Tea: An Alternative Adsorbent for the Preservation of Cellulose Triacetate Film

Abstract

Cellulose triacetate (CTA) film, the main film base of the Twentieth Century, is inherently unstable, affected by autocatalytic deterioration through hydrolysis. The release of, and subsequent exposure to, acetic acid known as ‘vinegar syndrome’ accelerates deterioration, placing all cellulose acetate materials at risk or actively deteriorating. Preservation techniques rely on cold storage to slow deterioration or microenvironments with adsorbent materials to remove corrosives and/or pollutants. However, commercially available adsorbents can be expensive and difficult to access. This research investigated the potential for tea and tea waste to act as an alternative, low cost, accessible adsorbent for the preservation of CTA film. Adsorption capabilities of various tea varieties and treatments were compared with activated charcoal, silica gel and molecular sieves. Testing established tea as an effective adsorbent of water and acetic acid vapour, with an aversion to adsorption of the plasticiser dibutyl-phthalate. Use of tea waste also involves additional cost, sustainability and accessibility benefits along with lessened corrosive potential. These findings support tea as a potentially viable alternative adsorbent for the preservation of CTA film, requiring further research into optimum application systems.

Keywords:

• Film preservation
• Cellulose triacetate
• Adsorbents
• Tea leaves
• Acetic acid and DBP adsorption

Acknowledgements

The authors would like to thank the National Film and Sound Archive, Canberra for identifying and proposing this innovative research topic, and the Grimwade Centre, The University of Melbourne for facilitating this research.

Author Biographies

Julianne Bell has completed a Master of Cultural Material Conservation (2016) specialising in objects conservation, and a Bachelor of Arts (Honours, 2013) majoring in Classics and Archaeology with a History minor, both obtained at the University of Melbourne. In 2017 Julianne commenced a PhD at the University of Melbourne funded by an ARC Linkage Project, supervised by Dr Petronella Nel and Prof Robyn Sloggett. Julianne's PhD research aims to focus on developing analytical techniques for characterising and identifying the condition and preservation requirements of three-dimensional objects composed of early cellulose ester plastics. Until his retirement in 2017.

Mick Newnham was the Manager, Conservation Services at the National Film & Sound Archive of Australia. He is the Immediate Past President of the South East Asia Pacific Audio Visual Archive Association and has contributed to the work of the International Federation of Film Archives (FIAF) Technical Commission, the Association of Moving Image Archivists (AMIA) Preservation Committee and the International Organization for Standardization's TC WG—the working group responsible for ISO standards and recommended practices pertaining to the care of audio visual materials.

Dr Petronella Nel is a lecturer at the Grimwade Centre. She has a BSc (Honours, 1990) in Chemistry and a PhD in Chemistry (2000) and MA in Cultural Materials Conservation (2006), from the University of Melbourne. She is currently leading an ARC Linkage Project ‘A National Framework for managing malignant plastics in Museum Collections’ in partnership with Museum Victoria, Queensland Museum, Museum of Applied Arts and Sciences—Powerhouse Museum, South Australian Museum, Art Gallery of NSW, University of Technology Sydney and Flinders University.

ORCID

Julianne Bell http://orcid.org/0000-0003-2825-1381

Petronella Nel http://orcid.org/0000-0002-8509-547X