WetCleaning of Historical Textiles: Surfactants and Other Wash Bath Additives
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| Format: | Article |
| Language: | English Slovak |
| ISSN: | ISSN 1605-8410 |
| Online Access: | http://www.viks.sk/chk/revincon4.doc |
| Abstract: | SUMMARIES. The paper is a review of the literature relating to the use of water, surfactants and other additives for cleaning historical textiles. Ethical considerations are introduced and the common types of soil that occurs on historical textiles are characterized. The review covers publications on the advantages and disadvantages of wet cleaning and discusses the properties of water, detergents and surface active agents. The paper underlines the importance of the HLB value, critical micelle concentration, solubility of surfactants, Krafft and cloud point in conservation. Washing processes using surface active agents, the connection between the chemical structure of surfactants and detergency, the role of soil/dirt anti-redeposition agents, foam, pH, washing time and temperature in cleaning are discussed and the composition of solutions for washing historical textiles are given. The paper introduces the dependence of rinsing on the adsorption of surfactant to textiles and reviews the use of vacuum suction in wet cleaning. The efficiency of washing and the effect of washing on fibres, textiles and dyes is assessed and the review ends with references to biodegradation of surfactants and a list of selected case studies. CONCLUSION. It is natural that a literature review also provides a historical overview. Publications on textile conservation from the 1950s and 1970s show the strong influence of industry on the surfactants and other ingredients used in wash baths for historical textiles. Working with conservators, scientists entering conservation from an industrial background, sooner or later recognized the limits in the use of the enormous number of different washing agents available and applicable to industry. Research in the 1980s and 1990s resulted in wash bath recipes much more closely tailored to conservation. However, there are several 'grey areas', such as the connection between critical micelle concentration, cloud point and Krafft point; how to determine the remained adsorbed surfactant in the washed historical textile (in September 2000 Howell and Carr [206] presented a promising new method using X-ray Photoelectron Spectroscopy); or simply, what is the appropriate washing time. After finding appropriate surfactant and washing solution compositions, many workshops started to use predominantly one type of surfactant routinely (see the popularity of Orvus WA in the USA and Synperonic N in the UK), despite there-being many varied surfactants available and recommended in the conservation literature. The method of choosing particular surfactants and washing solutions according to the specific need of the object to be treated, or using them in combination is still rare. Fast dissemination of information is characteristic of recent years but not of the past: although Rice published on the use of amomc detergent in the first, and non-ionic in the second wash bath in 1966 [95], it was only in 1995 that Gentle and Muller systematically researched the use of mixtures of amonics and non-ionics in the same wash bath [80]. Dating from 1995, Walker's recommendation to start with a lower, and end with a higher HLB surfactant in a two-step washing process seems to have had little influence on the textile conservation field [43]. The environmental concerns, both relating to conservators' health and the biodegradability of surfactants, necessitated new researches in this field, not for the purposes of the conservation of historical textiles, but for the conservation of human beings and their environment. It is true that there are negative remarks on the health effects and slow biodegradability of some popular surfactants in specialist literature before Schick's work of 1966 [177]; however, the first warning relating to the use of nonlyphenol ethoxylates in the field of textile conservation came from Potter in 1992 [178], followed by Gentle and Müller's 1995 thesis [80] and ending with Daniels' dramatic announcement in 1999 [179]. Now, as increasing numbers of conservators and scientists are searching for a replacement for Synperonic N, it should be asked why it took such a long time to start dealing seriously with the problem. Also, it may be questioned, as did Howell [206], whether the very small quantities, which are used highly diluted in textile conservation, are really the cause of such a serious problem or if this is much more a problem for industry. In conclusion, the author hopes that the above review shows the importance of studying the 'industrial' literature, of allowing enough time for a thorough conservation-related 'critical' adaptation and of being sufficiently fast in following initiatives towards new research. |
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| ISSN: | ISSN 1605-8410 |
