NBSIR 74-501

Development of Specifications for

Arcliival Record Materials

W. K. Wilson

Paper Evaluation Section

Institute for Materials Research

National Bureau of Standards

May 23, 1974

Annual Report Covering the Period

July 1, 1973-June 30, 1974

Prepared for National Archives and Records Service

Washington, D. C. 20408

NBSIR 74-501

DEVELOPMENT OF SPECIFICATIONS FOR

ARCHIVAL RECORD MATERIALS

W. K. Wilson

Paper Evaluation Section

Institute for Materials Research

National Bureau of Standards

May 23, 1974

Annual Report Covering the Period

July 1, 1973-June 30, 1974

Note: This document has been prepared for the use of National Archives and Records Service. Responsibility

for its further use rests with that agency.

Prepared for National Archives and Records Service

Washington, D. C. 20408

U. S. DEPARTMENT OF COMMERCE, Frederick B. Dent, Secretary

NATIONAL BUREAU OF STANDARDS, Richard W. Roberts. Director

CONTENTS

Page

1. SUMMARY 1

2. BACKGROUND 2

3. OBJECTIVES 3

4. COMPLETED SPECIFICATIONS 4

5. EVALUATION OF STABILITY OF COPIES FROM

OFFICE COPYING MACHINES 5

6. ACCELERATED AGING OF BOOK PAPERS AT 100°C

COMPARED WITH 36 YEARS NATURAL AGING 6

7. STUDY OF UNCOATED BOOK PAPERS AFTER

10 YEARS OF NATURAL AGING . 8

8. AN ANALYSIS OF THE AGING OF PAPER: POSSIBLE

REACTIONS AND THEIR EFFECTS ON MEASURABLE

PROPERTIES 8

9. STATUS OF REPORTS AND MANUSCRIPTS 13

10. PLANS FOR THE PERIOD JULY 1, 1974-JUNE 30, 1975 . 14

1 . SUMMARY

Effort on a long range program on the Development of

Specifications for Archival Record Materials has included:

(1) Reappraisal of research needs.

(2) A study of 18 papers made in 1937, tested before

and after dry accelerated aging in 1937, and tested again in

1973.

(3) Evaluation of 19 commercial papers, evaluated

before and after moist accelerated aging in 1963, and tested

again in 1973.

(4) Development of specifications for copies from

office copying machines.

A review of the literature on stability of paper and data

obtained in this laboratory over the past several years indicate that a fresh approach is needed to a study of the

stability of paper. The following tasks are suggested :

(1) Continue to use handsheets of known compositiono

(2) Study old papers to determine changes that

probably have occurred during natural aging.

(3) Confine testing to methods that give some clues

concerning v;hat happens during aging such as zero span

tensile, wet strength, peroxide formation, functional group

content, and molecular chain length distribution.

(4) Study the effect of cycling of relative humidity

on the properties of paper.
2

2 . BACKGROUND

In response to a request by the National Archives and

Records Service, the National Bureau of Standards is developing information on the variables associated with the

stability of archival record materials, especially paper.

Several U.S. (bvernment agencies and the Society of American

Archivists have joined in sponsorship of the project through

National Archives and Records Service.

Many record materials of archival or long-term historical

value in repositories in the Federal Government and throughout the United States are in bad physical condition. If

proper specifications were available for materials that are

designed to be used for permanent records, future problems

concerned with the deterioration of record materials and the

cost of repairing the mistakes of the past would be greatly

minimized

.

Much of the earlier work on this project was directed

toward the development of an accelerated aging method. As

this is a long-range effort, in terms of time and scope, and

as archivists and librarians need specifications today for

record materials, interim specifications based on pH requirements have been prepared for selected materials. Specifications for manifold papers, for bond and ledger papers, and

for file folders have been cleared through the American Society

for Testing and Materials (ASTM) . In response to an urgent

need to establish permanence criteria for papers that can be

used in office copying machines, interim specifications have

been written. An accelerated aging method is required for

this specification. Other materials that merit attention

are inks, typewriter ribbons, carbon paper, laminating film,

mending tape, binding materials, and manuscript boxes.
3

3. OBJECTIVES

The objectives of this program are as follows:

(1) The development of information on the stability of

paper and other record materials.

