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WHITE PAPER
Why System Drive Type Matters
in Cleaning and Sanitation
Introduction
Repeated maintenance and sanitation halts processing each day in
food manufacturing. Worse yet, operations can experience costly and
unexpected shutdowns whenever plant conditions are not up to food
safety standards strictly enforced by governmental and regulatory
agencies. Balancing these realities with ever-increasing production demands
places unique and immediate challenges on food manufacturing facilities.
When it comes to power transmission equipment used in the food processing
industry, some types of drive systems are easier to clean and sanitize than
others. This paper will examine drive system cleaning and sanitizing challenges
facing the food manufacturing industry and compare washdown considerations
for roller chain and belt drives. The proof points discussed in this paper will help
to educate food manufacturers so that they can make informed decisions that
will allow them to maintain the highest level of productivity while meeting or
exceeding food safety standards.
WASH DOWN DRIVES WITHOUT
WASHING AWAY PROFITS
POWERING PROGRESS™
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Balancing Food Safety
Regulations with Productivity
The food manufacturing and processing industry is subject to food safety
regulations designed to control or eliminate microbiological, chemical and
physical safety hazards. Microbiological hazards are the most prevalent.
They include bacteria, viruses and parasites that can produce disease
in humans (pathogens). According to the Centers for Disease Control
(CDC), more than 250 known diseases are transmitted through food. In
the U.S. alone, an estimated 48 million cases (1 in 6 people) of foodborne
disease occur each year, ranging from mild to severe, and resulting in
approximately 3,000 deaths annually.
Depending on the type of food manufactured, processors must meet
standards imposed by federal agencies such as the Food & Drug
Administration (FDA) or the U.S. Department of Agriculture (USDA), plus
those of state and local regulatory bodies. In addition, processors must
comply with workplace safety and environmental protection regulations
imposed by the Occupational Safety and Health Administration (OSHA)
and the Environmental Protection Agency (EPA).
The goal of the regulations implemented by the Hazardous Analysis and
Critical Control Point (HACCP) is to increase food safety, reduce the
outbreak of diseases and provide consistency. The HACCP regulations
address the control of biological, chemical and physical hazards from
raw material production, manufacturing, handling, distribution and
consumption. These regulations include standards that are backed by
the FDA, which sets forth quality guidelines for food manufacturers and
requires them to develop a program of good manufacturing practices to
keep foods pathogen-free.
In short, food manufacturers and processors are under relentless
pressure to ensure that their manufacturing environments meet or
exceed ever-stricter standards for cleanliness and hygiene. The cost of
failing to ensure the safety of food can be high, as witnessed by recent,
highly publicized product recalls and the ensuing effect on reputations
and bottom lines.
Paradoxically, cleaning and sanitation to ensure food safety is vital to a
food processing operation, yet it adds no direct value to the product. This
poses a challenge for management. To remain competitive, plants must
operate with maximum efficiency, eliminating downtime whenever and
wherever possible. Cleaning and sanitation, however, requires downtime.
While the frequency and intensity of washdowns vary by type of food
produced, any time spent in this activity reduces production capacity.
It stands to reason that food manufacturers are looking closely at durable,
maintenance-free equipment designs that lend themselves to quick,
effective cleaning, in order to minimize downtime and maintain higher
levels of productivity. Power transmission drive systems are no exception.
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Productivity Costs of Cleaning and Sanitizing
According to various industry estimates, the American food and beverage
industry, including animal processing and packaged goods manufacturing,
will account for $850 billion in U.S. gross output in 2013, employing 1.565
million people. If downtime spent in cleaning and sanitizing represented a
mere 1% of that gross output, the cost of this activity would amount to $8.5
billion every year.
To cite a more specific example, a major international meat processor
operating 24/7 measures downtime in tenth-of-a-second intervals. Due
to this operation’s high throughput rate, a few minutes of downtime costs
thousands of dollars.
