Verringerung des stereolithographischen Verbiegens

• Main Authors: LEWIS, CHARLES WILLIAM, FREED, RAYMOND SAMUEL, VINSON, WAYNE ALLAN, SMALLEY, DENNIS ROLLETTE, SPENCE, STUART THOMAS, HULL, CHARLES WILLIAM
• Format: Patent
• Language: German
• Published: 02.05.2002
• Edition: 7
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; APPARATUS SPECIALLY ADAPTED THEREFOR; CALCULATING; CINEMATOGRAPHY; COMPUTING; COUNTING; DECORATIVE ARTS; ELECTRIC DIGITAL DATA PROCESSING; ELECTROGRAPHY; HOLOGRAPHY; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; MACHINES, APPARATUS OR TOOLS FOR ARTISTIC WORK, e.g. FORSCULPTURING, GUILLOCHING, CARVING, BRANDING, INLAYING; MATERIALS THEREFOR; ORIGINALS THEREFOR; PERFORMING OPERATIONS; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

An improved stereolithography system for generating a three-dimensional object by creating a cross-sectional pattern of the object to be formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, information defining the object being structurally specified to reduce curl, stress and distortion in the ultimately formed object, the successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process. A stereolithographic distortion known as curl is defined, and several techniques to eliminate or reduce curl are described, including dashed line, bent line, secondary structure, rivets, and multi-pass techniques. In addition, a quantitative measurement of curl known as the curl factor, and a test part known as a quarter cylinder are described, which together can be used to measure the effectiveness of the above techniques in reducing curl.