(2) The development of test methods for the evaluation

of the stability of paper and other record materials.

(3) The development of specifications for materials

suited for permanent records.
4

4. COMPLETED SPECIFICATIONS

The following specifications have been cleared through

the American Society for Testing and Materials (ASTM)

D-3208, Standard Specification for Manifold Papers for

Permanent Records. This specification was completed about

a year ago and appears in Part 20 of the 1974 ASTM Book of

Standards. It also is available from ASTM as a single

reprint.

D-3290, Standard Specification for Bond and Ledger

Papers for Permanent Records. This specification has been

printed and is available as a single reprint. It does not

appear in the 1974 ASTM Book of Standards.

D-3301, Standard Specification for File Folders for

Storage of Permanent Records. This specification has been

printed and is available as a single reprint. It does not

appear in the 1974 ASTM Book of Standards.

These specifications are now ready to use for procurement

purposes.

These specifications are being submitted through channels

to Committee P3, Paper, of the American National Standards

Institute (ANSI) for consideration as ANSI standards.
5

5. EVALUATION OF STABILITY OF COPIES FROM

OFFICE COPYING MACHINES

Technology has provided over the past 20 years a plethora

of machines for making copies of originals by pressing a button. As some of these copies have not proven to be particularly stable, and as these copies have found their way

into permanent record files in various organizations, specifications for this type of copy are urgently needed. Paper

must be capable of being transported through the copying

machine for which it is intended. The paper may be plain,

coated, or impregnated, and supplies may be purchased from

sources other than the suppliers of the copying machines.

As pH can be used as a sole criterion of probable longevity

only for plain uncoated paper, an accelerated aging method

is required. The only official accelerated aging method for

paper involves oven aging for 72 hours at lOS^C. In addition,

stability of the image must be evaluated.

Representative samples were obtained from several manufacturers and tested in order to obtain the data necessary

for preparing specifications for the paper and for stability

of the image. This work has been completed, and a report is

in the editorial process. The specification is based on:

(1) minimum pH requirement, (2) minimum retention of tear and

fold after accelerated aging, and (3) retention of reflectance

of image after exposure to a xenon arc and after abrasion by

a standard technique.
6

6. ACCELERATED AGING OF BOOK PAPERS AT 100 "C

COMPARED WITH 36 YEARS NATURAL AGING

In 19 36 a group of book papers made in the NBS paper

mill was tested before and after accelerated aging for 72

hours at lOO'^C. Although there was no plan to test these

papers after natural aging, a collection of some of these

papers had been kept in an office for several years. The

manufacturing history was known and the physical and chemical

properties had been extensively evaluated for that time. Out

of a total of 72 papers, 18 were found that could be assembled

to form a reasonably coherent set of samples.

The fiber furnishes fall into three categories: (1) 50-50

soda-sulf ite , (2) purified wood pulp, and (3) old rag. Chemically, these papers are very different. The soda-sulfite

papers contain a high percentage of hemicelluloses , the

purified wood pulps are low in hemicelluloses, and the rag

papers contain no hemicelluloses. The hemicelluloses are

more vulnerable to degradation than cellulose.

The following conclusions may be drawn from data obtained

on these papers:

(1) Elongation is fairly sensitive to natural aging.

(2) Folding endurance is very sensitive to natural

aging, but the scatter of the data is very great.

(3) A plot of retention of folding endurance against

acidity (pH measured in 1937) shows some correlation, if data

on each set of six papers are viewed separately.

(4) A water leaf paper containing neither rosin nor alum

was very unstable with respect to folding endurance and

tensile strength and was not outstanding with respect to

retention of tearing strength. Fiber strength did not appear

to deteriorate, but the fiber bonding deteriorated badly.

Thus, the basic stability of the structural components is

high, but the structure itself became weak. This is a new

concept in the natural aging of paper.

