veyors are inoperable — whether due to failure or the time needed for cleaning — they
aren’t conveying product and making money
for the processor.
Spiak: There are many ways conveyors
can improve productivity and profitability.
Conveyors aren't always simply used to
move a product from Point A to Point B
anymore. Oftentimes, the processor will
want a conveyor to do something other than
simply move the product. Examples could
be orientation of product on the production
line, keeping a product in a particular lane
or position on the line, or spreading product
out from a narrow section of conveyor to
a wider section of conveyor. In the case of
spreading conveyors, we have seen companies reduce labor costs by using a conveyor
to spread product out in the line, rather than
having manual intervention in their process.
This might even improve a processor's safety
record, or lower risk of accidents, by keeping
people's hands away from moving conveyors.
Q. What innovations have been
developed recently regarding food
safety in conveying equipment?
A. Kadinger: To improve food safety,
processors are replacing conveyors made of
coated mild steel with stainless steel because
it resists bacterial growth and better withstands caustic washdowns. The most hygienic
conveyors feature no laminations and no
enclosed hollow bodies that can harbor bacteria and leak. Tubes, which traditionally
have been used on conveyor frames, are
increasingly being replaced by open-section
supports made of plate or formed sheet metal.
Free draining surfaces, such as a conveyor
bed at enough of a slope to drain, minimize
the build-up of moisture during production
and ease washdown. Conveyors with drives
that use food-grade oil and oil-free drives
help reduce the risk of this potential source
of product contamination, especially when
equipment is mounted over other equipment.
Vibratory and horizontal motion conveyors
are inherently more sanitary than belt conveyors, all else equal, because they minimize
product contact with moving parts and present a flat-bed surface that is easy to clean.
Belt conveyors that feature fabric belts
with exposed edges are the least sanitary
because the belt can fray and contaminate
product. Fabric belts with encapsulated
edges are preferred and can be more sani-
tary than plastic interlocking belts that fea-
ture crevices that can trap bacteria and are
time-consuming to clean. The most sanitary
type of belt conveyor features a positive
drive urethane (PDU) belt made of smooth,
Spiak: Wire Belt has implemented many of
the criteria for Sanitary Design. All welds
are sealed, all contact surfaces are made of
stainless steel and other hygienic materials,
and everything is designed with washdown
and superior drainage in mind.
Q. What challenges do food processors face when integrating new
conveyors into existing equipment?
A. Kadinger: It is important when
integrating new conveyors into existing
equipment to be sure the design is properly
matched to upstream and downstream equipment in terms of speeds, loads, transitions
and, if needed, proper presentation of the
product to the equipment the conveyor feeds.
It is also a challenge to install a conveyor on
an existing line with minimal disruption to
production. Because of these challenges, a
processor should consider both the cost and
the value of changing only the conveying
equipment versus delaying the upgrade until
later when more equipment could be consid-
ered together as a whole.
Integrating a new conveyor into an existing
line is further complicated when the processor wishes to integrate the controls. Each
machine has its own control system, but the
key to maximizing the performance of the
line is linking these independent machines so
they communicate with the others to improve
the efficiency of the system. Fully integrating the controls costs more initially, but the
added cost is quickly recovered by increases
in overall equipment effectiveness (OEE).
Spiak: There are multiple challenges when
adding new equipment to an older processing line. The processor should always work
very closely with the equipment manufacturer to ensure compatibility. This includes the
simple things like conveyor height, length
and width, as well as the more complex
issues, such as speed controls, drive mechanisms and even PLC integration.
Q. What considerations should
food manufacturers make when
selecting new conveying equipment
for their facility?
A. Batka: Time is money. Therefore,
they should look for conveyors that are quick
and easy to clean and sanitize. The time it
takes to clean and sanitize costs money, in
addition to the fact that when the conveyors
are being cleaned, they aren’t conveying
product and making money.
King: Food manufacturers should carefully
consider the long term cost of ownership
when purchasing new conveying equipment.
However, when analyzing cost of ownership,
they should be looking at the belt separately
from the conveyor. All too often, the conveyor belt is viewed as an accessory on a
conveyor and not as an engineered product.
This viewpoint can potentially have a profound impact on conveyor performance and
operating cost. This is especially true when
considering the purchase of spiral coolers,
proofers and freezers. There are two specific
styles of belt used in spiral coolers, proofers
and freezers: metal and plastic. While both
belt styles can effectively be used in each of
these applications, each style of belt has an
entirely different cost of ownership. ◆