View Full Version : Casting resins still toxic when cured?

03-07-2006, 04:37 PM
I want to use casting resins like smooth-on urethanes or alumalite to make items that will be in constant contact with skin (when cured of course). Would be a thing of EVIL if they irritanted skin or caused allergic reactions. The reason I want to use resins is that for short run plastic parts I believe castings will be cheap and fast once the molds are made especially when super tight tolerances are not a must have.

03-07-2006, 04:56 PM
Not to come off as dirty, but these wouldn't be products of an...ahem...adult nature, would they? Because one needs to be VERY careful what materials are used there.

If this is just jewlery or similar it is a bit different. ;)

03-07-2006, 05:08 PM
Its not really an adult item

03-07-2006, 05:19 PM
Java, you jumped all over that one, what's you been makin on the cnc? naw, there's just too much material here to work with, not even going start in earnest

you'll probably the last snicker though, bet that's one heck of a high magin market

03-07-2006, 05:29 PM
LOL its nothing "adult"... Just need info about the cured plastics.

03-07-2006, 05:37 PM
ahhhhh you changed that post! lol should've quota ya :D

High Seas
03-07-2006, 05:39 PM
Guess you've seen this on the Smooth-On site?:
you piqued my interest - I hadn't seen the Life casting items there before - so hadda go look. The MDS is available there too as a pdf.
Good Luck - Jim

03-07-2006, 05:40 PM
Have to watch how I word things around here what I had before made it sound just bad somehow

03-07-2006, 05:42 PM
The MSDS are about the liquid resins I assumed but there is nothing said about if the cured resins are just as nasty. I am not interested in the life casting rubbers just the machinable urethanes.

03-07-2006, 06:07 PM
Have to watch how I word things around here what I had before made it sound just bad somehow

Nah, just wanted to be clear on what type of "skin contact" was going to occur here. ;)

I haven't come across any urethanes that say they would be 'skin safe', you may want to try checking directly with the MFG to see if they have any additional info.

Are you married to the use of a urethane for your product though?

03-07-2006, 06:33 PM
It doesn't have to be a urethane just a safe resin that hardens to be something like nylon and can be cast in silicone molds.

03-07-2006, 07:52 PM
You are surrounded by cured polyurethane. It is used to coat fabrics, make soles for shoes, flexible mounts for truck bodies, the core of plastic bumpers and all manner of things. Nearly all polymeric plastics are bad news in the uncured form but when cured are pretty much innocuous. When you heat or burn them it can be a different story because this can release chemicals similar or identical to the uncured forms.

04-05-2006, 09:44 PM
Most prosthetics and orthotics are made from acrylic or polyester resins. They are all in contact directly with skin all day.