My own interest in the vinyl plastics industry began in 1958 while assisting Frye and Horst in their classic studies on the mechanisms of PVC degradation and stabilization carried out at Cincinnati Milacron. Interest rapidly focused on rigid PVC in two ways: when Milacron became the major supplier of multi-screw extruders (Anger AGM and Anger APM acquisitions in 1970-71), and when Milacron’s Chemical Division (now Rohm & Haas) pioneered significant additive improvements for rigid PVC in the early 1970’s.

During the development and commercial introduction of these additives and later additive improvements, a considerable amount of extrusion experience (both desirable and undesirable) was accumulated.

Over 150 developmental extrusion
trials and over 100 extrusion runs in a variety of pipe and profile plants in the U.S., Latin America, and Europe are bound to leave impressions concerning problems of PVC extrusion and how to minimize them. This small book is an attempt to share these impressions with those who are concerned with achieving and maintaining optimum quality rigid PVC extrusion.

I hope the following discussion specific  to rigid PVC extrusion will help fill a void in available literature on this subject. Further, if this discussion aids someone in avoiding at least one of the problems that can occur during extrusion, the effort and time spent on this booklet will have been justified.

George A.(Skip) Thacker, Jr.
February,2006   This is an updated edition of the booklet, originally printed in 1976.