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:
Jun. 13, 1989
Filed:
Dec. 18, 1985
Rene Delphin, Fontenay aux Roses, FR;
Bernard Regnaut, Antony, FR;
Occidental Chemical Corporation, , CT (US);
Abstract
A method of manufacturing a highly electrically conductive plastic material from thermoplastic resin and carbon fill through a two-screw mixer having a screw length of more than twenty times the screw diameter involves continuously inserting a thermoplastic resin into a first zone of the two-screw mixer and compacting and preheating the thermoplastic resin. The resin is then passed into a second zone where it is kneaded and plastified. A particulate carbon fill is continuously inserted into a third zone with the fill constituting 30 to 50% by weight of the mixture and being dispersed in said resin within the third zone. The speed of rotation of the two screw mixer lies in the range between 150 to 250 RPM and the temperatures of the zones lie within the range of 165.degree. C. to 300.degree. C. After passage through the various zones, the mixture is removed via an outlet of an extrusion head. A copolymer propylene and ethylene forms the thermoplastic resin in the carbon black and the carbon black constitutes the particular carbon fill. A fill of not more than 10% by weight carbon fibers may be inserted at one of the zones. Further, a fourth zone may follow the third zone with the method further including the step of degasing the mixture at a pressure lying in the range of atmospheric pressure to a few millibars at the fourth zone.