Katuščák S, et al. Comparative Evaluation of Deacidification Processes. In: Die massenentsäuerung auf dem prüfstand. Ergebnisse des projekts "Nachhaltigkeit der massenentsäuerung von bibliotheksgut“, 26. october 2010, German National Library, Frankfurt

1

Comparative Evaluation of Deacidification Processes

Svetozár Katuščák Michal Jablonský1, Katarina Vizárová1, Milena Rehakova1,

Silvia Holúbková1, Jozef Hanus2, Martina Bajzíková3, Jozef Rychly4 and Štefan Vodný5

1 – Slovak University of Technology2 – Slovak National Archives3 – Slovak National Library4 – Slovak Academy of Sciences5 – Bel Novamann International/EUROFINS

2

Content

• A frame of this presentation of the comparative evaluation.

• What is out of the frame. Where to find additional information, that could be important but out of the scope of this presentation.

• Results of the SK & more objective studies.• Summarising & sequences of processes efficacy

from evaluating studies worldwide.

3

Introduction. Scope of the presentation

The paper degradation process of paper is complex multistimular proces, where the main stimulae are mechanical stress/damage,prehistory of folding, abrassion, effect of mechanical impurities, etc. (M), heat (H), light (L), and oxygene /oxidation (O), and biological (B) stimulae.

The scope of this presentation is a comparative evaluation of heat-induced accelerated ageing of test paper and books, deacidified by most important mass deacidification processes in the conservation industry, as performed by national project of the Slovak republic Kniha SK

•summarising similar objective measurement studies worldwide. •Because of the time limit for the presentation – the processes are evaluated here only according to the heat induced ageing and stability; I will get you acquanted with sequences of the processes according to the results of testing of mechanical permanence, compared with solution properties, chemiluminiscence, risk factors and reactive products analysis.

4

Out of the scope of this presentation

Out of the scope of this presentation have to stay the following phenomena of multicriterial efficacy evaluation:

• The effect of mechanical stress prehistory of paper (Brazinova 2004) on paper and paper conservation efficacy is not known; In the comparative studies in SR, EU, Switzerland and USA we all are dealing with the mechanically perfect test paper only. ; we do not know any objective comparative evaluation study evaluating efficacy of exibitions, logistic processes on the mechanically prestressed test paper, or critical parts of documents, usually determining the lifetime of the documents in praxis.

• Using the old preaged test paper (Rychly et al. 2006) and more (Matisova-Rychla et al. 2007; Bukovsky et al. 2007; Bukovsky and Trnkova 2003a,b) is out of the scope of this evaluation and presentation. The testing and comparative evaluation were performed in the collaborative testing of universities, academy, national archives and library in the Slovak Republic, and testing laboratory Bel Novamann International /Eurofins.

Bražinová, V. Štúdium možností zvyšovania stálosti tlačovín v procese ich starnutia. Bachelor Thesis, Slovak University of Technology, Bratislava, 2004.

5

Introduction

• the light induced aging, the role of organic and inorganic photo-sensibilisators, and compound with high specific area (Bukovsky et al. 2006a,b; Katuscak 2000)

Matisová-Rychlá, L., Bukovský, V., Rychlý, J., Pleteníková M. Chemiluminescence - a Novel Method in the Research of Degradation of Paper. I. The Effect of Light on Stacked Sheets of Paper, Macromol. Symp. 247, 2007, p. 340-349.Bukovský, V., Trnková, M., Nemeček, P., Oravec, P. Light-induced oxidation of newsprint sheets in a paper block. Part 1: Color changes in paper. Restaurator, vol. 27, no. 2, 2006a, p. 114-130.Bukovský, V., Trnková, M., Jakubíková, Z. Light-induced oxidation of newsprint sheets in a paper block. Part.2: Extent of degradation changes. Restaurator, vol. 27, no.3, 2006b, p. 200-217.Rychlý, J., Matisová-Rychlá, L., Bukovský, V., Pleteníková, M., Vrška, M. The progress of ageing of lignin-containing paper induced by light and its relation to chemiluminescence temperature runs. Makromolecular Chemistry, Polymer Symposia, 231, 2006, p. 178-192.Bukovský,V., Trnková, M. The influence of secondary chromophores on the light induced oxidation of paper. Part I: The influence of light on cellulose and secondary chromophores. Restaurator, 24, no. 1, 2003a, p.18-35.Bukovský, V., Trnková, M. The influence of secondary chromophores on the light induced oxidation of paper. Part II: The influence of light on groundwood paper. Restaurator, vol. 24, no. 2, 2003b, p.118-132.Katuščák S.: Photo-induced Modification of the Optical Properties of Lignocellulose Materials. Effect of Substrate Surface on the Photoyellowing of Surface-Coated Lignin Model Compounds. Wood Research vol. 45, no. 2, 2000, p. 1 – 14.

