- Hinges that open wide around the
sprockets maximize cleaning access to
the hinge area, but close on the con-
veyor bed to prevent debris from clog-
ging the belt. - Hinge openings should be large enough
to permit spray to reach the top and
bottom surfaces. - Belts should permit catenary sag to
enable more effective cleaning because
the extra space enhances water spray
penetration to loosen soil and scraps in
the hinge area. - Belts should include drive bars under-
neath to channel water and debris to
the side away from the production line. - Belts should be compatible with the belt
lifters. When lifting the belt, a belt-
lifting device whether portable or frame
mounted, should lift the belt evenly
across its width without causing damage. - Belt designs should be tested to validate
or improve hygienic features.
Pest control design
The topography near a food facility
should be sloped to permit water flow away
from the building without the formation of
puddles. Puddles provide available water for
pests and attract them close to the facility.
A rodent lip installed 60 cm down on the foun-
dation and extending out 30 cm prevents rats
from burrowing under the slab and entering
the plant by chewing through felt expansion
joints or through drains inside the building.
Cavities within walls should be avoided
because they become nests for rodents and
insects. All parts of the structure should
allow easy cleaning of ledges, scale pits, and
elevator pits. The installation of electric
lines, cables, conduit, and electrical motors
should eliminate harborage sites. Motor
housings provide ideal nesting sites for mice.
Ventilation stacks should be equipped with
adequate screening to prevent pest entry as
mice can enter through a hole approximately
6 mm in diameter, and the Norway rats (the
largest rat) can go through a 12-cm hole.
Locker rooms and eating areas are vulner-
able to pest entry because of traffic, food
particles, and moisture. These facilities
should be designed and constructed with
interiors that can be cleaned, covered
wall/floor junctions, and smooth, water-
impermeable walls and washable floors.
Drinking fountains, vending machines, and
other fixtures should be mounted far enough
from the walls for access to routine cleaning
or mounted on casters for moving during
cleaning. Locker tops should contain a 60°
slope to avoid debris accumulation. These
facilities should not open directly into a pro-
cessing room or any area with exposed food.
The toilet facilities should have a negative air
pressure, and the internal air should be
exhausted directly to the outside.
Renovation Considerations
Preparation for renovation should involve a
plan for the reduction of the spread of parti-
cles from the contaminated construction site
to the processing and/or storage area. Thus,
the new site should be sealed off before con-
struction through building false walls, either
taped-down sheet plastic or a temporary wall
out of plywood on the renovation side. An
ideal arrangement is the erection of stud walls
with insulation. Fiberglass reinforced panels
on the production/storage side with caulked
joints provide an impervious barrier to con-
struction debris and other contamination.
A plant-wide air balance study to deter-
mine how to maintain positive pressure in the
processing area should be considered (Stahl,
2004). Positive pressure may be obtained
through a ventilation system that pumps a
higher volume of air into the production
side. Further hygienic considerations involve
Sanitary Design and Construction for Food Processing 265