SMAC is known for electronics but these same actuators can be used in food processing for safe and accurate quality applications.

1. Overcoming Food Processing and Packaging Challenges:
Using 21st Century Robotics to
Improve Quality
and
Speed Up Food and Liquids Processing
Edward Neff
President
SMAC Moving Coil Actuators

2. Robotics in Food Processing
Robotic capabilities are expanding to meet higher throughput,
higher quality, and more flexibility demands in the 21st century.

3. Robotic Capabilities
Food and Packaging are important industries that are pushing
the capability envelope of Robotic Devices. This presentation will
review:
• What capabilities have been missing?
• Why these capabilities are now
available and where did they come
from?
• How are these capabilities used in
applications in the Food & Liquid
processing industries today?

4. What capabilities have been lacking?
• Faster cycle times - with the aim of doubling the output.
• Long cycle life - going from MTBF of 10M to 10X that.
• More precise control over the amount of product being filled to
virtually eliminate the necessity to overfill.
• Ability to do work and verify its quality at the same time - to
insure 100% quality in real time. For example, in capping.
• Ability to adjust work capabilities on the fly - to eliminate down
time for changeover.
Let’s look at each of these…

5. Faster Cycle Times
There is a continuous push for this but there are
limits due to movement device technology.
Air cylinders are a primary means of achieving
movement in packaging but are speed limited
due to their inability to slow down at end of cycle
(shock absorbers have a low cycle limit and air
cushions slow down the cycle time).
Ball screw drives can operate at similar cycle
rates but have other problems - there is a trade
off in position with accuracy and cycle life is
similar to air cylinders.
Max rates - for nitrogen dosing for example –
have been stuck in the 1000 cpm range.

6. Long Cycle Life
Both air cylinders and ball
screws are capable of
achieving cycle life in the
10M range. If a machine is
running at 3 CPS rate, 24
hours a day, then these
devices will last a few months
at the most.
Moving coil actuator running at twice the maximum speed of an air
cylinder. The moving coil actuator is faster and lasts longer. Air cylinders
on average fail in high cycle rate applications within 3 months.

7. Precise Control
• Ability to precisely control cycle time. Air cylinder systems have
an inherent variation in the +/- 20s of millisecond range. Ball
screw drives are an improvement but still there is a significant
mass to start and stop. The lower the variation in movement
time the more precise the amount to fill can be controlled -
hence savings to the customer.
• Ability to adjust work parameters on the fly. Air cylinders not
able to do this although speed, position, and force can be
adjusted manually. Ball screw drives can provide the on the fly
adjustable speed and position but not the force.

8. Precise Control
• Ability to do the work and feed back the success of the work
done is now an increasing demand in this industry and is not
something either air cylinders or ball screw drives can provide.
A comparison of these demands to those found in the Electronic
Assembly Industry at the start of the 21st century.

9. The Electronic Connection
In this industry the primary work is to assemble circuit boards. These are composed of
very fragile parts - a lot of them. Any assembly failure results in the complete failure of the
product.
So what has to be done?
• Objects must be picked up an precisely orientated in rotation - after
their “bent” connector pins have been viewed by a laser or camera
and compared to the target contact pads on the board.
• The board must be found - it has a +/- 1 mm warp to it.
• The part must be softly landed upon the board and this action must
be recognizable.
• The part must then be pushed - with a specific precise force - onto
the board and the bonding adhesive.
• This must be done in fractions of a second.
Linear Rotary Moving Coil Actuator
MTBF: 250 million cycles

10. Electronics Technology
Initially, this was done by assembly made up of a number of separate components - ball screw or pneumatic
slide - rotary motor - spring over travel mechanisms that were switched depending on part. MTBF in the 10 X 6th
range.
Gradually, new robotic devices were developed that integrated all the needed functions - except the camera - and
were able to reach MTBF of 250m cycles plus, i.e., the life of the machine.
The key developments were:
• Linear servo motors with light moving mass (i.e., not moving magnet)
• High resolution small encoders
• High strength neo-dynium magnets
• Improved linear guides with built in permanent lubrication
• Small high torque rotary servo motors.
The development of these devices brought into play a number of new capabilities not available in the older
technology actuators.