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Introduction• There exist different attitudes to comparative objective measurement of

deacidification processes efficacy allowing for an objective comparison and sequences of the processes, all having their limitations, e.g.: Lienardy 1994; Buchanan et al. 1994; Durovic 2000; Banik 2004; Banik at el. 2006; Hanus et al. 2006, 2008; Ramin et al. 2009).

• The parameters presented in this presentation are namely pH, alkaline reserve, mechanical, solution, and chemical properties and corresponding relative stability or efficacy factors.

Lienardy, A. Evaluation of seven mass deacidification treatments. Restaurator vol. 15, no. 1, 1994, p.1-25.Buchanan S, Bennet W, Domach M. An evaluation of the Bookkeeper mass deacidification process, Library of Congress, Pittsburgh, USA, 1994.Ďurovič, M Zaverečná správa grantového úkolu „Hromadné odkyslovanií papírových archiválií“. Praha, 2000.Banik, G, Evaluation of the efficacy of CSC- Booksaver® Process for the deacidification for archives and library materials, based on test treatments at the Preservation Academy Leipzig (PAL), 2004. http://www.cscbooksaver.com/files/banik.pdfBanik, G., Doering, T., Hähner, U. Current efforts to establish an effective quality management for mass deacidification. Conference SAVE PAPER, 2006, p.94-109.Hanus, J., Bakoš, D., Vrška, M., Jablonský, M., Katuščák, S., Holubková, S., Bajzíková, M., Bukovský, V., Rychlý, J. The Kniha Project in Slovakia. Durability of Paper and Writing, 2nd International Symposium and Workshops. National and University Library of Ljubljana, Faculty of Chemistry and Chemical Technology, Ljubljana, Slovenia, July 7-10, 2008, p. 17-19.Hanus, J., Bakoš, D., Vrška, M., Jablonský, M., Katuščák, S., Holubková, S., Bajzíková, M., Bukovský, V., Rychlý, J.: The Kniha Project in Slovakia. Durability of Paper and Writing, 2nd Int. Symp. and Workshops. National and University Library

of Ljubljana, Faculty of Chemistry and Chemical Technology, Ljubljana, Slovenia, July 7-10, 2008, p. 17-19. Ramin M, Andres H., Bluher, A., Reist, M., Wälchli M. Paper De-acidification A Comparative study. J. Paper Conservation vol. 10, no. 3, 2009, p. 17-25.

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The scope of the evaluation. 1. Mechanically perfect test paper used, but ...

• out of the scope of all deacidification efficacy testing studies summarised here are critical parts of paper and documents. We know that e.g. folded parts of newspaper or any other defective/ pre-exposed parts of paper could be critical for the lifetime of the document, time of achieving zero strength. The effect of the mass deacidification processes on the life expectancy extension of such critical places in paper has not been studied and evaluated sufficiently.

8

The scope of the evaluation. 2. No light-induced ageing and stability considered.

• The scope of this presentation is heat induced ageing and stability, taking in mind the multistimular complexity of the degradation in practice. The other stimuli and dimensions of evaluation are a subject of some specialised testing or projects.

