JEC COMPOSITES MAGAZINE - Issue #81 - May/June 2013 - 80

adhesives
costly for new products developed using this
conventional method. Now, however, CFD
simulations help to identify the optimal
mixing ratios and thus guarantee efficient
and reproducible mixing outcomes. And not
only that: They also significantly shorten the
whole development process, thereby also
cutting costs.

Getting A and B in the right place at
the right time
The purpose of simulation is to optimize the
mixing ratio for multiple components. Factors such as viscosity, pressure, density and
surface tension all affect how a substance
flows. Based on the mixing geometry and
properties of the components, the experts
simulate the best possible dispensing system
to generate high-quality – i.e. very homogeneous – mixes. Using CFD simulations, it is
possible to calculate the optimal retention
time for a substance in the mixer. If this
time is too long, components would already
begin to react before leaving the dispenser. It
would be similarly counterproductive if, for
example, so much pressure was needed to
eject the substance from a manual mixer that
users could not do this by hand. Numerical

flow simulations thus make sure that the two
substances both spend the same amount of
time in the mixer – and that they meet at the
right time.
Since many of the materials used in industry
are viscous, Sulzer Mixpac focuses on calculating the fluid dynamics of highly viscous
substances. These components exhibit what
are known as laminar flow patterns, i.e. they
flow in layers with no visible interference
between layers. As soon as a customer
supplies the company with data about the
relevant material properties, the latter’s engineers can begin the process of computation.
Alternatively, if the customer does not have
access to properties such as the rheology
(viscosity curves) of its substances, Sulzer
Mixpac can also do the work in its own laboratories. In cases like these, the company’s
application laboratories begin by conducting
test materials on behalf of the customers to
obtain the product data needed to ensure
proper product configuration. Simulation
runs are performed at a purpose-built data
centre fitted with a cluster of more than 200
high-performance processors. When the calculations indicate an optimal outcome, the
next step is to go ahead and actually mix the
components in order to validate the CFD
findings. Comparative images demonstrate
how closely the simulations match actual
mixing ratios. The golden rule is: the more
precise the calculation conditions, the more
accurate the result.

Passing the test of internal use

Visualization of flow conditions in a mixer

More information ...

Sulzer Mixpac also uses CFD simulations
internally, which has helped develop the
new MIXPAC™ T mixer, a completely new
mixing technology that, for certain components, delivers vastly superior results in
a number of ways. Originally, the company

Sulzer Mixpac AG, a subsidiary of the Sulzer Group, develops, manufactures and distributes
mixing, metering (dosing) and dispensing systems from its base in Switzerland’s Rhine Valley.
It is the global technology leader in two-component mixing systems used in applications such
as the processing of adhesives of all kinds in the automotive, aerospace, leisure and electronics
industries, to name but a few. Product development at Sulzer Mixpac also benefits from the vast
expertise of its parent company, which numbers more than 17,000 employees, has amassed
over 175 years’ experience in fluid dynamics and ranks as one of the world’s foremost pump
manufacturers. The Sulzer Group’s wealth of experience and its broad range of offerings enable
Sulzer Mixpac AG to permanently and efficiently expand its own portfolio too. Its parent company
provides intensive support for innovation activities and financial backing to enable the research
and development of new products and services.

80 jec composites magazine / No81 May - June 2013

At left: Proven mixing systems based on the
Helix and QUADRO™ mixing technologies. CFD
simulations facilitated development of a new
mixing technology – the T mixer (at right) –
which further improves the mixing ratio

started using CFD to develop and optimize
its own mixing systems. Starting now,
however, Sulzer Mixpac wants its customers to reap the benefits too. The company
rigorously tests all mixing systems that are
subsequently to be applied by customers.
You get through a huge amount of packaging
materials and mixers before arriving at the
perfect mixing ratio. However, in an age
when environmental awareness is growing
and raw materials prices are rising, that is an
unnecessary waste of resources. Nor does it
guarantee a high-quality outcome.

Expertise and experience are the key
Backed by the experience of a global
Group, Sulzer Mixpac has been able to put
a wealth of specialized expertise to excellent
use – and position itself as the technology
leader in CFD for multi-component mixing
systems. The benefits to the customer are
obvious: customers’ time to market is
slashed, while the need for substantially
fewer disposable dispensers for testing
purposes also cuts costs. The company presented its extensive new range of offerings
for industrial applications for the first time
at this year’s JEC Europe trade show. Its new
services will enable tailor-made mixing and
applications solutions for chemical formulas
to be developed, calculated and, ultimately,
marketed in a far shorter time, giving customers additional competitive advantages on
the market. n
More information:
www.sulzer.com

http://www.sulzer.com

JEC COMPOSITES MAGAZINE - Issue #81 - May/June 2013

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