US 4,003,773 AGranted

Method of preparing graphite fibers of ultra-short length and narrow size distribution

AssigneeHercules Incorporated

InventorMichael Anthony Grable

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Abstract

A process for cutting a multi-filament tow into fibers of ultra-short length and narrow size distribution is provided. Initially, a multi-filament tow is passed through a bath of liquid impregnating material at elevated temperature. The impregnated tow is then passed through a die which is sized to control the quantity of material impregnating the tow and to compact the filaments of the tow into a closely packed bundle. The resulting tow is then cooled to solidify the impregnating material and to convert the tow to a rigid form. The rigid tow is then cut, yielding wafer-thin disks. The impregnating material is then stripped from the wafer-thin disks with a solvent followed by removal of the solvent, thereby yielding fibers of ultra-short length and narrow size distribution.

Claims8

Dependent claims

A method for preparing fibers of ultra-short length and narrow size distribution from multi-filament tow comprising the steps of:

a. providing a source of multi-filament tow;
b. passing said multi-filament tow through a bath of liquid impregnating material at elevated temperature, said impregnating material being one which is solid at ambient temperature;
c. passing said impregnated tow through a die sized to control the quantity of material impregnating the tow and to compact the filaments of the tow into a closely packed bundle;
d. cooling the compact tow to solidify the impregnating material therein and to convert the tow to a rigid form;
e. cutting said rigid tow to produce wafer-thin disks therefrom;
f. stripping the impregnating material from said wafer-thin disks with a solvent to yield fibers of ultra-short length and narrow size distribution;
and
g. removing solvent from the fibers.

5 more elements

Dependencies are inferred from the claim text.