3d-printing device and process for producing an object with use of a 3d-printing device

Abstract

Improved 3D printed articles are produced in a 3D printing apparatus by controlling the apparatus in response to the measurement of the size, geometry, and/or weight of print materials exiting the discharge device of the apparatus.

1 .- 14 . (canceled) 
     
     
         15 . A method for producing an object using a 3D printing device having at least one printhead with at least one discharge device,
 wherein the discharge device is configured to place print materials at target positions in order to additively manufacture the object, comprising:   detecting and/or geometrically measuring print materials and/or support materials exiting from the discharge device by means of at least one luminance measurement in transmitted light operation or in reflected light operation in the region of the discharge device while the support materials and/or print materials are exiting or have exited the discharge device and before they have been placed.   
     
     
         16 . The method of  claim 15 , wherein the weight of the print materials that have exited from the discharge device is also measured. 
     
     
         17 . The method of  claim 15 , wherein the measured geometry and optionally the measured weight of the print materials that have exited from the discharge device are used to detect print errors, especially erroneously unplaced print materials, ingress of foreign bodies and/or stringing. 
     
     
         18 . The method of  claim 17 , wherein at least one print error is an erroneously unplaced print material, ingress of a foreign body, or stringing. 
     
     
         19 . The method of  claim 15 , wherein erroneously unplaced print materials detected are reprinted. 
     
     
         20 . The method of  claim 19 , wherein reprinting takes place prior to a method step of curing. 
     
     
         21 . The method of  claim 15 , wherein on the basis of a measured geometry of the print materials that have exited from the discharge device, cleaning of the printhead is triggered and/or maintenance advice is issued. 
     
     
         22 . The method of  claim 15 , wherein the geometry of the print materials exiting from the discharge device is under closed-loop control by means of one or more operating parameters of the 3D printing device, at least one parameter selected from the group consisting of:
 a movement speed of the printhead;   a discharge height (H) above a baseplate on which the object is additively manufactured;   a physical pressure that prevails in the discharge device, to which the print material is subject;   a physical supply pressure in the material reservoir;   in the case of voxels, a print frequency, a ram advance speed, a ram withdrawal speed, opening time of the jetting valve, and the ram stroke, and   in the case of strands, a flow rate, a feeder speed and a material retraction characteristic at the end of a line.   
     
     
         23 . The method of  claim 22 , wherein the luminance measurement comprises an evaluation of a comparison of a signal received over time with a reference signal, where the reference signal is recorded in a calibration of the 3D printing device or at the start of the printing of the object or of a layer of the object. 
     
     
         24 . The method of  claim 15 , wherein the object is an elastomer part. 
     
     
         25 . The method of  claim 24 , wherein the elastomer comprises a silicone elastomer. 
     
     
         26 . The method of  claim 15 , wherein the actual position of the printhead is constantly determined by a position measurement unit and the print materials are placed by the discharge device depending on the constantly determined position of the printhead. 
     
     
         27 . A 3D printing device for manufacture of an object by a 3D printing method, comprising:
 at least one printhead with at least one discharge device, where the discharge device has a control unit to control placement of print materials at target positions in order to additively manufacture the object,   at least one optical measurement unit positioned and configured such that print materials exiting from the discharge device are detected and/or geometrically measured by means of at least one luminance measurement in transmitted light operation or in reflected light operation in the region of the discharge device as an optical measurement unit while print materials are exiting or have exited and before the print materials have been placed.   
     
     
         28 . The 3D printing device of  claim 27 , wherein the optical measurement unit is arranged in an axis of movement of the printhead. 
     
     
         29 . The 3D printing device of  claim 27 , wherein the optical measurement unit comprises at least one optical fiber, the light exit area of which is integrated into the discharge device or is secured on the discharge device by means of an attachment. 
     
     
         30 . The 3D printing device of  claim 27 , comprising at least one baseplate on which the object is to be additively manufactured, and a weight sensor assigned to the baseplate. 
     
     
         31 . The 3D printing device of  claim 27 , wherein the 3D printing device has a position measurement unit by means of which the position of the printhead is constantly determined,
 wherein the position measurement unit is connected to the control unit of the discharge device,   and wherein the discharge device is configured to place the print materials as a function of the constantly determined position of the printhead.