A discussion of the benefits of Vacuum Workholding in the manufacturing industry from the Magna-Lock USA archives
How do you hold nonmagnetic exotics, thin strips, and delicate workpieces? Atmospheric pressure can do it without deforming or marring surfaces. It’s just as dependable as gravity, and it’s powerful, too. There are 14.7 lbs. of air pressure for every square inch at sea level; and we can get sufficient vacuum in a chuck to generate about 13lbs./square inch holding power. That’s over 1,100 lbs. for a workpiece the size of a standard piece of paper. Here’s how to use this free force.
To meet challenges of holding exotic alloys, sophisticated products, and machining them to tolerances in ten thousandths of an inch, tool engineers are turning to vacuum chucks to supplement or replace mechanical and magnetic chucks. The vacuum chucks perform hold-down and positioning functions heretofore impossible. For example, dramatic results are being obtained in holding plate glass for polishing on a high production basis for the automotive industry. Elimination of hold-down clamps solves the breakage problem and leaves the entire surface unobstructed for polishing the edges.
Processing of ultra-thin foil, plastic, and shim materials as thing as 0.0005” is possible too, and it can be done with large-are sheets without wrinkling or patterning.
Similarly, the uniform distribution of vacuum pressure over the entire area of the workpiece makes it possible to produce highly polished surfaces with uniform thickness. The machine designer and tool engineer can have practically unlimited design freedom as far as size is concerned. Vacuum chucks are holding workpieces from 1 square inch to 20’ x 60’.
The instant hold and release of vacuum chucks adapts them well for high-speed automatic CNC machines. The use of instant-acting fail-safe switches protects machines, materials and operator. The vacuum chuck has wide versatility for all types of machines and operations including milling, drilling, profiling, broaching, grinding, sanding, and polishing.