I hope this question isnt too general but Im a little stuck. I have an idea for an invention in the home/pet sector and have a prototype in use made from plyboard. I want to look at making a version myself in plastic - possibly to take further as an innovation.

Is there anything I can get hold of cheaply that I can heat and mold myself (approx 2mm thick). The finished product will be reasonable simple in design with only 3/4 bends and be made from a rectangular sheet approx 400mm x 250mm.

Any pointers would be really helpfull.