The Abbey Newsletter

Volume 23, Number 2
1999


Letters

To the Editor:

I was recently provided with a copy of the Abbey Newsletter, v. 23#1 and read with interest, your article entitled "ASTM/ISR Paper Permanence Research." While a good portion of your piece was accurate, unfortunately, it contained a number of factual errors. I am writing now in hope that you will provide your readers with the correct information. I will follow a procedure in which I will quote your article and then will provide the correct information.

You suggest that ASTM has "two big research projects underway ." In actual fact, there is only one program. It has many parts. The key thrust is to conduct sound scientific study of methods to accelerate the aging of printing and writing papers. To be considered broadly usable, the sponsors of the program have required that it be shown that the accelerating methods involve mechanisms of chemical and physical change that are essentially the same as those which occur in the natural aging process.

You report that ASTM's long-term natural aging study involves "fifty " papers. The fact is that there are only fifteen papers in the program. Books containing 350 pages of each of the fifteen have been placed in each of ten libraries around North America.

You suggest the purpose of the long-term study is "to see whether lignin interferes with permanence in any way ." While lignin is included in the composition of some of the papers, it is not at all the focus of the study. What the study is about is to develop thoroughly documented curves of property change in the fifteen papers over the century-long study. Since there are ten libraries involved in different geographies and with varying qualities of storage conditions, it will be interesting to those who have the final results in 2098 to see if storage conditions made much of a difference. With excellent curves of aging, it will possible in future years to develop very reliable correlations between natural and accelerated aging experiences.

You say "the project was advocated and planned largely by the manufacturers of lignin-containing pulps ." It is true that such manufacturers have strongly supported the study and have been part of the planning group. However, it is very unfair to the academics, government groups, libraries and archives, and manufacturers of lignin-free papers who have contributed large sums of money and have reliably attended and participated in many planning meetings to imply that they have not been fully and equally involved.

You talk about the "confluence of developments and conditions " that got the program started. The reality is that all stakeholders said from the start that they wanted to be able to develop performance-based standards. The only way that would be possible would be if scientifically sound accelerated aging test methods were developed and widely supported. While it is today possible to describe in detail how a freshly-made paper will perform, it has not been possible to predict how long it would perform within the parameters of importance to the end user. The ASTM program is all about developing such test methods. It is clearly not about writing new permanent paper standards. It is reasonable to expect that new performance based standards will be developed by others when all agree that the test methods put forward are sound, but that is a task for others.

You mention a "newly-developed 'acid tolerant' calcium carbonate ." I am not aware that one calcium carbonate is different from another. It is added to alkaline papers to serve as a buffer to any acidic atmospheric pollutant gases that may find their way into such papers. The calcium carbonate is more reactive than the cellulose fibers and thus protects the cellulose. It is true that Specialty Minerals Inc. has developed a patented additive that enables the use of calcium carbonate in an acid/near-neutral papermaking system. This has enabled the development of "physical permanence" characteristics for high lignin content newsprint and magazine papers. "Acid- tolerant" carbonates are unrelated to the use of hardwood BCTMP (bleached chemithermomechanical pulp) in "free-sheet" papers. These papers are made in conventional alkaline processes where a portion (10-15%) of the hardwood kraft pulp is replaced with BCTMP. The lignin content in such a case is less than 4% of the total fiber composition.

You suggest that the paper "industry does not perceive loss of brightness as a permanence issue ." You would do well to ask the sales departments of companies selling lignin-containing fiber how they stand. There are a great many paper applications for which their fiber can simply not be sold exactly because of the brightness issue. Their customers certainly consider it a permanence issue.

You state, "The manufacturers of groundwood pulps hope that the outcome of ASTM's accelerated-aging and natural-aging studies now underway will demonstrate to their customers that paper made from their product has been 'scientifically proven' to be permanent. They rarely if ever qualify this statement to say that it is permanent provided the paper is also buffered with calcium carbonate or some other alkaline compound ." For this research program, the position of all the sponsors is that the test methods will provide both producers and users of any printing and writing paper with a means to test the permanence of the paper regardless of its composition. Thus, a paper will meet the end-use needs of the customer, or it will not and if so should not be purchased and/or placed in the intended end-use.

You talk about "yellowing has always been taken as a sign of poor quality, weak and short-lived paper ." While this perception has indeed existed, it is scientifically incorrect. The mechanism of yellowing involves very different chemistry than that which causes loss of strength. An alkaline paper made with lignin-containing fiber and an appropriate alkaline reserve such as calcium carbonate is every bit as mechanically stable as that made with pure chemical wood pulp or cotton. That the lignin-containing paper yellows quite rapidly when exposed to light or heat is easily demonstrated. The historic loss of strength in groundwood papers (newsprint) was because they were strongly acidic, having been sized with rosin and alum. It was the acid that attacked the cellulose which, in turn, caused the loss of paper strength.

You say that, "The ASTM project will not be a pioneer study of natural aging ." We disagree to the extent that there has never been a set of papers put aside with such thorough documentation of their conditions of manufacture, extremely thorough characterization of their aging experiences in accelerated procedures, and that will be tracked with such thoroughness over a 100-year period. While the Wilson/Parks and Samuelsson/Sörner studies have real merit, they cannot compete with the ASTM program in terms of scientific reproducibility and thoroughness.

