Technology: The Useful Void

Though nature abhors the vacuum, businessmen have learned to regard it highly. By emptying air from sealed chambers to create a void, U.S. industry keeps the $16 billion electronics industry going, adds life to jet engines and makes the vitamins in cod liver oil easy to take. Sales of the machinery used to produce vacuums for industrial uses are growing 10% to 15% a year; awareness of the vacuum’s almost limitless potential is growing even faster. Last week in Toronto this potential was probed at a meeting of physicists who specialize in working with vacuums. Though their esoteric experiments in the labs are far in advance of industry’s needs, they will almost certainly produce new uses. Said Dr. Robert Bakish of New Jersey’s Electronics & Alloys Inc.: “The developments of this conference today will go to business tomorrow.”

Sucking a Straw. Taking advantage of vacuums is nothing new; everyone who sucks a straw, works a pump or runs a vacuum cleaner uses the principle. But the first big breakthroughs in efficient methods of using vacuums industrially did not come until World War II, and improvements and refinements have piled up so quickly since then that industry has achieved vacuums equivalent to conditions in outer space. While dozens of companies turn out vacuum-making equipment, including such giants as G.E. and Westinghouse, the biggest in the field is Rochester’s Consolidated Vacuum, a subsidiary of Bell & Howell, which produces a line of pumps and airtight vacuum chambers for all industrial and laboratory uses.

The value of the vacuum to industry lies in the fact that materials act differently when not surrounded by air than they do when surrounded by it. In a vacuum, atoms of gas in any material float away because they are unobstructed by air pressure. Last week U.S. Steel announced that it will build a giant vacuum “degasser,” similar to one already at Jones & Laughlin, that releases contaminating gases from hundreds of tons of molten steel in minutes. Result: steel with so few harmful impurities that castings made from it for automobiles last 25% longer.

Loose particles of any material tend to travel in a straight line in a vacuum—a phenomenon that made television a reality by allowing the direction of electron beams to be precisely controlled in a vacuum tube. Liquids, from water to molten metals, boil and evaporate quickly at low temperatures in a vacuum and condense in an even film on any surface they strike. Thus industry has been able to lay thin metal grids in microcircuits (TIME, Feb. 7) and coat cheap plastic jewelry, auto trim or Christmas wrappings so that they look like gold or silver.

Cool Boil. Cool boiling in vacuums has also revolutionized the food industry. To concentrate its frozen orange juice, Minute Maid boils the water out of regular orange juice in a vacuum at such low temperatures that the juice does not take on a cooked taste. But Antle Inc., California’s largest lettuce grower, cools whole boxcar loads of lettuce at once by spraying them with water and evaporating it quickly in giant vacuum chambers, thus extending shelf life by 20%. Armour & Co. has a quick freeze and a vacuum process, called freeze-dry, that removes 98% of the moisture from such foods as beefsteak and stew so that they will keep up to five years without refrigeration. As for the vacuum approach to cod-liver oil, producers now extract heat-sensitive vitamin A from fish oil by cool boiling, then dole it out in candy-coated pills.