New technologies are making themselves a place in conservation. Today we introduce 3D scanning a technique that we will use very soon in our projects.
3D scanning has been extensively applied in museum and cultural heritage environments for the purpose of documentation and conservation because of its non-contact and non-destructive nature. However, this technique is limited if the objects with transparent surface. More techniques are developed to resolve the problem, based on analyzing the properties of reflective and scattered optical wave. Nevertheless, these methods require strict light control during implementation and highly skilled post-analysis involving complicated algorithms. Hereby, I would like to introduce a more feasible method to improve the acquisition problem on scanning transparent object. It is a new application of a common conservation material that using cyclododecane as whitening spray on the object’s surface prior to 3D scanning.
A brief introduction of Cyclododecane
Cyclododecane (CDD) is a cyclic alkaline with the chemical formula, C12H24. It appears translucent colorless solid in a form of irregular crystal and is a very volatile substance. The most attractive characteristic is that it sublimes, eliminating additional chemical or physical treatment steps to remove it. In addition, its hydrophobic characteristic is ideal to use as a temporary consolidant for fragile materials during transportation and for cleaning treatment with water-sensitive material.
Being part of my MA dissertation research, I cooperated with UCL museum and asked for the transparent objects as scanning samples from the collections of Science and Engineering. These samples are the historical light bulbs and valves, which were produced in around 1920s (Fig.1). Due to surface property of transparency, these objects have difficulties in applying scanning for 3D documentation. They were generally documented with texts and photographs. Through 3D scanning, the morphology of objects can be precisely recorded for preservation and monitoring purpose, Also, the 3D data can be used to create replicas and visualized display on the website enhancing its educational value.
In the scanning project, a NextEngine 3D Laser Scanner, provided by Institute of Making of UCL, was employed to scan these objects (Fig.2). The average scanning time is estimated around 50 minutes for each object. Fig.3 demonstrates the result of 3D scanning with CDD coating. This application provides a desirable 3D model for transparent object and also reaches 3D documentation purpose in regards of substance reversibility and data completeness.
Nevertheless, since the CDD application is solvent-based, the transparent materials that are sensitive to organic solvent are not suitable for this approach, such as plastic objects and specimens. Except for this, using cyclododecane as an opaque coating for scanning transparent surface is a great choice!