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a: Wood pulp samples after different types of chemical processing. Bottom: unbleached kraft; center: unbleached sulfite; top: bleached pulp. From: G. Banik, I. Brückle, Paper and Water, Elsevier, 2010, in print.
Source publication
Similarities and differences between paper conservation bleaching and the bleaching of pulp in papermaking are examined in this short review. The oldest conservation bleach, light bleaching, is considered for the common roots it shares with textile and paper bleaching.
Contexts in source publication
Context 1
... pulp and bleaching paper follows the same chemical principles. Pulp and aged paper have, however, different technical requirements for treatment due to the fact that one is a fibrous raw material (Fig. 7.a) and the other is already a paper sheet that is part of an object (Fig. 7.b). Similarities and differences can be summarized as ...
Context 2
... pulp and bleaching paper follows the same chemical principles. Pulp and aged paper have, however, different technical requirements for treatment due to the fact that one is a fibrous raw material (Fig. 7.a) and the other is already a paper sheet that is part of an object (Fig. 7.b). Similarities and differences can be summarized as ...
Similar publications
As a result of the constantly growing demand for textile fibres interest in utilising cellulose pulps for manufacturing regenerated cellulose fibres is growing. One promising water-based process for the manufacture of regenerated cellulosic products is the Biocelsol process based on an NaOH/ZnO solvent system. The drawback of the Biocelsol process...
Citations
... In addition to the bleaching of fibers before the manufacture of paper, bleaching treatments also have been used for conservation and repair of paper-based items (Burgess 1988;Henniges and Potthast 2009;Brückle 2009Brückle , 2012Smith 2012). Smith (2012) emphasized the importance of maintaining a sufficiently high pH (above 9) during bleaching with hypochlorite, for instance, in order to minimize the formation of carbonyl groups, which is highest at pH 7 (Lewin and Epstein 1962). ...
For about two millennia, paper has served as a main medium for preservation of people’s ideas, stories, contracts, and art. This article reviews what is known about the various components that make up paper from the perspective of their long-term stability under typical storage conditions. Literature evidence is considered relative to the susceptibility of different paper components to embrittlement, acid hydrolysis, microbiological attack, and discoloration, among others. The cellulose that makes up a majority of most paper items is demonstrably stable enough to persist for many hundreds of years on the shelves of archival collections, though it is susceptible to acid-catalyzed hydrolysis, which can be accelerated by byproducts of decomposition. Though less attention has been paid to the archival performance of various minor components of modern paper products, evidence suggests that at least some of them are subject to likely breakdown, embrittlement, or decay in the course of prolonged storage. Based on these considerations, one can envision different categories of paper that can be expected to meet different levels of storage stability: ancient recipes for handmade papermaking, e.g. washi and hanji, archival-grade paper products, ordinary modern alkaline paper products, and paper manufactured without concerns for its longevity.
... Documents or office paper is a highly valuable raw material for making recycled paper because it is homogeneous, easy to collect, and recyclable. The obtained raw material does not have to be bleached and can be recycled without the use of chemicals [36,37]. ...
Sustainability is a premise that has been implemented in all technologies, industries, and service activities to have as little impact on the environment as possible. Typography as a profession made its contribution by creating eco fonts. In each country, the law regulates the lifespan of the storage of everyday business documents. One of the ways to reduce the impact on the environment is to reduce the consumption of ink, which can be achieved by printing the document with more sustainable fonts. By using the mentioned fonts when creating documents, the user should not notice a visual difference, and the document should have the same level of readability. Earlier research on ecological standards was only related to the environmental acceptability of materials, i.e., inks or printing substrates. Using eco fonts, each ink can have a reduced environmental impact. The more environmentally friendly fonts, Ryman Eco and Ecofont Sans, were tested in this experiment. Arial as a standard sans serif font and Times New Roman as a standard serif font were used as reference fonts. In the research, coverage data of different document samples created with different types of typeface and spacing are interpreted to investigate the possibility of saving ink. As eco fonts have been used since the end of the previous and beginning of this century, some stored documents are certainly ready for waste management, which is almost always recycled. By recycling document samples, the optical characteristics of laboratory paper sheets obtained by chemical deinking flotation were investigated. Another aim of the investigation is to provide insight into the quality of recycled fibres after the recycling process.
... The first known approach to brightening works of art on paper was the use of light bleaching, mentioned as early as the seventeenth century (Stevenson, 1990). After the invention of chemical bleaches for industrial use, particularly the introduction of chlorine in paper production in the eighteenth century (Smith, 2012), bleaching agents began to be adapted and modified for use in treating artworks (Brückle, 2009b). As paper conservation developed into a modern profession, the necessity arose for researching the risks associated with these chemically potent agents (Hey, 1977;Burgess, 1988). ...
