JEC COMPOSITES MAGAZINE - Issue #119 - March 2018 - 46

MANUFACTURING curing
or resin transfer moulding, conventional
systems require a balance between the need
for sufficient time to impregnate all the fibres
evenly, and the need for fast curing to reduce
cycle time. With UV curing, fast curing can be
triggered once the fibres are evenly impregnated, allowing for reduced cycle times without
compromising on part quality.
A complication in closed moulding processes
is the need for UV-transparent moulds.
Fig. 2: Flexural modulus versus temperature
of non-reinforced UV-cured resins and a typical
glass fibre-reinforced (fibre content: 83 wt.%) UVcured composite relative to monolithic glass. The
set of UV-cured resins ranks from grey to black
according to an increasing level of crosslinking
density from medium to high (Photo: allnex)

New opportunities
While the benefits of UV curing equally apply
to hand lay-up and spray-up processes, manufacturers looking for process improvements
tend to focus on automation before turning to
UV.
In a closed moulding process like infusion

Material properties
Obtaining the desired material properties
starting from a UV system requires the aligned
fine-tuning of all parameters: resin and photoinitiator selection, UV lamp selection and
installation, as well as application parameters.
While off-the-shelf solutions are available for
applications using UV technology, composites
manufacturers will benefit from the assistance
of UV lamp and raw material suppliers during
the process development stage, ensuring that
the optimal environment is implemented.
Because of the possibility to create highly
crosslinked materials, systems having good

mechanical performance even above their
glass transition temperature can be designed
(see Figure 2).
In general, the variety of oligomers and
monomers gives the ability to tailor the final
properties of the composite.
For diverse applications, allnex, a global
produced of coating resins and additives, is
guiding the process to select the most suitable
materials.
Table 1 summarizes the mechanical properties of selected and typical UV systems, highlighting the possibility to manufacture flexible
parts, parts that withstand high temperatures
or that can carry heavy loads.
To sum up, the value of using UV technology
in composite applications is that it is a green
solution that also increases throughput and
reduces process costs.
The adoption of UV technology in diverse
applications is accelerating due to its ability to
cure fairly thick parts while the understanding
of material properties keeps improving.
More information :
www.allnex.com

Flax & Hemp Fibre Composites, a market reality
The 2012 and 2014 reference works
"Flax and Hemp fibres: a natural
solution for the composite industry"
analysed and reported on the
mechanical performance of flax
and hemp fibres, and gave an initial
presentation of the processing methods used and the application of the
fibres in composite products.

illustrations of brand-new opportunities for the end use of flax and
hemp fibres.

This new 2018 edition contributes
new technical innovations, with more
detailed processing descriptions
and application examples, as well as

Available on JEC Group's website
jeccomposites.com/e-store and also
at JEC World, Publications Stores,
Hall 5 and 6 entrances.

A work by the experts of the
European Scientific Council of the
European Confederation of Flax and
Hemp - CELC. JEC GROUP Edition.
Illustrated, English language. €149

www.jeccomposites.com/e-store

WICKERT Composite/Messekatalog JCE Paris 2018: 1/6 Seite quer, 177 x 40 mm, 4c, DU: 00.00.0000, ET: 00.00.0000

Visit us at JEC world in Paris
6th - 8th March 2018
Hall 5 - Booth M56
WICKERT Maschinenbau
Wollmersheimer Höhe 2
76829 Landau - Germany
+49 63 41-93 43- 0
info@wickert-presstech.de

COMPOSITE PRESSES
"Solutions for components
beyond standard"

jec composites magazine / N°119 March 2018

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http://www.allnex.com http://www.jeccomposites.com/e-store http://www.wickert-presstech.com

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #119 - March 2018