11. Moving Coil Type Linear Motors
Low moving masses combined with over-sized linear guides with built
in permanent lubrication increased cycle life by a factor of >10.
Speeds doubled because of higher accelerations (up to 100G) and the
ability to programmable stop very precisely at the end of the desired
move. This combination is not possible with ball screw slides - you get
either high speed or precise movement.

12. Moving Coil Type Linear Motors
Low moving mass combined with low friction guides (static
breakaway less than 20 grams) results in a move time
repeatability of under 1 millisecond.

13. Moving Coil Type Linear Motors
Servo control combined with real time
position, speed, and force (current) feed
back provides a number of new tools to
use:
• The ability to “soft land” or bump into an
object at low impact force and recognize
the fact that the contact has been made.
• The ability to program precise forces in
real time
• The ability to detect changes in position
and real time movement.

14. Soft-Land

15. Food and Liquid Processing
In Food and Liquid
processing the introduction
of Robots with these new
capabilities began several
years ago. Today I would
like to show the benefits of
their usage in 3 common
applications found in
packaging and processing:
Capping
Filling and
Dispensing
Ejecting

16. Filling
In Filling challenges are in Filling accuracy, Filling speed, precise adjustment of Filling amount, and cycle life of the Filler Actuator
and Valve.
Moving Coil type Linear servo actuators use a very strong motor magnetic circuit (developed as part of the worlds first direct drive
Robotic finger). High forces are achieved at relatively low currents - 1.5 amps at 48 vdc. These devices achieve very good results
in Filling applications. Here’s why;
Filling Accuracy - this can be a costly problem if the device operating the Filler valve has a significant shot to shot time variance.
Pneumatic devices - due to valve and cylinder seal friction - have variation in the 20s of milliseconds. This means that there must
be an overfill time in order to insure that all products meet the stated fill amount. A reduction of Fill variation time by a factor of >
10X has been achieved by the MCA actuators.
Over thousands (or millions) of bottles, this small
amount adds up.
Air = +/- 20 msec response time so it must always overfill
to ensure there is no underfill.
MCA = +/- 0.5 msec response time, so it will not overfill
(very much).

17. Filling
The moving mass vs Force is very low - enabling accelerations of up to 100G - at very low current
draws of 1 - 2amps.
The static and dynamic friction found in the device is also very low - with breakaway in the 10 gram
range and moving friction much lower than that.
The result is a variation in time of less than 1 milli-second. This leads to substantial savings in overfill.
One major consumer products company has calculated that the savings will cover the cost of the
device in 2 weeks. The cycle time is monitored on every shot by the way - quality check.

18. Filling
Filling Speed - an example can be found in Dispensing. High Speed dispensing - liquid nitrogen for example (used to stiffen plastic bottles) -
have been limited to a max rate of 1000 cpm. This is due to the limited cycle life of air cylinders and / or ball screws. A very fast linear servo
motor - with low moving mass - that uses linear guides with built in permanent lubrication - can be cycled as fast as 2000 - 2500 CPM. There
is no slamming at the end of stroke - its a servo. Life testing at one customer at the 2000 cpm rate has passed 1 Billion cycles and is still
running.

19. Filling
Precise adjustment of the filling amount. Servo linear devices
with high resolution encoders (1 micron) can make precise stroke
adjustments on the fly. (A micron is 40 millionths of an inch).
Contrast that with air cylinders using nuts and bolts - literally or
ball screws that must be have a large screw pitch in order to
generate any kind of speed. Both require manual adjustment at
the end of stroke. Using MCA to change from 1 volume to
another is programmable and immediate.

