PRELIMINARY TESTS REGARDING THE ENDOGENOUS AND EXOGENOUS ENDOGENOUS AND EXOGENOUS

FACTORS THAT INDUCE BOOK AND DOCUMENTDOCUMENT

DEGRADATION

Catalina Mihaela Talasman, Constantin Stanciu, Daniela ManeaResearch Department SC CEPROHART SA Braila ROMANIAResearch Department SC CEPROHART SA, Braila, ROMANIA

Valentin I MoiseTechnological Irradiation Centre, Physics and Nuclear Engineering

Institute “Horia Hulubei”, Bucharest, ROMANIA

The main characteristics that defines the paper p pdurability

Were performed determinations for the main characteristics that defines the papers’ p p pdurability: breaking load, breaking length, folding endurance, whiteness, bursting strength, Cobb size test, opacity, tearing resistance according to the following standards:

• Grammage SE EN ISO 536:97, • Thickness SR EN ISO 534:2005, ,• Breaking length SR EN ISO 1924- 2:2009, • Opacity ISO 2471:2008, • Sizing STAS 4748:1985, • Whiteness ISO 2470-1:2009, • Smoothness SR ISO 5627:1995• Smoothness SR ISO 5627:1995, • Bursting strength SR EN ISO 2758:2004, • Tearing resistance SR EN 21974:97 g• Cobb size test SR EN 20535:96 • Folding endurance SR ISO 5626:96

SR ISO 5630 1 :1995 Paper and board• SR ISO 5630-1 :1995. Paper and board. Accelerated ageing. Part 1: Dry heat treatment at 100oC

• SR ISO 5630-3 :1997. Paper and board.SR ISO 5630 3 :1997. Paper and board. Accelerated ageing. Part 3: Moist heat treatment at 80oC and 65% relative humidity80oC and 65% relative humidity

• SR ISO 5630-4 :1996 Paper and board. Accelerated ageing. Part 4: Dry heat treatment at 120oC or 150oC

• SR ISO 9706: 1996 – Information and documentation Paper for documentsdocumentation. Paper for documents. Requirements for performance

THE CAUSES THAT PRODUCES PAPER AGEINGCOULD BE DIVIDED IN TWO MAIN CATEGORIES:

• The category of internal or endogenous factors that consists of the raw materials nature and that consists of the raw materials nature and the manufacturing category of process

tparameters

• The category of external or endogenous factors that comprises the influence of environment that comprises the influence of environment (temperature, humidity, corrosive gases,

i i t )microorganisms etc)

The experimental program consists in an accelerated ageing process performed on:g g p p

a) samples of old documents naturally aged and manufactured in 1881 2006manufactured in 1881 ÷ 2006

b) tests realized on paper samples obtained at laboratory scale and in various conditions

Both sets of experimentations evaluated the Both sets of experimentations evaluated the influence of the endogenous and exogenousfact the h ical a d echa ical factors on the physical and mechanical properties of paper sheets providing information regarding their resistance to the ageing processg g p

a. Laboratory scale experimentations performed l i d f ld d on samples various grades of old paper and

documentsWithin the experimental program we used samples of:Batch no. 1

W t k SC L t SA B ă (WMP)Watermark paper SC Letea SA Bacău (WMP)Coated paper SC GHIMBAV SA (CP)Neutral sized copy paper manufactured in Austria (XP)Neutral sized copy paper manufactured in Austria (XP)

Batch no. 2Pronosport paper 70 g/m2 (the first neutral sized paper manufactured in Romania)manufactured in Romania)1A type paper 60 g/m2 (the first neutral sized paper manufactured in Romania)

Batch no. 3pages from a book printed in 1940 in Romania (private library)pages from a book printed in 1981 in Romania (private library)pages from a book printed in 1981 in Romania (private library)

Batch no. 4pages from a book printed in 1923 in France (private library)

b. Laboratory scale experimentations performed l d f t d th on paper sampled manufactured on the

CEPROHART PM or in the RD laboratory and submitted to an accelerated ageing process in

various conditionsAnother set of experiments were performed on:

A class copy paper with a grammage of 80 g/m2A class copy paper with a grammage of 80 g/mmanufactured on the SC CEPROHART SA Brăila paper machinepaper machineTwo handsheet sets on the Rapid Köthen sheet former from CEPROHART’s pulp laboratory

