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View Full Version : Is "urea plastic" relatively safe to laser etch?



Chris Schenck
05-13-2012, 12:49 AM
I'm a new laser owner, and I know the danger of lasering PVC and other chlorinated plastics. I have some plastic products I want to laser engrave, and I asked the manufacturer about the type of plastic used in the product. I was told it's "urea plastic" which I've never heard of before. After Googling a bit, I wasn't able to find anything that definitively told me whether this would be harmful to my machine.

I have adequate ventilation, so I'm not concerned about my exposure to the vapors and smoke. My main concern is whether lasering urea plastic will damage my machine in a way similar to PVC. Does anyone here have any experience with lasering urea?

Thanks in advance!

Gary Hair
05-13-2012, 2:03 AM
A quick search tells me that there is no pvc in urea plastic so it should be fine for your laser. Technically, everything we laser has harmful gasses or byproducts, but pvc and teflon are especially dangerous. Bottom line, if you don't find pvc or teflon in the contents then it's probably safe.

Nick Foley
05-16-2012, 11:59 AM
"Urea-formaldehyde resin" is toxic stuff. From Wikipedia:

"Urea-formaldehyde releases formaldehyde emissions into the air. This triggers watery eyes, nose irritations, wheezing and coughing, fatigue, skin rash, severe allergic reactions, burning sensations in the eyes and throat, nausea, and difficulty in breathing in some humans (usually 0.1 ppm). Studies have shown that exposure may cause cancer in humans and animals."

I wouldn't work with it. But is it going to damage your machine? Formaldehyde is corrosive to steel, not as a gas, but when dissolved in water. Maybe it reacts with the moisture in the air the same way chlorine gas does to form HCl and corrodes metal? Probably nowhere near as bad though.

Michael Hunter
05-16-2012, 12:47 PM
Combines with water vapour in the air to form formic acid which is medium-strong and rather unpleasant. Ant bites : also used as kettle de-scalant.

Although on paper urea-formadehyde looks bad, I doubt that it is any worse than wood which releases all sorts of nasties when heated (including a variety of acids and carcinogens).

Comes down to the usual thing - good exhaust and an activated carbon scrubber if you have neighbours to worry about.


Many domestic electric sockets and switch plates are made from urea-formldehyde. They engrave very well!

Gary Hair
05-16-2012, 2:51 PM
"Urea-formaldehyde resin" is toxic stuff.

If you look up the MSDS on every material you laser, you will find a lot of similarities - they all produce toxic byproducts with effects very similar to what you found for urea-formaldehyde. The key, as was already posted, is to vent the byproducts properly.
Maybe it reacts with the moisture in the air the same way chlorine gas does to form HCl and corrodes metal? - if you are not sure then why make a statement like this?

Gary

Nick Foley
05-18-2012, 2:04 PM
if you are not sure then why make a statement like this?

Gary[/FONT][/COLOR]


Well, because like someone else also posted, it does react with moisture in the air to form a corrosive acid. The uncertainty is whether there's enough of it (and it sticks around long enough) to affect the machine. Probably not at all... but are you really advocating that a having a total lack of information is better than having information with (clearly stated) uncertainty attached?

Gary Hair
05-18-2012, 2:52 PM
As it turns out, that statement about it formic acid is also incorrect. Formic acid and formaldehyde are both byproducts of methanol. According to wikipedi formic acid has low toxicity. This thread is a prime example of how one small piece of bad information can lead to other bad info and cause concern for something that there is nothing to be concerned about. If you want to read up on formic acid, here is the link: http://en.wikipedia.org/wiki/Formic_acid

If you want to be concerned about urea-formaldehyde-resin, then you need to stop lasering mdf - it's the glue that is used to hold it together, and if you look up acrylic, you'll find that it releases formaldehyde when heated. So, I'll go back to my original statements - everything emits toxic byproducts, you just need to mitigate your exposure.

Michael Hunter
05-18-2012, 7:57 PM
Sorry - it was me said that it combined with water to form formic acid and I was wrong. (I though I remembered from school chemistry, but that was a very long time ago!).
Note that I did not say that formic acid was toxic ; merely that it is unpleasant (which is why ants use it).

I've now looked up to see what really happens -

Mechanism of thermal degradation of urea-formaldehyde polycondensates

G. Camino,
L. Operti,
L. Trossarelli




....which undergoes extensive fragmentation above 300°C. Water, formaldehyde, carbon monoxide and dioxide, methane, ammonia, monomethylamine and trimethylamine are the gaseous products evolved.



I have spent 50 hours over the last week or so, lasering logos into MDF and I can testify that the fumes are horrible