How much downtime does a typical plant need to incur in cleaning and
sanitation? It depends on the operation. Manufacturers have some
flexibility in determining cleaning intervals, as indicated in the USDA/
Food Safety Inspection Service (FSIS) requirements: “All food and non-
food contact surfaces of facilities, equipment and utensils used in the
operation of the establishment must be cleaned and sanitized as frequently
as necessary to prevent the creation of unsanitary conditions and the
adulteration of product.”
Interpreting this standard, an operator might have to clean processing and
packaging equipment at the end of every line change, shift and workday.
This could add up to 15 or 20 hours of mandatory cleaning each week. As a
minimum, one washdown per shift is a common practice.
To decrease downtime, increase production efficiency and minimize
expense, establishments can extend the period between cleanups.
However, establishments must develop, implement and maintain written
standard operating procedures for sanitation that are proven to be
effective in preventing direct contamination or adulteration of product—in
order to stay within compliance of strict governmental and regulatory
requirements for food sanitation.
It goes without saying that food manufacturers can extend the period
between cleanups and minimize downtime more easily when their
equipment is easy to clean and maintain to begin with.
Drive System Washdown Considerations
Regarding safety issues for cleaning and sanitation, 3A Standards divide
food equipment surfaces into two categories:
1. Food product contact surfaces
2. Non-product contact surfaces
A food product contact surface is one in “direct contact with food residue,
or where food residue can drip, drain, diffuse, or be drawn” (FDA, 2004b).
These surfaces must meet rigid sanitary design criteria to prevent food
product contamination. Non-product contact surfaces are those parts of
Although crucial to meeting strict
food safety standards, cleaning and
sanitizing reduces productive capacity
and adds no direct value to the product.
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the equipment (e.g., legs, supports, housings) that do not directly contact
food. Because they may indirectly contaminate food product, however,
these surfaces also should follow sanitary design principles.
In terms of sanitary design, all food contact surfaces should be:
› Smooth
› Impervious
› Free of cracks and crevices
› Nonporous
› Nonabsorbent
› Non-contaminating
› Nonreactive
› Corrosion resistant
› Durable and maintenance-free
› Nontoxic
› Cleanable
Surfaces coated with metal alloy or non-metal material (e.g. ceramics,
plastic, rubber) must also meet the above requirements.
Power transmission drive systems, whether belt drives or roller chain drives,
would typically fall into the category of a non-product contact surface.
Following 3A Standards, non-product surfaces of equipment should be
constructed with appropriate materials and fabricated in such a manner as
to be reasonably cleanable, corrosion resistant, and maintenance-free.
Let’s examine roller chain and belt drive systems in the light of cleanability,
corrosion resistance and maintenance.
Roller Chain Drives
Stainless steel is the preferred surface for food equipment. It is generally
resistant to corrosion, smooth-surfaced and impervious (unless corrosion
has occurred), resistant to oxidation at high temperatures, non-magnetic
and easily cleaned.
Standard roller chain drives are constructed with carbon steel. Wet
environments pose a problem for standard carbon steel roller chain
drives. Lubrication is one of the most important factors affecting chain
performance, and it is difficult to maintain the proper degree of lubrication
in an environment where drives must be washed down at least daily.
Insufficient lubrication causes increased wear, chain seizures and galling of
pin surfaces. Premature wear will also create the need for more frequent
replacement of the chain drive, leading to maintenance downtime and
affecting other areas of plant operation.
A single roller chain link presents
hiding places for microbes.
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In lieu of standard carbon steel chain, food processors can turn to “problem
solving” chain, such as stainless steel chain or O-ring chain. Both are quite
costly. Moreover, a roller chain drive, regardless of construction material, is
comprised of many parts—pins, bushings, link plates—that provide myriad
cavities and spaces for microbes to hide. Because chemical sanitizers lack
penetrability, they may not be able to destroy the microorganisms present
in these cracks, crevices and pockets.
Cleaning a roller chain drive with a high-pressure spray poses another
problem, namely, dispersion of the lubricant. Lubricating greases and oils
are insoluble in water, alkali, or acid. Melting them with hot water or steam
often leaves a residue, requiring surfactants to emulsify the residue to
make it suspendable in water and flushable. In any case, one should use
care when cleaning a roller chain drive to avoid dispersing lubricant onto
food contact surfaces.
