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Well welcome to another Lightblade learning lab today we’re not even going
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to turn the machine on because apart from warning you about the dangers of
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burning yourself on the laser, burning your eyeballs on the laser, looking after
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your laser looking after your mirrors looking after your lenses it’s one
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continuous look after – the one thing we haven’t mentioned is looking after
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yourself. Now this machine is actually relatively benign because as soon as you
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put this lid down everything is pretty safe with the exception that once you
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start cutting material in here you produce fumes, you produce smoke you
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produce horrible smells now anything that smells horrible anything that’s got
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smoke should serve as a warning don’t breathe in because it could be dangerous
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to you. This is a piece of industry standard equipment which basically looks after
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you your eyes your lungs and your health, now if you were in industry in a factory
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or running a business then it would be mandatory for you to have one of these,
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it’s not mandatory for me to have one of these in this workshop because I’m a
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private individual and I can do what I damn well like but don’t really want to
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kill myself. Now you can buy this machine without this piece of kit this fume
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extraction now this is a recirculating fume extraction system which means that
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if you’re in a heated environment and I’m not, I’m in a very cold workshop any
Transcript for Laser Material Hazards – Don’t Ignore (Cont…)
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air that you draw in you recirculate any heat that you draw in you recirculate so
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you don’t waste heat by pumping it out through an external venting system now
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I’m not a Salesman for pure X but what I’m going to do is explain to you today
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that this optional extra that you can get with this machine
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really shouldn’t be considered as an optional extra it should be considered
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as an essential and I think you’ll soon understand that once I start talking
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about some of the chemicals that this machine can produce and some of the
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dangers it can have to your health, I’m not even going to explain how this
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Purex system works you know you push a button it turns on it makes a noise
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it sucks in here it recirculates clean air and what happens in here is magic. But you can
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find out all about that on the Purex website now you will see me using this
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machine with the door open that’s not a major problem because this system here
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has got so much air flow through it that it just sucks in huge volumes of air
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through the front there and it never gets near me, so all the fumes are
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wafted back into and through this unit before they’re recirculated now there’s
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absolutely masses of data online about cutting and burning various plastic and
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wood materials. I mean even wood you would think as a safe material but some
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of the reasons in the wood can produce carcinogenic fumes don’t trust anything
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before you cut it do your research! Now have here a piece of MDF which is
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full of all sorts of resins that hold the woodchips together it’s supposedly
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laser grade material now what laser grade material is I don’t really
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understand because any resin any plastic will produce fumes so even
Transcript for Laser Material Hazards – Don’t Ignore (Cont…)
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though it may well cut nicely it probably produces toxic fumes in some
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way shape or form so let’s now move to the office and we’ll take a look at some
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of the data that’s available online I’m only going to show you a small portion
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of data just to frighten you a little bit. Well, we’re going to start off here at the
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Purex website because if we move across to fume extraction it just goes through
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some of the stuff that I’ve already summarized for you now I just point out
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this to you depending on where you are and your neighbors it may well be that
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external emissions regulations will be a problem to you, you know it’s not
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environmentally friendly to just check your fumes outside the door as I have to
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admit I do with my original Chinese machine. Now here we’ve got a very neat
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summary of some hazardous fumes and particularly I
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want to bring your attention to this section here which is called laser marking
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and obviously laser cutting because marking & cutting both require heat if we
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take a look at some of the materials that we’ve got down here and we see some
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of the emissions that can occur I mean things like benzene phenol HCN now
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some of you guys will know what HCN is that basically is hydrogen cyanide which is
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a I think you’d probably understand a killer gas it’s used in gas chambers
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horrible things like benzene they all seem to produce benzene in some way
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shape or form Toluene, these are all and hydrocarbon type gases which have
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got if we take a look down the bottom here at benzene a known carcinogen responsible
Transcript for Laser Material Hazards – Don’t Ignore (Cont…)
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for leukemia all I can do is just ask you to look down this list here
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and this list here and you’ll compare and see what the problems are I’ll bring
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your attention particularly to PVC polyvinyl chloride now one of the most
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dangerous gases that you’re going to encounter is hydrogen chloride now HCl gas
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is basically a gaseous form of an acid as soon as
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it touches something aqueous like your eyeballs which have got fluid on them or
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your lungs which are full of fluid it will immediately turn to hydrochloric
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acid you don’t want that either in your machine because it will corrode the
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slide ways or you don’t want it in your lungs now this is one of the things that
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you really must never cut on a laser machine and one of the simple tests that
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you can use to check the plastic before you do it is what I’m doing here, Look
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I’ve got a piece of copper wire here now when you heat the wire up you’ll see that
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it glows red-hot
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don’t get these fumes up your nose but look I’ve got here a piece of old wire
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which I know to be PVC covering on this wire
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they don’t use PVC covering on a lot of cables these days because of its dangers
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but look what happens when I put it in the flame we’re looking for a green
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colour there we go can you see that green colour now that tells me categorically
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that that piece of cable contains PVC the other sort of thing that you might
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find with PVC in it I mean this is a handle off of one of these flexible dips
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handles now the chances are that this is PVC but we can check so we’ll
Transcript for Laser Material Hazards – Don’t Ignore (Cont…)
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make it warm and we’ll just get a little bit of it on the surface, a smear of it and then
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we’ll pop it in the flame
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and my goodness me, there’s PVC for you that’s chlorine gas that you’re seeing,
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turning green now this is not a test that I invented this is a test that I’ve
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seen somebody else doing on the internet so I’m taking no glory from this all I’m
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saying is it is a very convenient way of testing as to whether or not you’ve got
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chlorine in the material that you’re cutting if you have don’t cut it. Doesn’t look
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to be anything deadly in there
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no green fumes
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That’s a glossy cardboard, just checking this nothing green comes off that so
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just because it’s card doesn’t mean to say it safe because it depends on what’s in
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the card what inks there are what what plastic you’ve got on the surface of
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it you’ll see that your electronics cabinet is not sealed so consequently
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this gas can also get in and corrode your wiring in there not a good idea
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PVC is one of the biggest nono materials for laser cutting but something that we
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would consider normally to be a fairly benign and non dangerous material is
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acrylic different people know it by different names it could be perspex it
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can be Plexiglas basically it’s this product here called poly well it’s a
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it’s called methyl methyl acrylate and it’s known as PMMA because it’s poly
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methyl methyl acrylate apart from the smokey bit that you can
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see which is the respirable dust it also produces MMA which is actually the raw
Transcript for Laser Material Hazards – Don’t Ignore (Cont…)
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methyl methyl acrylate it produces benzene and ethyl acrylate now benzene
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in particular as we look down here we find that you know it’s this known
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carcinogen again you can go and you look at these fact sheets which come from all
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parts of the world some of them are american some of them are british
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standard some of you european standards you will find out you know just how
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dangerous methyl methyl acrylate is how methyl acrylate enters and affect your
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body now i’m not going to go through the details of this all i want to show you
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is that there is a hell of a lot of data online relating to the safety of these
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materials so here we are at another very useful website it not only tells you
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materials that you should never cut sometimes it doesn’t explain why but it
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also tells you materials that you can cut and what sort of results that you
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will expect very useful well that’s about as far as I want to go
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today thank you very much for watching and I’ll catch up with you in the next
