PET Food Processing - June 2018 - 40


A Mettler-Toledo X36
X-ray system inspects
cans, cartons and metalized bags for metal,
glass, bone and heavy
plastic contaminants.
Mettler Toledo

to the packaging formats that the products are offered to
the market in," says Kyle Thomas, strategic business unit
manager for Eagle Product Inspection, Lutz, Florida.
"Our customers are not just looking for contaminates or
foreign objects that pose product safety risks. Our systems can find and verify that specific items are indeed in
the package."
Many products are packaged in case-ready packaging,
which means the case acts as the store display. X-ray inspection systems detect the position of pouches inside
a case and verify the case contains the correct number
of pouches. Often in pouch applications, x-ray systems
verify that each pouch includes a resealable closure. For
canned products, x-ray systems check for fill level, product voids and that cans are properly sealed.
As inline inspection and detection requirements get
more complex, equipment manufacturers develop their
own unique technologies to solve these challenges.

Reading the signals
Eagle Product Inspection applies dual energy to address
complexities. "Dual energy allows us to look at a high
energy spectrum image and a low energy spectrum image," Thomas says. "The system looks at both values and
fundamentally classifies those values as organic and inorganic. It does so by taking the resulting differential
or ratio of energy absorbed, which is then associated
with its chemical composition or atomic number. That
result allows us to mask off organic items making the
inorganic items pop." Through product set up, opera-



tors teach inspection systems the uniqueness of specific
product configurations enabling the system to recognize
Eriez Magnetics helps tackle the challenges of
pet food applications with a user interface
similar to today's smart phones in that
it's all icon based. "Overcoming different
product variations starts with setting up
the product," Spurgeon says. "Eriez systems
feature automatic setup through a full-color
touchscreen that has a polar graph allowing
an operator to visually see feedback from
the metal detector. It's not just values. It's intuitive and simple to troubleshoot." The system's
algorithm can detect a visual representation of the product and evaluate if it meets the target criteria and is free
from foreign objects.
Addressing the challenge of product effects caused
by moisture in pet food, the Interceptor metal detector from Fortress is designed to inspect conductive
applications in paste, slurry or gravy form, helping to
eliminate false rejects. The challenge is differentiating
between the signal generated by the product as a result
of moisture or mineral content and any metal contaminant. "The Interceptor transmits multiple frequencies at
the same time which allows it to achieve much higher
performance levels especially when inspecting products
that have an effect due to moisture," Gidman explains.
"Compared to the traditional approach where inspection systems tune into specific frequencies, this method
can identify the product effect and eliminate it from the
higher-frequency signal, where the potential effect of
the metal is more prominent."
Gravity flow or throat detectors from Mettler-Toledo
can inspect dry kibble products using Mettler-Toledo
Safeline's zero-metal-free-zone (ZMFZ) technology.
This technology allows the metal detector to be close to
other equipment and still accurately operate in plants
with limited space. "Internal cancellation field (ICF)
technology for highest sensitivity ICF is a special technique, patented by Safeline, that enables higher operational sensitivity settings to be used in close proximity
to metal structures, such as weigh hoppers, metal chutes
and forming shoulders," Rogers says. "This technology
enables the detector to locate small pieces of non-magnetic-grade stainless steel. The detector internally generates a secondary magnetic field that is opposed to the
primary magnetic field produced by the detector. This
technology prevents leakage of the primary magnetic
field outside the detector, effectively suppressing interference from any nearby source including metallized
film or aluminum foil."
For detection technology to work intuitively, a system

Table of Contents for the Digital Edition of PET Food Processing - June 2018