JEC COMPOSITES MAGAZINE - Issue #102 - January/February 2016 - 56

infusion

airtight. This procedure ensures that the
mould is free of leaks and the vacuum
foil has been correctly applied. It takes
between one and two hours.

Fig. 2: Busch Mink claw vacuum pump for evacuating air from the moulds prior to resin infusion

The Mink claw vacuum pump is dimensioned to allow simultaneous air
evacuation in the moulds for two boat
hulls and three smaller components. If
future production output increases, a
second claw vacuum pump may be installed, doubling the system output. The
controller and system frame are already
configured for this expansion.

Automatic mode
Component manufacture takes between
five and seven days, from the application
of the gelcoat to the removal of the finished component from the mould. The
mould (Figure 3) is first waxed and the
gelcoat resin is applied. After the gelcoat
resin has hardened, a few layers of glass
fibre are applied in a hand lay-up process. Then, several dry glass fibre layers
are placed into the mould. Their number
depends on the size of the part.
When this process is complete, the
mould is enclosed in a vacuum foil, the
resin inlets are inserted and the mould
edges sealed. The mould is then connected to the vacuum system and air
is extracted. The vacuum pump runs
continuously at this time to allow any
leaks to be detected and sealed by hand.
Sensors attached to the vacuum connection indicate when the required vacuum
level has been achieved and maintained,
showing that the mould is completely

Between 200 and 600 kg of resin are
then sucked into the mould, depending
on the mould size. The vacuum in the
mould ensures that the resin is evenly
distributed and inhibits the formation of
air bubbles. A further one to two hours
are required to ensure the resin reaches
every part of the mould. During this
process, the vacuum pump runs continuously in "automatic" mode. This means
the vacuum pump creates a predetermined vacuum level in the upstream
reservoir, then turns itself off. The air
extracted from the mould flows into this
reservoir. If the reservoir pressure rises
above a certain level, the vacuum pump
is switched back on. The vacuum pump
thus runs intermittently, saving energy.
During the infusion process, the mould
is also monitored by Galeon personnel
to ensure that any leaks occurring are
rectified immediately. This is of the
utmost importance, as the company
wishes to offer its customers products
of the highest possible quality.

sion in favour of selecting Busch and its
Mink claw vacuum technology.
The Mink claw vacuum pumps are dry,
which means the extracted air cannot
enter in contact with the operating
fluids. This is important as resin vapour
can react with the operating fluids in
conventional vacuum pumps, reducing
their lubricating properties and diminishing the system output. In addition,
the Mink vacuum pumps are contactfree, not subject to wear, and require almost no maintenance. After two years of
operation, Busch technicians replaced
the inlet filter and changed the gearbox
oil. An inspection of the vacuum pump
revealed no wear or damage, and the internal components were free of particles
and condensed resin vapour deposits.
The decision to opt for the Mink claw
vacuum technology is considered by
Galeon to be correct, as the Busch consulting services and support provided
during the installation process were first
class. An additional advantage is the
simple system expansion of the Busch
solution, as Galeon is certain that production will increase in the future. n

No wear or damage
Product quality and system reliability
were the primary reasons for the deci-

Fig. 3: Mould for manufacturing a boat hull

56 jec composites magazine / No102 January - February 2016

More information:
www.buschvacuum.com

http://www.buschvacuum.com

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #102 - January/February 2016