(5) Three alkaline papers performed well after 36 years

of natural aging, but retention of properties was not as

great as expected.
7

(6) Data obtained in this laboratory show that much

more acid is generated in moist accelerated aging than in

dry accelerated aging. Some acid, as measured by differences

in pH values, was generated in most of the papers during

natural aging. It would appear that some moisture should

be present in an accelerated aging atmosphere, but a relative

humidity of 50 percent probably is too high.

(7) Bonding strength in short fibered papers appears

to contribute heavily to folding endurance but not to zero

span tensile strength.

(8) There is a recognizable relationship between cold

extract pH measured in 1937 and wet strength measured in 1973.

(9) It is possible to specify stable papers using

retention of folding endurance and retention of tearing

strength after accelerated aging for 72 hours at 100°C,

especially when coupled with a pH requirement. The specification can be as rigid as the use requirements dictate.

(10) There is some evidence that the cycling of relative humidity as a factor in the deterioration of some types

of paper should receive attention.

Although a draft of the report on this work has been

prepared and could be submitted essentially in its present

form, data on alkali solubility and reducing power (a measure

of oxidized structures) should be obtained. These data were

obtained in 1937 before and after accelerated aging. This

work will require approximately two months.

Evaluation of materials by methods that are almost 40

years old never is very satisfying, but a review of the

reactions that may occur during the aging of paper and their

effects on measurable properties (Section 8) has made this

task more meaningful.
8

7. STUDY OF UNCOATED BOOK PAPERS AFTER

10 YEARS OF NATURAL AGING

Work on the retesting of these papers has been completed,

but a report has not been started. Some preliminary conclusions were given in NBS Report 73-249. These data are not

likely to be as valuable as the data from the papers made in

19 37, as the manufacturing details are not known and the

spectrum of composition is very broad.

8. AN ANALYSIS OF THE AGING OF PAPER: POSSIBLE

REACTIONS AND THEIR EFFECTS ON MEASURABLE

PROPERTIES

About two years ago three reports on the accelerated

aging of laboratory handsheets were submitted to NARS, NBS

Reports 10 627, 10 628, and 10 687. These reports are based

on data obtained from the evaluation of carefully prepared

laboratory handsheets. Although the significance of the

data was discussed in each report, there has been a need to

bring the data in these three reports into a coherent picture

and to draw some conclusions about the significance of accelerated aging. An attempt was made to do this, but it soon

was realized that this would be useless without an analysis

of the possible reactions that might occur during the aging

of paper and their effects on measurable properties. This

was intended to be an introduction to an analysis of the

data in the three reports mentioned above, but the effort

developed into a report that stands by itself.

This report includes a review of the literature and

draws to some extent on data obtained on the papers made in

1937. The preparation of this report has been extremely

valuable in reviewing the status of our knowledge on the

stability of paper and in preparing plans for future work.

Section 6, Summary, and Section 7, Recommendations, of this

report are included here because they sum up our current

thinking on stability and aging of paper and in what directions further research should go.
9

Summary of Draft Report, An Analysis of the Aging of Paper

(1) The predominant chemical reactions in accelerated

aging are hydrolysis, oxidation, and crosslinking . In some

cases, especially waterleaf papers, a decrease in bonding

order may be predominant.

(2) Hydrolysis in a heterogeneous system is enhanced

by oxidized structures, especially by aldehyde on the No. 6

carbon of anhydroglucose

.

(3) Hydrolysis and oxidation are synergistic.

(4) Hydrolysis is catalyzed by acid.

(5) Aluminum catalyzes degradation.

(6) Aluminum, other metals, and acids enhance and also

destroy c^^osslinking.

(7) Under proper experimental conditions, aldehydes

and carboxyls enhance crosslinking.

(8) Cycling of moisture content degrades physical

properties of paper.

(9) Some degradation reactions decrease moisture regain.

(10) Moisture greatly enhances some types of degradation.

(11) The "fines" in paper contribute significantly to

the degradation of paper.

