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:
Mar. 30, 1976
Filed:
Jan. 10, 1973
William H Hartman, Rolling Meadows, IL (US);
Raymond E Mietz, Barrington, IL (US);
John R Peschke, Prospect Heights, IL (US);
Donald H Ruge, Crystal Lake, IL (US);
American Can Company, Greenwich, CT (US);
Abstract
A method of extruding bark and of forming a solid article, solid synthetic fuel or fireplace log comprising from about 60 to 95 percent by weight bark, which comprises physically blending pieces of combustible thermoplastic of an extrudable size with pieces of bark also of an extrudable size and having less than 7 percent preferably less than 2 percent moisture, to form a bark thermoplastic mixture of from about 60 to 95 percent by weight bark and about 2.5 to 40 percent by weight thermoplastic, feeding the mixture to an extruder, heating the bark thermoplastic mixture in the extruder, controlling the heat of the extruder so that its temperature is insufficient to char the bark pieces yet sufficient to melt the thermoplastic and disperse it between the bark pieces so that it acts as a binder therefor and adheres sufficiently to the interior barrel wall surface of the extruder to allow the mixture to be moved therethrough by the extruder screw, extruding the mixture in the form of a composite extrudate, and cooling the composite extrudate to solidify it into the solid synthetic fuel. Preferably, the extruder screw tip is cooled and the heat of the extruder is controlled to range from about 200.degree. to 400.degree. F. with certain temperatures maintained in the respective extruder barrel zones.