Characterisation of speck impurity sources in cellulose pulp by analytical pyrolysis

Pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC-MS) was used for characterising the chemical composition of specks and possible specks impurities sources in cellulose fibre (additives, polymeric materials and wood extracts) found in the Brazilian pulp mills. Speck pyrograms were analysed and compared with reference sample pyrograms, showing that the main source of impurities is the polymeric materials containing Teflon. The results showed that the visual classification is not totally reliable. These studies demonstrate that the Py-GC-MS could be a complementary tool to correctly facilitate classification of the specks, to thus trace them back to their source, and to define strategies for their control.