[timmy808]

I am trying to find a plastic that can be used to make "Hard Candy Molds". The plastic needs to be able to handle temperatures of 325-350 deg. I have seen candy molds described as "White Tempered Plastic". Does anyone out there have any experience with this?

Thanks, Tim

[ckelloug]

If they don't have to be clear, I would recommend food grade silicone. More durable and easier to demold though a bit expensive. Chef Rubber is a retail supplier.

If I had to guess, I'd say that there's a good chance that the molds made out of white tempered plastic have a fair chance of being polystyrene. I'm not sure but a quick check of the melting point indicates that it shouldn't melt at that temperature.

[Juan.Sanchez]

Not Styrene. Styrene softens at about 190 degrees. There is no 'tempered' plastic materials. Polycarbonate takes about 280 continuous, but is commonly used for candy type molds. For materials that can take higher temperatures and be formable I think the silicone idea is a good one.
For listings of plastic materials for vacuum forming : Looking For Vacuum Formable (Forming) Plastics | Industrial Plastic Supply, Inc.
Most materials don't need to be able to take the temperature of the candy, because they cool quickly, probably some trial and error.