(12) It is obvious from a review of the literature on

accelerated aging of paper that:

(a) Accelerated aging conditions that would

satisfy all possibilities are impossible to define.

(b) An accelerated aging test does not tell what

a paper will be like after 25 or 50 years of storage.

It only provides information concerning the ranking of

different samples with respect to storage properties.

(c) Some conclusions can be drawn concerning

aging conditions.
10

(d) Some conclusions can be drawn concerning

useful tests for evaluation of aging.

(e) Published data do not give a coherent

picture of the aging of paper.

(f) Most of the data are of limited utility

because the samples were not adequately defined.

(g) Arrhenius plots are not likely to be a

particularly useful tool in the evaluation of stability.

(h) The correlation of natural aging with accelerated aging is never likely to be perfect, or even high,

as different natural aging conditions produce different

results.

(i) Extensive mathematical treaiiment of data, and

predictions of stability based on these treatments, are

not likely to be very fruitful.

Recommendations of Draft Report, An Analysis of the Aging

of Paper

(1) The following tests should.be useful in determining

what happens during the aging of paper:

(a) Zero-span tensile (fiber strength)

(b) Wet tensile (crosslinking)

(c) pH (generation of acid)

(d) Alkali solubility (some chain scission and

alkali sensitivity)

(e) Functional group content (oxidation)

(f) Molecular chain length distribution (chain

scission and randomness of chain scission)

(g) Peroxide formation (probably oxidation, but

peroxides apparently can be formed in cellulose in the

absence of air)

(h) Oxygen sorption (oxidation)
11

(2) The following tests should be useful for detecting

changes during the aging of paper, but are not particularly

useful for identifying the nature of the change:

(a) Folding endurance

(b) Tearing strength

(c) Elongation

(d) Tensile energy absorption

(e) Alkali solubility

(f) Copper number

(g) Viscosity

Alkali solubility appears under both (1) and (2)

.

Without additional information, it belongs under (2)

;

with information on functional group content, change in

zero-span tensile, viscosity, and peroxide content, it

can be evaluated properly and belongs under (1)

.

(3) Other tests that may be somewhat less useful are:

(a) Tensile strength

(b) Burst

(4) The following general conditions for accelerated

aging should be evaluated;

(a) Low temperature (50°-70°C)

(b) Cycling of relative humidity, probably between

0 percent and 70 percent on hourly cycles.

(c) Oxygen atmosphere.

(5) General guidelines for the composition of permanent

record paper (not for specification purposes) are as follows:

(a) Low functional group content (aldehyde, carboxyl,

ketone)

(b) Alkaline filler, or pH in the neutral range

(c) Stable sizing material
(d) Large percentage of long fibers (2-3 mm)

(e) Low percentage of fines

(f) No lignin

(g) No aluminum salts during manufacture

(6) Recommendations for future work:

(a) Examine papers that have been in storage for

some time and attempt to identify the changes that have

taken place during storage.

(b) Devise one or more accelerated aging methods

that cause these same changes to occur.

Work is in progress on both of these tasks.

The tests that should be most useful in determining

what happens during the aging of paper and should give the

most information for the least investment of time:

(a) Zero span tensile (fiber strength)

(b) Wet tensile (crosslinking)

(c) pH (generation of acid)

(d) Peroxide formation

If time and resources are plentiful, alkali solubility, functional group content, oxygen sorption, and molecular chain

length distribution should be valuable.

For detecting changes during aging of paper, folding

endurance, elongation, tensile energy absorption, and alkali

solubility should be most useful for time expended. It is

clear that folding endurance is not a good test for defining

what happens during the aging of paper. Inasmuch as the

folding endurance of a stable paper can deteriorate very

badly, folding endurance can be misleading.
13

9. STATUS OF REPORTS AND MANUSCRIPTS

(1) An Analysis of the Aging of Paper: Possible

Reactions and Their Effects on Measurable Properties. In

NBS editorial process.

(2) Evaluation of Archival Stability of Copies From

Representative Office Copying Machines. In NBS editorial

process. This includes a draft specification that will be

started through the ASTM standardizing process as soon as

it clears the NBS editorial committee.