• Wood (polyphenolic substances) containing test paper was selected as a characteristic, most sensitive paper in collections from last centuries. As an example of potential effect of sensitizing model phenolic compounds in wood containing paper are shown on the following graphs:

Photoreversion of apocynol (I), -methylveratryl alcohol (II) and acetoquaiacone (III) on Whatman No.1 filter paper.Temperature of sample surface 37°C; Conc. of model on filter paper 7%

Katuščák S. Photo-induced Modification of the Optical Properties of Lignocellulose Materials. Effect of Substrate Surface on the Photoyellowing of Surface-Coated Lignin Model Compounds. Wood Research vol. 45, no. 2, 2000, p. 1 – 14.

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Photo-induced ageing and photosensitisingMonostimular testing vs. multistimular complexity of degradation in praxis. But interactions and synergism could hardly be predicted because of complexity of real paper.

• Few examples: Cellulose do not absorb UV, so it should be lightfast. Why it is not?

• As it can be seen, even stable practically pure cellulose whatman paper can be sensitized and deteriorated by UV sufficiently by meny sensitisers.

• The substances used for the conservation should be considered as potential chemical impurities in terms of photoinduced ageing stability, and complex permanence of the paper documents in real use of the documents, and real conditions in deposits.

Photoreversion of apocynol (I), acetoveratrone (IV), and their 1:1 mixture on Whatman No. 1 filter paper. Temperature of sample surface 37°C; Conc. of model on filter paper 7%; Conc. of each model in 1:1 mixture, 3.5%.

Katuščák S. Photo-induced Modification of the Optical Properties of Lignocellulose Materials. Effect of Substrate Surface on the Photoyellowing of Surface-Coated Lignin Model Compounds. Wood Research vol. 45, no. 2, 2000, p. 1 – 14.

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The scope of the evaluation. Out of the scope is: The potencial effect of inorganic particles and high specific area substances, like SiO2, TiO2, ... on the light induced ageing and stability

• The effect of the high specific area matters are highly sensitizing compounds, silicon dioxide (SiO2.xH2O), is shown on the graph. The photoreversion of the other cellulose senzitizers was increased by 40 times. The light-absorbing, e.g. phenolic compounds, underwent extended photoreversion on cellulose and much more more in presence or when deposited on silica gel.

• Any paper can contain substances from production or conservation processes, process and non-process elements. The selection as well as testing of components should be complex and careful, because of their potential sensitising effect on particular way of degradation, e.g. photoinduced degradation.

Comparison of the photosensiting effect of acetoveratrone (IV) on apocynol (I) when deposited on filter paper and silica gel.

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Old/preaged test paper vs. new test paper

• It is recomended to test any new process of deacidifying, strengthening, antioxidising or sterilizing substances and technology processes using both types of test paper, new and the old/ preaged paper as well.

• The most important differences between old and new test paper, and/or the big changes achieved by controlled preaging are as follows: (1) controlled decreasing of degree of polymerisation (↓ DP), (2) changes in polydispersity /polydispersity parameters, R(Mw/Mn,..)(3) decreasing mechanical properties, such as folding endurance (↓ω ), and breaking length (↓ lt), (4) increasing carbonyl content ↑C=O, carboxylic acids (RCOOH), and aldehyde (RCOH) contents, and more, depending on the pre-conditioning, atmosphere and conditions used in the reactor.

• (5) old brittle paper seems to be much more sesnsitive to alkaline reserve value, Ar (%CaCO3) than the new one1.

1-Liers J.: Mass deacidification. The efficacy of papersave process. 2001.

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Old or preaged test paper and test books• The conservation processes are

used, and should be therefore developed and tested maily for old paper.

• At the first stage of the testing and evaluation, both new and „old“ preaged test papers were used.

• We have estimated that in this case no significant differences had been found for the processes tested between the preaged, but since not brittle paper and new acidic test papers. Inspite of this fact very significant differences can be found in some cases e.g. of testing new substances and processes, between results with the new and old preaged paper (Vrska et al. 2005; Kirschnerova et al. 2007) .

The pH distribution in individual 10 mm thick layers of the test paper from the pretreatment and the reactor

Reactor used for the preaged test paper production

Vrška, M, Tiňo, R. Shahani Chandru, Katuščák, S. Controlled process of the production of model aged test paper in the sealed reactor. Chem.listy vol. S, no. 99, 2005, p.409-410.Kirschnerová, S., Vrška, M., Vizárová, K., Katuščák, S. Artificial ageing of wood containing paper in the stack. Papír a celulóza, vol. 62, no.1, 2007, p.7-10.

