104
A. K. Samanta et al.
2.7 Flammability Test
The jute fabric samples cut in size of 2.75 inch wide × 10.0 inch long, were mounted
in a suitable clamp in a standard vertical flammability tester made by MAG-Solvic
–Coimbatore, India. The bottom edge of the fabric was then subjected to burning
using a standard flame for exactly 10 s time. After removal of the flame, the flame
spread time or flame extinguishing time, char length and afterglow time were noted
using a stopwatch and scale. This test was done as per ASTM D6413/D6413M-13b
standard test method [24].
2.8 FTIR Analysis
Selected samples of both untreated and treated jute fabrics were repeatedly washed in
water followed by washing by ethyl alcohol and acetone before taken for analysis for
FTIR spectra as per usual KBr pallete method using Perkin Elmer make SPECTRUMII model of FTIR.
2.9 Method of Optimization of Fire-Retardant Formulation
Using Response Surface Methodology
Response surface methodology (RSM) is a useful statistical tool for understanding
and optimizing interactive effects amongst different process variables for optimizing
the process conditions. Response surface methodology (RSM) thus determines interactive effects between selective experimental input variables for obtaining selective
output response/resultant variables by using suitable statistical design of experiment
model such as UDQM (user-defined quadratic model). This UDQM model [25] was
used earlier for optimization of fire retardant formulations by application of nanoZnO powder along with poly-hydroxy amino siliconate binder on jute. Based on
experimental results of the preliminary study, the average dosages of fire-retardant
chemicals (ammonium sulfamate and urea) and numbers of test run for UDQM model
of experimental design set up under fixed conditions of treatment are determined for
optimizing these two most important input process variables (concentration of ammonium sulfamate and concentration of urea) for maximizing limiting oxygen Index
(LOI) value, minimizing char length and loss of fabric tenacity for corresponding
fire retardant treatment of jute fabric, for optimum results.
As per UDQM model of statistical experimental design, total numbers of test run
required (15) for optimizing 2 input variables, that is, x i (concentration of urea, i.e.,
x 1 or A and concentration of ammonium sulfamate, i.e., x 2 or B) at 5 levels (−2, −
1, 0, + 1, + 2) to determine three resultant response variables (Yi), that is average
LOI value (Y1 or R1), char length in mm (Y2 or R2) and loss of fabric tenacity %
A. K. Samanta et al.
2.7 Flammability Test
The jute fabric samples cut in size of 2.75 inch wide × 10.0 inch long, were mounted
in a suitable clamp in a standard vertical flammability tester made by MAG-Solvic
–Coimbatore, India. The bottom edge of the fabric was then subjected to burning
using a standard flame for exactly 10 s time. After removal of the flame, the flame
spread time or flame extinguishing time, char length and afterglow time were noted
using a stopwatch and scale. This test was done as per ASTM D6413/D6413M-13b
standard test method [24].
2.8 FTIR Analysis
Selected samples of both untreated and treated jute fabrics were repeatedly washed in
water followed by washing by ethyl alcohol and acetone before taken for analysis for
FTIR spectra as per usual KBr pallete method using Perkin Elmer make SPECTRUMII model of FTIR.
2.9 Method of Optimization of Fire-Retardant Formulation
Using Response Surface Methodology
Response surface methodology (RSM) is a useful statistical tool for understanding
and optimizing interactive effects amongst different process variables for optimizing
the process conditions. Response surface methodology (RSM) thus determines interactive effects between selective experimental input variables for obtaining selective
output response/resultant variables by using suitable statistical design of experiment
model such as UDQM (user-defined quadratic model). This UDQM model [25] was
used earlier for optimization of fire retardant formulations by application of nanoZnO powder along with poly-hydroxy amino siliconate binder on jute. Based on
experimental results of the preliminary study, the average dosages of fire-retardant
chemicals (ammonium sulfamate and urea) and numbers of test run for UDQM model
of experimental design set up under fixed conditions of treatment are determined for
optimizing these two most important input process variables (concentration of ammonium sulfamate and concentration of urea) for maximizing limiting oxygen Index
(LOI) value, minimizing char length and loss of fabric tenacity for corresponding
fire retardant treatment of jute fabric, for optimum results.
As per UDQM model of statistical experimental design, total numbers of test run
required (15) for optimizing 2 input variables, that is, x i (concentration of urea, i.e.,
x 1 or A and concentration of ammonium sulfamate, i.e., x 2 or B) at 5 levels (−2, −
1, 0, + 1, + 2) to determine three resultant response variables (Yi), that is average
LOI value (Y1 or R1), char length in mm (Y2 or R2) and loss of fabric tenacity %