ACCELERATED DRYING OF PLASTER CAST WITH A MICROWAVE OVEN
Charles Asbelle, Gerald Porter · 1972
Early microwave medical applications prioritized efficiency over safety, highlighting our ongoing pattern of technology adoption before health research.
Plain English Summary
This 1972 technical report examined using microwave ovens to accelerate the drying process of plaster casts, developing prototype equipment for this application. The research focused on the engineering aspects of applying microwave energy to medical materials rather than health effects. This represents early exploration of microwave technology in healthcare settings before widespread understanding of EMF exposure risks.
Why This Matters
This 1972 technical report represents a fascinating glimpse into the early adoption of microwave technology in healthcare, long before we understood the potential health implications of EMF exposure. The research focused purely on engineering efficiency - using microwave energy to dry plaster casts faster - without considering biological effects on patients or healthcare workers operating the equipment.
What makes this particularly relevant today is how it illustrates our historical pattern of embracing new electromagnetic technologies for their convenience while overlooking potential health consequences. Healthcare workers using prototype microwave equipment in 1972 had no established safety protocols, exposure limits, or understanding of cumulative EMF effects. This mirrors our current situation with newer technologies like 5G, where deployment often precedes comprehensive health research.
Finding
Experimental results appear to justify the following conclusions: 1. Microwave drying of "set" orthopaedic plaster is a viable process. 2. For the drying time of a 3 kg. knee cast to a level of mechanical workability can, for example, be reduced from the twelve hours required by a hot air oven to 30 minutes with an air-assisted microwave oven.
In their words
“Experimental results appear to justify the following conclusions: 1. Microwave drying of "set" orthopaedic plaster is a viable process. 2. For the drying time of a 3 kg. knee cast to a level of mechanical workability can, for example, be reduced from the twelve hours required by a hot air oven to 30 minutes with an air-assisted microwave oven.”
Figures from the Original Paper
Diagram extracted from the original research document.
Exposure Information
Specific exposure levels were not quantified in this study. Duration: 20 minutes for initial test, 30 minutes for final test
Study Details
To reduce the drying time of plaster casts from periods of 12 to 24 hours, presently attainable with hot air ovens, by using microwave energy to effectively dry 'set' samples of wet plaster.
Three different microwave ovens were tested: Sears-Roebuck, Litton Industries, and Bechtel Corporati...
Microwave drying reduced plaster drying time from hours to minutes. The Sears oven required 20 minut...
Microwave drying of 'set' orthopaedic plaster is a viable process. Drying time can be reduced from 12 hours to 30 minutes with an air-assisted microwave oven. Air assistance is beneficial for high drying rates and good quality. The process yields a product with a hemihydrate core and dihydrate exterior. No observable differences in strength, shrinkage, or mechanical capability were noted compared to conventional hot air drying.
Show BibTeX
@article{accelerated_drying_of_plaster_cast_with_a_microwave_oven_g5821,
author = {Charles Asbelle and Gerald Porter},
title = {ACCELERATED DRYING OF PLASTER CAST WITH A MICROWAVE OVEN},
year = {1972},
}