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11. Commercial sources for freezing and drying

11.1 Cold storage

The most obvious place to begin a search for freezing and cold storage facilities is the commercial section of the telephone book. Rentals or purchases of chest freezers or larger units are usually found in the Appliances section; space for freezing and storing under Cold Storage 'warehouses. And, although other industries, small or large, which have their own cold storage facilities do not cater to outside requests, many will and have made exceptions in an emergency, Among such organizations are frozen food processors including retail and wholesale outlets, ice cream and frozen desserts companies and their wholesalers and distributors, dairy companies and their outlets, and ice makers. Even supermarkets may have space or idle freezers which may be available.

11.2 Freeze-drying

In the case histories summarized above, some of the vacuum chambers operated by aerospace companies had either been idle or used sporadically. The reactivation of these facilities occurred when help was sought for drying large numbers of documents or books which had been damaged by water. As a consequence, what began as a trial test of a new technique became so successful that it is now an established salvage service available on a commercial basis. The literature cites several entities in this category.

This "spin off" concept seems to be gaining ground among organizations that use vacuum chambers for other purposes: Taxidermy, freeze-drying of biological specimens, experimental and testing laboratories. Capacity, of course, is limited. Nevertheless, advertisements are beginning to appear in periodicals that offer reclamation of books and documents soaked by water leaks, firefighting, or floods. Cost estimates are available along with the service of a technician who will arrange the preparation of wet materials for treatment in a vacuum chamber (53).

11.3 Vacuum chambers

There are several companies on the international market engaged in manufacturing vacuum chambers for freeze-drying. With experts ready to advise potential customers on the type of system best suited for specific needs, the companies can supply vacuum chambers for use in laboratories or in larger versions for industrial purposes. One example is the VirTis Company (54) of Gardiner, New York. Included in its line of products is a system normally used by taxidermists which is castor-mounted and completely self contained. The system can use chambers of various sizes, the largest being 35 inches (88.9 centimeters) in diameter and 68 inches (172.7 centimeters) deep. The basic unit, called "Preservator," will permit the lengthy dehydration of animals at room temperature. Although the system is recommended for taxidermists, it can be used for freeze-drying wetted archival and library materials.

Another organization, internationally known in the field, is Edwards High Vacuum (55) located in Crawley, England. EHV also manufactures its products in Marburg, West Germany; Milan, Italy; Grand Island, USA. Among its line is a small unit intended for freeze-drying of biological and pharmaceutical preparations which has been used for freeze-drying books. The unit is called the Modulyo 4K. It has a drying chamber made of perspex in cylindrical form which can be custom designed to hold up to 50 books.

Vacu-Systems Incorporated (56), Houston, Texas, carries in its line of vacuum chambers a mobile freeze-dry system called the MD 24. It has a chamber with capacity for about 100 books. The system sells for about $14,000 (1985 prices); rental for this unit runs about $1250 per month with a two month minimum rental.

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