Printing a 3D model that sticks
The FDM 3D printing technology uses melted filament (plastic) that is printed onto the print bed by the nozzle. For a perfectly printed model, it’s crucial that the first layer of filament adheres well to the print bed. Most filaments tend to warp when the material cools down too quickly, especially on the print bed. So, without the right adhesion to the bed the filament will warp, deforming the product and making it useless. There are several ways to prevent this from happening: the biggest benefit comes from using a heated print bed.
Temperature is very important when making a 3D print. Without the right temperatures, it’s impossible to make a good print. The filament needs to be melted before it’s able to go through the nozzle and be printed in layers. The temperature at which the filament changes from a solid to a liquid form is called the glass transition temperature. This temperature differs per filament: for PLA it’s between 60 and 65°C, for PET-G around 70°C and for ABS even between 110 and 115°C. Especially for filaments with a high glass transition temperature, like ABS, it’s crucial to have a high temperature inside the printer. This can be achieved by using a heated print bed that warms up the printing chamber.
Adhesion to the print bed
An extra advantage of the heated print bed is that the first filament layers on the print bed don’t cool down immediately, but stay at the right temperature. This is essential for the adhesion. Filament layers adhere well to each other, but not so much to a different surface -in this case the glass print bed. This can be solved by setting the right temperature per filament. Additionally, several tools are available to prevent warping from the print bed. Examples are Kapton tape (adhesion tape) or Dimaxif (adhesion spray). The popular PLA filament can be printed without heated print bed, but more high tech filaments like ABS, PP or PC -often used for industrial purposes- cannot be printed without a heated bed and closed chamber. Using an adhesion spray or tape is not sufficient, the model will still warp.
High tech filaments
The advantage of filaments with a high glass transition temperature is that they can also resist higher temperatures as a product. ABS is therefore commonly used in the automotive industry for e.g. dashboards and bumpers. ABS also has a longer lifespan compared to PLA, because it’s less prone to for instance weather influences.