PET Food Processing - March 2018 - 74
without an expander that requires a threaded nut on
the exposed foot. They've designed other creative solutions as well, says Gerard Nelson, sales director, Spooner
Vicars, Golborne, UK. "If you imagine a sheeting line
to make dog biscuits, it's full of rollers. You have conveyor belts and rollers to drive them. To make it easily
accessible, we designed it so the supporting panels rest
by gravity and the rollers rest in slots with quick release
pins and they can simply be lifted out."
Even how wires are routed should be addressed.
"Traditionally, wires are routed through conduit or
metal boxes. True sanitary design principles don't allow
that," Cavanna's Kehrli says. "Cables should be accessible
to be cleaned, whether it's a motor or valve, all the way
back to the electrical panel every night."
Rethinking every aspect of a complex machine might
seem daunting, but Uebele sees it as an opportunity. "It
is an exciting challenge for engineers to eliminate complexity not only to reduce niches and crevices, but to
create an assembly that is easier to clean."
Cleaning protocols are key
If the total environment
isn't designed to handle
harsh washdown chemicals,
different procedures need
to be established to keep
mild steel as well as stainless steel and stainless steel
washdown depending on the application. Two of the
primary principles behind sanitary design is to limit
the areas for bacteria to harbor and if you can't reach
it, you can't clean it."
All areas of the equipment should be open, accessible
and easy to clean. That's a tall order, according to Christian
Uebele, engineering manager, Multivac Inc., Kansas City,
Missouri. "The sanitary design of the interior of the machine is arguably more important that the exterior. The
interior of a machine is harder to clean and inspect, so it is
important to eliminate niches or places for product to collect." Flat surfaces should be rounded or sloped whenever
possible. Welds should be full continuous beads. Lap joint
frames can't be touching. They should be stepped off from
one another. All areas of the equipment should be readily
accessible with no tools required.
"It's not an inexpensive way to manufacture equipment, but it's absolutely necessary," says Keith
Shackelford, group vice president of marketing,
Middleby Processing and Packaging Technology Brands,
Elgin, Illinois. "We've always designed the food contact areas to be sanitary and very easy to clean and very
robust. It's the support members like the legs and the
framework that really don't contact the food or the ingredients that are under scrutiny now."
Spooner Vicars provides sheeting lines for dog biscuit
applications. To eliminate threaded components, they
designed special feet so the line height can be adjusted
PET FOOD PROCESSING | March 2018 | www.petfoodprocessing.net
How a machine is designed is just one part of the equation for keeping equipment sanitary. Good cleaning
processes need to be in place and followed for it to stay
sanitary. "Depending on cleaning policies and frequency, a sanitary machine design will allow personnel to
be thorough and aggressive in their cleaning practices,"
says Ryan Fernholz, regional sales manager, Douglas
Machine Inc., Alexandria, Minnesota.
Martinez agrees, "As part of the design, it is important to have the access needed to adequately clean the
system to the expectations defined in cleaning validations. It's much safer for equipment operators when
this is considered in the design of the equipment."
For every type of pet food and pet treat being made
there are probably just as many unique cleaning protocols. "The best thing we can do is show processors
how to take the machine completely apart 100%," says
Mike Jacko, vice president of applications and new
product innovation, Urschel, Chesterton, Indiana.
"Manufacturers must have a cleanable machine, a
process to clean it and paperwork to verify that it was
done. We work with our customers to help them establish their specific sanitary plan."
The reduced number of components and good access makes sanitary design equipment easier to maintain and service. "Today with 24/7 production, it's all
about small tolerances. If you can improve efficiency by
1% that's a massive amount when you look at it over
a year," Nelson explains. "If you're talking about mass
production of one product over 24/7, it's all about the
margins. I've known of cases where it previously took