(3) Accelerated Aging of Book Papers for 72 Hours at

100°C Compared with 36 Years Natural Aging. Most of the work

is finished and a draft of a report has been prepared. A

review of the data showed that alkali solubility and reducing

power, both of which were measured in 1937 before and after

accelerated aging, should be run. This should require about

two months.

(4) Accelerated Aging of Commercial Book Papers at 90°C

and 50 Percent Relative Humidity Compared with 10 Years

Natural Aging. The testing of these papers is completed

but no progress has been made toward writing a report.

(5) A Review of Accelerated Aging of Laboratory Handsheets. This will be a review of three earlier NBS reports,

10 627, 10 628, and 10 687. It is hoped that a review of the

data in these reports coupled with data obtained on the naturally aged papers will enable some conclusions to be drawn

concerning an accelerated aging test. This report is in the

incubation stage.
14

10. PLANS FOR THE PERIOD JULY 1, 1974-JUNE 30, 1975

(1) Complete alkali solubility and reducing power measurements on the 36 year papers.

(2) Complete the reports mentioned in Section 9.

(3) Measure oxygen sorption at 50°C on representative

pulps

.

(4) Determine the effect of cycling of moisture content

on properties of paper.

(5) Explore the possibility of aging paper in oxygen

at 50°C.

(6) Examine old papers as time permits to determine

what changes have occurred during aging.
i 3. i bibliocraphmC ::ata i \... SH^ri ::BbiR 74-dOI 1

4. 11 1 Li s; 1< i 1 i i.i- Development of Specifications for

Archival Record Materials

5. i \ih\ ;i atioii D.ite

6. Perlorminj; Or^an i /.at mii ( (vie

W. K. Wilson

8. Pirlorminp Oruan. Report No. NBSIR 74-501

9. PKRl-ORMiNt. 0RC,AX1/AT10\ NAMi- AND ADPRI-SS

NATIONAL BUREAU OF STANDARDS

n P P A D T u P k) T np r* n u Li P D f~ P WASHINGTON, D.C. 20234

10. I'^roieet. Task W'oiU Unit No. 3000442

11. (^-oiuraet. drant -W).

12. Spon-<orinp Organization Nami- and Complete Address (Street, City. State, ZIP)

National Archives and Records Service

Washington, D.C. 20408

13. 1 ype of Re|->:->'t x Period Covered Annual,

7/1/73-6/30/74

14. Sponsc)rin^ .•\geney Code

15. SUPPLK.MI-NTARV NOI L.s

16. Ai<^lR.-\( 1 fA 200-\vord or lesx (actual summary of most .si^r/jcvinf information. If docun: nt includirs a significant

bi bl ioC,rapbv or I lieraturc .survey, mention it herv.)

Effort on a long range program on the Development of Specifications

for Archival Record Materials has included: ( 1

)" Reappraisal of research j needs. (2) A study of 18 papers made in 1937, tested before and after \ dry accelerated aging in 1937, and tested again in 1973. (3) Evaluation

of 19 corj-ercial papers, evaluated before and after moist accelerated j aging in 1963, and tested again in 1973. (4) Development of specifica- i tions for copies from office copying machines.

A review of the lit2rature on stability of paoer and data obtained

in this laboratory over the past several years' indicate that a fresh

approach is needed to a study of the stability of paper. The followina

tasks are suggested: (1) Continue to use handsheets* of known com.posi-' tion. (2) Study old papers to determine changes that probably have

occurred during natural aging. (3) Confine testing to methods that

give some clues concerning what happens during aging such as zero span

tensile, wet strength, peroxide formation, functional group content,

and molecular chain length distribution. (4) Study the effect of cycling of relative humidity on the properties of paper.

17. KEY UORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons)

Aging of paper; archival materials; natural aging; old paper; paper,

aging of; paper, stability of; paper testing; stability of paper

18. AVAILABILITY Unlimited

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21. NO. OF PAGES

14

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