Types of Laboratory Press Explained

A laboratory press is a device used to apply pressure to a sample, in order to compress or compact it. Laboratory presses are often employed to study the properties of materials, or to prepare samples for further analysis.

Goto tpypress to know more.

Laboratory presses are typically equipped with a hydraulic system that can generate up to 1,000 pounds per square inch (psi) of pressure. The press can be used to apply pressure to a variety of materials, including powders, sheet materials, and polymer beads.

A hydraulic press uses an oil-filled hydraulic cylinder to generate a compressive force on a moveable piston. The machine works using the principle of Pascal&#;s law, which states that the pressure exerted on a fluid is transmitted evenly throughout that fluid. The force generated by the press is proportional to the area of the piston, multiplied by the applied pressure. The press consists of a cylinder with a piston inside, and a pump that is used to apply pressure to the oil inside the cylinder.

What are the different types of hydraulic press?

Laboratory presses are available in a variety of sizes and configurations, including manual or automated operation. Choosing the right hydraulic press for your lab will, unsurprisingly, come down to its intended application &#; as well as how much time and energy your technicians will expend on using it.

A laboratory press is frequently used in conjunction with a pellet die for compacting powders into solid disks. Other tools and moulds can be used for pressing, bending, or forming thin films.

Manual Hydraulic Press

A manual hydraulic press uses a hand-operated lever to pump the oil and apply load to a sample. A hand-operated valve is used to relieve the pressure and remove the load.

The manual presses manufactured by Specac are available in 15 and 25-tonne maximum load configurations and are ideal for FTIR, KBr and XRF sample preparation.

There are no electronic components in a manual hydraulic press and, as a result, this machine is often cheaper than its automatic counterparts; however, choosing a manual press shouldn&#;t just come down to the purchase price.

When you consider if a manual hydraulic press will suit your laboratory operations, it&#;s best to review your workflow. Manual presses require more physical effort to operate than an automatic equivalent &#; so if your technicians will need to use them often, it can become labour-intensive work.

A manually operated press is also harder to use in a repeatable fashion, with every sample being pressurised to a slightly different load by the operator.

However, for infrequent use, a manual press can be a cost-effective addition to your laboratory set-up.

Automatic Hydraulic Press

An automatic hydraulic press uses an electric motor to drive the pump and electric switches to open and close the relief valve. This means they can be controlled to a high accuracy and repeatability.

Automatic hydraulic presses are often used for industrial XRF applications and other laboratory sample manipulation activities. However, their versatility makes them suitable for small and large-scale manufacturing practices, too &#; including hot embossing, laminating and melting polymers for thin films.

Unlike the lever on a manual hydraulic press, an automatic press is operated by a button. The general mechanics of the two machines are similar &#; you set the load you want to be applied, which the pump then fulfils &#; but the die used in an automatic machine can often press and release via automated actions.

Automatic hydraulic presses often improve the workflow in busy laboratories, as &#; once the press is programmed &#; it can operate autonomously, allowing the technician to get to work on other tasks.

Available in 8, 15, 25 and 40 tonne configurations, automated presses aren&#;t as laborious to operate as a manual counterpart. This makes them suitable for frequent pressing work &#; as well as often being more accurate and consistent, due to the lack of variable factors during use.

Presses for XRF pellet preparation

Where laboratories are running XRF measurements on a large quantity of samples, it makes sense to have a high-throughput hydraulic press for XRF, specifically adapted to the demands of preparing sample pellets. These presses feature integrated pellet dies and have swifter operations for repeated use. In particular, they focus on automations and mechanical systems for quickly extracting the pellet and leaving the press available for the next sample.

Are you interested in learning more about Hydraulic press types? Contact us today to secure an expert consultation!

Hydraulic Mini Press

A hydraulic mini press is a small, portable press that uses hydraulic power to produce force. They typically only weigh 4 kilos but are still capable of applying around 2 tons of pressure.

Mini presses are typically used to produce KBr discs for FTIR. As the surface area of these pellets are about 7mm &#; smaller than the usual 13mm diameter of a regular pellet &#; this enables an equivalent pressure to be applied, despite the lower tonnage.

