Ignition and combustion characteristics of polyethylene film in high temperature field (1^st report : Effects of film size on ignition delay time and combustion time)

Abstract

The objective of this research is to investigate the ignition and the combustion characteristics of polyethylene film in a high temperature field. Polyethylene was inserted in a high temperature chamber. The polyethylene was used as a film-type. 4 mm, 5 mm, 6 mm, and 7 mm square of polyethylene were used. Polyethylene inserted in the chamber was melted and formed the droplet during the ignition delay time, and after ignition, polyethylene was burned along with the puffing by the pyrolysis. For the 4 mm film size, polyethylene has ignition limit at 850 K surrounding temperature. Ignition delay time on various surrounding temperature was based on the Arrhenius law. However, ignition delay time for various surrounding temperature has two tendencies. On the other hand, combustion time of the polyethylene has different tendency from ignition delay time. As the surrounding temperature increases, the burning time became longer. This has influence on the amount of polyethylene remained at the ignition without pyrolysis during the ignition delay time. In a high surrounding temperature, large amount of polyethylene was left during the ignition delay time, and combustion time was longer than when the surrounding temperature was low. The temperature history of polyethylene for various surrounding temperature had approximately the same tendency during ignition delay period.