Detecting carton blanks in feed magazines

The Safeguard
Detector is a T√úV-certified safety system for detecting residual stacks of
carton blanks in feed magazines used in machinery such as carton erectors, tray
packers, or wraparound packers. It ensures that there is always a sufficient
quantity of blanks available in the magazine, eliminating the need for
operators to intervene in the machine’s extraction and setup mechanisms. Not
only is the system much more space-saving and ergonomic compared to physical
guard solutions, it also offers unparalleled flexibility for format changes –
offering significant cost and efficiency benefits for machine builders and
operators alike.

One
of the beer market’s most successful container sizes is the six-pack – whether
it comes in the form of the classic six rings and cardboard sleeve, with a
top-clip, or as a tray with a carrying handle. To enable systems such as
wraparound machines to create these multi-packs, blanks magazines provide a
supply of flat carton blanks, which are extracted from their stack by a
rotating collector or a vacuum gripper element, for example, before being
singulated and set up in the machine.

Protecting the blank infeed against
the risk of accidents

From
a safety perspective, maintaining a sufficient quantity of carton blanks in the
magazine provides a physical guard, as this blocks the opening between the
blanks magazine and the actual packaging process, thus preventing the operator
from having to reach directly into the moving mechanical parts of the machine.
If the blanks magazine becomes empty, however, this area of the machine finds
itself without protection and becomes accessible. Reaching into the parts of a
machine while they are moving and therefore dangerous during a material change
or troubleshooting for instance, poses a serious risk of injury. This must be
prevented using appropriate safety-related measures. This is especially important
given that standard EN 415-7, “Safety of packaging machines”, requires
protection for the kinds of openings in physical guards that are created by
factors such as empty blanks magazines.

Safety without ergonomics or
flexibility reduces productivity

To
date, many applications have provided a protective function in the form of
mechanical tunnels that are used to maintain the required minimum distance from
the hazardous point. An alternative design involves positioning the magazine at
a height that in some cases can only be reached using climbing aids. However,
not only do both strategies offer little in the way of ergonomics, they also
complicate the routine process of filling the magazine and make it extremely
time-consuming. What’s more, they require significant additional work on the
mechanical elements, need a large amount of space, and offer either no
flexibility or only a little when it comes to changing carton formats.

Elegant and intelligent: Safe
magazine monitoring with the Safeguard Detector

In
recent years, intelligent sensor and control solutions have made it possible to
achieve certain aims associated with both productivity and safety. The same has
happened in monitoring applications for blanks magazines on packaging machines.
Safeguard Detector represents an alternative approach that ensures certified
safety monitoring and, from a design perspective, opens up new possibilities
for more ergonomic and space-saving machine configurations. The system solution
consists of two MultiPulse photoelectric proximity sensors plus a modular Flexi
Soft safety controller. As a certified system, Safeguard Detector meets
criteria up to SILCL2 in accordance with EN 62061 as well as PL d in accordance
with EN ISO 13849.

Safeguard
Detector’s MultiPulse sensors identify carton blanks in the blanks magazine and
are able to detect both very light and very dark colours and surfaces on the
blanks with outstanding reliability. The two sensors are connected to a modular
Flexi Soft safety controller, which evaluates the MultiPulse sensor signals
using certified function blocks. As soon as the MultiPulse photoelectric
proximity sensors detect that the residual stack quantity is at a critical
level, the Flexi Soft outputs are switched off and the machine stops safely. It
then cannot be restarted until the blanks magazine has been refilled to a
sufficient level.

Productivity and safety in perfect
harmony

Whether it is part of a new set of machinery or being
retrofitted, the Safeguard Detector has sensor and control technology that is
easy to integrate. The system ensures reliable monitoring of the required
minimum quantity available in the blanks magazine, thus ensuring optimum
availability and productivity of carton erectors and wrap-around packers during
the process of creating packaging units. Not only that, it also provides
machine operators with the utmost flexibility in cases involving changing blank
formats. Thanks to the small sensor housing, the MultiPulse photoelectric
proximity sensors require hardly any installation space. In contrast to tunnel
systems, it is possible to keep the distances to the hazardous point short, which
in turn ensures a small machine footprint. When a format change takes place,
there is no need for any alterations in the layout of the safety-related
equipment, as the side guides of the carton magazine consistently maintain the
same distance from the contour of the format blanks. This monitoring method
makes carton magazines easier to access and considerably more user-friendly. It
takes hardly any time before the packaging machine is ready for new carton
formats. Where machine operator protection is concerned, Safeguard Detector has
safety certification as a whole system, so there is no need for an additional
safety review.

Prepared to handle overarching
safety functions

The
Flexi Soft safety controller can be custom-programmed with the user-friendly,
license-free Flexi Soft Designer configuration software. This allows Safeguard
Detector to be operated in a network with other safety applications that are
typical of the kind associated with packaging machines. To enable this, the
system provides appropriate modules for applications such as motion control.
With Flexi Loop, sensor cascades can be connected as part of a Flexi Soft
control solution. As a result, this provides an efficient way to monitor
aspects of packaging plants such as doors, protective flaps, and covers
reliably, with minimum wiring required and maximum safety. Finally, optional
fieldbus gateways offer numerous integration and diagnostics options as well as
outstanding investment security.

With its ability to detect
quantities available and prevent the risk of accidents, Safeguard Detector from
SICK is the ideal solution for automation and safety-related monitoring of
blanks magazines on packaging machines.

Written by Andreas Heim, Strategic Industry
Manager Consumer Goods, SICK AG, Waldkirch.

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