Hydraulic Press Types

A hydraulic press, also referred to as a Bramah press, is a press machine that functions by either, fluid pressure or hydraulic pressure. Hydraulic presses function under a dynamic known as Pascal’s principle, which asserts that pressure that is built up throughout any closed system will exert equal force on all areas of the containment. Hydraulic presses are, by far, the most common type of press used, primarily due to the fact that they are easily the most efficient and dependable. The force achieved with hydraulic presses can’t be achieved with either mechanical or pneumatic presses.

There are multitudinous types of hydraulic presses, with each having its distinctive applications; however, here are some applications that overlap with different types of hydraulic presses. Platen presses are designed to function by using a ram in addition to a solid and a surface designed for stability. A good example would be a C-frame press, which can be used for various applications and operations, including banking, straighten, drawing, forming, punching, bending and timing. On the other hand, vacuum and laminating presses possess several specialized capabilities, which encapsulating numerous layers of plastic materials for certain application such as credit cards. Additionally, laminating presses have the capacity to apply film. Another type of press that has specialized capacity is a stamping press. The stamping press is primarily used for cutting and shaping materials through the process of deformation with die — used primarily in the automotive and metal working industries. For the molding and stamping of rubber, metal and plastic, the transfer press works best, and this type of application is used predominately in the aerospace and medical industries. Forging presses are used exclusively on metal.

The hydraulic press would be classified as a power press. There are several power press categories, which include hydraulic, mechanical and pneumatic. Pneumatic presses have similar applications to hydraulic presses, including crimping, bending, punching, metal working, and piercing; however, the distinction between the two types of presses is that pneumatic presses used compressed air to produce their dynamic movements, whereas hydraulic presses use some type of fluid to produce the pressure that facilitate the dynamic movements of the press. Hydraulic presses are generally differentiated by two primary elements — design and application. C-frame presses have the capacity to be operated either manually or automatically. They also require less floor space than other types of hydraulic presses, due to their unique, yet sturdy, C-shaped frame, which is usually made of steel — providing very little deflection.

The H-frame press differ from C-frame presses in shape as well as their capacity to facilitate multiple operations. The laminating press is a compression press that has two individual openings called plates. One of the plates is designed to be used for heating and the other for cooling. This expedites the lamination process. Transfer presses function by feeding flat material, such as rubber, metal blanks, or plastic into the right end of the press. The feed bar finger then take the material and pass it from die to die. The vast majority of machines are designed with the capacity to manage heavy loads that can reach 3,500 tons; however, there are some smaller machines as well.

As the name implies, hydraulic presses are powered through the use of hydraulic fluid, which is used to generated pressure. The hydraulic press consists of all of the primarily elements found is the common hydraulic system, such as pistons, hydraulic pipes, cylinders and a stationary die or anvil. The piston is designed to create a thrusting or plunging motion, using liquid that is under pressure to help it exert the force necessary to perform its purpose. The hydraulic system is comprised of two primary cylinders. The fluid, either oil or water, is generally poured into the smaller of the two cylinders. This smaller cylinder is commonly referred to as the slave cylinder while the larger cylinder is referred to as the master cylinder. As the pressure builds, it is exerted on to the piston in the larger cylinder, causing the larger piston in that cylinder to press in the master cylinder. This action cause the punch to come in contact with the die, subsequently deforming the metal into the desired shape. The vast majority of hydraulic presses are constructed from stainless steel for durability, and both single and multi-station configuration are available. The single station variety only has one set of tools inside of the table, whereas the multi-station press can facilitate multiple operations simultaneously.

There are some alternative to the hydraulic press, such as mechanical presses, pneumatic presses and electric presses. The mechanical press is driven by what is known as a flywheel, which builds up pressure then releases, subsequently transferring energy to the primary side. This is normally accomplished through the uses of an eccentric knuckle joint, crank or toggle. The stroke of a mechanical press can be adjusted with certain limitations. The strokes are classified as either single, double or triple action, which corresponds with the number of ram or slides they possess. Eccentric presses are relatively new in their development, having the capacity to provide a more efficient drive mechanism. This is primarily due to the linkage of the drive motor and the ram, ensuring that the operator is able to send a signal to the motor to set a specific speed. The only way that the speed will not be reached is if the motor become overloaded.

Pneumatic presses provide an advantage due to the fact that they have the capacity to have stroke cycles that are capable of reaching up to 400 strokes per minute. Pneumatic presses are capable of providing a controlled flow rate, which makes it ideal for applications in which the ram velocity or flow rate or crucial to the job. Because pneumatic presses do not convert rotary motion to linear motion, it has fewer moving part when compared to the machine press or the hydraulic press. However, when shear force is necessary, the hydraulic press remains the best choice

Hydraulic Press Types

There are multitudinous types of hydraulic presses, with each having its distinctive applications here is a list of presses that are found in shops around the world.

4 Post Hydraulic Press - precision tooling applications.

Arbor presses — can be used for bearings removal and other demanding assembly, seating stamping, as well as repair of production jobs.

Assembly presses — have the capacity to generate immense pressure in order to assemble and secure parts together

C-frame presses —  streamlined, yet sturdy presses that require less space, generally consisting of a single press application.

Compression Molding Presses —   comprised of two separate plates that are pushed together in order to compress the material into the desired mold.

Forklift Tire Press — Used to remove solid tires off of forklifts.

Gantry Straightening Press -- Used to straightening steel or other material.

Forging presses —  metal forming machinery that is powered through hydraulic means, forcing metal pieces to take on the shape of a product using a particular mold.

H-frame presses — also referred to as four-column presses, and they acquire their name for the H-shaped frames.

Hydraulic presses —  industrial strength machines that utilize fluid to generate the pressure necessary to form or shape an object.

Laboratory presses —   smaller presses that have single applications, and they are generally used in labs as other testing facilities.

Laminating presses —  used for the impression of polymers onto other materials, such as paper, lumber or metal.

LIM presses — refers to liquid injection molding presses which handle plastics, which are produced through an injection process.

Mechanical presses — primarily used for the purpose of punching, shearing or assembling certain materials by using dies or tools that are attached to rams or slides.

Platen presses — are industrial hydraulic press, which utilize tow large, heated steal for the purpose of condensing, forming or molding a number of different products.

Power presses — are a type of hydraulic press that uses dies and tools to punch, form or shear materials.

Pneumatic presses — use compressed airflow to generate energy transfers in order to facilitate and control movement. Typical applications for this type of press are bending, forming, shearing and punching.

Press brakes — can be mechanical, hydraulic or manual presses that have the capacity to cold work metal into different types of shapes.

Stamping presses — are machines that utilize stamping dies.

Straightening presses — apply pressure to certain metal for the purpose of straightening it.

Tableting Press — is generally used for the purpose of shaping powdered materials into compacts or tablets.

Transfer presses — are hydraulic presses that are designed to automatically move products from one process to the next.

Vacuum presses — are industrial systems that are powered by hydraulics, creating air pressure necessary force for laminating operations.

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Also see Hydraulic Press Terms