How to choose a Right Fume Extraction System For Your Laser Machines

Why Fume Extractor is a must for Laser Marking and Engraving systems?

Laser marker or engraver uses optics that is light energy, which changes the property of substrate on the process. The varying Power, frequency defines the Quality of marking and design pattern, which results in heating and cooling effects on the laser engraving machine.

The laser engraver produces an enormous amount of heat energy is also calculated in the term of energy density S.I. unit is megawatt/centimeter squared (M.W./cm2). Laser processing on different substrates reacts in ways where there is always a by-product: wastes, burns, chemical fumes/smoke, vapors, bubbles, and melts.

You must understand the difference between all the different types of by-products of varying laser processes. Debris is typically those particles with a larger size larger than microns, which falls closer to the particle on the process. The fumes are smaller than the micron size in gaseous form. All these products can be controlled but cannot be eliminated from the system while processing any substrates.

Now extraction of this fume can only be carried out only when we can create a vacuum all around the material’s area and environment on laser processes. The fumes come out when the substrate’s chemical and physical proper changes, resulting in harmful vapors.

The fume extraction unit not only removes stinks but also eliminates any smell or powerful odor. This Laser fume extraction system traps all the particles which are micron-sized.

There are many ways in which a fume extraction happens, examples as tip fume extraction, downdraft vacuum, room evacuation system, fully enclosed evacuation, and extraction hoods, etc.

All the above methods will affect the right quantity of air required to meet the minimum value of 0.55 m/s, implemented by the U.S. Code (USC) for emissions, British COSHH (LEV guidance and regulatory), and the United States EPA Clean Air Act (CAA).

Once the fumes are trapped and consumed by the extraction unit, it passes through many HEPA types of filters. And all the contaminants and chemicals get removed. There is a charcoal filter to eliminate the smell from the system.

How to Choose the right Fume extraction Unit?

The topmost consideration is that we must decide the airflow across the system. Calculation of airflow is in cubic feet per minute (CFM) as per the laser marker’s technical requirements and specification and engraver.

Ensure with the laser fume extractor manufacturer that the fume extraction airflow system must be well equipped with filters and no free-blowing capacity. In simple words, the CFM value helps in installing the right configuration of Laser systems/machines.

I have mentioned below the necessary configurations.

• Cabinet Extraction Configuration

Extraction of the laser cutter fumes via a channel. The extraction is from the enclosure’s back face having a gap between 2.55 to 6.5 in diameter.

At the time of extracting the fumes from the cabinet, it generally requires a higher CFM value. The reason is that the contamination and pollutant are airborne. There is a need to evacuate the enclosure as soon as possible.

• Source extraction Configuration

Source extraction is a type of configuration in which a cylindrical nozzle, also known as the extraction arm, is the main component. Placing the extraction arm near the laser application is a must. So that the at that time cleaning of contamination happens itself.

This configuration is entirely dependent on the diameter of the nozzle or extraction arm. It will help us choose the best-suited system. The airflow specification and structure of the source extraction method are less than the cabinet extraction method.

Acquiring an excellent source extraction configuration is only possible only when there is a balance between the static pressure, airflow, and most importantly, the nozzle tube parameters’ diameter. (Keeping the important note that the value of static pressure is in feet or inches of the water column).

If the diameter is 3.5 inches, that means the arms are larger-sized. There is still a requirement of excellent airflow, and the static pressure value must be less. Typically as the nozzles, mouth diameter starts shrinking, the airflow will also get limited, and the importance of static pressure rises and becomes significant.

Let us assume; if we are using an extraction system with 22.5 inches of the water column, you will find the airflow speed gets faster. When the laser applications create and generate much debris, this method’s implementation suggests the best solution. If we use this approach, it won’t spread up and away from the processed laser application.

• Downdraft tables configuration

This method or design is mostly applicable to larger laser applications where the working area is more extensive. It requires a larger industrial fume extraction system or an extractor.

In the above configuration, we need to maintain a value of 100fpm speed of the air. As a result, this will suck down the air from the open space of the table. Varying the CFM values ultimately depends on the type of laser application versus the table size.

In many cases, the source extraction method is in use, utilizing fume nozzles or arms. The place where the laser marking or engraving head moves over a larger area with a higher pace or velocity could be challenging. So many applications are custom-made and developed. They are part of the designing and development processes. We must recognize or identify the substrates.

The substate could be a metal, plastic, or composite

These substrates are laser marked, laser cut, laser engraved, or etched. In most cases, pure metal or pure glass won’t create any smell. We must only capture the generated particle when the substrate is on a laser process that is laser engraving.

The odorless gas doesn’t imply that the gas or fume is toxin-free. This fume could be dangerous to health and may lead to health issues. One of the examples is laser marking or engraving on chrome alloy. It could be a chrome alloyed plate or could be a part of metal with stainless steel.

Once the laser process is on, it vaporizes and creates fumes. The fume that reproduced is a highly toxic Hexavalent chain of chromium. The Hexavalent Chromium shouldn’t exceed its threshold value and is highly restricted according to OSHA regulation.

