Hydraulic Press: Design, Applications and Sizes

The hydraulic press is used when very high forces must be applied to a workpiece, for example, to perform forming operations.

Its disadvantage is that it operates very slowly. The hydraulic press is therefore primarily used for processing individual pieces. In serial production, its use is a challenge, as semi-finished products can accumulate at the machine.

Design of a Hydraulic Press

A hydraulic press consists of:

• Base frame
• Hydraulic power unit
• Interchangeable tool
• Working area
• Control unit

The base frame accommodates all components of a hydraulic press. It defines the construction and installation size of the equipment. In small, manual presses, the hydraulic power unit consists of a master-slave cylinder configuration with releasable check valves.

Larger presses use a hydraulic pump instead of a master cylinder. Interchangeable tools are used in straightening presses or for the serial forming of workpieces. One application for this is, for example, embossing presses in mints.

The working area is the zone in which the product to be pressed is placed. Finally, the hydraulic press is controlled via the control unit. There is always one unit located on the device itself. Depending on the size and configuration of the equipment, operation can also take place via a remote control station.

Sizes of Hydraulic Presses

The shape and size of a hydraulic press can vary significantly. The smallest presses are known as “shop presses.” They are manually operated and have a bottle jack integrated as the hydraulic power unit. However, presses of this type can already exert a pressure force of up to 15 tons. They are used for straightening frames or pressing in bearings.

The largest hydraulic presses operate in the three-digit meganewton range. Their dead weight can easily exceed 4,000 tons. Such presses are used, for example, for the production of pressure hulls for submarines.

Applications of Hydraulic Presses

Hydraulic presses are used for the following applications:

• Straightening and processing existing finished products
• Manufacturing new products
• Compacting recycled products
• Dewatering residual materials
• and much more.

Straightening and processing using hydraulic presses is a common application in workshops. In addition to pressing in bearings, damaged frames are also straightened there and pressed into the desired geometry.

In addition to individual and series production using sheet metal forming, hydraulic presses are also used to produce “compacts.” These are previously powdered materials that are converted into precisely portioned sizes by pressing, without the risk of disintegration. In this field of application, mechanical presses are predominantly used, for example in pellet or tablet production.

Hydraulic presses are also found, for example, in the production of compacts in environmental technology. They are used for the analysis of residual materials by means of spectrometers or gas chromatographs.

Hydraulic presses play a very significant role in recycling technology. When compacting metal scrap, such as end-of-life vehicles, they are practically the universally used tool. They prepare the metal scrap for transport by compacting it. Subsequently, the compacts are shredded and separated into their individual raw materials using various processes.

In the beverage industry, hydraulic presses are used in washing stations for reusable bottles. During the washing and rinsing process, labels and any foreign objects in the bottles are removed. These are compacted into large bales and freed from the washing water as much as possible. Furthermore, there are numerous other possible applications for hydraulic presses.