MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
This is a question for a separate article. In short. Most of the plastics have two characteristic teperatures. Glass transition temperature (Tg) - when the plastic becomes sort of elastic, but do not flow yet. And melting point temperature (Tm) - when it starts to flow.
Glass transition is used when printing on heat bed - it have to be preheated above this temperature. For PLA this is around 65°C and for ABS 105°C.
Melting point temperature is most commonly used as a hotend temperature. For crystalline PLA it is 175-180°C. With amorphous ABS it is a bit more complicated, depending on the pressure. Temperatures above 200°C have to be used in 3D printers. In both cases the hotend temperature actually have to be a bit higher. You have to heat the previous layer with the actually printed layer above the melting point temperature so they will bound together.
Now when you are printing first layer on plastic cold bed you are using similar principle. The first layer have to be printed at a temperature that will just bound, so the printed model will hold on the plate, but not too high so it would let you remove the model from the plate when print is done! For this reason, Plexiglas (polyacrylate or rather polymethylmethacrylate) with melting point around 160°C or polycarbonate (PC) with melting point at around 155°C are commonly used as cold beds. You can use any other material, with similar melting point (for ABS it may be even a bit higher). Just check its datasheet.
Anyway, you will have to experiment to find the right temperature for the first layer with your printer. As you can see on my videos the cold bed surface get damaged over time.