Questions on PETE

I have some plastic soda bottles (polyethylene terephthalate) which I would like to convert to flat panels for a project. I have cut some up and tried
to glue them in place flattened out, but their curvature causes them to stress the glue as it cures, which I'd like to try to avoid. I could clamp them down but that's more trouble than it's worth, for the number of panels I'd have to clamp down.
If I flatten PETE panel cut-outs under a brick, and then heat them to just below their melting point in that position, will they reshape themselves flat? Or would I need to actually melt them down (which should be possible, as PETE is a thermoplast, and actually preferable in some ways, as I'd be able to use the entire bottle mass)?
Important ancillary question: does PETE outgas significantly when heated, either to just below melting, or just above melting? This will determine if I can melt them in my indoor shop, or if I'll have to do it outside. My wife keeps many reptiles (snakes, geckos) in the house, which are extraordinarily sensitive to airborne toxins. We cannot cook using nonstick surfaces, or use insecticides anywhere in the house, even with much ventilation, or they get sick (or die, since some of them are already of dubious health -- my wife is a herpetological verterinarian, and many of the snakes are "patients").
Thanks in advance, -- TTK
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Won't work. As Al points out they are oriented and will warp on heating. Besides potentially noxious fumes if overheated, if not done in an absolutely dry atmosphere, the polymer will degrade. Recyled bottles, when properly handled, are an excellent source of PET. Frank
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You can buy already flat sheet stock fairly cheaply, probably for less than the return deposit value in those states that charge it.-Jitney
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Thank you! This is exactly the information I need.
Thanks to Frank Logullo, too, for the warning about atmospheric moisture degrading the polymer.
-- TTK
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