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Specifications of the quality control applied in Library of Congress (LoC) 1994

1. Efficacy. Mechanical permanence folding endurance index related to unmodified control.

2. Completeness of deacidification. pH 2D-distribution (RFP90 -21 Requirement – C.2.1.7)

3. Alkaline reserve. (RFP90 -21 Requirement – C.2.1.8) 4. No damage to processed materials and media. (RFP90 -21

Requirement – C.2.1.10, C.2.1.11, C.2.7.12) 5. Potential to treat books on a mass scale. (RFP90 -21

Requirement – C.3)

Buchanan, S, Bennet, W, Domach, M. An evaluation of the Bookkeeper mass deacidification process, Library of Congress, Pittsburgh, USA, 1994, p. 4-7.Anonym. Library of Congress Technical Specifications for mass deacidification. Preservation Directorate, Library of Congress Washington, DC, 2004.

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ID Evaluation criteriaRecommended requirements for selection procedure of best available technologies (BAT) applicable in SR

KSustainability of development in Slovakia

(1) Supplier must document sustainability of development in Slovakia. (2) Fundamental condition of sustainability in SR is research and development carried out in SR. Foreign supplier is thus required to provide evidence of its interest in R&D cooperation with STU and SNL at continual improvement (continuerliche Verbesserung) and to document sustainability of competitiveness and BAT position in SR.  (3) Provide supporting data: duration of research in SR or cooperation in development of deacidification, supporting or directly related conservation technologies, interest in technical joint actions. Illustrate potential growth of employment of university educated employees in corresponding research, development and education in SR. Provide evidence on BAT, age of technology and equipment.

KPermanence. Permanence factor.

Factor of mechanical permanence S should be at least 3.

K

Damage or destruction of books. Extent of deterioration.

Supplier is required to document percentage and extent of deterioration in existing operation. Proposal of quaranteed max. deterioration. Proposal of quality control system.

Specifications of a complex evaluation of deacidification processes of Consortium Kniha SK. Prerequisite criteria

15

ID Evaluation criteriaRecommended requirements for selection procedure of best available technologies (BAT) applicable in SR

K4pH and alkaline reserve

pH exceeding 7. Within standard accelerated ageing pH shall not decrease under 6,5. Provide supporting information, duration (in days) and conditions of applied accelerated ageing. Demonstrate deacidification homogeneity.

K5 RisksCertify safety in the following areas: (K5.1) Toxicity, sanitary and senzoric properties; (K5.2) Environmental impact; (K5.3) Fire hazard, safety and health protection at work in deacidification facilities, libraries and archives.

K6 EconomyMin. price at max. quality K. The ratio of costs to guarenteed quality is evaluated. Sustainable development of quality and risk management system efficacy.

K7Supplementary criteria and methods

Supplier may introduce supplementary information supporting quality of its technology, quality and efficacy of supporting sustainable cultural heritage protection, competitivenes of the memory institution.

Specifications of testing and evaluation of deacidification processes. Prerequisite criteria

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• Practically all archive documents from the 19th century are acidic and should be protected using conservation processes including mass deacidification.

• Survey of 1400 books, analysis of the particular decades from the period 1900-2000 was performed

• 7 parameters were followed (1st level):– Acidity (pH – indicator, surface electrode), – Strength (puncture depth – centre & edge of page), – Thickness of the sheet,– Sizing degree,– Lignin content,– Yellowing, and – Alum content - Al2(SO4)2

Collection survey at the archives and the Slovak National Library and creation of database – example (V. Bukovský et al.: SNK Martin)

Maršala, M., Švehlová, D., Bukovský, V., Kuka, I.: Najdôležitejšie parametre hodnotenia stálosti papierových dokumentov. Knižnica, 2009, roč. 10, č. 10, s.35-38.Bajzíková, M., Hanus, J., Bukovský, V.: Characterisation of the Slovak national library collections. In Strlič. M., Kolar, J.: Durability of paper and writing. 2nd Inte. Symp. and workshops. Ljubljana, 2008, p. 51-52Bukovský, M., Cedzová , M., Trnková, M., Kuka, I.: A Survey of Library Collections: PAPER STRENGTH AND ACIDITY, Saving the Past for the future Varšava, 2007.

