Pneumatic: These rely on a pump that builds air pressure in a reservoir which is then released as needed for the right amount of pressure.
Hydraulic: These consist of two cylinders that are joined by a tube which is filled with oil. The piston in one cylinder creates pressure and thus push the fluid through the tube between the cylinders. This type relies on Pascal’s Law which says that the pressure in the large cylinder will stay the same as the pressure in the small cylinder.
*Fun Fact: One of the largest Hydraulic Press machines in the world resides in Massachusetts with a height around 88 feet and about 49 feet of it is underground. It weighs 8,000 tons and has a press capacity of 50,000 tons! This specific press is called a die-forging hydraulic press. It is used for various military aircraft production programs!
Mechanical: There are types that create pressure through leverage created by turning a screw (screw press) or pressure is applied when the material passes through rollers (manual printing press). There is also an arbor press that has a rod and gear that are used to create pressure.
The Hydraulic and mechanical presses are classified by the frames the moving parts are located on. There is a C-frame (gap frame) and a straight side press.
The straight side press consists of vertical columns on either side of the machine. An advantage with straight side presses is that they do not have mis-alignment issues. A disadvantage would be that due to the side frames, they cannot have the sheet metal fed from the side of the machine.
The C-frame (gap) is shaped like a “C” (an open gap in the frame for feeding material) and consists of a single press application. They typically require less floor space than other press machines. In addition to those, there are back geared, open back inclinable and open back stationary presses.
What types of forming processes do these machines assist in? Press machines are used in stamping, straightening, flanging, cold extrusion, pressing, sheet drawing, forging press, and powder metallurgy to name a few.
Revelation Machinery can always help you find what you need! If you have any questions about press machines or need to find a specific brand/type, please feel free to contact us! If you need to sell your used press machines, do so here!