Laser cutter filtration?

[Munty Scruntfundle]

Hi there.

I have a laser cutter coming in a couple of weeks. It has it's own extraction system including a fan unit and hose, but I'd like to filter the exhaust before blowing the air into the outside. The company have a unit but it's expensive and large. I have a space under the intended table roughly 600x400x180 and thought I'd build a box around this size, pack it with some kind of filtering and give it an outlet.

Anyone done this and have any advice?

Many thanks.

 

[pe2dave]

DIY? Look around for chip extractor and their filters? I think HEPA is the higher level?
If you can bodge up something like that, with a mains / 12v fan to blow air?
Could be a fun project.

 

[Distinterior]

I dont think he means a filter for dust/chips Dave,....I'm more inclined to think he wants to remove the fumes..??

A mate of mine has a laser engraver and during use, it does produce a fair amount of fumes whilst etching wood as you would expect considering the process is burning away the surface to create the engraving effect.

 

[MARK.B.]

Quite a few on youtube seem to use Activated Charcoal as a filter medium in their home made filters.

 

[gog64]

We’ve got a fairly powerful laser. When cutting, especially MDF you get “smoke”. I put quotes around that as the trainer explained that the laser ablates, it doesn’t burn. Anyway, that went over my head. If it looks like smoke and smells like smoke, that’s what it is. So, if you can’t legally VENT the smoke you have to have an expensive filtration system that removes it 100% before venting the air internally or externally. AFAIK you need to speak with the council to see whether you can vent the smoke. No idea whether you can DIY a smoke filtration system.

 

[pe2dave]

I dont think he means a filter for dust/chips Dave,....I'm more inclined to think he wants to remove the fumes..??

A mate of mine has a laser engraver and during use, it does produce a fair amount of fumes whilst etching wood as you would expect considering the process is burning away the surface to create the engraving effect.

Understood. Same thing, just less airflow, finer filter and less 'collection' Distinterior ?

 

[Distinterior]

Some kitchen extractor hoods utilise charcoal filters. It helps reduce the smell/fumes of cooking before blowing the air back into the room.
Perhaps you could try a couple of these type of filters in your own DIY laser etching /cutting set up...?

I think I may have a couple of (old)new spare ones stashed somewhere in a cardboard box....If you think they may be of use to you MSF, drop me a message in the private "conversations" and I will send them for you to try.

 

[TheTiddles]

We’ve got a fairly powerful laser. When cutting, especially MDF you get “smoke”. I put quotes around that as the trainer explained that the laser ablates, it doesn’t burn. Anyway, that went over my head. If it looks like smoke and smells like smoke, that’s what it is. So, if you can’t legally VENT the smoke you have to have an expensive filtration system that removes it 100% before venting the air internally or externally. AFAIK you need to speak with the council to see whether you can vent the smoke. No idea whether you can DIY a smoke filtration system.

The laser guy is right and slightly wrong, if you a laser some material they eject as a plasma etc... wood mostly doesn’t unless you pump an awful lot of shielding in, which most don’t, it’s just a fine powder of burned cellulose, might as well call that smoke.

Have a care what you cut and where it goes, PVC for instance will out-gas chlorine and that does sting the eyes somewhat

Aidan

 

[Inspector]

Perhaps a used portable welding fume extractor, the self contained units with the snorkel hose, would do the trick. New ones can be quite expensive but some of the used ones on eBay can go cheap. Another option is the filters for one. Some are self contained metal canisters that look like a hose and attached suction fan would be relatively easy to attach to.

Pete

 

[Keith 66]

I used to work in a school where we had a much used laser cutter. The fumes from them are carcinogenic. Usually you will be cutting organic materials such as wood, birch plywood, veneers & plastic such as acrylic. Polypropylene can be cut but not well as the edge melts too much. PVC is an absolute no no as it will give off Chlorine gas & hydrogen chloride which is highly corrosive.
Our 30w laser had an Oracle Bofa filter unit that took a large prefilter & hepa filter with a large amount of activated charcoal.
To replace both filters cost about £500 & we had to do this twice a year. The laser cutter was located in my prep room & the exhaust from the Oracle extractor vented into the room. Frankly it stank after just a few weeks with new filters & i would not entertain the same set up in my own workshop. Activated charcoal isnt cheap & the quantities you will need will cost.
Cooker filters will be overwhelmed by a laser within days.
I have looked into extraction systems for these as i will shortly be buying one for my own workshop, I have installed 150mm steel ducting with silencer & 1500m3 centrifugal fan. It can be used as an extractor for welding fume or for the laser. Its vented straight outside, you will need a good air inlet into the room otherwise the eficiency drops off quickly.
Outside the workshop the outlet can barely be heard more than 15 feet away so happy with that.

 

[southendwoodworker]

I have a 40w laser cutter at home, and a 100w + 60w available to me. I primarily cut mdf, acrylic, polypropylene and ply. I don't use any fume cleansing system, I just pump straight out of the shed which is 10m from the house, and have it facing away from my neighbours. The wind easily dissipates it.

