JEC COMPOSITES MAGAZINE - Issue #113 - June 2017 - 23

Snap-cure material toolbox for high-volume applications

Fig. 2: Comparison between the relevant characteristics of SGL's snap-cure system (E420) and those of a standard autoclave system (E320)

no significant differences, despite the
glass transition temperature and cycle
time (Figure 1).
The mechanical properties that may be expected when using a unidirectional E420
prepreg based on SIGRAFIL® 50k carbon
fibres are given in Table 1.
Degrees of freedom -
different materials
SGL has developed a toolbox of carefully
selected complementary materials that
work perfectly together (Figure 3).
The toolbox contains many different
products, each of which is helpful for specific tasks: prepregs based on various fabrics with different architectures, pre-impregnated carbon fibre nonwovens for
isotropic material characteristics, towpregs based on carbon fibres (24k and
50k) for highly effective automated pro-

duction, and tailored stacks, laid in the
right contours and orientation to avoid
production scrap and leverage maximum
lightweight potential.
All products offer additional degrees of
freedom such as customized resin content, customized width or area weight,
or different reinforcing fibres (e.g. glass
fibres). The resin may be optionally formulated with an internal release agent
without changing other characteristic or
the basic composition of the resin system.
By combining expertise in epoxy resin
chemistry with in-depth knowledge of
fibres and textiles, it was possible to address the needs of the future with regard
to reactivity, dimensional stability under
heat, and automation and to provide a set
of complementary reinforcements. The
resulting snap-cure toolbox offers great
flexibility for customers while reducing
material complexity to a minimum.

Summary
- SGL has developed a "real" snap-cure
prepreg resin (E420) for short cycle
times (≤ 3 min), with rapid build-up
of dimensional stability (Tg > 140°C);
highly efficient isothermal processes
may be used; very high-volume serial
production (several hundred thousand
parts per year) is now possible.
- The pre-impregnated materials have a
long shelf life of more than one month
under ambient conditions; high reactivity without compromising storability.
- A set of complementary products is
available. The user can pick the right materials for his target application and use
combinations of different products to
leverage the highest lightweight potential through intelligent FRP design.
- All products are based on one standard
resin system that ensures maximum
compatibility between the different
products in the toolbox; the low material complexity leads to a higher degree
of standardization and reduces qualification and testing efforts.
- Pre-impregnated materials offer high
mechanical performance and reliable
processing and eliminate the need for a
resin infusion step and handling of resin
components.

Fig. 3: SGL Group has developed a
toolbox of pre-impregnated snap-cure
materials

No113 June 2017

More information:
www.sglgroup.com

/ jec composites magazine

http://www.sglgroup.com

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #113 - June 2017