Flame blocking liner materials
A fire blocking non-woven textile containing a first carded web of char-forming fibers containing aramid or melamine/formaldehyde fiber and a second carded web of oxygen-depleting fibers comprising a blend of polyacrylonitrile copolymer with a halogen comonomer and a polyester polymer. The webs may be needled-punched or thermally bonded and remain as separate layers separating the action of the char forming and oxygen depleting layers to optimize char strength, provide a light weight product, which may satisfy 16 CFR 1633 at thicknesses of up to 3.0 mm.
1. A process for forming a two layer fire blocking non-woven textile comprising:
supplying a first carded web providing a first layer of char-forming fibers comprising 5-25% by weight aramid and 95%-75% by weight a viscose fiber containing silicic acid wherein said carded web has a basis weight of 100-350 g/m 2 and a thickness of 0.1 mm to 1.5 mm;
supplying a second carded web providing a second layer of oxygen-depleting fibers comprising a blend of polyacrylonitrile copolymer with a halogen comonomer and a polyester polymer wherein said polyacrylonitrile copolymer is present in said second carded web at a level of 70% to 30% by weight and said polyester copolymer is present at a level of 30% to 70% by weight and said second carded web has a basis weight of 100-350 g/m 2 and said second carded web has a thickness of 0.1 mm to 1.5 mm;
forming said two layer fire blocking non-woven textile by the method consisting of feeding said first and second carded web into a needle loom and needle-punching the entirety of said first carded web to said second carded web and forming said two-layer textile wherein said char-forming fibers of said first layer are present in said second layer at a level of 0-5.0% by weight and said oxygen-depleting fibers of said second layer being present in said first layer at a level of 0 to 5.0% by weight; and
wherein said non-woven textile has a maximum thickness of 3.0 mm and when applied to a mattress, according to 16 CFR 1633, indicates a peak heat release rate of less than 200 kW within 30 minutes of testing and the total energy released of no more than 15 MJ for the first 10 minutes of testing.
2. The process of claim 1 wherein said first carded web has a basis weight of 110 g/m 2 and said second carded web as a basis weight of 110 g/m 2 .
3. The process of claim 1 wherein said first carded web has a basis weight of 70 g/m 2 and said second carded web has a basis weight of 70 g/m 2 .
4. The process of claim 2 wherein each carded web is present at a thickness of 1.25 mm.
5. The process of claim 2 wherein said two layer fire blocking non-woven textile is applied to a mattress of a latex of natural rubber.
6. The process of claim 2 wherein said two layer fire blocking non-woven textile has a thickness of 1.5 mm to 2.5 mm.