Plate-out in PVC extrusion. I. Analysis of plate-out

Samples of extruder plate-out from industrial rigid PVC production lines have been investigated using a number of analytical techniques. The combined use of SEM-EDX (scanning electron microscopy – energy dispersive x-ray analysis), thermal analysis, FTIR (Fourier Transform infra Red spectrophotometry) and LIMA (laser induced mass analysis) has enabled most plate-out components to be identified, and linked to likely formulation ingredients. FTIR and thermal analysis were used to identify organic components. FTIR was also useful for identifying some inorganic compounds present in sufficient quantities, while EDX detected elements present. LIMA was the most sensitive technique, detecting trace quantities of both cations and anions. Calcium carbonate, titanium dioxide and lead stabilizers were found in all die plate-out samples studied, together with small amounts of lubricants.