Optimizing a formulation

When
looking at a production formulation it is impossible to understand the nature
of the cost centres in the formulation and therefore
how to cost optimize that formulation.

In the
CompuChem formulation optimizer the formulation is presented in such a way that
it is easy to manipulate the formulation for cost optimization

The
optimization process in CompuChem begins with importing a production
formulation into the Paint Laboratory database using the menu option shown
below

Once the
formulation is imported into the paint laboratory database the optimization
process can begin

When the
formulation has been imported it is initially in the same format as the
production formulation but excluding the manufacturing instructions the vital
statistics of the formulation are displayed at the bottom of the screen

The first
stage of optimization is to sort and consolidate the raw materials so that
recurring raw materials are brought together under the same code and the
materials are sorted in the order of pigment filler binder solvent and
miscellaneous

formulation
before optimization

To start optimization select the following menu options to sort and
then consolidate raw materials

Formulation
after sort and consolidate

At this
stage no constraints have been set on the formulation.

if we look at the bottom of the screen we can see the calculated vital statistics of the
formulation

Now we have
covered the basics of working with the optimizer let's look at a typical
example of recalculating the formulation

Notes that
whatever constraints we set on the formulation the formulation will always be
optimized using the objective function ‘minimize cost’

Let's say
for example we wish to increase the volume non volatile of this formulation while keeping the
hiding power constant and staying below the critical PVC

Note that
the calculated PVC is well below the critical PVC in this particular
formulation

By clicking
on the maximum PVC box and the minimum volume non volatile box the existing values will
automatically be inserted into these boxes

Say for
instance we wish to increase the volume non volatile
to 50% while keeping the PVC
below the critical PVC value at say 40%

We simply
change these values in the corresponding boxes

We now set
constraints in the formulation in order to retain the properties of the coating

Let's set
the mass per liter of the pigments as a constraint, the ratio of the binders as
a constraint, the ratio of the solvents as a constraint and the mass percent of
the miscellaneous items as a constraint (using the appropriate menu options
from the top menu)

The
formulation will instantly be re calculated using the objective function
minimize cost

Notice
that's the cost of the new formulation is instantly calculated

we can
experiment with how the cost will vary changing volume non volatile's
and PVC simply by clicking the up and down arrows in the appropriate box or or entering new values

Notice for
instance how increasing the PVC closer to the critical PVC value reduces the
cost

careful
consideration of the constraints on the raw materials is essential in order to optimize the formulation without changing the
physical properties of the final coating.