Application of using 3D modeling and FDM 3D printer in restoration and prototyping of ivory historical-cultural objects

Today, the use of new technologies and methods of preservation of ivory objects has led to a better understanding and safe protection of objects. The purpose of this article is to evaluate the feasibility of using new methods of rapid prototyping technology, including dimensional modeling and FDM 3D printer, to achieve a suitable method for reconstructing missing parts and making a Moulage of ivory objects using the existing equipment to apply it in Restoration and restoration of ivory objects. In line with the investigation of the introduced method, an example of a chess piece made of ivory, with a statue of a man riding a camel carved with great detail, was selected, and a similar piece was missing. Documentation was done from the same bead and according to the available images, 3D modeling was done with Zbrush software, which is a special software for sculpting and sculpting. The existing 3D model was first adjusted manually in Simplify 3D printer management software, and then it was converted to G-Code and printed with a 0.3 nozzle. The result was the high quality of the sample print and the supports were easily separated from the piece without damage. The results of this research showed that the use of 3D modeling with Zbrush 3D software and printing with a 3D FDM printer as a suitable method for making a moulage of ivory objects can be useful and can also be used to reconstruct missing parts. Historical-cultural objects should also be used. Introduction & MethodThere are different types of ivory, and the identification and separation of each type of ivory leads to the understanding of trade and exchanges in historical and prehistoric periods. The high demand for ivory objects and their subsequent popularity have led to the endangerment and extinction of several animal species, particularly elephants. As a result of the declining elephant population, the Convention on International Trade in Endangered Species (CITES) banned ivory trade in 1989 (Stiles, 2004). Given the limited availability of ivory and its illegal status, its use is not only against the law but also morally unjustifiable (Ratha et al., 2021). In order to preserve and revive absent sections of historical-cultural objects made of ivory, various alternative materials are employed. These include tagua palm tree or jarina seed as plant substitutes (Chu, et al. 2015), as well as natural materials like bone, polymer composite materials with mineral particles, casein, and ivory sawdust (Baker, et al. 2020: 56-62). Additionally, appropriate putties can be utilized to fill certain cracks.The damaged surface is covered with a putty that has been infused with a color that matches the desired effect. This technique was employed in the restoration of the ivory statue of Christ, where missing parts were repaired using Milliput Superfine White epoxy putty and polyurethane resin (Alconada, 2017). In addition to these materials, other options like plaster, wax, synthetic materials, micro balloons, and a specialized substance called Digory can be utilized for the restoration of ivory objects. However, it should be noted that using alternative materials and engraving on them can be a time-consuming process and may lead to restoration errors.     Therefore, using a method that requires the least intervention of the restorer with high accuracy in the shortest time and can be processed with 3D technologies can be a suitable alternative. By using these technologies, it is possible to restore the original artist's style and preserve the appearance of an artwork exactly as intended. 3D technologies are a suitable tool for virtual 3D representation of objects, reconstruction of missing parts, and making montages of cultural and historical artifacts for conservation purposes in cultural and archaeological heritage sciences (Fantini, et al. 2008). In this article, ZBrush software was used for 3D modeling, and the FDM 3D printer, which is the most common type of 3D printer in Iran and the world, was used for prototyping. The working method of this printer is based on the fusion layer, which can perform 3D printing with a minimum layer thickness of 100 microns.     Considering the remarkable progress made in the field of rapid modeling in the industry and the availability of new technologies today is a good platform for the introduction of such technologies in the field of archaeological studies as well as the conservation and restoration of cultural heritage. Such technologies, and indeed the most important ones, are scanners and three-dimensional printers. These technologies can be used to build a copy of objects and sculptures, relief and rock arts, valuable works and decorations in real dimensions (and/or with changing dimensions), as well as to reconstruct missing parts of destroyed works. The main advantages of using these methods are: Reducing contact with sensitive objects and avoiding conventional and time-consuming commonly used contact and to some extent destructive, such as molding, casting, and filtration processes in the rebuilding of archaeological worksMore precision in the implementation of outstanding and complex designs than the traditional method,Achieving similar levels of quality to historical cultural effects using a combination of modeling techniques.Construction of parts in different dimensions with asymmetric geometric models, so that there is little constraint on the form and geometric shape for construction.Ability to evaluate and modify the 3D layout and repeat it in case of dissatisfaction with each section in the shortest possible timeThe risk of connection to the reconstructed piece is due to the neutral propertiesReducing the time in making missing parts ConclusionThe reconstruction process can be achieved in a very short time and with higher accuracy. The printed piece can be an exact match of the masterwork. Several pieces of the missing part or the whole subject can be printed. A soft copy of the subject would be available for future works and can be used in other research centers. The subject can be reprinted with any desired changes in the Ivory work's original design. Temporary attachment of the printed piece to the masterpiece while preserving the potential of reversibility in the conservation of the object is achieved. The study was subject to the following limitations though: mono color printing of the missing piece, using a polymer as printing material, limited transparency in printing filaments, and minor errors in the performance of the 3D scanner itself. As the content of the research goes, with the superiority of the advantages of these methods, we are faced with their disadvantages. In general, it can be said that the process undertaken is acceptable and can be used in the reconstruction of the cultural heritage and in particular the archeological object. Whereas the above methods, with the least effective interference, harmless interference, maximum compatibility with the host’s effect on the neutrality of matter, and the preservation of the aesthetic aspects of the effect, can lead to a greater understanding of the work for the audience and researchers.