The Art in Homeland Security
"From Artists Clay & Paints to Explosive Simulants"
Robert Augur, V.P.XM Division, Van Aken International
XM is a division of Van Aken International located in North Charleston, South Carolina. Founded in 1986, Van Aken International manufactures paints
and modeling clay used by artists worldwide.
In 1998, on a lead from the FAA Technical Center, Lawrence Livermore
National Laboratory (LLNL) and Van Aken International collaborated to
provide a commercial source for the production of non-hazardous X-ray
explosive simulants. There were many technical and process development
This paper summarizes how the process technology developed for the production
of artists supplies was used in the production of X-ray explosive
Determining Simulant Compositions
Over 200 preliminary trial formulations were made at LLNL. The key
parameters relating to X-ray transmission were to match density and
average atomic number. It was also very important to match the physical
state of the target explosives while insuring the non-hazardous, non-toxic
nature of these simulants.
Thirteen of these formulations were chosen for production. They are
representative of the range of X-ray signatures exhibited by almost
all of the many thousands of explosive materials available worldwide.
SEMTEX, Comp C-4 and Detasheet explosives are moldable high-energy
explosives that have had extensive military use. Their physical properties
are very similar to artist's modeling clay. XM Division's
large sigma mixer (Figure 1)
is ideally suited for preparing these materials.
Plastic and plasticizer are first added to the large mixer heated to
about 110C. Solids with the appropriate density and atomic number are
then added. After mixing is complete, the hot putty-like solid is removed
in approximately twenty-pound blobs.(Figure
2) compares product from a 1,200-pound mix of modeling clay
to product from a Comp C-4 simulant mix.
Artist's modeling clay and plastique explosives are extruded to final
shape. XM Division installed a high capacity vacuum extruder to obtain
the high densities required for the plastique X-ray explosive simulants.
See Figure 3.