Laser Cleaning

SONOMATIC are excited to bring this game-changing patented laser technology (ablation) to clients in all industries. How it works – the process clears away undesired material from a solid surface by irradiating it with a laser beam. By absorbing the energy of the laser beam, the molecules of the targeted material are excited very quickly, making it break apart and ablate or vaporise off the surface. As the surface below does not absorb any energy, it remains unaltered.

By manipulating the laser fluence, its wavelength and its pulse length, the amount of material that is being removed by a single laser pulse can be controlled with extreme precision, making laser cleaning equally suitable for rapid and deep rust removal as it is for removing only one thin layer of paint, without damaging the base coat.

Science Behind the Laser

An image of laser cleaning in action

The high-speed circular scan results in no hot spots, as well as safer and faster cleaning due to two exposures per physical pass of the laser as a circle has a leading arch and a trailing arch.

The conical shape of the beam means that the leading edge of the cone hits a surface at one angle, and then the trailing edge of the cone hits the surface at the opposite angle, allowing multiple angles of incidence in one pass and allowing the beam to conform to complex shapes and surface features.

Ferrous materials are known to easily flash rust after abrasive blasting and to resist rusting after laser cleaning, providing a bigger window of time for a new coating application. Abrasive blasting typically increases the surface area of a metal surface, thus increasing its corrosion potential while laser cleaning does not.

Laser cleaning can also be tuned to create a protective passivated skin of magnetite on the surface. Laser cleaning is also very effective at removing salt from crevices that pressurized media can have a hard time reaching due to blowback and back pressure.

The Benefits

Environment

The laser system does not emit any harmful elements to the environment. Unlike abrasive blasting which emits debris, noise and potential threats to personnel and equipment near-by, the laser is fitted with its own extraction system immediately removing any light dust that may be produced.

It causes no damage or contamination to sensitive equipment, for example, precise seals, moving parts etc that are in the area. Our laser technology is specifically designed by Conservators and Engineers in the USA to safely clean a variety of surfaces without damaging the substrate and without damaging the planet.

Safety

Mature assets typically may have lead based paints which using current technologies, run the risk of being disturbed and subsequently enter the atmosphere. To prevent that and to protect the work-force, sheeting must be installed and the area deemed as a lead working area, effectively closing it down to any other work (SIMOPS), in the area.

While still following the exact same safety protocols of working with lead, the extraction system removes the dust/fumes and scrub through special filtration systems scoped for the particular job. The fume extraction system is designed to capture and collect the ablated/vaporised material via a series of appropriate filters, ensuring people and equipment are not exposed to any danger from contaminates.

Integrity

Unlike other laser systems in the market, our unique patented design means the laser does not create heat-spots as it works. In addition, the advanced laser cleaning process does not result in wall thickness loss which is a major concern or consequence of traditional abrasive cleaning techniques as they can significantly affect the quality and reliability of an Inspection.

Costs

Advantages of Sonomatic RAIS Laser Cleaning
  • Quick installation and setup time
  • Suitable for hard-to-reach areas or surfaces
  • Suitable for use in hazardous or dangerous environments
  • Highly accurate
  • Non-contact technology
  • Lower operational costs than most other cleaning techniques
  • Safe for any kind of substrate, even very delicate surfaces
  • Unrivalled level of control
  • Absolute minimum of residue, mostly dust
  • Dry and clean
  • Easy to use
  • No debris
  • No unwanted side effects
  • Minimal maintenance

Solutions

A before and after of laser cleaning on rotational equipment

The laser does not require double skinned habitats to be built, it does not require a cleaning team behind it like the grinder, it can be used from ropes and we can attach it to crawlers.

Ferrous materials are known to easily flash rust after abrasive blasting – however they resist rusting after laser cleaning, providing a bigger window of opportunity for a new coating application.

Abrasive blasting typically increases the surface area of a metal surface, thus increasing its corrosion potential – laser cleaning does not. Laser cleaning can also be tuned to create a protective passivated skin of magnetite on the surface. Laser cleaning is also very effective at removing salt from crevices which pressurised media can have a hard time reaching due to blow back and back pressure.

Traditional method of surface preparation
  • Average team of 10-12 operators.
  • Scaffolding tent structure required for blast materials. (Erection and hire costs)
  • Scaffolders - Blasters - Cleaners - Forklift driver.
  • Forklift to transport shot
  • Continual cleaning
  • Final clean to remove the spent shot
  • Skips hire to store removed spent shot
  • Costs of disposing this waste.
  • All sensitive equipment has to be sheeted in to protect it from the shot dust.
  • Blasting on a tank/vessel produces mass noise pollution, stopping all other work
SONOMATIC Laser/NDT Team
  • Team of 2 technicians
  • Removes all the above constraints!!

Risk

Surface Preparation provided by Sonomatic RAIS Rope Access Inspection Services with patented laser cleaning technology with no preparation and no cleanup crew

Grinders and blasters are notorious for the residue and debris they leave behind causing a risk of damage to nearby machinery and equipment. Reliability impact of dust, debris contacting moving equipment shafts of pumps, compressors, blower or fans (rotating equipment) or shafts of actuated valves. Traditional wide scale blasting will see a reliability hit for months and years following blasting activities. Grinders when used incorrectly, can and do cause severe injuries. In fact, data shows over 5400 injuries per year are caused by the incorrect operation of grinders, including injuries from kick-back from the grinder, entanglement, contact with the grinding wheel, injuries from projectiles and in some cases causing fires.

The laser system does not create any of these risks.

What is the efficiency of the technique with respect to conventional blasting/grinding (m2/h)?

