 4 seconds per ASTM F1930, while maintaining a Category 2 arc rating.
1. A yarn for use in arc and flame protection consisting of:
(a) 50 to 80 weight percent meta-aramid fiber having a degree of crystallinity of at least 20%;
(b) 10 to 30 weight percent flame-retardant rayon fiber;
(c) 10 to 20 weight percent modacrylic fiber;
(d) 0 to 5 weight percent para-aramid fiber; and
(e) 0 to 3 weight percent antistatic fiber;
said percentages on the basis of components (a), (b), (c), (d) and (e).
2. The yarn of claim 1 with the meta-aramid fiber has a degree of crystallinity in a range from 20 to 50%.
3. A fabric suitable for use in arc and flame protection comprising a yarn consisting of:
(a) 50 to 80 weight percent meta-aramid fiber having a degree of crystallinity of at least 20%;
(b) 10 to 30 weight percent flame-retardant rayon fiber;
(c) 10 to 20weight percent modacrylic fiber;
(d) 0 to 5 weight percent para-aramid fiber; and
(e) 0 to 3 weight percent antistatic fiber;
said percentages on the basis of components (a), (b), (c), (d) and (e);
the fabric having a basis weight in the range of 186.5 to 237 grams per square meter (5.5 to 7 ounces per square yard).
4. The fabric of claim 3 wherein the meta-aramid fiber has a degree of crystallinity in a range from 20 to 50%.
5. The fabric of claim 3 having a char length according to ASTM D-6413-99 of less than 6 inches.
6. The fabric of claim 3 having arc resistance according to ASTM F-1959-99 of at least 1.1 calories per square centimeter per ounce per square yard of fabric.
7. The fabric of claim 6 wherein the arc resistance is at least 1.3 calories per square centimeter per ounce per square yard of fabric.