Visor Manufacture
Development responsibility:
HARC
Origin of concept
Protective visors for deminers can be made in most
mine-affected regions from polycarbonate sheet material. The process
requires a temperature controlled oven with forced air circulation.
This kind of oven can easily be constructed from commercial components
almost anywhere.
Safety tests
Many groups have conducted many tests using live
mines and inert mines re-filled with plastic explosive or TNT. Test
results are highly variable, and that typical mine cases re-filled with
plastic explosive go off with more energy than the original mines with
TNT.
Oven Development
Development responsibility: HARC
Origin of concept
A special oven is needed for heat forming polycarbonate. The
temperature needs to be between 158 and 160 degrees Celsius.
Demonstration prototype
James Trevelyan
designed an oven with a door on the bottom to minimise heat loss during
loading and unloading. This concept has been designed in detail and
constructed by HARC in Islamabad. UWA sent the principal components
of a fan forced electric oven from Australia because they are not readily
available in Islamabad. These components included a fan (with motor),
heating element (with spare), high temperature wiring and thermostat
controller.
smith/visor-oven-Zimb-1-s.jpg |
This is an oven constructed in Zimbabwe under the guidance of Andy
Smith, for the development of visors. |
HARC/HARC-6-s.jpg |
The oven was completed in October1997 and is now being
used for making visors. |
For more information on eliminating and testing for residual stresses
in vsiors, see a special report
prepared in 1998.
In 1999, the over was modified extensively to improve performance.
Here are some photographs.
View
of fan drive motor attached to end plate. bbbbbView
of fan enclosure with fan just visible in centre
View of
fan enclosure with cover removed, showing the heater element and fan.
| Demining Home Page | James Trevelyan's Home Page
| UWA Home page |
For
more information on any of these send us E-mail at demining@mech.uwa.edu.au
All graphics by Demining
Research Team. Jan 2000.
Webmaster: Edin
Tabak
|