Pencil comprising a marking core and a porous resin sheath
AssigneeHasbro Industries, Inc.
InventorsIrving J. Arons, Robert Eller, Richard E. Merrill
Life of this patent
Estimating the term…
Abstract
Pencils made with a resin-based sheath to replace wood sheaths. A sheath material consisting essentially of a resin binder, a fibrous filler and a metallic soap is extruded around a marking core. The resulting extrudate is immediately chilled after leaving the die, and cut into pencil lengths. The apparatus includes core feeding and transport means, core preheating means and chilling means. The resulting pencils possess the physical qualities associated with wood-sheathed pencils due to the fine, closed cell structure of the sheath material. The surface of the sheath is smooth and may be coated with a pigmented resin or painted.
Claims4
A pencil comprising a marking core and a sheath bonded to the core, the sheath comprising an extrusion grade thermoplastic resin binder having a Vicat softening point above about 180.degree. F., a comminuted cellulosic fiber filler, and a substantially water-insoluble metallic soap, the binder/filler ratio being approximately 1.5 to 3.0, the sheath being provided with closed cells having a maximum diameter of approximately 100 microns, the size of the cells decreasing radially outward from the core to provide a substantially smooth outer surface on the sheath.
A pencil comprising a marking core and a sheath bonded to the core, the sheath consisting essentially of, by weight, approximately 50 to 75% of an extrusion grade thermoplastic resin binder having a Vicat softening point above about 180.degree. F., approximately 20 to 40% of fibrous filler particles selected from the group consisting of cellulose and leather, the binder/filler ratio being approximately 1.5 to 3.0 and approximately 0.5 to 15% of a substantially water-insoluble metallic soap, the sheath being provided with closed cells and having a substantially smooth outer surface.
Dependencies are inferred from the claim text.