Vibration isolation & damping, function, needs and the right solution

What is vibration isolation and why is it needed?

Vibrations are mechanical oscillations that occur when a force acts on an object. In industrial and engineering contexts, these are often unwanted by-products of motors, pumps or external influences such as traffic. If left unchecked, vibrations can propagate through floors and frames (structure-borne noise) and disturb neighbouring equipment or people.

Vibration isolation is about decoupling the source of vibration from the ground to prevent propagation. Vibration damping, on the other hand, is about absorbing and converting the kinetic energy into heat to reduce the amplitude of the vibration. Often, a combination of both techniques is used to achieve a stable and quiet result.

Common sources of vibration in industrial and laboratory environments

Vibrations can come from many sources. In industry, it is often rotating or striking machinery such as presses, fans and compressors that are the culprits. In laboratory environments, much more subtle sources - such as footsteps, ventilation or even traffic far outside the building - can disturb sensitive instruments. What they all have in common is that they create resonance that needs to be managed.

The difference between active and passive vibration isolation

There are usually two main types of insulation:

• Passive insulation: The most common form that uses torsion element, rubber cushions or air bellows. These systems do not react to changes but offer a constant damping based on the properties of the material.
• Active insulation: One more advanced system which uses sensors and actuators. The sensors read the vibrations in real time and the system generates a counterforce to "take out" the motion. This is often used in extremely sensitive environments, such as in Atomic Force Microscopes (AFM), Scanning Electron Microscopes (SEM), Extreme UV lithography, (EUV), Nano imprint lithography (NIL) and more.

Vibration damping for industrial machinery

In heavy industry, vibration damping is not just about comfort, but pure production economics. Machines that vibrate uncontrollably wear out faster, consume more energy and risk damaging the foundations they stand on.

Machines that often require vibration damping

Virtually all equipment with moving parts benefits from insulation, but it is critical for:

• Punching and eccentric presses
• CNC machines and lathes
• Generators and compressors
• Industrial washes and centrifuges
• Conveyor belts and vibratory feeders

Effects of insufficient vibration isolation in industry

If the damping is missing or incorrectly dimensioned, problems often arise. These can include fatigue failure of machine parts, loose bolts, or the loss of calibration of neighbouring precision machines. In addition, structure-borne noise creates a noisy working environment that can exceed legal limits for sound levels.

Common industrial solutions - springs, rubber, steel dampers and hybrid systems

To solve these problems, different techniques are used:

• Kilblock: Best for low frequencies and heavy machinery. They have a long lifetime and can withstand harsh environments.
• Rubber/elastomers: Excellent for attenuating higher frequencies and structure-borne noise. They also act as shock absorbers.
• Hybrid system: Combines the insulating ability of the spring with the damping of the rubber to handle complex vibration patterns.

Vibration isolation for lab equipment and research environments

In the research lab, tolerances are minimal. Here, it's not a question of the machine lasting, but of the measurement result being correct. Even imperceptible vibrations can ruin a whole day's work.

Vibration-sensitive equipment in chemistry, physics and biotechnology

Equipment that often requires customised insulation includes:

• Electron microscope (SEM/TEM)
• Laser and optical systems
• Analysing scales
• NMR spectrometers
• Micromanipulators for IVF or cell research

How microvibrations affect measurement results

Microvibrations act as 'noise' in the data. For a microscope, this means a blurred image at high magnification. For a laser setup, the beam can miss its target by a few micrometres, invalidating the experiment. Stability is a prerequisite for repeatable results.

Solutions for advanced laboratory environments

Simple rubber mats are rarely enough here. Instead, they use air suspension (pneumatic insulation) that makes the table top "float", eliminating almost all contact with the floor. For the most extreme requirements active systems which electronically counteracts every movement in real time.