Transcript EquipDesign

Equipment Sanitary
Design
© Penn State Food Safety and Sanitation for Food Manufacturers Course
http://www.foodscience.psu.edu/e-learning.html
Overall Design
• Equipment should
be designed so
that it is easy to
clean and sanitize
• The equipment at
right looks like it
would be difficult
to disassemble and
clean.
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http://www.foodscience.psu.edu/e-learning.html
Overall Design
• Closed-box construction
should be avoided
unless the seams can be
hermetically sealed.
Do you think this seam is
adequately sealed to
prevent moisture entry?
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Overall Design
• Areas where any type
of particle can get
inside should have a
wide enough access
point for cleaning
fluids to enter and
drain out.
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This hole
looks too
small to
allow for
quick
drainage
This hole is
large
enough for
cleaning
brushes to
penetrate
and water
to quickly
drain.
Overall Design
• Crevices, overlapping
parts, bolt threads, and
other contamination
collection points should be
eliminated through simple
uncluttered design.
Bolt spacers are good sanitary
design. They help to keep
moisture away from threads
Is this hole necessary? Could
this edge be better sealed?
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Overall Design
• Parts should be
connected by smooth
welds, or spacers and
bolts with unexposed
threads.
These are collection points
for soils and bacteria
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Overall Design
© Penn State Food Safety and Sanitation for Food Manufacturers Course
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Overall Design
• Equipment floor
supports should be
constructed to they
will not accumulate
soils.
• These are
examples of poor
sanitary design and
construction
Collection points for soils
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Porous Metal
• Porous materials such as
this piece of aluminum
are a potential breeding
ground for bacteria.
• Stainless steel polished
to a high level or the use
of anodized or similar
processed aluminum are
acceptable.
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Corroded metal
• Corrosion introduces
sites where soils can
accumulate and
bacteria can grow.
• They are almost
impossible to clean
and sanitize
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Build-up areas for soils
• A scratch on a piece
of stainless steel acts
as a harborage point
for Listeria.
• An incorrectly
designed piece of
equipment provides
sites for soils and
bacteria to
accumulate.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
http://www.foodscience.psu.edu/e-learning.html
Build-up areas for soils
• Collection points like
this are
unacceptable.
• Where buildup occurs
harmful bacteria or
allergens can
accumulate.
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Build-up areas for soils
• This modified piece of
food equipment
provides places for
harmful contaminants
to hide. The best
design is the original
design.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
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Connection joints
• Connections such as
this one give many
areas for contaminants
to build up while
keeping out cleaning
solutions.
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Connection joints
• This connection does
not provide adequate
space for pressurized
water to enter, but
does provide a place
for bacteria to hide
and multiply.
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Connection joints
• The polished round
spacers used with this
connection joint keep food
particles and bacteria from
hiding and give plenty of
places for water to wash
out contaminants.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
http://www.foodscience.psu.edu/e-learning.html
Connection joints
• Another picture of the
spacers from below.
Acceptable connections
need to be done using
either smooth welds or use
spacer connectors such as
these.
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Overlapping Parts
• Tight fittings provide
excellent places for
containments to hide,
while making disinfecting
difficult and almost
impossible for cleaning
crews to perform.
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Overlapping Parts
• Wide-open
mountings allow
adequate room for
pressurized water to
force out any
bacteria harboring
food particles.
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Overlapping Parts
• This particular design
provides a removable
tray for cleaning. The
removable tray does
not provide sufficient
overlap to prevent food
particles from entering
the body of the piece of
equipment.
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Overlapping Parts
• This piece, in contrast,
has a minimal-contact
overlapping design
which does not allow
material to enter the
equipment body during
normal use.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
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Overlapping Parts
• Metal / plastic
junction provides a
site for soils to
accumulate and is
difficult to clean
© Penn State Food Safety and Sanitation for Food Manufacturers Course
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Overlapping Parts
Overlapping surfaces of belt tensioner are
not accessible
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Drainage – Equipment Edges
Good design
Poor design
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Drainage
• The drainage hole on the
bottom of this piece of
equipment gives a place
for water and
contaminants to drain
• The placement of a
connecting piece with no
spacers next to the
drainage hole will ensure
the buildup of bacteria.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
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Drainage
• This design, on the
other hand, provides for
easy unobstructed
draining.
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Drainage
• Another example of
potential drainage
problems.
• Although the drainage
hole has been provided in
the design, there are
many obstructions where
contaminants can be
trapped.
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Wash Access Points
• Corners are almost
completely closed on this
piece of equipment
• Particles can get stuck
allowing bacteria to grow
• Not enough room for
cleaning solutions to
enter and drain
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Wash Access Points
• Better corner
• Wide openings allow
cleaners and
sanitizers to enter
and drain
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Crevices
• The closed-box
construction of the back
of this piece of
equipment, which is not
hermetically sealed
provides many small
places for contaminants
to enter but not enough
area for cleaning fluids
to enter and drainage to
occur.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
http://www.foodscience.psu.edu/e-learning.html
Crevices
• This particular design
uses an open-back
construction for a
supporting piece.
• Since hermetically
sealing a box is difficult
and expensive, this type
of design is preferred for
its cleanability.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
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Crevices
• Interface between serial number plate and the
equipment surface provides harborage sites
• Attachment screws make thorough cleaning
impossible
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Crevices
• The control panel on this
piece of equipment has a
crevice around the
controller.
• This type of design is
especially dangerous since
the bacteria-harboring
design is also a main point
of contact for the user who
is likely to touch (and
contaminate) food after
using this panel.
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Crevices
• The corner construction
on this piece of
equipment is particularly
bad. A supporting piece
of welded bar steel
provides a point for food
material to hide and
bacteria to grow.
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Crevices
• The shock absorber
shown here is yet
another point for
contaminants to
hide.
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Crevices
• The shock absorber
shown cannot be easily
removed and replaced
without tools. It also is
not adequately sealed
and is not made of nonporous neoprene, a
bacteria resistance
bushing material.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
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Crevices
• The spring and screw
head used here are
both difficult and
likely impossible to
clean. A major
bacteria harborage
point.
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Crevices
• The spiral-type cord
connector is yet
another place for food
particles to collect and
bacteria to hide. All
surfaces should be
smooth when possible.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
http://www.foodscience.psu.edu/e-learning.html
Exposed Threads
• These types of
polished stainless
steel nuts, cover
bolt threads and
provide few places
for bacteria to cling.
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Exposed Threads
• The nuts used here
minimize thread
exposure, while the
nut's plastic top and
bottom also ensure
that bacteria will not
collect on the
unexposed parts of
the threads.
© Penn State Food Safety and Sanitation for Food Manufacturers Course
http://www.foodscience.psu.edu/e-learning.html
Acknowledgments
• American Meat Institute for equipment photos
www.SanitaryDesign.com
• Don Ewes, Girton Manufacturing for weld and
equipment edge samples
© Penn State Food Safety and Sanitation for Food Manufacturers Course
http://www.foodscience.psu.edu/e-learning.html