Over the years, numerous handbooks and design guides on the subject of plastics have been published. None of these dealt in any depth with the subject of this handbook-blow molding. The recent growth of blow molding as an economically feasible process has been rapid in many areas. This growth, coupled with the lack of technical publications relating to blow molding, prompted the Board of Directors of the Blow Molding Division of the Society of Plastic Engineers to undertake the assimilation of available information and the editing of this milestone publication. We believe that this Plastic Blow Molding Handbook will provide the reader with a greater understanding of the unique process characteristics of blow molding, enable the reader to apply proven techniques in developing new products and applications for blow molding, and will serve as a valuable reference for all who are interested in the plastics industry. Our thanks are heartily extended to the various authors for their contributions to this pioneering effort in blow molding. J. H. Moran Chairman Blow Molding Division Society of Plastic Engineers xi Preface The blow molding of plastic articles has in the past had an aura of the mystic around it. As a result, little comprehensive work on the subject has been published. Advances in the technology of polymeric materials, machine controls, computer science, and management techniques have made it nec­ essary to correct the myths and magic.