Vacuum Freeze-Drying, a Method Used to Salvage Water-Damaged Archival and Library Materials: A RAMP Study with Guidelines (UNESCO, 1987): 14. What freeze-drying will not do

Vacuum Freeze-Drying, a Method Used to Salvage Water-Damaged Archival and Library Materials: A RAMP Study with Guidelines (UNESCO, 1987)

		(introduction...)
		Preface
		Foreword
		1. Introduction
		2. Water-soaked paper
		3. Stabilization by freezing
		4. Vacuum freeze-drying
		5. Alternate methods of drying
		6. Vacuum freeze-drying vs vacuum-drying
		7. freeze-drying is not a new process
		8. Early experiments in freeze-drying books and documents
		9. The use of vacuum chambers for recovery of water-damaged archival and library materials
		10. Other vacuum and freeze-drying activities
		11. Commercial sources for freezing and drying
		12. Cost of vacuum-drying and freeze-drying
		13. Low cost freezing and drying in an emergency
		14. What freeze-drying will not do
		15. Cooperative approach to the use of freeze-dry chambers
		16. An open forum on freeze-drying
		17. A final word: disaster preparedness planning
		18. References

14. What freeze-drying will not do

Freeze-drying is a salvage process; salvage in the sense that its purpose is to save water-damaged archival and library materials from destruction. This is done by freezing to stabilize, then sublimate to dry. It will not return to pristine condition any books or documents which were in a damaged state at the moment they were frozen for subsequent drying. Freeze-drying will not press out cockled or wrinkled sheets and pages, nor straighten out warped covers. These will be locked in that position on drying. It will not release the pages of a book printed on coated shock if blocking has set in before freezing.

It will not remove discoloration, tide marks, or stains that were there at the start. Freeze-drying will not press out vellum or leather. And as pointed out, it will not destroy mold spores.

In short, apart from the end purpose of the process, frozen materials come out of the vacuum chamber in just about the same condition as they entered. At the end of the drying cycle some will look surprisingly good; others will be scheduled for minor repairs. Some may have to bear the high cost of restoration; some may have to be discarded or replaced. In any case, the fault is not in the freeze-dry process. It is still the most effective method known for the physical, chemical and biological stabilization of water-damaged archival and library materials, especially when large quantities are involved and time is of the essence.