Examination of Thermal Damage Simulated on Natural, Blended and Synthetic Clothing by Two Different Thermal Sources

Abstract

Introduction: Forensic examination of burned or charred clothing plays a crucial role in incidents related to arson, accidental fires, homicidal burn incidents, and electrocution. This field provides valuable acumens into fire dynamics, ignition sources, and the sequence of thermal events. Different textile fibres respond differently to thermal exposure depending on their composition and structure. By identifying the characteristic damage patterns generated by various thermal sources, forensic experts can identify the probable origin and mechanism of clothing damage in such cases.

Objectives: To examine and compare the thermal degradation patterns of different clothing fabrics when exposed to two distinct thermal sources, and to identify characteristic damage features that can assist in determining the source of thermal damage during forensic investigations.

Methods: Twelve types of clothing fabrics covering natural, synthetic and blended fabrics were selected for analysis and were subjected to controlled thermal exposure under two experimental conditions: (i) direct flame exposure using an LPG Bunsen burner and (ii) spark-induced exposure using an arc welding apparatus. Microscopic examination was conducted to observe the morphology of thermal damage, and fifteen distinct fibre damage characteristics were documented. Statistical analysis was performed using Analysis of Variance (ANOVA) to evaluate the influence of fabric type and damage parameters on the observed thermal effects.

Results: The statistical analysis revealed a significant effect of fabric type on flame-induced damage (F = 214.34 > F₍crit₎ = 2.01), indicating that different fabrics exhibit distinct responses to direct flame exposure. In contrast, spark-induced damage showed significant variation based on damage parameters (F = 15.16 > F₍crit₎ = 2.58) rather than fabric type, suggesting that the mechanism and extent of damage in spark exposure differs from that of direct flame. Microscopic examination demonstrated observable variations in damage morphology across fabric types and thermal sources.

Conclusions: The study demonstrates that different thermal sources produce distinguishable damage patterns in clothing fabrics, and these variations can be statistically validated. The findings provide useful forensic indicators for differentiating between flame-induced and spark-induced damage, thereby aiding in the reconstruction of fire-related incidents and determination of the source of clothing damage in forensic investigations.