The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 04, 2003
Filed:
Jan. 19, 2001
Stephen J. Derezinski, Penfield, NY (US);
Eastman Kodak Company, Rochester, NY (US);
Abstract
A vented, multi-staged rotary screw extruder is taught for extruding thermoplastic materials. The screw has a final pumping-section of the screw that includes two or more channel depths which provides exit-pressure and flow stability. The channel-depth of the first segment of the final pumping-section is deeper than the channel depth of the second segment of the final pumping-section. The axial length of the first segment is preferably about two-thirds (⅔) of the final pumping-section length. The deeper first channel-depth acts as a reservoir resulting in smaller fluctuations in axial final fill-length as the input flow to the total pumping-section varies. The second channel-depth in the remaining approximate one-third (⅓) of the total pumping-section is preferably sized so as to optimize pressure development.