There are four main steps in the production of carbon fiber 1) melt spinning 2) oxidization/precarbonization 3) carbonization and 4) graphitization.

1. CARBON FIBER SYNTHESIS
AKASH RAJ D
2020248026
M.Tech Polymer science and
engineering

2. PRODUCTION SOURCES
PITCH
PAN

4. SYNTHESIS
There are four main steps in the production of carbon fiber
• 1) melt spinning
• 2) oxidization/precarbonization
• 3) carbonization and
• 4) graphitization.

5. 1) Melt spinning is the method of
forming fibers through the rapid
cooling of a melt; In melt spinning
polymer (fibre-forming substance)
is melted and pumped through a
spinneret (die) with numerous
holes (one to thousands). The
molten fibres are cooled, solidified,
and wound on a suitable package.
Melt spinning uses the heat to
melt the polymer to a viscosity
which is suitable for the extrusion
through the spinneret.

6. 2) Oxidization/Precarbonization is
used in order to cross-link the
fibers to the point where they
cannot be melted or fused
together. This step is extremely
important because it produces
fibers that are stable at the high
temperatures of carbonization
and graphitization; otherwise, the
fibers would fail in those steps of
the process.
• Temperature:200-300 C

7. 3) Carbonization is the process removing all non organic elements. In
the case of carbon fibers, all elements except for carbon are removed.
This is achieved by heating the fibers to high temperatures(700-1800 C)
in an environment without oxygen.This step removes all impurities
from the fibers and leaves crystalline carbon structures. These
structures are mostly hexagonal in shape and are composed of entirely
carbon.

8. 4) Graphitization is the process of treating the fibers at high
temperatures (2000-3000 C) in order to improve the alignment and
orientation of the crystalline regions along the fiber direction. Having
the crystalline regions aligned, stacked, and oriented along the fiber
direction increases the overall strength of the carbon fiber.

10. The high strength of carbon fiber can be attributed to these four main
processes.
• Having high levels of crystalline regions allows the fibers to withstand
high levels of stress.
• These crystalline regions are formed via the melt spinning process;
the crystals are stiff areas that do not deform when an external stress
is applied.
• Orienting and aligning these crystalline regions gives further strength
to the fibers, specifically if the orientation is along the fiber axis.
• Carbonization and graphitization are the two processes responsible
for this alignment of the crystalline regions

11. THANK YOU