Dust explosion risk in polymer powder processing: Review and testing

Abstract

The plastics industry, a global giant employing over 1.5 million people in Europe, faces a formidable challenge. Almost all plastic is combustible, and generating fine particles during processing (such as mechanical operations or recycling) can cause a potential explosion hazard. There is a wealth of literature on polymer powders in their 'pure' form, exploring the basic principles of dust explosions or measuring the effectiveness of inert dust in suppressing or preventing explosions. However, despite their frequent presence in the industry, there is a significant gap in research on polymer powder mixture, and actual industrial samples conditions. Which needs to be investigated urgently. The paper overviews relevant polymer dust explosions and accident dynamics and includes experimental testing and results. Statistical data on polymer dust explosions worldwide were examined to obtain a detailed picture of the materials involved and the severity of the explosion in terms of immediate damage and interruption of operations, furtherly, discussing lessons learned concerning dust explosion risks. Finally the experimental results presented here showed that more than 90% of the samples were combustible according to ISO 80079 and should therefore be considered “explosive.” Polyolefins have more severe explosive properties (regarding maximum explosion pressure and K_St) than more complex molecules (resins or polyesters). The highest value was shown by a mixture of PS/PPE dust collected in a recycling plant. These results revealed information on the likely synergistic effect of some polymers in a mix and the potential hazard that may affect different plastics industry sectors.