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Classification of books based on • acidity measurements, • mechanical properties • lignin content enabled their categorization into four groups

M. Reháková et all: Preselection of historical books in the process of their stabilization. Durability of paper and Writing, Ljubljana 2004.

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Experimental

Materials Wood-containing acidic test paper using alum rosin sizing, grammage 45 g/m2, cold extract pH: 4.5 – 5.0, surface pH = 5.6 ± 0.3, containing mechanically bleached, groundwood (55%), bleached sulphite pulp (20%), catch trash fibres (15%) and clay (10%) was used in all experiments. Testing books with 150 sheets of paper in size A5 format were used.

DeacidificationThe following deacidification processes: Booksaver, IPC (Institut Politecnic del Campus de Terrassa); Booksaver, PAL; Bückeburg, Neschen; Papersave Swiss, NCW; Papersave, BI; SoBu, Fürth; Papersave, ZFB were applied in the treatment.

19

Experimental

Accelerated ageing

Samples of paper were conditioned according to TAPPI T402 om - 93 at 23 ± 1 °C, and at relative humidity of air RH = 50 ± 2%, until achieving the homogeneous humidity of test books and test paper, prior the artificial ageing. The samples from all tested deacidification processes were subsequently aged according to ISO/DIS 5630-5, at 96 ± 1 °C and 50% RH, corresponding to paper humidity 4- 5 %. The standard test method for accelerated ageing of printing and writing paper in which the sealed ageing tubes were replaced by a composite bags made of polyethylene/ aluminium/ polypropylene (TENOFAN Al / 116S). 75 sheets of paper (A5 format) were encapsulated inside a PET / Al / PE bag. A preliminary comparison of kinetics and efficacy parameters have shown that the ageing of test paper in stacks at 96°C in closed bags was 3 times faster than the ageing the loose sheets of paper at 80°C.

TAPPI T402 om - 93: Standard conditioning and testing atmospheres for paper, board, pulp handsheets, and related products.ISO/DIS 5630-5: Paper and board – Accelerated ageing – Part 5: Exposure to elevated temperature at 100 °C.

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Experimental

Mechanical and solution properties• Surface pH was measured according to TAPPI T 529 om-88, using

a flat combined glass electrode.• Alkaline reserve was measured according to STN ISO 10716

(500441).• Folding endurance was determined using a MIT apparatus

according to TAPPI T511 om – 96 with a tension of 0.3 kg.Efficacy of treatment• The life expectancy has been determined by linear regression of

logarithm of the folding endurance. The efficacy has been expressed as factor of relative increase of the life expectancy, measured for each characteristic property, e.g. folding endurance  (St ω) has been calculated as follows:

n

m

t

tS

,0log

,0log

TAPPI 529 om – 88: Surface pH measurement of paper.STN ISO 10716 (500441): Paper and board. Determination of alkali reserve. TAPPI T511 om - 96: Folding endurance of paper (MIT tester).

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0 = - 0,0182.tlog ω=0, m + 3,2758 → tlog ω=0, m = -3,2758/-0,0182 = 180 days (papersave swiss process)

0 = - 0,1436 .tlog ω=0, n + 3,2702 → tlog ω=0, m = -3,2702/-0,1436 = 22,8 days (Control)

9,78,22

180

,0log

mod,0log

control

ified

t

tS

22

0 = - 0,0221.tlog ω=0, m + 3,3189 → tlog ω=0, m = -3,3189/-0,0221 = 149,9 days (papersave Battele)

0 = - 0,1436 .tlog ω=0, n + 3,2702 → tlog ω=0, n = -3,2702/-0,1436 = 22,8 days (Control)

6,68,22

9,149

,0log

mod,0log

control

ified

t

tS

23

0 = - 0,00551.tlog ω=0, m + 3,2007 → tlog ω=0, m = -3,2007/-0,00551 = 58,1 days (Booksaver process, IPC)0 = - 0,1436 .tlog ω=0, n + 3,2702 → tlog ω=0, m = -3,2702/-0,1436 = 22,8 days (Control)

6,28,22

1,58

,0log

mod,0log

control

ified

t

tS

24

+ good; = average; — poor; R rejected; x untested.The sequence of the processes was estimated as an overall evaluation, without weighing the meaning of partial visual observations and tests of rag, chemical and wood paper parameters.

