Hopkins signs up for new process to help preserve its library books

May 09, 1991|By Luther Young

The Johns Hopkins University took unprecedented action yesterday to preserve old and valuable books in its Eisenhower Library by awarding a $40,000 contract for chemical treatment of deteriorating volumes printed on acid-based paper.

The library agreed to ship 4,000 books during the next year to the Texas plant of Akzo Chemicals Inc. for "mass deacidification" with a chemical vapor that neutralizes the acid and could dramatically extend the life span of the 19th-century books to as much as 500 years.

"If we don't act swiftly to stop the decay of our books, all that will remain of them is dust," said Scott Bennett, library director, who graphically illustrated the effect of acid deterioration by crumbling a yellowed, brittle page from a not-so-rare 1887 biography.

The problem has been recognized since the mid-1800s, when increasing demands for printing paper forced manufacturers to switch from the original "rag" papers made of cotton fibers to a product made of readily available wood pulp.

But pulp-processing and subsequent improvements in paper finish introduced acids. Modern printing papers have an acid content 100 times higher than that of the beautiful rag papers produced in the 1500s, which remain white and supple indefinitely in climate-controlled libraries.

At the Eisenhower Library, 90 percent of the collection's 2 million books were published on acid paper over the past 200 years, and 30 percent are already so brittle they can only be saved through laborious photocopying or microfilming, which costs $70 $100 per volume, Dr. Bennett said.

That leaves a potential 1.2 million books to be saved from further decay by deacidification with the Akzo vapor method, known as the DEZ (diethyl zinc) process. It was developed at the Library of Congress and licensed to Netherlands-based Akzo in July 1989.

"Yes, 4,000 books is a drop in the bucket, but we've got to make a start," Dr. Bennett said. "This is a research institution. These books are a part of the wealth of our nation, and they must be protected."

The majority of monthly shipments for the first year will consist of 19th-century foreign language books published in paperback, said Dr. Bennett. Printed on highly acidic paper in limited quantities, they would be the hardest to replace.

Richard Miller, director of book and document preservation for Akzo, said yesterday that the Johns Hopkins agreement

represents the first commercial contract for the Akzo process with a library anywhere in the world.

The treatment exposes up to 350 books at a time to the DEZ vapor in an enclosed chamber for 2 1/2 days. The vapor penetrates the pages, neutralizing the acids and depositing an alkaline buffer on the paper that protects it from future acid damage caused by indoor air pollution.

Diethyl zinc is an extremely volatile material that ignites spontaneously when exposed to air, and the first pilot plant for the process -- built at Goddard Space Flight Center in Greenbelt by the Northrop Corp. -- was closed down by an explosion in 1986.

But Mr. Miller said Akzo has safely treated 15,000 books in 50 separate runs with the DEZ process. He's also confident the company can correct the vapor's tendency to dissolve binding glues used in paperback books, such as Hopkins' foreign language volumes.

Akzo's plant near Houston has the capacity to treat 40,000 books a year, with room for expansion to 140,000 books a year. If business warrants it, Akzo envisions five regional plants in the United States, including one on the East Coast, Mr. Miller said.

The 4,000 books Hopkins will ship the first year represents about 10 percent of the library's annual book acquisitions.

Mr. Miller said the $11 per volume that Hopkins will pay for treatment and shipping costs could drop to $6 to $10 per volume if Akzo can operate "on a full commercial scale of 500,000 books a year."

There also appears to be a potential cap on the acid deterioration problem, as more and more new volumes are printed on acid-free paper.

"Optimistically, by the turn of the century, we'll be seeing light ahead," Dr. Bennett said. "In the meantime, we're running as fast as we can just to keep up with our losses, but we're probably not running fast enough."

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