Bill Minter and his sons at the ISU Library Conservation Lab.

ISU Preservation owns one of the first protoypes of William Minter’s Ultrasonic Encapsulator machine.  For quite some time, the lab had been making do with a Polyweld machine because the ultrasonic encapsulator motor had burned out, among other issues.  The Polyweld works well, but it has three distinct disadvantages compared with the ultrasonic encapulator: it relies on heat to melt the polyester film together; it can weld a seam only at the very edge of the film; and it has a rather limited width (60 cm).

Polyweld Machine

We were finally able to send the encapsulator back to Bill for repair and an upgrade early in the summer.  He provided us with instructions on how to detach the weld head and motor, which we sent to him along with the anvil, which also needed to be remodeled.  Our original model had a pointed weld head and a flat anvil surface; the upgrade has a flat weld head and a raised ridge along the weld-line.

Kristi and Henry disassembling the ultrasonic encapsulator.

Our summer interns, Henry and Kristi, disassembled the unit and packaged it in a large, wooden crate (also provided by Bill) for safe shipment.  Bill worked with his machinist to repair and remodel the machine’s parts, which he and his sons drove out to Iowa to reinstall.  We spent a very informative day and a half watching Bill reassemble the encapsulator, and receiving detailed training on the varied subtleties of its use.  I’ve been using various models of the encapsulator for years, but now realize I had considered only a fraction of its versatility.

Bill explaining the way the weld head works.

A big thanks to Bill and his sons for their visit!  We’re delighted to have a working ultrasonic encapsulator again.