20. Filling
Cycle life of the cylinder and valve. Slamming and shock cause wear. Seals are a problem
to air cylinders and to valve seats in Filler valves. The intelligent ability to move quickly and
then
“Soft land” and push with a programmed force on a surface - developed for light contact in
circuit board assembly - has 3 direct benefits:
a)The actuator can cycle easily 10 X longer than old tech devices. Customer life testing of
the device in dispensing has actually passed 1 Billion Cycles and is continuing.
b)The soft land and push greatly reduces the wear of the valving element and the valve
seat.
c)The ability to vibrate at 1000 hz just as the valve closes to knock off droplets.
Today - these devices are designed as inherently IP units and have miniature sized
controller amplifiers built in so that their complexity is about on the order of a pneumatic
system.
Costs are now moving below $1000.

21. Filling

22. Capping
Capping is another common application where the introduction of up to date robotic technology is having a very positive and rapidly expanding impact.
Challenges in capping are very much quality related. Cross threading leads to leaks. Short capping (not reaching the target capping final height) leads to
leaks. Bad torquing leads to leaks.
Capping technology up to recently focused on torque measurement as a quality check. But that really is a 2nd order check. Cross threaded caps torque
out. Caps that only go on partially to the desired end location - leak. Caps that torque out but do not move - can leak.

23. Capping
A 2 axis - Z-Theta - Robot developed for the Electronic Assembly industry brings in technology to resolve these
problems:
• “Soft land” function allows the cap to located the bottle top.
• Reverse direction turning or the cap - causes the cap to move upwards until threads match. At that point the cap
drops and that can be detected by the linear encoder. If the drop does not occur - bad bottle or bad cap.
Linear Rotary Moving Coil Actuators
• The capping movement can be tracked both by the
number of turns and by the linear distance travelled.
One is feed back by the rotary encoder and the other by
the linear.
• The cap can be “snugged” (like bolts when you change
your tire). This sets up a datum reference. Then a
specified torque can be applied and the final rotary
position can be compared to an allowable position
window.
This all can be done in 1 second or 2 - including the
quality checks and feedback. Cycle life based on field
experience (over 100,000 sets in use as of today) is in the
range of 100 - 150M cycles.

24. Eject/Divert/Laning
Eject and Divert also provide challenges to older technologies:
• Containers can have different masses - due to different sized products or errors in filling.
• Sorting based on identified types requires variation in sorting speed and or force.
• Variation in actuation time results in slower eject/sort times - the problem is similar to over filling.
To counter 1 obviously programmable force and speed is needed. Pneumatic have nether - ball screws have
the latter only. A Moving Coil Actuator has both so that containers can be moved with forces and speeds that
are correct for the particular mass that is needed to move.

25. Eject/Divert/Laning
Sorting is quite interesting. Programmable force is needed. The addition of the ability to soft land is also a benefit -
as it is when dealing with small or over balanced containers. The Soft-Land acts kind of like a shuffle board. Bump
into the object then push it with enough force to get it to a certain point. Here again the Electronic assembly
technology comes in handy. (Another interesting variant is that these devices have built in vacuum through the
shaft - parts have to be picked up! There is some early development going on where the container is vacuum
captured then push to a precise position).
Variation in time - of course means a higher
sorting speeds a miss can occur and either
a good part is ejected or - worse - a bad
part gets by. Air cylinders have a 20 X larger
time variation that Moving Coil Actuators
and ball screws are speed limited.

26. Conclusion
21st century Robotic technology has been developed for the highly
sophisticated Electronic Assembly Industry. It features:
• Programmable control over speed - position - and force
• The ability to check the work done and verify its success
• The ability to change parameters on the fly so that production lines can
easily run a variety of products.
• The ability to do unusual things like - softly bumping into surfaces, moving
both in linear and rotary axis (developed initially in 1995) - and the ability
to check as part of the program changes in position and speed which are
helpful in improving the ability to do work.

27. Conclusion
Robotic devices are rapidly
expanding capabilities and
these capabilities - when
applied to work in Food and
Liquid processing - increase
output, improve quality,
and save money.

28. Questions and Discussion
Ed Neff
President
SMAC Moving Coil Actuators
5807 Van Allen Way
Carlsbad, Ca
USA
Phone: 760-929-7575
Email: info@smac-mca.com
www.smac-mca.com