Flame-resistant fiber blend, yarn, and fabric, and method for making same
A fiber blend, a yarn spun from the fiber blend, and a fabric made from the yarn, wherein the fiber blend is a blend of staple fibers comprising non-FR cellulosic fibers, modacrylic fibers, and aramid fibers intimately blended together. The blend is such that the cellulosic fibers constitute at least about 45 wt. % of the fiber blend, a weight ratio of the modacrylic fibers to the cellulosic fibers is at least 0.8 but not exceeding 1.0, and the aramid fibers make up no more than 15 wt. % of the fiber blend.
1. A flame-resistant intimate fiber blend of staple fibers comprising non-FR cellulosic fibers, modacrylic fibers, and aramid fibers intimately blended together, wherein:
the cellulosic fibers constitute at least 45 wt. % to at most 54 wt. % of the fiber blend;
the modacrylic fibers constitute at least 36 wt. % to at most 49 wt. % of the fiber blend, where a weight ratio of the modacrylic fibers to the cellulosic fibers is at least 0.8 but less than 1.0; and
the aramid fibers make up at least 3 wt. % to at most 15 wt. % of the fiber blend.
2. The flame-resistant intimate fiber blend of claim 1 , wherein the aramid fibers constitute para-aramid fibers.
3. The flame-resistant intimate fiber blend of claim 2 , wherein the non-FR cellulosic fibers comprise non-FR synthetic cellulosic fibers.
4. The flame-resistant intimate fiber blend of claim 3 , wherein the blend comprises:
45 wt. % to 50 wt. % of the cellulosic fibers;
38 wt. % to 45 wt. % of the modacrylic fibers; and
wt. % to 15 wt. % of the para-aramid fibers.
5. The flame-resistant intimate fiber blend of claim 3 , wherein the blend comprises:
45 wt. % to 50 wt. % of the cellulosic fibers;
38 wt. % to 42 wt. % of the modacrylic fibers; and
10 wt. % to 15 wt. % of the para-aramid fibers.
6. A flame-resistant fabric constructed from yarns spun from the intimate fiber blend of claim 1 , the fabric having a weight of 4.0 oz./yd 2 to 10.5 oz./yd 2 .
7. The flame-resistant fabric of claim 6 , having a weight of 6.5 oz./yd 2 to 9.0 oz./yd 2 .
8. The flame-resistant fabric of claim 6 , wherein the fabric is woven.
9. The flame-resistant fabric of claim 6 , wherein the fabric has an average char length less than 2.5 inches when tested in accordance with ASTM D6413.
10. The flame-resistant fabric of claim 6 , wherein the fabric has a thermal shrinkage less than 3.0% when tested in accordance with NFPA 2112-2012.
11. A garment constructed from the flame-resistant fabric of claim 6 .
12. A method of making a flame-resistant fabric, comprising the steps of:
forming an intimate blend of staple fibers, the staple fibers comprising non-FR cellulosic fibers, modacrylic fibers, and aramid fibers, wherein:
the cellulosic fibers constitute at least 45 wt. % to at most 54 wt. % of the fiber blend;
the modacrylic fibers constitute at least 36 wt. % to at most 49 wt. % of the fiber blend, where a weight ratio of the modacrylic fibers to the cellulosic fibers is at least 0.8 but less than 1.0; and
the aramid fibers make up at least 3 wt. % to at most 15 wt. % of the fiber blend;
spinning the blend of staple fibers into yarn; and
knitting or weaving the yarn to form fabric.
13. The method of claim 12 , further comprising the steps of:
dyeing the modacrylic fibers with basic dye; and
dyeing the cellulosic fibers with fiber reactive or direct dye.
14. The method of claim 13 , further comprising using a dye fixative to fix the dyes.
15. The method of claim 12 , comprising weaving the yarn in a twill pattern to form the fabric.
16. The method of claim 12 , wherein the spinning step comprises open-end spinning the blend of staple filers into yarn.
17. The method of claim 12 , wherein the spinning step comprises ring spinning the blend of staple fibers into yarn.
18. The method of claim 12 , wherein the spinning step comprises air jet spinning the blend of staple fibers into yarn.
19. The method of claim 12 , further comprising the step of calendaring the fabric to reduce air permeability of the fabric.
20. A yarn formed from a blend of staple fibers comprising non-FR cellulosic fibers, modacrylic fibers, and aramid fibers intimately blended together, wherein:
the cellulosic fibers constitute at least 45 wt. % to at most 54 wt. % of the fiber blend;
the modacrylic fibers constitute at least 36 wt. % to at most 49 wt. % of the fiber blend, where a weight ratio of the modacrylic fibers to the cellulosic fibers is at least 0.8 but less than 1.0; and
the aramid fibers make up at least 3 wt. % to at most 15 wt. % of the fiber blend.
21. The yarn of claim 20 , wherein the yarn is ring-spun.
22. The yarn of claim 20 , wherein the yarn is air jet-spun.
23. The yarn of claim 20 , wherein the yarn is open-end spun.