The 100w and 60w are in the similar situation but in a council owned building, usage is so low (short periods) the neighbours/public arent even aware of what is happening. The council are aware of them, have done renovations to support their use, see them regularly. They have cared more about the noise when being run late at night and the fire safety in the room. We have decided to only address the problem with it when someone complains.

I've done about 50 hours of cutting on my one at home and the neighbours have not even noticed. I obviously don't do it when they are using their garden or have washing out. Are you planning to spend a lot of time cutting? If not, try using your cutter for a while before trying to answer this fume cleansing problem - you might find that you use it for such small periods of time no one will notice.

Acrylic fumes give headaches, mdf stinks and gives a nasty cough. Polypropylene after extraction gives off a bit off a dust.

Maybe I am naughty with what I am doing, I'm not too sure. The regulations around it are confusing and cumbersome.

What laser cutter did you go for?

 

[pe2dave]

We have decided to only address the problem with it when someone complains.

Sounds like the government on road hazards. We'll do something about it when someone is killed.
Yuk.

 

[TheTiddles]

Sounds like the government on road hazards. We'll do something about it when someone is killed.
Yuk.

I see your point there and I’m halfway to agreeing with you, but then they do (and probably can’t) nothing about people burning treated timber, old ply, plastic packaging on bonfires so compared to that it’s nothing.

That said, just because you can get away with something doesn’t mean it’s acceptable to do it

Aidan

 

[Ozi]

The actual volume of material you are burning must be tiny, if you avoid things like PVC and blow through enough air then the concentrations must be minimal. With a bit of consideration, not blowing it at the neighbors etc. I'm guessing you do more environmental damage driving into town for materials. Clean the air filter on your car, check the tire pressures and you will probably offset any effect.

 

[pe2dave]

I did note the carcinogenic nature of the fumes from cutting wood. Strikes me that lungs might appreciate a decent filter, which means
one of the HEPA range IIRC?

 

[TheTiddles]

I did note the carcinogenic nature of the fumes from cutting wood. Strikes me that lungs might appreciate a decent filter, which means
one of the HEPA range IIRC?

Depends what you’re trying to catch! Many things are carcinogenic, yet pubs still serve beer, vans sell ice cream and aeroplanes fly high up in the air, it’s a question of degrees. Ozi is pretty well dead on with the car analogue
Aidan

 

[paulrbarnard]

I only have a 5000mw laser but I have vented it to outside. I use a Screwfix bathroom extractor fan and the ducting it came with. It seems to do the job quite well. I built a box to house the laser.
I built the box and fitted the extraction very quickly after I got the laser. The fumes were pretty nasty just from wood and MDF. Even paper and card makes a nasty stink.

 

[cowtown_eric]

Our makerspace has two laser cutters, joined to a common and boosted exhaust to the room. There is a 1/4" grid on the vent, which has to be cleaned about every six months. as it just plugs up, not only from ?condensed fumes, but also by teeny tiny cut outs from the laser which are light enuf to get blown straight up 15 feet or so. A blocked air duct means fumes aren't extracted very efficiently at all, so apparently smoke from cutting also accumulates on lens, and things just don't work

so figure out how to clean any exterior vent easily.

Eric

 

[Jelly]

. If it looks like smoke and smells like smoke, that’s what it is. So, if you can’t legally VENT the smoke you have to have an expensive filtration system that removes it 100% before venting the air internally or externally. AFAIK you need to speak with the council to see whether you can vent the smoke. No idea whether you can DIY a smoke filtration system.

Having looked into this previously for more than one organisation, it's not subject to regulation:

It's not a regulated activity under the Environmental Permitting Regulations 2016 as it's:​

1. Not explicitly mentioned in the Industrial Emissions Directive, The Integrated Pollution Prevention and Control Directive, Environmental Protection Act 1990 or the Alkali Act 1863, and thus is not subject to regulation or permitting requirements.
   1. Even if it was, the type of emission it is would mean it was far too small an emission source to be subject to regulation, even via the abbreviated "Part B" process operated by local authorities.

Nor does it fall under the provisions of the Clean Air Act 1993 which provide for Smoke Control Zones, because they only provide for regulation of emissions from the burning of materials as fuel, in a hearth, heating appliance, furnace or boiler.​

I would advise OP that:

Firstly,​

It is safe, legal and appropriate to directly vent their LEV system to the outside.​

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Good practice would be to do this via a vent or stack well above head height to a pedestrian outside, alternatively into an area which is known not to be frequently used during LEV operation.​

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Secondly,​

They should not attempt to jury rig a filter if they are unable to confirm that the back pressure of their filter hasn't reduced the LEV's effectiveness.​

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If the vent blower isn't removing the fumes effectively it will cause issues with the laser mirrors and tubes accumulating residues which bit reduce the cut quality, and risk damage if not frequently cleaned off;​

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In extreme cases it could also allow fumes to accumulate in the cabinet and/or workspace, which is not safe or appropriate.​