Mini presses are often favoured due to their compact size. They&#;re hand-held, easy to transport and low-cost, making them an accessible choice for pharmaceutical labs, polymer testing labs, undergraduate chemistry labs and many other places where FTIR is commonplace.

View our quick summary video

Why use Specac for your FTIR and sample preparation equipment?

Specac offer a comprehensive range of sample preparation accessories for FTIR, including presses, pellet dies, high temperature film makers, and consumables such as KBr powder.

Besides these, a variety of other sampling techniques &#; including single and multiple reflection ATR, DRIFTS, and Specular Reflectance &#; are available.

Our accessories are customised and calibrated for the user&#;s needs, so why not contact our experts for a quote?

Selecting a Hydraulic Press

• Introduction
• Hydraulic Presses - Fast, Reliable, Productive, and Flexible
• 10 Advantages of Hydraulic Presses
• Glossary
• Formulas and Data
• Selecting a Hydraulic Press
• Hydraulic Press Limitations

1. Tonnage. Is the tonnage required to do a job the same for a hydraulic press as it is for a mechanical press? The answer is yes. There is no real difference. The same formulae are used to determine tonnage. The tooling is usually interchangeable. There may be certain applications such as deep drawing where the full power stroke characteristic of a hydraulic press reduces the tonnage, but there are no known instances where using a hydraulic press requires more tonnage.

   Selecting press tonnage in the typical press room is often little more than guesswork. If, for example, a job is successful on a 100-ton mechanical press, it tends to stay there for the life of that job. The job may never have been tried at 75 tons or at 50 tons.

   With a hydraulic press, however, you can adjust tonnage quickly and easily, tuning the press to precisely the right tonnage for each specific job.

2. The action of the machine. Even though the tonnage question might be settled, the question of the effect of the stroke on the work is often asked. Is it the same as with a mechanical press?

   The answer, again, is yes in most cases. There are some specific limitations. Drop hammers and some mechanical presses seem to do a better job on soft jewelry pieces and impact jobs. The coining action seems sharper if the impact is there.

   In deep drawing, however, the full power stroke of a hydraulic press produces significantly better results.

   Otherwise there are very few examples where the application of 100 tons of hydraulic force produces any significant difference in the character of the part given the same tooling.

   Shear in the dies will reduce blanking tonnage for hydraulic presses in the same way it does for mechanical presses.

3. Type of press selection. Open-gap presses provide easy access from three sides. 4-column presses insure even pressure distribution. Straight-side presses offer the rigidity required for off-center loading in progressive die applications.

   The more critical the work and the more demanding the tolerances, the greater the reserve tonnage capacity should be.

4. Accessories. Most hydraulic press builders offer a wide array of accessories. These commonly include:
   • Distance reversal limit switches
   • Pressure reversal hydraulic switches
   • Automatic (continuous) cycling
   • Dwell timers
   • Sliding bolsters and rotary index tables
   • Die cushions
   • Ejection cylinders or knockouts
   • Electronic light curtains and other devices
   • Touch screen controls
   • Servo system feedback for precise, consistent, repeatable stroke control
5. Quality. The industry offers various levels of quality. There are light-duty presses that are capable of "spanking" the work momentarily and reversing, and there are heavy-duty machines designed for general purpose metalworking applications.

   Here are just a few construction points that will provide a basis for comparison of one machine with another:

   1. Frame. Look at frame construction-rigidity, bolster thickness, dimensional capacity, and other factors.
   2. Cylinder. What diameter is it? How is it constructed? Who makes it? How serviceable is it?
   3. Maximum system pressure. At what psi does the press develop full tonnage? The most common range for industrial presses is to psi.
   4. Horsepower. The duration, length, and speed of the pressing stroke determines the horsepower required. Compare horsepower ratings.
   5. Speed. See page 5 to determine the speed of a hydraulic press.

Next Section

Contact us to discuss your requirements of How Hydraulic Press Works. Our experienced sales team can help you identify the options that best suit your needs.