fastening & assembly solutions and technology - Approved Business

cost effective production method was
discovered. Furthermore, adhesives also
meant that preferred pre-chromed cylinders
could be utilised and, significantly,
the assembly time was cut from several
days to a matter of minutes.
Blowing hot and cold
It can also be demonstrated that the characteristics
of adhesives are not compromised
by extremes of environment.
At the design stage, an anaerobic
threadlocker was specified for the threads
of bolts on burner frames and swivel
joints of several ninety feet high balloons.
These balloons, which had been
constructed for a transatlantic race,
would be required to fly at around 20,000
feet – altitudes that produce temperatures
of about minus 300C. Even at such
extreme cold, the threadlocking adhesives
continued to provide the joint security
that was crucial – especially to the
balloons’ crews.
At the opposite end of the temperature
scale, threadlocking adhesives are commonly
found in hot environments such as
exhaust manifold to cylinder head joints
on car engines.
Without doubt, threadlockers provide
confidence when it comes to fastener
security. However, there are further
bonuses on offer to users of anaerobic
adhesives.
First, there can be a significantly
A threadlocker is used to secure vital bolts on trams
lower cost. That’s because plain fasteners,
rather than specific locking fasteners,
can be employed.
Next, the adhesive fills completely the
spaces between the threaded components
and then cures to a solid. This means no
moisture can penetrate the joint to initiate
corrosion.
Thirdly, anaerobics allow materials of
different thermal expansions to be joined
together. Again, the ability to fill completely
the gaps between the two materials
is relevant, as it means no opportunities
for the parts to move in relation to
each other.
More than metal
Threaded fasteners made of substrates
other than metal – principally plastic –
can also be secured through the use of
adhesives.
For such applications, a cyanoacrylate
adhesive is the best option. These
‘instant’ adhesives cure in a matter of
seconds when they come into contact
with air-borne moisture. Alongside conventional
locking applications, such
instant adhesives are frequently used to
tamper-proof threaded components.
Some engineers feel that applying an
adhesive is a messy operation. However,
that is simply not the case. In many
instances, threadlockers can be applied
directly from their bottle to the threaded
part. And with modern nozzle designs,
FAST OCTOBER 2011
directing the adhesive to the exact spot is
an easy operation. Beyond that, anaerobics
are also available in ‘stick’ form.
The semi-solid formula means there are
no drips and each application can be very
accurate.
When production targets call for high
speed assembly lines or where precise
dispensing is necessary, a range of equipment
available from adhesives suppliers
will usually answer the demands. And
there is little or no contact between the
adhesive and the operator – so no problems
of messy application there.
Secure bonding
Traditional fastening methods have been
around for many years. And they have
proved successful in numerous instances.
But times change, new technologies
develop and demands become more
acute.
And with these changes there is often
a requirement to rethink methods.
Without doubt, threadlocking adhesives
are the way forward when it comes to
nuts, bolts and other fixing systems.
Sometimes adhesives will replace former
methods – on other occasions, they will
augment existing processes. Either way,
adhesives represent a highly efficient and
very cost effective method to ensure vital
parts do not work loose under shock or
vibrating conditions.
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