Loading patent…
AssigneeConte
InventorsLudovic Chochoy, Hélène Baillieu, Jacques Bachelet, Lucien Foscarin
Estimating the term…
The method of continuously manufacturing pencils or crayons consists in coextruding a filled first thermoplastic material referred to as “lead” material, and around it both an intermediate “protective” layer of a thermoplastic material having no expanding agent and a second thermoplastic material containing an expanding agent and referred to as “wood” material, and in cooling said coextruded thermoplastic materials. According to the invention, the thermoplastic material constituting the protective layer is determined so that during cooling it remains deformable while the lead material shrinks. The pencil is constituted by superposing a core of a filled first thermoplastic material referred to as “lead” material, a protective layer of a non-expanded thermoplastic material, and a layer of an expanded second thermoplastic material referred to as “wood” material. According to the invention, the thermoplastic material constituting the protective layer has a solidification point which is lower than that of the thermoplastic material constituting the lead material.
A method of continuously manufacturing pencils or crayons by simultaneous coextrusion, the method consisting in coextruding a filled first thermoplastic material referred to as “lead” material, and around it both an intermediate “protective” layer of a thermoplastic material having no expanding agent, and a second thermoplastic material containing an expanding agent and referred to as “wood” material, and in cooling said coextruded thermoplastic materials, wherein the thermoplastic material constituting the protective layer is determined so that during cooling it remains deformable while the lead material shrinks.
A pencil obtained by simultaneous coextrusion, the pencil being constituted by superposing a core made of a filled first thermoplastic material referred to as “lead” material, a protective layer of a non-expanded thermoplastic material, and a layer of an expanded second thermoplastic material referred to as “wood” material, wherein the thermoplastic material constituting the protective layer has a solidification point which is lower than the solidification point of the thermoplastic material constituting the lead material.
Dependencies are inferred from the claim text.