ProcessSequence1- the best

DEZ 1

Bookkeeper 2

Wei to 3

Sablé 4

FMC 5

Vienna 6

BPA 7

Lienardy 1994. One of the first comparative studies of older processes, semiquantitative. Some of the processes, such as DEZ or Vienna, are not existing any more.

Buchanan S, Bennet W, Domach M. An evaluation of the Bookkeeper mass deacidification process, Library of Congress, Pittsburgh, USA, 1994.

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Buchanan et al. 1994. An evaluation of one process (Bookkeeper) on 4 grades of test papers

MD, 90°C 50%RH, up to 30days A B tlog=0 S log=0

Alum rosin sized paper - control 1,9564 -0,0565 34,63 1,0

Alkaline sized paper - control 1,556 -0,01 155,6 1,0

Clear spring offset paper – control 2,0028 -0,0652 30,72 1,0

Newsprint paper - control 1,96 -0,0526 37,26 1,0

Alum rosin sized paper - treated 1,8957 -0,0247 76,75 2,2

Alkaline sized paper - treated 1,5419 -0,0078 197,68 1,3

Clear spring offset paper – treated 2,0461 -0,0261 78,40 2,6

Newsprint paper - treated 1,9322 -0,0254 76,07 2,0

Buchanan S, Bennet W, Domach M. (1994) An evaluation of the Bookkeeper mass deacidification process, Library of Congress, Pittsburgh, USA, p. 4, summary report, TABLE I.

S(LoC) – efficacy factor of Library of Congress is consistent with

our factor of mechanical permanence S logω=0

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Grachová 2005: An evaluation of Bookkeeper spray

Sample  A B tlogω=0 S logω=0

Control (80°C, 65%RH, up to 12 days) 2,3397 -0,0617 37,92 1,0

Bookkeeper (80°C, 65%RH, up to 12 days) 2,3813 -0,058 41,06 1,1

Control (MD, 105°C, up to 36 days) 2,1872 -0,0538 40,65 1,0

Bookkeeper (MD, 105°C, up to 36 days) 2,091 -0,0574 36,43 0,9

Grachová, L. Porovnanie a optimalizácia vybraných metód ochrany kníh a dokumentov, Diploma Thesis, Slovak University of Technology, Bratislava, 2005.

The use of Bookkeeper spray suspension for impregnating the wood-containing test paper was not effective in increasing paper permanence Inspite both the pH and Ar (%CaCO3) were good.

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Banik 2004: Comparison of the risk indicators for three mass deacidification processes.

To establish the risk indicator, 37 books were evaluated. The data reflect.

• Risk indices are calculated from three data:

• Frequency (F) of damage, calculated by the percentage of all recorded alterations of the same type divided by ten.

• Intensity or degree (D) of the recorded alterations expressed in three levels: – Slight (1); Noticeable

(2); Significantly noticeable (3).

Banik, G, Evaluation of the efficacy of CSC- Booksaver® Process for the deacidification for archives and library materials, based on test treatments at the Preservation Academy Leipzig (PAL), 2004. http://www.cscbooksaver.com/files/banik.pdf

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Banik 2004. Comparison and the sequence of the 3 deacidification processes.

The higher the number, the greater the risk posed to a collection by a certain treatment. The lowest possible value is zero, the highest possible value is 2’250.

