Custom Etch, Inc.

process are automatically extracted by vacuum to guarantee a
clean process.
“The LASER machines are basically 5-axis milling machines
with lasers instead of milling heads,” explained Melonio.
“However, GF AgieCharmilles created a completely new proprietary
software to run the laser heads from common IGES
and STEP files. Programming is easy and basically requires
only the same programming skills as would be needed to
machine a simple component on a conventional CNC machine
tool.”
Rhino is Custom Etch’s preferred mapping/imaging software
used to create surface designs and transfer them on to mold
cavity surfaces for laser texturing. These same files are the
ones used by the machinist that cut the tool cavity shape on
milling machines.
According to Melonio, the key to the laser-texturing operation
is positioning the laser’s focal point at the correct distance
from the workpiece surface. Material ablation rate is based
on the frequency and power setting of the laser. Power settings
can be adjusted anywhere from 0 to 100 percent, and the
frequency from a level of ten to 90, for instance, to determine
how fast the laser will ablate/cut material.
Because they use fiber lasers, the systems are extremely precise
and can remove microns at a time. This allows Custom
Etch to make very light and shallow cuts or not make a cut
at all, but instead use the lasers to only change the color of a
part’s surface for strictly aesthetics if so desired.
With its most recently acquired LASER 1200 5Ax, Custom Etch
increases the range of part sizes to which it can apply surface
texturing. The machine’s table measures 31.5” in diameter and
handles workpieces weighing up to 3,747 lbs.
Custom Etch’s LASER 1000 5Ax is fully automated with an integrated
GF AgieCharmilles pallet changing system that accommodates
six modular pallets from System 3R. And according
to Melonio, automation is the one factor that definitely makes
the technology economical for the shop and completely justifies
the investment.
The pallet system uses six 11.02” square pallets that each
hold workpiece fixtures an outside shop developed for Custom
Etch. As opposed to vises, the adjustable fixtures allow Custom
Etch to effortlessly load and unload workpieces.
In operation, the laser machine runs an automatic probe
cycle, and the part program is such that every part locates in
the same place on the pallet thanks to the custom fixtures.
Removing parts is as simple as loosening a couple of screws,
sliding the finished part out and placing a new one into the
fixture.
“For our type of work, it would be tough to make money with
the laser machine if it didn’t have the pallet system. Without
such automation, parts would have to be manually loaded one
at time into the machine, which would add huge labor costs
and time to the process,” explained Melonio. “Plus, once pallets
are loaded, the system basically runs unattended.”
To illustrate the value of the pallet system, Melonio cites having
to produce 40 soft drink plastic bottle molds – a job that
entailed texturing 80 mold halves (cores and cavities) and 40
base pushups. For this particular job, the shop had to process
all 80 halves and all 40 base pushups through the GF
AgieCharmilles 5-axis laser-texturing machine in a matter of
three days to make the required delivery time. And according
to Melonio, the only way the shop accomplished the task was
being able to have only one person load and unload pallets
while the machine continued to work non-stop and unattended.
Typical part sizes run on the LASER 1000 5Ax machine measure
up to 8.5” x 10.63”, so the shop uses every workable
inch of its pallets. About 200 molds per week are processed
through the laser machine, and the system has increased
the shop’s throughput month after month without the need to
dramatically increase shop floor size or workforce.
However, it should be noted that Custom Etch uses its laser
machines to impart complete surface textures only some of
the time. Instead, explained Melonio, the lasers will most
often be used first on a part, followed by the acid etching
process. The reason, he said, is that imparting an 0.008”-deep
pattern in a soft drink bottle mold, for instance, would take
about 1.5 hours per one mold half using only laser texturing.
Such a processing time is reasonable for one or two parts, but
consider if the job required 60 molds with a total of 120 halves.
For its dual texturing technology processing, Custom Etch will
apply an acid resistant paint on to the mold cavity surfaces. It
then laser textures the desired pattern on to the parts, but in
such a way as to only remove the paint, not actual part material.
The operation takes only minutes as opposed to hours and
basically serves the same purpose as the wax transfer does in
traditional chemical etching.
With traditional chemical etching, a film negative of a design
is etched into a magnesium plate. A wax substance is then
burnished into the plate and the excess removed, leaving only
the wax in the design etching. Pottery tissue is burnished on
to the plate, and when the tissue is lifted off, the design comes
with it, so to speak. This 2D wax rendering of the texture
design can then be wrapped around a 3D surface, such as the
cavity of a mold.