Effect Of Layering And Aging On The Combustion Characteristics Of Latex Foam

Upholstered furniture usually has a typical two-layer structure with an ultra-thin surface layer.The surface layer has a significant effect on the overall fire performance of upholstered furniture.In this paper,the latex foam of the mattress filling material is selected as the research object.The fire spread law of latex sponges with different thickness conditions(d=1,2,5cm)was explored.The experimental results show that the flame propagation laws of the hot thin and hot thick latex sponges are different.The latex sponge with a thickness of 2cm has a high fire risk.Its flame spread rate,maximum flame height,maximum mass loss rate and maximum temperature are 2.93×10^-3M/s,851.88mm,1.83g/s,948?.On the one hand,this may be due to the different flame propagation mechanism,leading to different preheating zones,the unburned area at the bottom of the hot thin latex sponge is located at the four edges,while the unburned area at the bottom of the hot thick latex sponge is located in the center layer of the bottom and is circular.The cone calorimeter was used to compare the characteristics of heat release rate,ignition time,and mass loss rate of latex foam under 40k W/m² radiation conditions under six textile fabrics covering hemp,polyester,cotton,blended,silk,and cashmere Parameters,analyze the four fire risk parameters of fire growth index(FGI),heat release index(THRI),smoke index(TSPI)and toxic gas generation rate index(Tox GI)by using analytic hierarchy process The fire hazard of latex foam under different coverage conditions was evaluated item by item.The results showed that:blended,hemp,polyester,cotton,cashmere,and silk all have inhibitory effects on the combustion of latex foam,and the inhibitory effect is from low to high.An empirical model for predicting the heat release rate of double-layer combustibles is proposed,and the prediction of the model is in good agreement with the experimental data.The latex foam material with a size of 25 cm×25 cm×2 cm was subjected to accelerated aging experiments.Through thermogravimetric analysis,the thermal behavior of the latex foam material and the pyrolysis process were experimentally and theoretically studied,and the combustion characteristics of the latex sponge were compared and analyzed through a small-sized combustion device.It was found that 250?to 440?should be the pyrolysis of latex sponge,the latex sponge scorched and produced a variety of volatile gases.With the increase of aging time,the time for the flame height of the material to reach the peak has been shortened,and the time for the temperature of the center of the latex foam to reach the peak has been shortened.