Paper grade Paper grade

CharacteristicsWatermark

paper LETEA BACĂU

Coated paper ECOPACKGHIMBAV

Watermarkpaper

LETEA BACĂU

Coated paper ECOPACKGHIMBAVLETEA BACĂU

Manufactured in 1996

GHIMBAVManufactured in

1996

LETEA BACĂUManufactured in

1996

GHIMBAVManufactured in

1996

Grammage, g/m2 91 97,0 91 96,8

Breaking load,N, L/T

123/38 86/34 112/34,6 75/29

Breaking length m 9200/2840 6033/2375 8364/2584 5246/2065Breaking length, m, L/T

9200/2840 6033/2375 8364/2584 5246/2065

Whiteness, % 55 86 50 76(yellow paper) (yellow paper)

T i i t 765/1048 334/417 693/953 290/363Tearing resistance, mN, L/T

765/1048 334/417 693/953 290/363

Folding endurance, 55/260 9/16 52/232 8/14g ,nr, L/T

9000

10000Breaking length WMPBreaking length CP 80

90 Whiteness WMP Folding Endurance WMP

Whiteness CP Folding Endurance CP

5000

6000

7000

8000

Breaking length CP

50

60

70

80

2000

3000

4000

5000

20

30

40

0

1000

1996 2009 0

10

1996 2009

Evolution of breaking length, tearing and bursting strength, whiteness, Cobb size test, folding endurance for watermark paper and coated paper from 1996

600

700

800 Breaking Load WMPTearing resistance WMPBreaking Load CP

300

400

500Tearing resistance CP

100

200

300

01996 2009

Paper grade

Characteristics Neutral sized Copy paper

Neutral sized Copy paper

AUSTRIAManufactured in 2006

AUSTRIAManufactured in 2009

Grammage g/m2 78 0 77 5Grammage, g/m 78,0 77,5

Breaking load, N, L/T 83/41 75,9/37,3g , , , ,

Breaking length, m, L/T 7970/3920 6640/3263

Whiteness, % 100 98

Tearing resistance, mN, L/T 415/445 347/373

Folding endurance, no., L/T 18/36 17/33

9000

10000Breaking length HX

450 Breaking load HX

5000

6000

7000

8000

250300

350

400 Tearing strength HX

1000

2000

3000

4000

50

100

150

200

02006 2009

02006 2009

Evolution of tearing strength, breaking length, whiteness and folding endurancefor a neutral sized copy paper manufactured in Austria in 2006

60708090

100Whiteness HX

Folding endurance HX

2030405060

010

2006 2009

Initial1996

Natural ageing 13 years

Accelerating ageing

Characteristics

1996 13 years

1A Pronosportpaper

1A Pronosportpaper

1A Pronosportpaper

Grammage, g/m2 63,5 70,0 62,7 69,7 62,4 69,5

Breaking length, m 4100 4570 3633 3805 3486 3650

Sizing, mm > 2 0,5 > 2 0,5 > 2 0,5

Whiteness, %R457/D65

87,0 80,0 85,0 69,7 83,37 69,0

T i 160 160 120 120 60 60Tearing resistance,mN

160 160 120 120 60 60

400045005000

Breaking length 1A

Breaking length PRONO350

400

450 Breaking load HXTearing strength HX

2000250030003500

150

200

250

300

350

0500

10001500

1996 2009 IN 2009 IA

0

50

100150

2006 20091996 2009 IN 2009 IA

Evolution of tearing strength, breaking length, whiteness for two neutral sized copy paper grades 1A Evolution of tearing strength, breaking length, whiteness for two neutral sized copy paper grades 1A and PRONOSPORT manufactured in 1996

100 Whiteness 1AWhiteness PRONO

50

001996 2009 I N 2009 I A

Characteristics

Sample of paper pages took from different book areasBook printed in 1923 in France

Characteristics1 2 3 4 5 6 7 8 9 10

Breaking 41 3/ 37 3/ 38 4/ 35 4/ 23 9/ 25 1/ 25 4/ 28 7/ 26 4/ 28 3/Breakingload, N, L/T

