Fire behaviors of single and laminated natural latex foam

Although natural latex mattresses have been increasingly used in our lives, its high fire risk could put occupants in big danger. Therefore, a series of experiments were carried out to investigate the fire behaviors of natural latex foam with single and laminated layers. Both single and laminated layer samples showed three burning stages: initial acceleration, stable and decaying stages. A fierce burning and bottom ignition were observed at the end of the stable stage for both types. It was known from the experiments that for laminated sample the shrinkage of the thin layers could increase the fire risk as it could accelerate the combustion process, while no obvious difference was found when the number of layers increases from 2 to 5. When comparing to the single layer sample, the laminated layer samples with at least 100 s shorter burning period showed 28.3% higher average flame height, 31.2% higher surface flame spread rate, 92.3% greater peak mass loss rate, and 43.4% higher fuel regression rate along the thickness direction. However, these two types showed a similar maximum flame height, indicating that the maximum flame height may be much dependent on the sample mass but not the shrinkage of the thin layers.