The goal of our survey was to learn how practicing paper conservators are thinking about treatment approaches and materials used in the bleaching of paper for the purpose of stain reduction and removal. We designed a survey, which we circulated via professional conservation networks. The feedback is formalized in this paper. The survey, consisted of multiple-choice questions; respondents were encouraged to leave comments in an open text option. The data collected were grouped according to general observations, practices regarding popular bleaching agents (hydrogen peroxide, light, and sodium borohydride) and individual comments from the respondents. In conclusion, bleaching plays an important, but not a dominant role in paper conservation practice. Those who bleach tend to apply well-known bleaching agents and pay attention to pre- and post-bleaching treatments. The results speak to a high level of awareness concerning potential negative effects, and a careful approach to the use of bleaching agents.
... The intensity of light exposure determines the rate of bleaching action (Feller et al. 1982;Palmer Eldrige 1982;van der Reyden et al. 1988). With sunlight and fluorescent tubes, the noted drawback concerns the potentially long duration of aqueous exposure (Baker 1982(Baker , 1986Saur-Aull 1996;Brückle 2009a;Henniges and Potthast 2009), due to their low light intensity (Gowland and McAusland 2003). The first light source with significantly higher luminous flux was the high-intensity-discharge lamp (HID) introduced by Perkinson (2001). ...
High performance daylight LED lamps are compared with HID lamps for light bleaching of paper. The LED can be placed in closer proximity to the object than the HID lamps, causing a significantly increased, uniform light exposure. Two commercial LED systems with 4000 K and 6500 K colour temperature were installed in a convertible test device with a polypropylene tray in default exposure distance of 10 cm and 20 cm. A HID lamp in 60 cm and 120 cm distance served as a reference. Samples of two naturally aged rag papers were bleached with both LED systems and with the HID while immersed in water. All three light sources increased brightness (CIELAB L*), though the LEDs with 4000 K colour temperature were most effective. They had no negative effect on the molar mass and the cellulose carbonyl group content while LEDs with 6500 K colour temperature caused molar mass decrease and carbonyl group increase. LEDs of a 4000 K or similar colour temperature are a promising option for improved light bleaching of paper, reducing the treatment and aqueous exposure time and eliminating UV radiation.
... The natural phenomenon of photobleaching was observed in early times and used to whiten paper and textiles [10][11][12][13][14]. Sun-bleached paper found first mention in a compilation of recipes dating back to the 17th century, in which it was suggested that prints could be bleached by exposing them to sunlight while wet [11]. ...
... The natural phenomenon of photobleaching was observed in early times and used to whiten paper and textiles [10][11][12][13][14]. Sun-bleached paper found first mention in a compilation of recipes dating back to the 17th century, in which it was suggested that prints could be bleached by exposing them to sunlight while wet [11]. ...
... It is considered that both thermal yellowing and light-induced yellowing are attributable to changes in ligninthe formation of complicated lignin derivatives-which are not easily identified [9]. Some aged paper may have chromophores, which result from the presence of lignin and also stem from the degradation of the cellulosic fraction [11]. ...
Photobleaching of aged traditional Japanese paper that has been thermally yellowed during storage for 200 years was examined from the standpoint of accumulated light radiation dos-age in a museum environment. The light inten-sity was evaluated using a blue wool reference of the Japan Industrial Standards (JIS) as a do-simeter. The wavelength sensitivity of the pho-tobleaching was compiled under monochro-matic light radiation. Color changes in the spe-cimens were measured in tristimuli values in color. by using a color analyzer. The aged pieces of paper were monitored continuously as they were photobleached under three different light-ing conditions in a museum environment for 8000 h. The combination of the yellowness in-dex changes of the aged pieces of paper and the color changes of a blue wool reference was in-terpreted as follows. Photobleaching was gov-erned by accumulated light intensities and was independant upon daily lighting conditions. The wavelength sensitivity of the photobleaching of aged paper showed that the maximum effect occurred at 420 nm in the visible light range. The blue wool reference was confirmed to per-form well as a dosimeter.
This paper surveys research and professional literature on preservation-related topics published in 2009 and 2010, identifies key contributions to the field in periodicals, monographs, and research reports, and provides a guide to the changing landscape of preservation in the digital age. The authors have organized the reviewed literature into five major areas of interest: tensions in preservation work as libraries embrace digital resources, mass digitization and its effects on collections, risk management and disaster response, digital preservation and curation, and education for preservation in the digital age.