41,3/22,1

37,3/21,6

38,4/21,2

35,4/15,1

23,9/15,7

25,1/15,8

25,4/11,3

28,7/10,9

26,4/15,5

28,3/13,3

Breakinglength, m,L/T

3845/2053

3472/2011

3575/1974

3296/1406

2225/1462

2337/1471

2365/1052

2672/1015

2458/1443

2635/1238length, m,L/T 2053 2011 1974 1406 1462 1471 1052 1015 1443 1238

Foldingendurance,no, L/T

2/4 2,4 2/4 3/3 1/1 2/2 2/2 2/2 4/4 4/5

%Whiteness, % 55,26 56,32 57,59 59,48 59,73 58,57 58,37 58,98 58,84 59,07

4000

3500

Breaking length

2500

3000

20001 2 3 4 5 6 7 8 9 10

The evolution of breaking length and whiteness inside the book from 1923

60

Whiteness

60

451 2 3 4 5 6 7 8 9 10

Characteristics Book 1981 Book 1981Characteristics Book 1981Initial

Book 1981NA

Grammage, g/m2 50,0 49,4

Breaking load, N, L/T 20,0/12,0 18,5/10,4

Breaking length, m, L/T 2700/1500 2548/1432

Whiteness, % R457/C 55,0 40,69Whiteness, % R457/C 55,0 40,69

B kk th F/S 35/28 34/26Bekk smoothness, s, F/S 35/28 34/26

2900

3000Breaking length

2700

2800

2900

2400

2500

2600

2300

2400

1981 2009 NA

The evolution of breaking length and whiteness after a natural ageing process of 19 years (book from 1981)

100Whiteness

50

01981 2009 NA

Paper sample

Characteristics

class copy paper with a grammage of 80 g/m2 manufactured on the SC CEPROHART SA Brăila paper machine

Initial Accelerating ageing72 hours72 hours

Grammage, g/m2 78 77,7

B ki l h 6216 6010Breaking length, m 6216 6010

Sizing, mm >2 >2

Whiteness, % R457/D65 86,48 83,14

Bursting strength, kPa 164 141

Tearing resistance mN 342 312Tearing resistance, mN 342 312

Cobb size test , g/m2 17,5/19,1 16,2/18,7

Folding endurance, nr, L/T 26/30 8/17

Breaking load400

Bursting strengthBreaking load

300

Tearing resistance

100

200

5500initial AA

100initial AA

Evolution of tearing resistance and bursting strength, of whiteness, Cobb size test, folding enduranceEvolution of tearing resistance and bursting strength, of whiteness, Cobb size test, folding endurancefor A class copy paper 80g/m2

80

100 WhitenessCobbFolding Endurance

40

60

0

20

40

0initial AA

Recipe Hardwood pulp, % Softwood pulp, % CaCO3 , % AQUAPEL, % CARTARETINE, %

P1 30 70 - 0,2 -

P2 30 70 25 1,5 0,8

Characteristics Sample 1 Sample 2

Breaking load, N 52,5 39,4

Breaking length, m 6725 5980

Tensile strength, kN/m 3,50 2,63

Folding endurance, no 251 99

Tearing resistance, mN 140 100

Bursting strength, kPa 222 109

Cobb60 size test-, g/m2 66,3 49,9

Characteristics P124T P148T P172T P196T P224T P248T P272T P296T

Breaking load, N 58,2 59,3 59,8 62,0 38,2 30,1 29,2 29,0

Breaking length, m 7461 7438 7600 8045 5806 4550 4410 4400

Tensile strengthkN/m

3,88 3,95 4,18 3,87 2,55 2,00 1,95 2,07

Foldingendurance, no

182 177 139 133 90 33 30 29

Tearingstrength, mN

110 100 96 76 90 68 64 52

Burstingstrength kPa

214 209 198 186 108 99 96 90

Cobb60- size test, g/m2

57,2 56,0 55,5 54,7 42,8 47,9 50,9 51,3

Bursting strengthT i i t

200Tearing resistance

100

0P1 P1-24 P1-48 P1-72 P1-96 P2 P2-24 P2-48 P2-72 P2-96

Evolution of bursting strength, tearing resistance, breaking load, folding endurance and Cobb size test at 105°C and 24, 48, 72 and 96 hours

