URLem_06_OK
0 (0 Likes / 0 Dislikes)
LEM Srl is a manufacturer
that specializes
in the production of sunglasses
and ski goggles.
It was established in the mid-1980s
as a producer
for a major eyewear company
that had market outlets
but no production facilities.
The company
has pioneered the implementation
of techniques such as over-injection
and the automation of processes
like lens cutting
and the assembly of eyewear parts.
Together with this
type of requirement
relating simply
to the production process,
there has been very strong
pressure from the market
to cut production costs
by improving workflows,
which propelled LEM
to look into automation.
As far as production
is concerned, in Italy
automation plays a key role
if you want to remain competitive.
This is for two main reasons:
first, the achieved product quality
is easier to replicate and control
and, no less important,
the financial benefits
enable you to stay in a market
that is becoming
increasingly competitive
in terms of both production
prices and sales prices.
The challenge
with this automation project
was to achieve laser marking
on this cylindrical lens.
So we had to maintain
a constant distance
between the laser focal point,
which is approximately 50 mm,
and the curvature of the lens,
which has a radius
of about 100 mm.
Automation has brought
two other benefits.
The first is that the workstation
is now fully autonomous.
Because the work cycle
lasts about 3 minutes
and the loader provides
from 20 to 40 lenses,
the workstation operates
entirely unmanned for about an hour.
Second, and equally important,
since lens handling
has been automated,
the repeatability of the
lens marking process
has achieved a precision
that would not be possible
with manual handling.
The requirement met
by this gluing station
is to apply the glue
on a very precise trajectory
and avoid the areas
that are not glued to the frame.
The operator then
transfers the padding
to a drying stage.
We have achieved two benefits.
One is the extreme precision
and uniformity of glue distribution,
which is therefore highly repeatable.
The second benefit is the
regularity of the process time:
the glue has a very
narrow usability window,
so the gluing stage has
to keep to very precise cycles
that are difficult to achieve
with a human operator.
We are working
on a mezzanine floor here,
which meant there were
limits on the weights
that could be installed.
We transported the cobot ourselves
with no particular
installation difficulties
and it required
a very lightweight structure,
so there were no weight
problems on the mezzanine.
With this application we used a cobot
to tend an injection molding press.
The operation was a demanding one
from the point of view
of the human operator.
It involves fairly heavy metallic
parts which are difficult
to manipulate over a period
of several consecutive hours.
A secondary consideration
was the need
to stabilize the machine cycle time.
So cycle times, pressure
and temperature are constant
and as a result
product quality has improved.
We have developed
a collaborative cell
exploiting the ability of these cobots
to work alongside the operator.
The operator collaborates
with the cobot at various stages,
assisted by audio and visual signals
that tell him when he can
move close to the robot safely
and when to move away
and let the cobot
perform the injection press operation.