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Embedded Graphite Lamination on Thermal Ribbon

IP.com Disclosure Number: IPCOM000050676D
Original Publication Date: 1982-Dec-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Findlay, HT: AUTHOR [+2]

Abstract

A temporary substrate is lightly coated with graphite and rubbed with a cotton cloth to remove any excess. A dispersion of resin, carbon black, and liquid vehicle is applied to the substrate, solidified by evaporation of the vehicle, and stripped from the substrate. This forms a resistive layer of a thermal ribbon which has graphite embedded in the outer layer. The graphite reduces current requirements, and, since it is embedded, free graphite cannot build-up on the printhead or transfer to the ink layer.

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Embedded Graphite Lamination on Thermal Ribbon

A temporary substrate is lightly coated with graphite and rubbed with a cotton cloth to remove any excess. A dispersion of resin, carbon black, and liquid vehicle is applied to the substrate, solidified by evaporation of the vehicle, and stripped from the substrate. This forms a resistive layer of a thermal ribbon which has graphite embedded in the outer layer. The graphite reduces current requirements, and, since it is embedded, free graphite cannot build-up on the printhead or transfer to the ink layer.

The material of the substrate is selected to be one which releases the material of the resistive layer well. It may be polypropylene or polyethylene terephthalate for certain materials of the resistive layer. Polypropylene is used with a resistive layer predominately of polyurethane and carbon black. Preferably before delamination, a 1000-angstrom layer of aluminum is applied by vacuum deposition, and an ink layer of thermo plastic resin and coloring matter is applied to the aluminum. The drawing shows a cross section of the final ribbon.

The graphite in the outer layer, to Which current is supplied for printing in the known manner by electrodes in a printhead, reduces required current. (Current is returned through the aluminum layer.) At the lower currents the tendency for the ribbon to have holes burned in it is greatly reduced. The graphite also appears to reduce frictional wear on the printhead. Since the graphi...