200

250Breaking loadFolding EnduranceCobb

150

50

100

0P1 P1-24 P1-48 P1-72 P1-96 P2 P2-24 P2-48 P2-72 P2-96

Characteristics P124U P148U P172U P196U P224U P248U P272U P296U

Breaking load, N 57,3 58,1 58,6 48,9 27,6 27,6 28,9 30,2

Breaking length, m 7389 7460 7512 6271 4168 4165 4380 4556

Tensile strength,kN/m

3,84 3,88 3,91 3,26 1,84 1,84 1,93 2,01

Foldingendurance, no

192 190 215 215 39,0 45,0 27,0 30,0

Tearingstrength, mN

80 84 100 90 80,0 80,0 84,0 90,0

Burstingstrength, kPa

194 192 211 209 88,0 98,0 90,0 95,0

Cobb60 size test-, g/m2

62,3 62,0 62,3 63,0 57,7 57,1 59,3 57,1

Bursting strength

200

Bursting strengthTearing resistance

100

0P1 P1-24 P1-48 P1-72 P1-96 P2 P2-24 P2-48 P2-72 P2-96

Evolution of bursting strength, tearing resistance, breaking load, folding endurance and Cobb size test at RH (relative humidity) of 65% and 24, 48, 72 and 96 hours

200

250

Breaking load

100

150

Breaking loadFolding enduranceCobb

50

100

0P1 P1-24 P1-48 P1-72 P1-96 P2 P2-24 P2-48 P2-72 P2-96

Characteristics P1 P124S P148S P172S P196S P2 P224S P248S P272S P296S

Breaking load, N 52,5 35,8 36,4 35,0 33,9 39,4 25,3 25,1 30,14 28,0

Breaking length, m 6725 4594 4670 4487 4356 5980 3814 3793 4675 4194

Tensile strength,kN/m

3,5 2,39 2,43 2,33 2,26 2,63 1,68 1,67 2,06 1,86

F ldi 251 153 154 108 104 99 103 105 108 91Foldingendurance,no

251 153 154 108 104 99 103 105 108 91

Tearing strength,mN

140 40 40 20 20 100 70 60 70 60

Bursting strength 222 184 45 21 19 109 43 24 19 16Bursting strength,kPa

222 184 45 21 19 109 43 24 19 16

Cobb60 size test, g/m2 66,3 63,3 62,8 60,9 59,6 49,9 40,7 58,8 60 60,7

Yellow index, % 46,05 31,8 28,32 27,22 23,97 50,26 49,13 48,74 46,3 44,77

200 Bursting strength200 Bursting strengthTearing resistance

100

0P1 P1-24 P1-48 P1-72 P1-96 P2 P2-24 P2-48 P2-72 P2-96

Evolution of bursting strength, tearing strength, breaking load, folding endurance and Cobb size test in SO2 atmosphere and 24, 48, 72 and 96 hours

225

250

275Breaking loadFolding enduranceCobb

125

150

175

200

25

50

75

100125

0

25

P1 P1-24 P1-48 P1-72 P1-96 P2 P2-24 P2-48 P2-72 P2-96

R l ti i t t tifi i l Relative resistance to artificial ageingageing

A 10000 X

BAR =

R th l ti i t t tifi i l R = the relative resistance to artificial ageingageing

A = the value obtained after the artificial ageing process

B = the initial value of the blankB = the initial value of the blank

Paper manufactured in the RD laboratory p y

Folding enduranceRecipe 1• Accelerating ageing at 105°C R = 52 98%• Accelerating ageing at 105°C R = 52,98%• Accelerating ageing at 65% RH R = 85,65%• Accelerating ageing in SO2 atmosphere R= 41,43%Recipe 2• Accelerating ageing at 105°C R= 29,3%• Accelerating ageing at 65% RH R = 30,3%Accelerating ageing at 65% RH R 30,3%• Accelerating ageing in SO2 atmosphere R = 91,92%

Paper manufactured in the RD laboratory Breaking load

Recipe 1 • Accelerating ageing at 105°C R = 118%• Accelerating ageing at 105 C R = 118%• Accelerating ageing at 65% RH R = 93,1%

A l i i i SO h R 64 %• Accelerating ageing in SO2 atmosphere R= 64,5%Recipe 2• Accelerating ageing at 105°C R= 73,6%• Accelerating ageing at 65% RH R= 76,6%Accelerating ageing at 65% RH R 76,6%• Accelerating ageing in SO2 atmosphere R = 71,0%

Paper manufactured in the RD laboratory Tearing strength

Recipe 1• Accelerating ageing at 105°C R = 54 3%• Accelerating ageing at 105 C R = 54,3%• Accelerating ageing at 65% RH R = 86,5%• Accelerating ageing in SO atmosphere R= 19 2%• Accelerating ageing in SO2 atmosphere R= 19,2%

Recipe 2Recipe 2• Accelerating ageing at 105°C R= 52,0%

A l ti i t 65% RH R 90 0%• Accelerating ageing at 65% RH R= 90,0%• Accelerating ageing in SO2 atmosphere R= 60,0%

