@teamlaser I know it was brought up in our last committee meeting we are looking into allowing pink foam being cut is it currently on do not cut list?
Thanks
Joshua
It appears standard spray foam is made of polyurethane which is “chemical product created by two materials, isocyanate and polyol resin”. I would suppose that the isocyanate is the dangerous part. I would also assume foam board is made out of the same thing.
Just test them for chlorine with a flame test:
Thanks for the input I know laser committee is looking into what is best for our equipment and members and in an effort to be excellent to other I was looking for clarification before I spoke as a laser committee member to another maker.
This will ultimately be decided by the laser committee.
Thanks
Joshua
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Pink foam (Owens Corning Foamular) and blue foam (Styrofoam by Dow) are both made primarily from XPS - extruded polystyrene. Flame retardants and talc from production processing make up the balance.
Note that this is different from the resin-based expanding rigid foam like Great Stuff which is made up of a bunch of stuff, some of which are irritants and includes flammable propellents which can remain embedded in the foam after it cures.
Here is the safety sheet for the Owens Corning Foamular ™ product.
http://www.buildsite.com/pdf/owenscorning/PINK-Foamular-Rigid-Foam-Insulation-SDS-149942.pdf
And the one for Great Stuff:
https://www.dow.com/webapps/msds/ShowPDF.aspx?id=090003e8806e64c2
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I cut XPS foam using a hot wire foam cutter without issue.
It does melt back with the heat and in theory could melt enough to catch fire (even with the added flame retardants) and/or make a gooey mess on the bed but I find that unlikely under normal conditions and with an observant user.
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Well, it says right in the MSDS.
Hazardous Decomposition Products:
Primary combustion products are carbon monoxide, carbon dioxide, and styrene. The HCFC-142B ingredient
thermally decomposes at temperatures in the order of 430ÂşC (805ÂşF). The decomposition products include
hydrogen fluoride, hydrogen chloride, carbon monoxide, carbon dioxide, fluorine, and chlorine. Other
undetermined hydrocarbon fractions could be released in small quantities.
Someone just needs to decide if that’s acceptable. Some you an obviously cross off, Carbon Dioxide, even Carbon Monoxide if you are 't cutting a ton of it (foam). It’s about as dangerous as mowing your lawn is. Others get questionable- Chlorine, Fluorine both are pretty reactive, they really want to find another electron somewhere and with do about anything to get it, and it doesn’t care if it’s a cell membrane or inanimate.
Hydrogen Chloride- IDK about this. I mean we all know about hydrochloric acid, but I’m not sure what a molecular version of this would do. It might very well be stable. It’s hard to find an MSDS on it, but it’s here:
Apparently, it is stable but really itching to get wet and make Hydrochloric acid, so it will dissolve in say the water in your eyes or mouth and make an acid. Now in small amounts it’s likely insignificant. It’s like putting a drop of acid in a swimming pool, little effect. But with enough drops, it could cause burns.
I guess I would wonder how much gas and how much (%) of each constituent would be produced. Is there an outside vent for the laser? There is, isn’t there?
If so, then I would hazard to say that it’s safe, and just put a limit on the amount cut at once to keep the toxic byproducts down. The dose makes the poison, as they say. And this is going to be all about dose here. Even water or oxygen is poisonous at an appropriate dose. So maintaining low concentrations of these compounds would be essential, but if it’s done, I’d say it’s safe. Maybe we can build an Arduino sensor to pick up CO or CH4 or whatever, Or a chlorine gas detector, I think those exist. From that, we can extrapolate the concentration of each other compound (by %) and find a table of what ppm things are toxic at, with whatever shows toxicity first being the Upper Limit of Normal. Once done we could install it over the laser. It would be easy to build. Pretty damn hard to calibrate though.
Source, have MD, though very definitely not a toxicologist. I’ve had at best maybe 3 or 4 hours instruction in this, and then only in a general sort of way. I know nothing of legal aspects (i.e. business codes/OHSA and the like- are we required to have an eyewash station if is HCl is produced as a byproduct? etc.)
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Florine etches glass, as in lenses so that is always a no go.
Meh, still thinking about this.
From the same MSDS, the underlying MSDSes
CAS # Component Percent by Wt.
9003-53-6 Polystyrene 80-90%
75-68-3 HCFC-142b 7-12%
3194-55-6 Hexabromocyclododecane 0.5-1.5%
14807-96-6 Talc 0-2 %
Polystyrene: "If polystyrene is properly incinerated at high temperatures (up to 1000 °C[58]) and with plenty of air[58] (14 m3/kg[citation needed]), the chemicals generated are water, carbon dioxide, and possibly small amounts of residual halogen-compounds from flame-retardants.[58] If only incomplete incineration is done, there will also be leftover carbon soot and a complex mixture of volatile compounds.[59][better source needed] According to the American Chemistry Council, when polystyrene is incinerated in modern facilities, the final volume is 1% of the starting volume; most of the polystyrene is converted into carbon dioxide, water vapor, and heat. Because of the amount of heat released, it is sometimes used as a power source for steam or electricity generation.[58][60]
When polystyrene was burned at temperatures of 800–900 °C (the typical range of a modern incinerator), the products of combustion consisted of “a complex mixture of polycyclic aromatic hydrocarbons (PAHs) from alkyl benzenes to benzoperylene. Over 90 different compounds were identified in combustion effluents from polystyrene.”[61][better source needed]" -Wikipedia
I guess the big one is HCFC-142b, but it’s only 7%, and it’s by-products would be even less, so I wouldn’t guess the amount would be that high. But that’s where the HCl, Cl, F gases come from. CO is a byproduct of any combustion really.
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Lenses in a laser cutter are not glass, they’re ZnSe which is not affected by HF.
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One of the combustion by products is chlorine. Don’t cut it with a laser cutter.
the amount produced is miniscule. MANY people laser cut foam board without issue.
Cool story. Do it on your own laser cutter then.
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If you’re going to make up rules, you should have some actual evidence of hazard, not just hysteria.
Here’s a laser manufacturer recommending cutting of expanded polystyrene foam: https://www.ulsinc.com/materials/styrofoam
Laser cutting works by vaporization and this product contains chlorine. Chlorine will corrode components. I’m surprised Universal says it’s fine to cut. They might use different materials in their machine construction or other measures to prevent the chlorine from corroding components. Also refer to our wiki and other sources saying it’s extremely flammable and to not laser cut it even if you think the chlorine in not an issue.
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Go Laser Committee, advocate for change in prohibited materials. If they agree, good to go. If not, then prohibition stands regardless of personal opinion.
Rules can change, but committee or Chair must do this.
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It would seem that some means to maintain positive air pressure in the vicinity of sensitive optical components could mitigate small quantities of corrosives in a laser.
It’s not really the optics that are of specific concern. It’s the entire machine.
While products containing less chlorine will cause less corrosion it still all adds up.
Polystyrene is on the approved list, and has been for a few years. It is cut very often on the lasers without noticeable damage or ill effect.
@lukeiamyourfather You and @william_petefish had reviewed this before and approved.
Thank you @Andrew_Timmons & @halachal for the additional research confirming the dangerous chemicals are minute and properly evacuated.
We can review the list at the committee meeting March 4th.
@heyheymama
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