This paper reviews the development of the application of high intensity discharge (HID) lamps for light bleaching works of art on paper. It describes the construction of a light bleaching unit using HID lamps, specifying key functionalities of the system. In addition, selected methods of bleaching are discussed for their principal working parameters, namely immersion bleaching, bleaching on the slant washing board, and on a moist blotter. An appendix lists terms important to know when working with HID light bleaching systems.
The detection of individual chromophores that contribute to the overall discoloration of paper ("yellowing") is a challenge because those substances are only present in very small amounts. In this research, two analytical approaches based on ambient ionization techniques, namely desorption electrospray ionization and paper spray, both coupled to mass spectrometry, are compared to each other with regard to their suitability for detecting acetylated cellulosic key chromophores. The paper spray approach proved to be the more sensitive and versatile method. Subsequently, paper spray (PS)-mass spectrometry was applied to model papers and historical papers in which the acetylated chromophores were detected successfully. Independent accurate mass measurements confirmed the results obtained from reference compounds, model samples and real-world specimens.
Several reagents were tested as possible future pre-treatments to hydrogen peroxide bleaching of discoloured paper with the goal of minimizing the degrading effect of hydrogen peroxide on cellulose. Two historic rag papers were used as testing substrate, one with high, the other with low levels of iron ion content. The two papers underwent the following test protocol: all samples were rinsed in deionized water for ten minutes. Samples were then divided to undergo seven different bleaching pre-treatments: (1) deacidification with calcium hydroxide solution at pH 9; (2) deacid-ification with magnesium hydrogen carbonate solution at pH 7.5; (3) hydrochloric acid (HCl, 0.1 M, pH 1) followed by deacidification with calcium hydroxide; (4) calcium phytate (1.75 mmol/L, pH 5.3) followed by deacidification with calcium hydroxide; (5) magnesium phytate (pH 6.5) followed by deacidification with magnesium hydrogen carbonate solution; (6) and (7) the chelating agent diethylene-triamine-pentaacetic acid (DTPA, 0.005 mol/L, pH 3) followed by deacidification either with calcium hydroxide or magnesium hydrogen carbonate. All samples were immersed in 3% hydrogen peroxide baths (pH 9, adjusted with calcium hydroxide). They were dynamically aged in a customized setup in a stack (20°C–80°C, three hour intervals, six weeks). The samples underwent analyses before treatment, after bleaching and after accelerated ageing. The molecular weight and carbonyl group content of the cellulose were determined with fluorescence labelling in combination with gel permeation chromatography (GPC-MALLS). Brightness reversion of the papers was determined by colourimetry. The iron content level was determined by inductively coupled plasma-mass spectrometry (ICP-MS) before and after treatment. The paper with low iron ion content did not benefit measurably from the pre-treatments, whereas the paper with high iron content benefited from some of the pre-treatments, as determined after accelerated aging. The least increase in carbonyl group content after accelerated ageing was achieved with calcium phytate (4); followed by magnesium phytate (5); and DTPA with magnesium hydrogen carbonate deacidification (7). The highest carbonyl group increase was caused by the calcium hydroxide pre-treatment (1). The M w was best with the phytate-treated samples (4 and 5), followed by DTPA with magnesium hydrogen carbonate deacidification (7) and hydrochloric acid (3); the calcium-hydroxide deacidified sample showed the greatest M w loss (1). All of tested iron removal and complexation treatments (3-7) diminished brightness reversion. DTPA (6 and 7) and hydrochloric acid (3) diminished the iron ion content of the high-iron-content paper by 30%. In sum, the tests 3–7 showed distinct benefits over deacidification alone (1 and 2) and may become viable as pre-treatment agents before hydrogen peroxide bleaching after further testing on object materials.
The main paper conservation methods are presented, classified in the following categories: preparation of the intervention, disinfestation and disinfection/sterilization, surface/dry cleaning, wet cleaning, chemical stabilization, paper repairs, consolidation and strengthening. Treatment documentation is also discussed. The targets, the historical aspects, the general principles, the materials and equipment, the acceptance and criticism pertaining to each method are briefly reviewed, and the most important research for their evaluation is presented. Several paper stabilization strategies, such as deacidification and iron gall ink stabilization, applicable to paper are elucidated. Specific consolidation and strengthening methods for paper, such as lamination and paper splitting are also discussed. The review mainly focuses on the established methods, but experimental, abandoned or insufficiently documented methods are also included. Shortcomings and limitations of several methods were found in the literature, concerning health issues, limited effectiveness, adverse side-effects on the treated artefacts and restricted applicability.
