Thomas C. Pedersen, Robert R. Kwapisz
Papers # 2016 Berlin
This paper presents rheological data on simple rigid PVC compositions lubricated paraffin wax, calcium stearate, and oxidized polyethylene wax. These three materials comprise the most widely used lubricant system for rigid PVC in North America. The influence of certain paraffin wax characteristics will be discussed. Rheological data will be presented on simple PVC pipe formulations containing only lubricants, calcium carbonate, and pigment together with diminishing amounts of heat stabilizer, including one compound without any heat stabilizer. These compositions all display remarkable rheological stability, and demonstrate that lubricants are, in fact, mechanical stabilizers. The North American paraffin wax based lubricant system is an excellent starting point for rigid PVC formulations containing new stabilization technology. The challenge in working with stabilizer free rigid PVC compositions is managing early color development and pinking.