酒精在常见可燃地面材料燃烧痕迹特征规律研究

易燃液体燃烧痕迹识别对助燃剂放火火灾调查至关重要。选用丙纶地毯和PVC地板革作为纤维和塑料地板的代表,以工业酒精作为易挥发助燃剂的代表,研究酒精用量、灭火方式等对燃烧痕迹形成及痕迹稳定性的影响。通过与未加载酒精的痕迹对比,发现丙纶地毯因热稳定性较差,燃烧后往往能形成烧坑或烧洞,其燃烧轮廓以典型的灰化形式存在,加载酒精的部位熔融严重,与地面紧紧粘连在一起;PVC地板革因为表面光滑,酒精在其表面不断流淌,燃烧后会留下清晰的轮廓,类似于细线状的印痕,而地板革本身基本不会燃烧。燃烧熄灭的方式也会对其炭化程度、燃烧图痕、残余形状产生影响。

Characteristic features of the trace patterns left-over by the burning of the room-flooring materials ignited by industrial alcohol

The present paper is aimed at reporting its investigation and identification of the characteristic features of the trace patterns left-over by the combustion of the room-flooring materials ignited by the industrial alcohol so as to provide references to the fire investigators to collect the trace evidence and disclose the real fire-leading causes.As is known,industrial alcohol has often been used in arson as one of the flammable liquid materials.What is more,due to its typical fluidity and volatility,it tends to result in some particular combustion patterns in the fire-accident scenario.Here,we would like to choose two flooring materials,the PP (polypropylene) carpet and the PVC coil floorings,to trace the combustion pattern characteristics through simulating the fire scene in a closely simulated form to the real status-in-situ.And,then,we have made a summary of the changing regularities of the pattern characteristics on different material surfaces through comparing the combustion patterns with and without the said industrial alcohol while attention has been paid to the fire extinguishing manners in the paper.The results of our investigation show that the PP carpet floor was seriously carbonized,and the typical combustion holes with ash appearance were easily to be formed due to the poor thermal stability of PP.Furthermore,the parts of the carpet loaded with the industrial alcohol were likely to get seriously deformed,or to get melted and then stuck tightly to the ground surface.On the other hand,for PVC floorings,the industrial alcohol tends to flow on the smooth surface of the compact surface rather than absorbed by it,leaving somewhat typical flowing traces with the noticeable boundary.Moreover,due to the self-extinguishing feature of PVC,little carbide would be formed and left-over on the floorings.The fire extinguishing style has a great impact on the combustion patterns,such as the carbonized degree,the residual shape and the fire traces.From what is said above,the finding results of the paper can be expected to provide an important guide for the investigation of arson applied the industrial alcohol as the indexical identifier to determine the fire accident scenario in the fire disaster field.