If we compare it to the traditional blasting method, at first glance the blasting method does seem to be the fastest. However, this can be a false positive because it is also the highest risk method to use, if it goes wrong, then it has the potential to quadruple in costs and harm.

If for example it damages other machinery in close proximity then you have several areas out of production, if it is incorrectly operated or malfunctions it can cause enormous injuries, the cleaning up alone after the shot-blasting is another cumbersome and costly part of the traditional method. And even then, it is impossible to clean all of the shot debris caused by the machine.

You are then left with the problem of disposing the bags and bags of collected excess shot debris. The grinding method requires many layers of costly preparation including sheeting, fire blankets (which still allow a risk of sparks to escape). Together, whether it is grinding or blasting, both are forms of mechanical force which can add to the original existing damage! And both carry the risk of also adding in debris to the area which can cause problems in the future.

The laser cleans as it goes, it has a kill switch meaning the power will immediately stop if pressure is taking off the switch, people can work side by side with us..and the laser cleans the matter to the standard, without causing any damage at all.

We believe (although we are still testing this), that from the moment an order is given to SONOMATIC Total services Team for the provision of access, removal of insulation/lagging, completing the surface prep process, performing the NDT Inspection, relagging of areas and returning it complete to the operators (so all done by one company), that the time we require would be at least HALF the time required by the traditional method.

You would require only one order, you would have one point of contact and within our total circle, we take responsibility for everything that is included in a Re-Inspection. Our lasers also come in different powers so the efficiency can be made even better depending on the scope.

Frequently Asked Questions

The laser can ignite flammable materials, however the spark potential is generally less than grinding as grinding sends sparks flying far, while laser cleaning creates a localised plasma reaction. For this reason laser cleaning has been chosen over grinding in many other applications.

The rate of cleaning always varies depending on the conditions. Surface rust is easy to remove, paint requires more energy and time. Mill scale requires a lot of energy to remove so this would usually involve higher powered units.

The lasers are in the Class 4 Category - to comply with this category - operators wear 1064nm laser goggles for eye protection and must also wear a respirator so as not to breathe in material that is being removed. Good ventilation/fume extraction is also important.

100% opaque shielding materials need to be used to prevent anyone not wearing laser goggles from seeing the laser beam. No other sheeting or habitat is required.

There is no temperature restrictions to the surface preparation, we perform a detailed risk assessment on each location to ensure the risk is kept as low as is reasonably practible.

As the laser requires a line of sight we would still need access but this is no different to the current mechanical prep that is used on sites across the world. There are different tricks that can be used to get into harder areas to see: Spray the area that has restricted access for the laser to reach with water, and the laser will bounce about still cleaning the area.

Surface temperature change is minimal. With a portable 100W system, for example, the surface temperature typically does not change by more than 5 degrees Celcius.

The system is splash proof so habitats will be required to protect the system if working in rain, the habitats would allow us to hang the laser shielding within. The optics cannot get wet. Also, the machine should be kept as dry as possible. It is water resistant but not waterproof.

Yes, it will - it depends on the wattage of the system selected. For more complex or large projects, a higher-wattage machine would be required. This can be determined on a case-by-case basis and priced accordingly.

Thicker scaling can usually be removed with higher laser power. Also, it is possible to do this with a lower power unit if you first remove loose scaling mechanically like with a brush and then use the laser to remove the remaining rust from the base metal surface. This is done in architectural cleaning where brushes are used to remove loose scaling corrosion and a laser is used to remove the remaining surface corrosion.

Based on general experience from surface prep for a variety of applications,  the laser should be able to give the clean and rust-free surface prep that is needed.

Laser cleaning will cover these methods with ease! It is also ideal for corrosion loops where the lagging has come off for example and one area is covered in surfaces scale. For turnarounds and shut-downs, getting the correct wattage which comes with the longest cable length, will prep and clean all internals in one run. The extraction system fitted to the machine will clean as it goes, again saving time and reducing costs - removing the need for special waste disposal!

For internal inspection removing all the product and other nasty things from the process would still be required, but likley to a much less standard than current cleaning methods.

Yes the technology works well on corrosion and coating removal. Paint requires more energy than surface rust but it is generally fully removable via either the laser ablation process or the laser spallation process.

This is exactly what we see the laser undertaking.  Our system has lifting points that allow us to use it via rope access.  Our system is portable and can operate with a 5-metre or 20-metre lead that will allow it to be kept on the ground or out in confined spaces. 

It works on alloys, brick, plastic etc.  To allow us to validate a particular type, we usually ask for a sample to be sent over to us where we video the entire scene and validate that the laser is the correct method for the job and confirm there was no damage done to the product while attaining the correct surface.

Our laser can remove all paint (including lead with the correct safety measures in place), rust, scabs, growth and scale. 

Our extraction system collects all the vaporised excess.  Practically eliminating all risk to neighbouring operating machinery which is commonly damaged by grit being shed by the blasting method. It also allows us to work in close proximity to other people and their equipment, including rotating equipment which again, is often damaged by debris from other methods. The extraction system itself has HEPA and Active carbon filters, the HEPA filter traps extremely small, micron-sized particles system and extracts 99.97 per cent of all airborne particles larger than 0.3 microns.

Our laser has the potential to cause a spark, as does our NDT equipment.  But the measures we instil to ensure it is safe for us to include the fact the spark potential on the surface never comes further than 1” from the point being cleaned. Of course, our specifically developed RAMS, gas monitors and highly specialised training our Technicians hold all contribute to our ability to deliver the laser service in a safe and professional manner at all times.

An image of the UKAS Inspection 4276 logo

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