Solid freeform fabrication using a plurality of modeling materials

Abstract

A system and methods for solid freeform fabrication of an object is disclosed. The system comprises a solid freeform fabrication apparatus having a plurality of dispensing heads, a building material supply apparatus configured to supply a plurality of building materials to the fabrication apparatus, and a control unit configured for controlling the fabrication apparatus and the supply apparatus based on an operation mode selected from a plurality of predetermined operation modes.

Description

RELATED APPLICATIONS[0001]This application is a continuation of PCT Patent Application No. PCT / IL2008 / 001025 having International Filing Date of Jul. 24, 2008, which claims the benefit of U.S. Provisional Patent Application No. 60 / 935,090, filed on Jul. 25, 2007. The contents of the above Applications are all incorporated herein by reference.FIELD AND BACKGROUND OF THE INVENTION[0002]The present invention relates to solid freeform fabrication and, more particularly, to a solid freeform fabrication using a plurality of modeling materials.[0003]Solid Freeform Fabrication (SFF) is a technology enabling fabrication of arbitrarily shaped structures directly from computer data via additive formation steps. The basic operation of any SFF system consists of slicing a three-dimensional computer model into thin cross sections, translating the result into two-dimensional position data and feeding the data to control equipment which fabricates a three-dimensional structure in a layerwise manner...

AI Technical Summary

Benefits of technology

[0034]The ability of the system of the present embodiments to utilize two or more different modeling materials, makes it is possible to use and / or produce many more, and more varied materials in solid freeform fabrication than has been possible to date in conventional solid freeform fabrication techniques, as well as providing many different possibilities for combining multiple materials, according to the final object and / or object properties desired to be obtained.

[0035]The ability of the system of the present embodiments to utilize two or more different modeling materials, allows the fabrication of parts or objects having properties which are difficult, if not impossible, to achieve using conventional solid freeform fabrication techniques. For example, modeling materials which have a great tendency to shrink as a result of the polymerization process are not usually suitable for use in traditional solid freeform fabrication apparatus. A modeling material suffering from high shrinkage during solidification makes especially difficult the manufacturing of bulky three dimensional geometries but may allow the fabrication of thin shell like three dimensional geometries, for example, around a bulky object which is fabricated of a material with acceptable shrinkage. The system of the present embodiments usefully provides a solution to this problem. For example, the system of the present embodiments can fabricate parts or objects in which the surfaces of the part or object are made of one material, while the internal regions of the part or object comprise a different material. In this example, the internal regions may be fabricated of a material which lacks mechanical strength, such as a gel or liquid, but having other desirable properties such as being easily burnt without leaving ash or other traces.

[0036]The ability of the system of the present embodiments to utilize two or more different modeling materials, also allows the fabrication of objects via a segmentation process, wherein layers are built in segments or “tiles”. Such process is described in U.S. Application No. 60 / 430,362 and U.S. Pat. No. 7,300,619, the contents of which are hereby incorporated by reference. The segments or tiles may be comprised of one material, and joined by dispensing a different material, e.g., a binder or glue-like material, in the breaks between the segments. By building in smaller segments or tiles instead of a full layer, this method serves to overcome problems of material shrinkage which may occur during the curing process.

[0074]According to some embodiments of the present invention the control unit is designed and constructed to ensure that the object's dimensions are rescaled along at least one direction so as to compensate for post-formation shrinkage of the object along the at least one direction.

Problems solved by technology

The present inventors also found that the number of building materials that can be used or produced in conventional techniques is very limited, and the properties of the materials that can be obtained are still far inferior compared to the properties of standard engineering polymers.

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