You may go through the website for more details. The following pdf link is for your reference: https://www.osha.gov/Publications/OSHA-3373 hexavalentchromium.pdf

The third consideration is the odor or the smell

The laser processing is happening. When processing the substrates such as plastics, polymers, woods, acrylics, etc., the capturing of residue and tiny particles from the fumes is a must.

The gases(fumes) produced from the vaporized substrate or material can create an irritatingly pungent smell. We can also call it obnoxious and nuisance-contaminated gases. The active carbon available in the market is the best absorber of most of the gases’ smell.

That’s is why carbon is standard in the market. Activated carbon helps in the elimination of obnoxious smell, but All the carbon is not the same. Activated carbon must be granular or bonded.

If we compare the bonded charcoal with granular charcoal, the granular charcoal is better & efficient than Bonded one. The different types of substrates and the diffused elements decrease and increase their effectiveness for the given set of gases.

Scientific studies have shown granular carbon is more effective than bonded. We must consult with the fume extraction system manufacture before integrating activated carbon. Carbon is a good source that sucks the gases and the smell at the time of laser processes.

To see the effectiveness of the activated carbon. The fumes and gases must be in contact with the active carbon for a long duration. When the carbon is in touch for an extended period, the activated carbon absorbs harmful chemicals.

An effective adsorption environment is only possible with systems that offer a larger quantity of activated carbon. Last but not least, there is always a question on safety, maintenance, and hygiene.

It is still advisable that we must keep industrial hygiene. It will not only make us feel better at the place, but it will be the best place for your employee and safe for your business.

Price becomes a factor in Self-cleaning & disposable fume extractor: Systems for fume extraction is either removable or self-cleaning devices. Discarding Disposable filters is essential after a specific time interval, as with time, it losses its efficiency. Regular cleaning of contaminants from the filter’s surface is a must in a “self-cleaning filter”  within a specific interval of time.

These units have their advantages. Both removable and self-cleaning versions can come with handheld(mobile) and stationary extractors.

• Disposable versions have lower initial prices, but filters will need replacement regularly.
• Self-cleaning prototypes have elevated capital costs, but since their filters are reusable, they can have cost savings.

 Flexible performance

Some factories need versatility and soldering/welding/engraving units that can adapt to their jobs’ changing nature, which will be a beneficial factor from a variety. In smaller shops/factories where welding activities switch daily, fixed devices might not be helpful. Similarly, for a shop where just some welding activities happen, a heavy-duty machine can not be applicable.

Comfort and better user experience

In choosing a fume extraction method, ancillary quality of life enhancements is a frequently neglected factor. For example, ensuring that the user interface is readily comprehensible would help keep operations running smoothly. All relevant factors are the usability of materials, the time needed for filter replacement, and washing.

Frequently Asked Questions

1. The volume of airflow Needed?

The volume of airflow is directly proportional to the proportional amount of material removed from the substrates. At the time, laser annealing or foaming a minimal amount of substrate waste releases.

On the other hand, other processes like laser deep engraving and laser cutting remove a larger quality of waste from the substrates’ surface, thus requiring a high amount of airflow. When you buy a laser system, you must know the airflow volume you need for your system.

2.How to filter the contaminants?

There are two ways by which air filtration Is possible. The first is to connect the fume extractor to your in-house duct unit; the second is to purchase a Filtration unit.

There are typically three types of filters available in the market: air filtration by ducting or a standalone system. Using the filter has the advantage that the air quality will be 100 % persevered for operated and employees. Once filters reach their saturation level, they need to remove them to maintain efficient, safe, clean air.

• Pre-filtration unit: it captures larger particle that is visible with naked eyes of human being
• HEPA filters: this filter captures a particle of size 0.4 to 0.5 microns. Know filter for collecting and capturing fine dust
• Activated carbon filter: is best for neutralizing the pungent irritation smell that may lead to suffocation.

3.What are the safety measures you must take while changing the filter?

While changing the filter in the fume extraction unit:
Eye protection is must be wearing safety eyewear to protect eyes from any exposure to harmful elements. Skin protection is taken care of by wearing gloves and avoiding contact with your skin for a long time. Barrier cream could be the solution while handling dust to protect us from toxic fumes particles’ exposer.

Respiratory protection: NIOSH-certified respirator is a must to prevent us from dust exposure. Personal hygiene and cleanliness a must: After the filter changes and is replaced. We must wash our hands.

Protective devices and instruments such as eyes, face, and respiratory protection: According to OSHA, protective equipment usage reduces employees’ exposure to hazardous chemicals or fumes. To ensure that the Laser technology is precisely safe in high-speed production and manufacturing. The Laser technology’s implementation and establishment must follow all the standards correctly, preventing health-related hazards.

4.What value of Sound is Too Loud?

According to OSHA recommendations, the employee or the operator must wear protection to prevent ear damage if the Sound level is more than 86 dBA. In most fume extraction systems, the noise level is between 21 to 80 dBa.