Banik, G, Evaluation of the efficacy of CSC- Booksaver® Process for the deacidification for archives and library materials, based on test treatments at the Preservation Academy Leipzig (PAL).2004. http://www.cscbooksaver.com/files/banik.pdf

0

10

20

30

40

50

To

tal R

isk

In

dic

ato

r

The Appraisal value (value number, V) in the context of the particular collection: a number that expresses the significance of the damage in the context of the collection. The multiplication of the three data produces the risk indices (risk numbers RN) for one damage category : (RN = F x D x V). When all the risk numbers are added, the total risk index (RI) can be determined according to: ΣRN = RI

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Comparative evaluation of mass deacidification processes efficacy according to the Library of Congress, Washington (LoC), Consortium and Testing Lab KnihaSK, Bel Novamann International, Bratislava. The sequence of the deacidification processes according to KnihaSK Consortium evaluation of mechanical permanence factors efficacySτ, ω - coefficient of ageing time change; the index Sτ, ω is related to a non-modified, non-deacidified control sample having Sτ, ω = 1.

Processes evaluated in the Consortium KnihaSK Testing Lab, the test books of A5 format (wood-containing paper, 55% of mechanical bleached groundwood, 20% of bleached kraft pulp, 15% scrap fibres and 10% clay, surface pH = 5.6), ageing conditions: accelerated ageing in closed bags from composite foil (PET-Al-PE), 961°C, 15 days

Ditto, the test sheets of A5 format, accelerated ageing, 105°C.

Process evaluated in the Consortium KnihaSK Testing Lab, the test sheets of A5 format (wood-containing paper, 55% of mechanical bleached groundwood, 20% of bleached kraft pulp, 15% scrap fibres and 10% clay, surface pH = 5.6), ageing conditions: accelerated ageing in closed bags (PET-Al-PE), 961°C, 15 days.

Process evaluated at the IPST, Atlanta and at the LoC, various kinds of test sheets (pH = 5.7 – 9.42), accelerated ageing at 90°C and relative humidity 50% during 30 days.

Hanus 20061-20082. Comparative evaluation of mass deacidification processes efficacy according to the LoC and the Consorcium Kniha SK specifications

Hanus, J., Bakoš, D., Vrška, M., Jablonský, M., Katuščák, S., Holubková, S., Bajzíková, M., Bukovský, V., Rychlý, J. The Kniha Project in Slovakia. Durability of Paper and Writing, 2nd International Symposium and Workshops. National and University Library of Ljubljana, Faculty of Chemistry and Chemical Technology, Ljubljana, Slovenia, July 7-10, 2008, p. 17-19.Anonym. Validácia, kritické hodnotenie a porovnanie nezávislých hodnotení v USA, Švajčiarsku, Nemecku a v Slovenskej republike 2008. http://www.knihask.eu/novinky_2009/Vyber_BAT_validacia.pdf

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Solution properties. Gel permeation chromatography

Figure 1: Molecular weight distributions of the tricarbanilates of the accelerated aged newsprint paper at 0, 2, 5, 10, 20 and 60 days.

Figure 2: Correlation between each pair of variables. These regression coefficients (R2) measure the strength of the linear relationship between the variables: = time of accelerated ageing.

Kačík, F., Kačíková, D., Jablonský, M., Katuščák, S. Cellulose Degradation in the Process of Newsprint Paper Ageing. Polymer Degradation and Stability, vol. 94, no. 9, 2009 1509-1514. Kačík, F., Kučerová, V., Výbohová, E., Kirschnerová, S. Hodnotenie starnutia papiera metódou gélovej permeačnej chromatografie. In: Acta Facultatis Xylologiae, XLIX, no. 1, 2007, p.27-34.

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Deacidification processes efficacy sequences according to 3 independent methods: mechanical permanence (MIT-folding endurance), solution properties/GPC and CL

  S ω Sequence S DP Sequence S kCL Sequence

Papersave swiss, NCW 7,9 1 13,1 1 1,51 1

Papersave, BI 6,6 2 3,00 3 1,35 2-3

SoBu 4,7 3 4,60 2 1,35 2-3

Papersave, ZFB 4,6 4 2,20 5 1,02 5

Booksaver, IPC 2,6 5 2,40 4 1,47 4

Booksaver, PAL 1,3 6 1,10 6 0,95 7

Control 1 7 1 7 1 6

1 - Sω – MIT-folding endurance factor / life expectancy extension factor ; 2 – S DP factor of increasing of effective lifetime (life expectancy extension) according to the solution properties (DP); 3 – S kCL chemiluminiscence factor of increasing paper stability

