JEC COMPOSITES MAGAZINE - Issue #116 - October 2017 - 44

WIND ENERGY
process

Perfect composite parts, thanks to the
«direct infusion» process and resin conditioning
In the composite industry, especially wind energy, metering and mixing
equipment for rotor blade manufacturing are fundamentals. One of the
key players in this sector, 2KM, now offers its "direct infusion" machine
concept with the capability to significantly improve blade production.
Erwin FrösE,
Key Account Manager Composite
2 Komponenten Maschinenbau
GmbH

R

esin vacuum infusion is a state-ofthe-art process, well established in
the manufacturing of rotor blades.
The vacuum infusion process is designed to
generate a bubble- and pore-free composite
part that meets the high quality requirements for rotor blades, due to the loads they
are exposed to. During the infusion process,
the low-viscosity resins must rapidly diffuse
throughout the vacuum mould, and then
cure spontaneously, preferably without releasing heat. However, these requirements
are incompatible with the chemical and
physical properties of the resin matrix used
(reactive, exothermic).
Vacuum infusion process
Resin consumption during vacuum infusion is not constant, as it depends on the
wetted area of the mould: the demand for
resin is high in the early stages of infusion
into the empty mould, but decreases as
mould wet-out progresses. Furthermore,
with these big composite structures, the
gating strategy involves an interim increase
in the resin demand. In the final stages of
the infusion, the demand will be very low.
In other words, the demand for resin during
an infusion process is varied and dynamic
rather than constant or proportional, and
this is a source of some problems. The usual
process is to use standard machine equipment to feed the resin mix into intermediate
vessels, from which the resin will be sucked
into the mould by effect of vacuum.

44

2KM Degassing
equipment
in full-scale
installation
for resin
conditioning,
ready prepared
for «Direct
infusion»

This process has a few disadvantages: the
resin mix is handled in open vessels, giving
rise to health and safety issues; in the vessels, an amount of reactive resin in the mix
already starts the chemical and exothermic
reaction, with undesirable effects on the infusion process; and, while state-of-the-art,
the mixing and metering equipment does
not have the capability to feed in the resin as
required during the infusion process.
Direct infusion solution
2KM developed a machine concept called
"direct infusion" with the capability to
regulate the resin flow dynamically and
to dispense the resin on demand, directly
into the mould. Special pressure sensoring
and monitoring inside the mould help
to regulate the required resin flow automatically. Because the resin is mixed only
on demand, a premature reaction of the
resin and development of exothermy are
avoided, minimizing the risk during the
process. The direct infusion concept also
eliminates the health and safety issues due
to open handling of the resin, and increases

jec composites magazine / N°116 October 2017

the quality of the infusion process, with the
opportunity for further optimization.
The continued evolution of the infusion
process calls for better conditioning of
the materials to be metered. For direct
infusion, this means degassing the resin
before the infusion process. To meet this
requirement, 2KM developed in-line or
batch degassing for the resin and hardener
components, providing greater potential to
improve composite part quality.
More information:
http://2km.org

Focus
2 Komponenten Maschinenbau GmbH (2KM)
is one of the leading companies in the area
of development/manufacturing of machine
equipment for processing with mono- or
multicomponent dispensing technologies.
Their engineering expertise and process
knowledge has developed from 40 years in
the field. The company is a specialist in the
processing of polyurethane, epoxy resin,
polyester, methacrylate, polysulphide and
silicone materials of all viscosities in any
environment, whatever the application.
http://www.2km.org
Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #116 - October 2017
