Patents by Inventor Laurence E. Dowd

Laurence E. Dowd has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Blown film extrusion
    Patent number: 4632801
    Abstract: A method of blown film extrusion of polyolefins having high elongational viscosity which is independent of applied stress, and high melt strength wherein a first air ring is disposed adjacent an extrusion die to assist in the formation and stability of a stalk bubble configuration, and a second air ring is disposed downstream of the first air ring to assist in controlled expansion of the bubble at a point where the bubble has dissipated its melt elasticity.
    Type: Grant
    Filed: September 23, 1985
    Date of Patent: December 30, 1986
    Assignee: Norchem, Inc.
    Inventor: Laurence E. Dowd