29133
Accession Number
27878
Author
Podany, Jerry C.
Editor
Vandiver, Pamela B.; Druzik, James R.; Wheeler, George Segan; Freestone, Ian C.
Author Affiliation
The J. Paul Getty Museum. Department of Antiquities Conservation
Title Of Article Chaper
Evaluation of rapid prototyping technologies for use in the production of art and artifact study copies
Title Of Journal Book
Materials issues in art and archaeology III: symposium held 27 April-1 May 1992, San Francisco
Volume
267
Pages
1079-1087
Collation
4 figs.
Reference Bibliography
6 refs.
Publisher
Materials Research Society
Publisher City
Pittsburgh
ISBN
1-55899-162-X
ISSN
0272-9172
Language Of Text
English
Language Of Summary
English
Literature Type
Monograph
Literature Level
Analytic
Meeting
Materials Research Society Symposium
Meeting City
San Francisco
Abstract
Many artifacts and works of art are too fragile to be accurately replicated for scholarly study by using traditional methods of plaster or silicone molding techniques. In addition to the potential for loss of surface and fracturing, the use of many modern silicone mold materials may lead to irreversible staining of the original surface. An evaluation of newly developed rapid prototyping technologies and their potential application to this problem was conducted by the J. Paul Getty Museum Departmentof Antiquities Conservation in conjunction with Laser Design Inc. of Minnestoa and Hughes Aircraft Corp. of California. Rapid prototyping technology allow accurate copies to be made with out surface contact with the original object. This paper discusses the outcome of an initial invesitgation into one of these processes, stereolithography. A plaster model was submitted for laser scanning using using a point laser probe, programmed for a 3.175 mm (0.125 ) distance between scan lines. The input was filtered and stored in an STL (stereolithography) format which provides the X, Y and Z coordinates of the A, B, C and normal vectors of a predetermined number of surface triangles. This data was then used to produce a three-dimensional copy. Stereolithography produces hollow or solid three-dimensional forms by feeding data that make up cross sectional slices of the onject scanned to a focused laser aimed along the Z axis of the potential copy. The laser polymerizes the outer contour of the slice in a thin layer of photopolymer deposited on a stage located below the laser. Following each slice production the stage lowers approximately 19 mm (0.75 ) below the surface of the liquid polymer reservoir and upon resurfacing positions approx 0.05mm (0. 002 ) lower than its previous position. A squeegee gently crosses over the surface resulting in a thin film of polymer available for the production of the next cross section. The laser is then sent the next cross sectional data and the sequence of section building continues. The specific challenge presented by this project was to assure that the surface detail of the copy formed presented acceptable fidelity to the original object (model), avoiding any need for follow up bench work or correction. The advantages, drawbacks and newly developed alternatives to this promising technology are discussed.
Keywords
rapid;prototyping;technology;art;artifact;copy -- CAL
pub_id
29133
Meeting Date
19920427-19920501