Measurement of pyrolysis contamination during crushing of waste printed circuit boards

The crushing of waste printed circuit boards(PCBs) can result in pyrolysis and environmental pollution.The transient temperatures during crushing were measured with a thermal infrared imaging technology.The resulting pyrolysis of FR-4 PCB was also measured with thermal gravity analysis and pyrolysis-Fourier transform infrared spectroscopy.The surface temperatures reached 300350℃ for over 3 seconds,the FR-4 quickly decomposed between 270350℃.The pyrolysis products included borminated hydrocarbons,methylbenzene,bromobenzene,bromomethyl-benzene and some hydroxybenzene,cresol and bromophenol.The tests show that temperatures during crushing cause the production of a variety of organic contaminants.Therefore,the crushing process should be modified to reduce the temperatures and the pyrolysis,so as to reduce the environmental effects.