Finally, one should also use care with sanitizing chemicals to ensure their
compatibility with the material on which they are used. For example, the
halogen family of chemical sanitizers (chlorine, iodine, bromine and fluorine)
can attack some grades of stainless steel, causing corrosion and pitting of
the surface. Chlorine, a sanitizer commonly used in food processing plants
in various forms and concentrations, forms an acid in solution, which can
also cause pitting on stainless steel surfaces if used in high concentrations.
Belt Drives
Belt drives are relatively simple in design, consisting of sprockets, bushings
and a belt of one-piece, uniform construction. Compared with roller chain,
a belt presents a relatively smooth, cleanable surface. Belt drives are also
clean-running, needing no lubrication. Moreover, without metal-to-metal
wear, belts and the sprockets they run on last considerably longer than roller
chain and roller chain sprockets. All these factors add up to a maintenance-
free drive system that is easy to clean.
In the wet, washdown environment of food processing operations, stainless
steel or nickel-plated sprockets can provide an extra measure of protection
against corrosion for belt drives. Stainless steel sprockets cost more than
conventional ones, but unlike roller chain drives, only the sprockets have to
be stainless steel, not the entire drive.
Belt materials vary depending on the application. Rubber belts with
fiberglass tensile cords, such as Gates PowerGrip® belts, are commonly
used for low-horsepower applications (1750 rpm motors under 50 HP) in
place of roller chain drives. Alkaline detergents do not affect rubber, which
stands up well to washdowns. Exposed tensile cords along the sides of the
belt can wick moisture into the belt over time, so maintenance personnel
should inspect belts for wear regularly. In addition, organic solvents and
strong acids used as sanitizers can attack rubber, so one must exercise
care when using these types of sanitizers.
The surface of a synchronous belt
is smooth, impervious, non-porous,
non-absorbent and free of cracks and
crevices, making it easily cleanable.
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For high torque applications, food processors can use a polyurethane belt
with carbon fiber tensile cords, such as Gates Poly Chain® GT® Carbon™
belt. Carbon fiber tensile cords provide excellent resistance to moisture and
chemicals, and polyurethane stands up well to most cleaners and sanitizers.
This belt offers a number of properties that make it highly suitable for food
processing operations, including:
› Excellent resistance to oils, fats, fruits, juices,
vegetables, dairy products, tomatoes, wine and vinegar
› Good resistance to food industry soils and chemicals
› Good resistance to high-pressure washdown sprays
› Excellent abrasion resistance
› Operating temperature range of -65°F to +185°F
What productivity advantage can be gained by using belt drives instead of
roller chain drives in food processing applications? Again, it depends on the
operation. In the case of the meat processor mentioned earlier, converting
a large number of roller chain drives to Gates Poly Chain belt drives reduced
cleaning, sanitizing and maintenance requirements dramatically, saving an
estimated 2,000 hours annually. That translates to a lot more meat coming
off the production line, and dollars falling onto the bottom line.
Stainless steel or nickel-plated
sprockets protect against corrosion.
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Conclusion
In food processing operations, the easier it is to clean and sanitize
equipment, the faster it is done. When food manufacturers measure
downtime in fractions of a second and tally the cost in thousands of dollars
per minute, they will spend every effort to speed the cleaning and sanitizing
process along, commensurate with food safety. Belt drives help accomplish
this goal better than roller chain drives, adding profit to the operation.
Additional Resources
Engineering design assistance with belt drive systems for food processing
applications is available from Gates Corporation. Contact the Gates Product
Application Helpline, (303) 744-5800, email [email protected], or
visit www.gates.com/polychain.
Washing Down Drives Without Washing Away Profits
Food manufacturers and processors may be spending unnecessary time cleaning and sanitizing certain power transmission drive systems, leading to lower productivity levels and reduced profits.
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