Baking & Snack - August 2005 - 57

QUALITY MATTERS

target speciﬁcations. This data can
be compiled to create control charts
and allow the quality and production staff to continuously monitor
performance, making the necessary
adjustments to assure that the process
remains in control. If ﬁll weights begin trend up or down with respect to
established control limits, the unit can
even tell some ﬁllers to compensate.
REMOVING DEFECTS. On- or atline systems have the ability to elimi-

ᮡ Automated visual scanners ﬁnd and remove
defective products faster than the human eye
- and human hand - can respond.
DIPIX TECHNOLOGIES

nate defects that can adversely affect
product quality, safety and consumer acceptance. The most common
systems for defect removal include
metal detectors, magnets (rare earth
and ferrous), visual scanners and
X-ray detection systems.
Scanners. Visual scanning technology has become more sensitive with
each passing year. It is one of the technologies that processors can adopt to
enhance efﬁciencies and reduce costs.
Sorting systems consist of four basic parts: a scanner, an image analyzer,
a classiﬁcation system and a system
to reject defects. The classiﬁcation
system is usually very basic, looking
60 / BAKING & SNACK / August 2005

for color, shade or size, but improved
software and cameras have signiﬁcantly increased sensitivities. These
systems can scan up to one million
units per minute.
A leading manufacturer of automated inspection equipment
recently unveiled new technology
that supports the company's optical
sorting system. The new approach
employs a technologically advanced
vision system and a battery of high
performance monochromatic, color

and VIS/IR cameras. According to
the manufacturer, these improved
features help optimize sorting performance and provide users with a
tool to further enhance removal of
defects and increase yields. The new
method allows sorters to detect more
subtle defects and remove them
thanks to the company's proprietary
ﬁeld programmable gate array.
Some companies have installed visual scanners that read bar codes on
individual packages. The rationale is
allergen control. The processor will
program their bar code scanner with
the code of the product being manufactured during that day or period.
If the system detects an improper
code, that unit will be automatically
removed from the line.
X-ray detection. X-ray technology is

a more expensive means for scanning
whole packages and provides much
greater ﬂexibility than metal detectors. It can detect metal, glass, stones,
bone fragments, plastics, rubber, shells,
ceramics and even defective containers
or ﬁll; however, it will not register nor
detect hairs, string or polyethylene.
According to some, the adoption of
X-ray technology may reduce customer complaints by up to 70%.
X-ray systems allow users to
identify size, weight, shape, length,
ﬁll level, counts, presence, thickness
and density. Some processors use the
technology as an on-line control device, while others use it only for suspect items. If there is a concern that
an X-ray-detectable foreign material
got into a product, the operator will
X-ray the suspect lots only.
As with any detection system, the
food processor needs to work with
its equipment manufacturer to get
the system properly calibrated and
operating. It is essential that processor understand not only its products
but also the limitations of the detection system. If the X-ray detection
system is set too ﬁne, it will likely
generate an excessive number of
false readings. These are issues that
need to be addressed when setting
up and testing the system. The goal
is increased quality and safety.
Metal detection/removal. Finding
and removing metal contaminants
is becoming commonplace in the
industry. Many buyers demand that
their vendors put every ingredient
raw material through metal detectors.
They may also demand that metal
detection be a Critical Control Point
(CCP) in that company's HACCP
plan. There are many processors who
use ferrous or rare earth magnets
to remove tramp metal and other
contaminants from their products
or ingredients. Operators who use
magnets should not take them for
granted. Magnets can lose strength
over time and should be tested at least
once a year using a pull tester.
A wide range of metal detection
systems are available to the baking

Baking & Snack - August 2005

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