Paper manufactured on the CEPROHART Paper manufactured on the C PROHART PM

The values of R are after 72 hours at 105°C• Whiteness R = 96,13%• Bursting strength R = 86%• Bursting strength R = 86%• Tearing strength R = 91,2%g g , %• Folding endurance R = 30,8 %• Cobb60 R = 92,6%

CONCLUSIONSCONCLUSIONS

• The importance of paper ageing process is strongly connected to the final utilization of the product and the connected to the final utilization of the product and the period of time after which the ageing process effects became visiblebecame visible

• The ageing process of the cellulosic fibrous materials determines transformations of the polysaccharide determines transformations of the polysaccharide compounds that manifests by modifications of the physico-chemical properties, by resistance property deterioration and whiteness decreasingp p y g

Th i l ti f ti l h t i ti i l • The involution of optical characteristics is slower than of the physico-mechanical properties of paper p y p p p pbased documentsTh f t t t k i t t th • The paper manufacturer must take into account the final utilization of paper in the moment when he p pestablishes the paper recipe

• A judicious selection of pulp furnish, alkaline sizing, utilization of calcium carbonate as filler assures the utilization of calcium carbonate as filler assures the premises to obtain some paper grades with a very

d d bilit good durability.

In order to increase paper stability we could choose one of the followingIn order to increase paper stability we could choose one of the followingmethods:

• Optimal pulp furnishes taking into account the Optimal pulp furnishes, taking into account the properties of different pulps (cotton, rags, sulfate, sulfite, wastepaper, mechanical pulp)

• Utilization of some polymers (polyether) in order to p y (p y )protect mechanical pulp or paper pulps within the color reversion process induced by lightreversion process induced by light

• To avoid the utilization of brighteners within time durable papers compositiondurable papers composition

• Surface treatment at the sizing press with starch and casein solutionscasein solutions

• Introduction of some buffer solutions within paper composition in order to mitigate the influence of air oxygen on the oxidative degradation (CaCO3, K2CO3, oxygen on the oxidative degradation (CaCO3, K2CO3, MgCO3, CaCO3· MgCO3)

• Paper treatment with antiseptic non-volatile compounds in order to increase the resistance to microorganism in order to increase the resistance to microorganism action

• Utilization of ionizing radiationsUtilization of ionizing radiations

• Utilization of modified pulps (grafted groups) or synthetic fibers at paper manufacturingsynthetic fibers at paper manufacturing

• Utilization of paper deacidifying methods

In order to extend the life cycle of the document papers is necessarynecessary

To assure appropriate storage conditions as regards t t h idit i i th i f temperature, humidity, corrosive gases in the air, for the entire document categories (new or old). SO2 gases g ( ) 2 ghave the most destructive effect

Utilization of new paper grades suitable to be used for archiving that will correspond to the requirements archiving that will correspond to the requirements imposed by the permanence conditions and an accurate selection of additives used within the paper grade composition in order to obtain positive effects grade composition in order to obtain positive effects during the entire document life cycleUtilization of modern methods to disinfest the archives with minimum effect on paper resistance archives with minimum effect on paper resistance characteristics (utilization of gamma radiations)

A i i t t t b t ti ll d Ageing resistance must to be systematically and differently studied throughout the following periods of y g g ptime: 1806, 1806-1990, after 1990 all correlated with the appearance of neutral alkaline sizing and with the the appearance of neutral-alkaline sizing and with the introduction of a number of additivesThe knowledge of the ageing process mechanism, of endogenous and exogenous factors allows endogenous and exogenous factors, allows establishing possibilities to increase paper durabilityg p p p y

The present researches are guided to the simulation of natural The present researches are guided to the simulation of natural ageing phenomena, by accelerated ageing on short periods of time in order to study paper behavior in comparison with the time, in order to study paper behavior in comparison with the main physical and chemical agent’s destruction agentsAssessment of paper resistance to the ageing process Assessment of paper resistance to the ageing process, assumes that modifications due to ageing, are to be characterized through determination of some properties characterized through determination of some properties, generally strength properties (furnish, grammage, tearing strength folding endurance aqueous extract pH alkali reserve strength, folding endurance, aqueous extract pH, alkali reserve etc) A paper resistant to ageing after a period of time still present’s minimum values of those properties that allow the paper to be used in accordance with its initial purpose