Instrumentation and objective evaluation of flammability of textiles by video image processing

On an average, about 2% of a country’s GDP is currently being spent for fire safety. The flammability of textile materials, ecofriendly flame-retardants (FR) and developing the dynamic testing protocol for diversified applications, now becoming a matter of growing concern for the prevention of fire hazards, burns, loss of life and property. Development of materials of inherent flame retardant fibre polymer or flame-retardants (FR) finish is useful for suppressing flame propagation in order to ensure protection against the hostile environment. There are various standard test protocols for the measurement of flaming exposure, ignition temperature, ignition time, flame time, char length, char area, mass loss, etc. However, more accurate and objective measures such as flame propagation rate, flame area catch up are also crucial for objective computation and visualization of flammability profile of the material. In this study, a simple scalable and multi-sample flammability testing equipment aided by video image processing was developed and evaluated. The processing of extracted flame images from the video for better segmentation of a generic fire pattern reported earlier to be complex and challenging. We tried various colour space transformations to obtain a simpler processing instead. It is observed that the transformation of NTSC luminance (Y) and chrominance (I and Q) color components have shown the better results for extracting flame parameters which is congruent with visual inspection. We employed it for obtaining and visualizing an objective and more meaningful flammability profile of textiles that current existing standards lack. Typical cases such as flame area propagation; evaluation after washing, testing of the shrunken area of FR treated textiles and visualization of segmented flame are demonstrated.