Danielle M Froio

US Patent:

7832998, Nov 16, 2010

Filed:

Oct 26, 2006

Appl. No.:

11/586278

Inventors:

Donald V. Beauregard - Jamestown RI, US
Nick R. Schott - Westford MA, US
Stephen A. Orroth - Windham NH, US
Dwayne R. Cote - Nashua NH, US
Danielle L. Froio - Watertown MA, US

Assignee:

The United States of America as represented by the Secretary of the Navy - Washington DC

International Classification:

B29C 47/88

US Classification:

425 67, 425192 R, 425377, 4253781, 425461

Abstract:

An extrusion apparatus is taught that employs a die adapter that is partially submerged in a heat transfer bath on a horizontal plane such that there is no air gap between the die extrusion aperture and the heat transfer bath. A porous dam is positioned between the die and the heat transfer bath. A heat insulating plate is positioned between the porous dam and the die to prevent the heat transfer medium from flowing onto the die. The heat insulating plate also prevents excessive cooling of the die tip thereby allowing the necessary precise thermal control over the extrudate skin formation to prevent melt fracture and form a low density extrudate with a smooth solid skin and inner foamed core.