| Abstract: | Plate-out is the undesired deposition of materials from a compound onto the surface of processing equipment. Plate-out causes problems with quality control and down-time. Changes in processing conditions can help alleviate plate-out, but adjustments in the formulation are usually needed for significant improvements in plate-out, the deposition. The addition of precipitated silica to a PVC formulation is a simple and effective method to reduce plate-out. This study explores the relationship between plate-out reduction and the physical properties of precipitated silica. Silica properties such as surface area, average particle size, and oil absorption can all be controlled by a patented process developed by the Chemicals Division of J. M. Huber Corporation. Plate-out reduction is related to the properties of precipitated silica, the loading of the silica, the order of addition, and type of PVC formulation. The effect of precipitated silica on the physical properties of the PVC compound, such as, tensile strength, tear strength, elongation and stiffness, are explored. Finally, the effectiveness of plate-out reduction by precipitated silica as compared to fumed silica will be discussed. |
