ARS | Publication request: Evaluation of three flame retardant (FR) grey cotton blend nonwoven fabrics using micro-scale combustion calorimetry

Submitted to: Fire Sciences Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 21, 2011
Publication Date: January 4, 2012
Citation: Parikh, D.V., Nam, S., He, Q. 2012. Evaluation of three flame retardant (FR) grey cotton blend nonwoven fabrics using micro-scale combustion calorimetry. Fire Sciences Journal. 30(3):187-200.

Interpretive Summary: The development of flame retardant (FR) nonwovens is an important field of investigation since fire protection is required for the safety of people. The fire safety of woven fabrics has been investigated over a long period of time; whereas, nonwovens are a relatively new field. The US Consumer Product Safety Commission (CPSC) is charged with protecting the American public from serious injury and death from the use of consumer products. In order to ensure safety of the public with regard to fire, the standards and regulations are continuously upgraded. The upgrading for the safety of residential mattresses has resulted in use of16 CFR 1633 since July 1, 2007. The high end mattresses have fire barrier/ fire blocker fabrics mainly prepared from the use of high performance fibers, and, thus, the costs are relatively high. The present work describes the eco-friendly FR barrier blend fabrics made of grey cotton NW which can serve the flammability barrier function well for low-to-medium value mattresses. Micro-scale calorimetry is an analytical tool to obtain precise data on peak heat release rate (PHRR) and total heat release (THR) for the analysis of fire performance. These data assist in determining whether a mattress will pass the dual burner test.

Technical Abstract: Unbleached (grey or greige) cotton nonwoven (NW) fabrics (with 12.5% polypropylene scrim) were treated with three phosphate-nitrogen based FR formulations and evaluated with micro-scale combustion calorimetry (MCC). Heat release rate (HRR), Peak heat rate (PHRR), temperature at peak heat release rate (TPHRR), heat release capacity (HRC), total heat release (THR), and char yield were determined. The PHRR and THR results demonstrated that NW fabrics treated with a formulation having higher diammonium phosphate (DAP) and no dimethyloldihydroxyethyleneurea (DMDHEU) were superior to those treated with a formulation containing DMDHEU. NW fabrics treated with these formulations were both superior to the NW fabrics treated with a commercially available flame retardant (FR) formulation. These results were supported by the percentages of phosphorus (P) and nitrogen (N) on these fabrics, confirming that P-N synergism imparts high flame retardancy to the NW fabrics. Grey cotton (untreated) consistently showed better flame resistance than (untreated) bleached cotton. As a result, its FR products had lower HRR/PHRR and other flammability characteristics than those of the bleached cotton. Additionally, grey cotton is softer than bleached cotton and saves the cost of bleaching and waste disposal. These three FR formulations were used primarily to treat the cotton component of the nonwoven blend to make it FR without FR improvement for the polymer component.