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Comparison of independent studies testing the mechanical permanence factors efficacy, from the testing laboratories and projects in USA (LoC-efficacy)1, SNL (ULE factor)2 and the Consortium of national archives, libraries, universities, academy of sciences and acredited lab BN/EUROFINS SR3– KnihaSK (Sω)

The Testing laboratory on the X – axis, is shown in brackets: [SNL] – Swiss National Library 2; [KnihaSK] - Consortium of national archives, libraries and universities of technology SR 3; [IPST] – Institute of Paper Science and Technology, Atlanta 1 1 Buchanan, S, Bennet, W, Domach, M. An evaluation of the Bookkeeper mass deacidification process, Library of Congress, Pittsburgh, USA, 1994.2 Ramin M, Andres H., Bluher, A., Reist, M., Wälchli M. Paper De-acidification A Comparative study. J. Paper Conservation vol. 10, no. 3, 2009, p. 17-25.3 Hanus, J., Bakoš, D., Vrška, M., Jablonský, M., Katuščák, S., Holubková, S., Bajzíková, M., Bukovský, V., Rychlý, J. The Kniha Project in Slovakia. Durability of Paper and Writing, 2nd Inter. Symp. and Workshops. Ljubljana, Slovenia, July 7-10, 2008, p. 17-19.

STS – the coefficient of relative increase of the lifetime for tensile strengthSBF - the coefficient of relative increase of the lifetime for tensile strength after Bansa-Hofer foldingS - the coefficient of relative increase of the lifetime for folding endurance

Deacidification of archival documentsDeacidification of books and closed archival boxes

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Summary of more independent evaluation studies including both mechanical permanence factors and chemical testing/stability factors. The sequence of the processes according to independent laboratories in Germany (DEG project Banik), Switzerland (SNL), USA (IPST) and Slovakia (Consortium KnihaSK). Each result is related to the best value achieved by each testing team, according to its independent attitudes and criteria (100%).

Y1 – factor of mechanical permanence for tensile strengthY2 - factor of mechanical permanence for tensile strength after Bansa-Hofer foldingY3 - factor of mechanical permanence for folding enduranceY4 – emission of furaldehyde, threshold growth of signalY5 – emission of acetic acid a – Swiss National Library (SNL)

b – Deutsche Forschungsgemeinschaft project (DEG)c – KnihaSK

d – Institute of PAper Science and Technology, Atlanta

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Conslusions

1. The independent measurement and comparative evaluation studies of mass deacidification processes efficacy performed by labs in the USA and EU have been compared and summarised.

2. The efficacy has been evaluated according to the mechanical permanence, solution properties, reaction produts, chemiluminiscence as well as risk factors. Inspite of the various attitudes and dimmensions measured, the results of the independent studies match quite well, mainly in substantial conclusions:

3. All most important deacidification processes have been efficient in achieving pH value above 7, and deposited necessary alkaline reserve. The pH and the alkaline reserve neither quarantee the long term mechanical permanence, nor the efficacy of the deacidification process (see results with the efficacy factor S<1), and some could even damage the documents of cultural heritage if used.

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Conslusions (cont.)4. The sequence of the processes ranges from the best available

technolgy most effective for books papersave swiss, through papersave, CSC and SoBu to less effective Bookkeeper process.

5. The measurement of kinetics of the mechanical, solution and chemical properties has shown that the processes providing good diffusion 3D distribution of the alkaline reserve, are generally more efficient.

6. More conlusions for Slovakia.EU: the following BATs are recommended for conservation of varios types of acid paper documents: the most effective papersave swiss/ papersave for books, aqueous Bueckeburg/Neschen for sheets of paper, the lowest cost and highest eco-quality SoBu, integrated with the swiss Quality and documents safety controle management (BAT/QSC) and NDE-Survenir. If a special, e.g. mobile equipment is required, also other processes fullfilling basic LoC/Kniha SK requirement, in case they provide proofs of efficacy for considered types of documents.