You state that "ASTM's news releases on this topic seem to be written by biased industry spokespeople ." The real fact is the press group at ASTM wrote them. It is hard to imagine that they would have bias with regard to the research program or the long-term study. The press group had input from a variety of individuals that ranged from industry representatives to members of the library and archive community in creating the news releases.

You suggest that, "The paper industry favors accelerated aging over composition as the basis for a paper permanence standard ." While that may be true, it is not part of the ASTM paper aging research program. The program is intended to produce three accelerated aging test methods by which both producers and users can make informed judgements about the life expectancy of any given printing and writing paper sample.

You mention only three of the five labs who are engaged in the ASTM paper aging research program, with a question about a fourth. The facts are the following:

Temperature Aging Studies:

Canadian Conservation Institute in Ottawa, Canada under the leadership of Dr. David Grattan and Mr. Paul Begin

US Library of Congress in Washington, DC under the leadership of Dr. Chandru Shahani

Light Aging Studies

Finnish Pulp and Paper Research Institute in Espoo, Finland under the direction of Dr. Ingegerd Forsskċhl

USDA Forest Products Laboratory in Madison, WI under the direction of Dr. Rajai Atalla and Dr. James Bond

Pollutant Gas Aging Studies

Image Permanence Institute at Rochester Institute of Technology in Rochester, NY under the direction of Mr. James Reilly and Mr. Peter Adelstein

You state, "The results are expected to be used by the industry to persuade standards organizations to specify accelerated aging results, rather than maximum lignin content ." That is not true. The intent is to provide scientifically sound accelerated aging test methods whereby all stakeholders can make intelligent judgements about the life expectancy for a given paper for its intended end use. For there to be a specification, the user must specify which properties are important and where the limits of acceptability are to be found in order for the test methods to predict life expectancy. Creating such specifications is work for others and is clearly not a part of the ASTM paper aging research program.

You make the following statement: "If groundwood papers are to be represented as permanent, the standard should specify a certain level of calcium carbonate, high enough to control the effect of the lignin on the paper ." If the new test methods are sound and successful, they will sort out a paper that does not have a sufficient alkaline reserve (or that contains other harmful - to permanence - additives) and will show it to be inappropriate for its intended end use.

Finally, you say, "Perhaps the new or revised permanence standards can have a second part in which brightness retention can be specified ." Again, the program is about creating useful test methods and not new paper permanence standards.

As a final word, I must say I am disappointed you did not ask our team for input before you wrote your piece. We would have been most willing to provide you with current information and to have helped you create a piece that was factual and accurate.

Bruce Arnold
Chair: ASTM Paper Aging Research Program

To the Editor:

Defining the technical requirements for permanent paper is difficult. The problem of making a standard for such requirements is the fact that there is no single direct test revealing paper permanence. Some experts have suggested that a standard could be based on accelerated aging tests alone. These tests take time, and the experts are still discussing the difficulties of defining a standardized procedure that will indicate future degradation in normal storage conditions and predict the expected lifespan of a document. Nothing much happens when papers are exposed to a climate of 80 degrees Centigrade and a relative humidity of 65%. In some papers containing lignin there is little loss in paper strength after accelerated aging in this [northern] climate, but the optical properties may at the same time be negatively affected, indicating that defining these papers as a permanent substratum for information in a long time perspective is difficult. More of the degradative changes we expect in paper in real time will manifest themselves when paper is exposed to a climate of 90 degrees Centigrade and a relative humidity of 50%.

Some critics want a higher kappa number in ISO 9706 to allow paper based on new high yield semichemical pulps to be included as permanent papers. An alkaline sized paper made of these pulps will degrade slower than an acid sized paper made of groundwood. The kappa number measures the tendency to become oxidized. Accepting papers that are likely to be oxidized as permanent paper may therefore be difficult.

The standard has no requirements safeguarding discoloration of permanent paper. By demanding a kappa number of less than 5.0 it was not necessary to introduce a technical requirement regarding color changes, which we have to expect in paper containing lignin. If the kappa number should be increased, new technical requirements limiting future discoloration must be considered.

Although this letter is not an official statement of the ISO-committee, I believe it reflects the majority view of the P-members of ISO/TC 46/SC 10 Information and Documentation/Physical Keeping of Documents.

Rolf Dahlø
Chairman, Subcommittee 10

To the Editor:

I noted in your v. 23 #1 issue that The Save America's Treasures program funded only one library or archival materials project. This is not correct. The program funded 62 projects, several of which will conserve library or archival materials. Among these are the Dutch Colonial Records at the New York State Archives, an Anti-Slavery Pamphlet Collection at Cornell University Library, and the Louis Armstrong Archives at Queens College, New York City. A full listing can be obtained from Karen Groce at Heritage Preservation.

Christine W. Ward
Chief Archivist
New York State Archives

The full list was not sent out in the press release from which the story was written. There were actually a dozen projects that involved library or archive material in the full listing that Christine Ward kindly forwarded to the office. -Ed.

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