Process for producing moulded articles from carbon or graphite by 3D printing

A process for producing non-ceramic shaped articles made of carbon or graphite by 3D printing, comprising:

• producing a base polymeric mixture consisting of
• a UV permeable and polymerizable polyacrylonitrile dissolved in a solvent selected from the group consisting of dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and N-methyl-2-pyrrolidone (NMP), and
• a UV crosslinkable resin selected from the group consisting of DLP photopolymer resin and SLA resin;
• thereafter
• admixing sugar and/or cellulose to the base polymeric mixture, the sugar and/or cellulose being added in an amount sufficient to impart a flowable consistency suitable for being filled into and processed by a 3D printer, thereby forming a flowable polymeric mixture;
• homogenizing the flowable polymeric mixture at an elevated temperature up to 60° C.;
• filling a 3D printer with the flowable polymeric mixture;
• layerwise printing a shaped article with the 3D printer with simultaneous exposure to UV radiation for layerwise crosslinking of the UV crosslinkable resin, thereby forming a UV precured shaped article;
• cleaning the UV precured shaped article of to remove liquid residues and foreign particles;
• introducing the UV precured shaped article into a furnace and stabilizing the UV precured shaped article in air at a predetermined stabilizing temperature of 200° C. to 450° C. until all volatile constituents have outgassed, thereby forming a prefabricated shaped article;
• and
• subsequently high temperature treating the prefabricated shaped article for carbonization or graphitization in a furnace under protective gas.