Dust explosion properties and mechanisms of polyphenylene ether mixed with volatile organic compounds

Polyphenylene ether (PPE), used in the production of copper-clad laminate resin, can emit methane and ethane at elevated temperature during the aforementioned production process. Moreover, a cloud of PPE dust can form during the feeding process. Both these scenarios can lead to a dust or inflammable gas explosion at the feed port. This study investigated the explosion characteristics of PPE in air, methane, and ethane atmospheres by using 20-L apparatus. The study findings revealed that the presence of methane and ethane lowered the minimum explosive concentration of PPE dust. In air, the minimum explosion concentration was 40 g/m³, which decreased to 30 and 22 g/m³, respectively, in the presence of methane and ethane. However, the addition of these gases also increased the severity of explosions from St-2 to St-3. Furthermore, the thermal depolymerisation of PPE dust was examined. PPE was discovered to undergo thermal depolymerisation when heated, releasing a substantial quantity of inflammable gases. These gases, in combination with oxygen, can form an explosive mixture, expanding the explosion range. Moreover, these inflammable gases exhibit various degrees of toxicity, posing substantial health and safety risks to workers involved in PPE manufacturing.