An improved version of composite layer manufacturing (CLM) has been invented. CLM is a type of solid freeform fabrication (SFF) — an automated process in which a three-dimensional object is built up, point-by-point, through extrusion of a matrix/fiber composite-material precursor. The elements of SFF include (1) preparing a matrix resin in a form in which it will solidify subsequently, (2) mixing fibers and matrix material to form a continuous preimpregnated tow (also called “towpreg”), and (3) dispensing the towpreg from a nozzle onto a base while moving the nozzle to form the dispensed material into a series of patterned layers of controlled thickness.

In CLM, the translation and the extrusion operation are such that the final size and shape of the fabricated object are as specified by a computer-aided design (CAD). Sometimes, in order to achieve the desired final shape, it is necessary to interrupt the deposition and cut the towpreg so that no material is deposited while the nozzle is translated to a position where deposition is to resume. The present improved version of CLM includes the use of an algorithm that generates a nozzle path with a minimum number of interruptions.

This work was done by Bor Z. Jang, Junhai Liu, and Shizu Chen of Auburn University for Johnson Space Center. For further information, contact the JSC Innovation Partnerships Office at (281) 483-3809.

In accordance with Public Law 96-517, the contractor has elected to retain title to this invention. Inquiries concerning rights for its commercial use should be addressed to:

Auburn University
Office of Technology Transfer
309 Samford Hall
Auburn University, Al 36849-5176
Phone No.: (334) 844-4977
Fax No.: (334) 844-5963
E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Refer to MSC-23452-1, volume and number of this NASA Tech Briefs issue, and the page number.

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This article first appeared in the February, 2009 issue of NASA Tech Briefs Magazine.

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