Three dimensional (3d) printer and filament material providing scanning protection for 3d printed objects

Abstract

A printer adapted for printing three dimensional (3D) objects that are difficult to copy by use of a 3D scanner and 3D printer. The printer includes a print head with an extrusion nozzle with a heated portion and a print bed with a surface for receiving material extruded from the extrusion nozzle. The printer includes a print material supply spool loaded with an anti-scanning filament. The print head is adapted for drawing the anti-scanning filament into the heated portion for heating prior to extrusion from the extrusion nozzle to form a 3D object. Further, the 3D object includes one or more scan protected exterior surfaces on at least one element of the 3D object. The scan protected exterior surfaces are either light absorbing surfaces or reflect light in one or more unconventional directions. The anti-scanning filament may be a plastic mixed with an anti-scanning additive such as a retroreflective material.

We claim: 
     
         1 . A three dimensional (3D) printer for printing 3D objects, comprising:
 a print head with an extrusion nozzle with a heated portion;   a print bed with a surface for receiving material extruded from the extrusion nozzle; and   a print material supply spool loaded with an anti-scanning filament,   wherein the print head is adapted for drawing the anti-scanning filament into the heated portion for heating prior to extrusion from the extrusion nozzle to form a 3D object, and   wherein the 3D object comprises one or more scan protected exterior surfaces on at least one element of the 3D object.   
     
     
         2 . The printer of  claim 1 , wherein the scan protected exterior surfaces are light absorbing surfaces or reflect light in one or more unconventional directions. 
     
     
         3 . The printer of  claim 1 , wherein the anti-scanning filament comprises plastic mixed with an anti-scanning additive. 
     
     
         4 . The printer of  claim 3 , wherein the anti-scanning additive comprises a quantity of a retroreflective material. 
     
     
         5 . The printer of  claim 4 , wherein the quantity is in the range of 2 to 25 percent of the material of the anti-scanning filament. 
     
     
         6 . The printer of  claim 5 , wherein the quantity is in the range of 5 to 10 percent. 
     
     
         7 . The printer of  claim 1 , further comprising a controller positioning and operating the print head based on a 3D object model defining a plurality of print layers for the 3D object including the scan protected exterior surfaces and wherein the controller prints the scan projected exterior surfaces with the anti-scanning filament and prints other portions of the 3D object using an additional print material supply spool loaded with a plastic filament free of an anti-scanning additive. 
     
     
         8 . The printer of  claim 7 , further comprising a printer interface system for receiving use input and processing the user input to designate the scan protected surfaces. 
     
     
         9 . A method for printing a scan-protected 3D object, comprising:
 generating or retrieving a digital model of the 3D object;   processing the digital model to define a plurality of print layers; and   operating a 3D printer to extrude a liquid plastic with an anti-scanning additive to form at least outer portions of one or more of the print layers.   
     
     
         10 . The method of  claim 9 , wherein the anti-scanning additive increases absorption of light by a surface formed with the liquid plastic. 
     
     
         11 . The method of  claim 9 , wherein the anti-scanning additive modifies reflection of light by a surface formed with the liquid plastic. 
     
     
         12 . The method of  claim 11 , wherein the anti-scanning additive comprises a plurality of retroreflectors. 
     
     
         13 . The method of  claim 12 , wherein the anti-scanning additive makes up at least 5 percent of material extruded from the 3D printer to form the outer portions of the one or more of the print layers. 
     
     
         14 . The method of  claim 9 , further comprising receiving a user input designating a surface of the 3D object for scanning protection and wherein the surface of the 3D object is provide by the one or more print layers formed with the liquid plastic with the anti-scanning additive. 
     
     
         15 . The method of  claim 9 , wherein the operating of the 3D printer comprises drawing a filament into a heated extrusion nozzle to provide a source of the liquid plastic with the anti-scanning additive. 
     
     
         16 . A filament for use with 3D printers to provide scanning protection, comprising:
 a base material comprising a plastic; and   an anti-scanning additive that increases light absorption by the plastic or that modifies reflectivity of the base material.   
     
     
         17 . The filament of  claim 16 , wherein the base material is acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) providing at least about 75 percent by volume of the filament. 
     
     
         18 . The filament of  claim 16 , wherein the anti-scanning additive comprises a retroreflective material. 
     
     
         19 . The filament of  claim 18 , wherein the retroreflective material makes up at least 5 percent by volume of the filament. 
     
     
         20 . The filament of  claim 19 , wherein the retroreflective material makes up less than about 25 percent by volume of the filament.