JEC COMPOSITES MAGAZINE - Issue #93 - December 2014 - 26

awards
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JEC innovation awards programme
Raw Materials

High-modulus PAN-based carbon fibre
UHT's project is to transform general PANbased carbon fibre into high-modulus carbon
fibre. This solution provides a more efficient
and convenient access to intermediate-modulus (IM) and high-modulus (HM) carbon
fibres, without considering precursor quality
and huge investments in a facility for the
whole production line. With a patented ultraheating technology - microwave heating,
combined with resizing and a re-winding
technique - a new graphitization system was
built. The system focuses electromagnetic
energy inside the carbon fibres and generates
a huge amount of heat in a few seconds. This
innovation has multiple advantages such as
a 70% reduction in energy consumption,
applicability to all types of PAN carbon
fibres, availability of a sizing alternation, and
being an environmentally friendly process.

So far, IM or HM carbon fiber products have
been very expensive and well-controlled
materials. This project eliminates most front
investments such as precursors, oxidation
and carbonization systems, along with higher
energy efficiency, enabling many new types
of IM and HM carbon fibre to be created at
lower cost. For example, it is now possible to
upgrade products like the Toray T700 grade
(to an IM-grade fibre like T800, called U30S
in UHT's system (strength: 5,300 MPa,
modulus: 295 GPa) with stable quality and
around 15 to 30% cost reduction. This will
encourage composite designers to perform
more high-level simulations or experiments,
leading to more evolution in final products.
UHT began to work on this innovation in
2011, and has now successfully built a new
IM CF product line with a 300 tons/year pro-

Innovative long-shelf-life prepreg systems

Pre-impregnated composite fibres containing
a pre-catalyzed epoxy resin system require
cold storage to prevent a staging reaction from
occurring before use. This staging reaction
is accelerated with elevated temperatures,
which can be problematic in countries with
warmer climates. Gurit has developed a
range of solvent-free prepreg technologies
with significantly extended storage shelf lives.
Gurit's long-shelf-life prepreg chemistry
allows prepregs to be produced with a life
span of up to 2 months when stored at an elevated temperature of 35°C, and greater than
6 months at 21°C, depending on the system.
Gurit achieved this by using advanced catalyst
chemistry to provide increased stability at
storage temperatures, yet remain reactive at
temperatures of 85°C and above, allowing

fast curing of components. This allows users
to replace their current prepregs with a longshelf-life version generating savings in their
storage requirements, simplifying their inventory management and without changing their
curing cycle or finished material properties.
The Product Development department
initially focused on improving the latency
of the catalysts used to cure epoxy prepregs.
The challenge was to significantly increase
the latency at ambient temperatures without
reducing the reactivity at the higher temperature used for curing. Once the core chemistry
was developed, Gurit proceeded to formulate
this into a range of prepregs for different applications. Initially, three different prepregs were
developed: one for industrial applications
(wind turbine blades), one for low-tempera-

26 jec composites magazine / No93 December 2014

Winner: UHT Unitech (Taiwan)

duction capacity in Zhongli, Taiwan. More
than 10 international patents have been set
up. The next generation of PAN carbon fibre
products with high and ultrahigh modulus is
expected to be launched ahead of 2015 with
a production capacity of 1000 tons/year.
Many potential applications are possible, for
instance in aeronautics, wind blades, vessels,
construction, etc.

Prepregs
Winner: Gurit (UK)

ture component manufacture (marine race
yachts), and one for high-performance autoclave parts (marine masts and spars). During
this development, the project team optimised
the formulations to ensure that mechanical
and thermal properties were maintained. The
teams then ensured that these new systems
could be manufactured on a production scale.
Once this work was completed, production
samples were manufactured for beta testing
with selected customers.

JEC COMPOSITES MAGAZINE - Issue #93 - December 2014

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #93 - December 2014