ABS (Acrylonitrile Butadiene Styrene):

It is the first material used in desktop 3D printing. It is a readily available engineering thermoplastic used by traditional manufacturing methods in making consumer and industrial products. It has excellent impact resistance, good machinability, excellent aesthetic qualities, it is easy to paint and glue, and has good strength and stiffness. 

Within the 3D printing community it is used to make durable parts that can withstand temperature up to 100 °C in air (85 °C sustained). It is less brittle than PLA and under mechanical stress it will firstly bend and deform, and then break. A common solvent for ABS is acetone which can also be used to "weld" ABS parts together. Acetone vapor bath could be used to provide a smooth, glossy finish to the parts.

ABS 3D printing:

ABS, like many engineering thermoplastics, will contract when cooled, therefore it will develop interlayer stress at the interface between a new hot layer 3D printed on top of a cold layer or bed surface. That can result in layer adhesion problems with the printing bed or in between 3D printed layers, and/or curling (upwards bending of the part corners and sides). This curling is more pronounced as the 3D printed object size is increased. This stress release behavior can be avoided by maintaining the entire 3D printed object at a temperature close to the glass transition temperature of the material and then cool it in its entirety after the 3D printing process is completed. Glass transition temperature is where the thermoplastic softens and becomes plastic (malleable, soft).

3FXtrud Uno printers use a heated bed which provides consistent and uniform heating across the whole bed surface. 3FXtrud Duo series of 3D printers have a heated bed and a full enclosure around the 3D printed volume which provides a consistent, stable, uniform warm air environment around the printed objects, thus improving the whole 3D printing process by minimizing further the interlayer stress problem. 

ABS consists of a blend of polymers resulting in a whole range of mechanical and thermal properties as a function of material composition. While some ABS blends will extrude at as low as 220 °C, it is more common that ABS blends with good impact resistance and strength will extrude between 240 °C to 250 °C. A reliable 3D printing head (or extruder) needs to withstand these temperatures for an indefinitely long time. 3FXtrud printers use a whole metal hot end design which works reliably and provides consistent 3D printing of ABS blends. 

ABS 3D printing requirements:

• A heated bed that can operate for a long time at a temperature of at least 120 °C is required.

• A full enclosure around the printed volume is required in order to prevent warping of larger 3D printed objects. From our observations, solid, high infill 3D prints from ABS with sides larger than ~4 cm require an enclosure. Smaller objects could be printed in ABS without an enclosure.

• For good, reliable 3D printing with ABS, the hot end must be able to sustain 250 °C continuously.

ABS is available in 1.75 mm and 3 mm. Pyra 2 uses 3 mm filament, while the newer 3FXtrud 20 Uno, 3FXtrud 25 Uno, 3FXtrud 25 Duo, and 3FXtrud 30 Duo use 1.75 mm. 

A few examples of ABS objects built with ShapingBits 3FXtrud 3D printers:

A time lapse movie of printing in ABS. if all the above mentioned conditions are fulfilled, you can get very nice prints, with reach details. ABS is an engineering thermoplastic so you can print functional parts with it.