Formulating technology for rigid cellular PVC sheet

Rigid vinyl can be considered as a highly versatile thermoplastic, finding its way into many different applications. Vinyl's capacity for innovation is virtually limitless, thanks in part to advances in formulation additives, which have enlarged vinyl's processing and end‐use performance capabilities. The importance of formulating is particularly evident in rigid cellular PVC, which can be extruded into a variety of shapes, such as profile, pipe, and sheet, all made with less PVC than their solid counterparts. The sheet application can be especially challenging, and it has been made the subject of this paper. The various types of extrusion processes, formulations, and uses for rigid cellular PVC sheet that are found in North America and Europe are compared. The effect of certain types of formulation ingredients on sheet density, surface, and impact strength is described. Reference is made to coextrusion of solid/cellular PVC layers as an economically feasible approach to handling industrial regrind PVC.