Abs Filament; Abs Filament Troubleshooting - MakerBot Replicator 2X User Manual

ABS FILAMENT

ABS is short for Acrylonitrile Butadiene Styrene. It is made of a combination of those three
plastics. The three plastics can be mixed in different proportions to formulate ABS intended
for different uses.
ABS is tough and somewhat flexible. ABS becomes softer with increased temperatures,
but at the extrusion temperatures used in a MakerBot it remains fairly viscous. That means
that ABS melts quickly inside the extruder but doesn't drip during travel moves. ABS can
also withstand heat well enough that we use it to make the plastic components of the
Replicator 2X's extruders.
TROUBLESHOOTING
ABS has a high rate of thermal expansion,
which means it expands as it is heated and
shrinks as it cools. This can cause certain
problems when printing.
Warping: Thermal expansion means that
layers closer to the extruder are cooling and
shrinking, causing strain on the layers below.
The shrinking layers pull at the stable layers,
warping the object.
Cracking: Cracking is a different
manifestation of the same problem. When
the bond between two layers is not strong,
sometimes the shrinking of a section of
96
newer layers will cause it to separate from
the previous layers. This results in horizontal
cracks in the side of the object.
Increasing the extrusion temperature
creates a stronger bond between each
pair of layers, but will also increase the
temperature differential between new
layers and older layers. The best way to
combat both warping and cracking is to
keep the whole object warm. This is why
the MakerBot Replicator 2X is fully enclosed
-- the heat of the extruder, instead of
dissipating, stays in the build area and keeps
the object at a more steady temperature.