Study on the thermal behavior of various fibers

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 14580127
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 家政学一般(含衣・住環境)
• Research Institution: Japan Women's University
• Principal Investigator: MASUKO Fumi Japan Women's University, Faculty of Home Economics, Professor, 家政学部, 教授 (10060708)
• Co-Investigator(Kenkyū-buntansha): MITANI Chizu Japan Women's University, Faculty of Home Economics, assistant, 家政学部, 助手 (40247094)
• Project Period (FY): 2002 – 2004
• Keywords: flammability / Limiting Oxygen Indices(LOI) / smoke emission / fabric / ammonium phosphate / sodium phosphate / 熱分解温度

Research Abstract

Purpose It is well known that smoke and many kinds of thermal decomposition gases are formed during burning of textile materials. However details of smoke emission and thermal decomposition gases are not well clarified. In this work, relationship between flammability and smoke emission is studied with many kinds of textile fabrics and 100% cotton fabrics treated with ammonium or sodium phosphates for flame resistance.
Method The samples used in this study were 30 kinds of various untreated fabrics and 100% cotton fabrics treated with ammonium or sodium phosphates for flame proofing. Limiting oxygen indices(LOI) and amounts of smoke formed were determined with a simultaneous LOI and smoke density measuring apparatus. After-burn time and after-glow time were determined with a 45-degree flammability tester, in a similar way to JIS L 1091 (Method A-1). Thermogravimetry(TG) and differential thermal analysis(DTA) were made to study thermal behavior of these fabrics with a simultaneous TG/DTA apparatus.
Results LOI values of thirty pure and blend fabrics were determined and the amounts of smoke formed from these samples were studied under artificial air in which the oxygen concentration was set equal to that of the LOI of the sample. The amounts of smoke formed from cellulose fabrics, which were easily flammable, were low while those from silk and wool fabrics, which were flammable, were moderately high. Polyester/cotton blend fabrics showed a higher amount of smoke than those of component fibers, 30 times that of cotton and 7 times that of polyester fabrics. The LOI value of cotton fabrics treated with sodium phosphate was ca 22 slightly higher than that of untreated cotton fabrics. The LOI values of cotton fabrics treated with ammonium phosphate were equal to or higher than 26,indicating that they were flame resistant fiber. The amounts of smoke from cotton fabrics treated with sodium phosphate were 1/20〜1/20 of that of untreated cotton. The amounts of smoke from the cotton fabrics treated with ammonium phosphate were 4〜16 times that of untreated one in most cases. The cotton fabrics with a high add-on of ammonium phosphate (P,7% owf ; N,3.5% owf) gave a very high amount of smoke : higher than 100 times of that of untreated cotton fabrics.