mable safety devices. Software will now be allowed “
safety-rated” control of various aspects of the robot’s function,
limiting the area in which the robot operates and the speed
of robot motion. This is a departure from older standards in
that programmable safety controls were not allowed.
STRETCH WRAP MACHINERY: A REGULATORY GAP
While some regulatory changes have been adopted to
keep up with the pace of some technological advances, one
area of plant operation in which new regulations have not
kept pace is with automated stretch wrap machines.
As with most other industrial processes, what began as a
manual operation (the arduous task of bending, pulling, and
moving stretch wrap around a pallet) is now commonly automated. Most workers are happy to not “stoop and circle” a pallet of product, but rather push a button and allow a machine to
take over the task.
of plant operation
has long been overlooked as a hazard.
With processors adding more automated functions to their floors (including intelligent conveyors, AGVs and AS/RS systems), it’s critical that
safety methodology is similar to that of other automated or
robotic processes and is compliant with current standards.
As ubiquitous as they are at the end of the processing
line and in loading dock areas, there are yet to be specific
OSHA guidelines regarding proper guarding of stretch wrap
Currently, these machines default to the general requirements for all machines per OSHA 29 CFR 1910.212 (a) ( 3) (ii)
stating that the point of operation of machines whose operation exposes an employee to injury SHALL BE GUARDED.
The code goes on to state that “in the absence of applicable
specific standards: the machine shall be so designed and
constructed to prevent the operator from having any part of
[his] body in the danger zone during the operating cycle.”
Fortunately, measures can be taken to isolate stretch wrap
machine operation with proper guarding devices such as
fixed fencing and automated barrier doors.
Additionally, every operation should at least uphold the
OSHA General Requirements of All Machines. As a basic rule,
companies should ensure the safety of their employees. The
OSHA General Duties Clause stipulates the following:
(a) Each employer:
(1) Shall furnish to each of his employees a place of
employment which is free from recognized hazards that
are causing or are likely to cause death or serious phys-
ical harm; and…
( 2) Shall comply with occupational safety and health
standards promulgated under this Act.
(b) Each employee shall comply with occupational
POINT-OF-INTERACTION SAFETY OPTIONS
safety and health standards and all rules, regulations,
and orders issued pursuant to this Act, which are appli-
cable to his own actions and conduct.
Certainly, presence-sensing devices such as light curtains
and laser scanners are potential solutions for point-of-interaction safety, including with an automated stretch wrap
machine. However, automated barrier doors may provide an
even better option, as they have many of the same benefits
as presence sensors, but with several additional advantages.
Most notably, automated barrier doors provide a physical
barrier that can protect an employee and contain the process,
while at the same time restricting access to dangerous machine
movement. This is particularly important for processes such
as stretch wrapping in which inertia keeps machinery in mo-
tion – even after it has been shut down. Additionally, automated
barrier door can be
located closer to the
process, allowing for
a much smaller foot-
print in the facility.
The most advanced
BROADER CONTEXT: LOOKING FORWARD
barrier doors offer high-speed, high-cycle technology, as well as
PLe hold-down mechanisms and safety rated non-contact inter-
lock switches and controls. Most automated doors function from
the top down, but some have been designed to operate from the
ground up. This allows machine operators to easily interact with
the process utilizing overhead cranes to load and unload large,
heavy parts. They are also a great option for interaction points
that have a very limited space.
With new regulations like RIA 15.06 and EN ISO 13849-1
now in place, it is important that facility managers keep
up on the latest safety technologies available to match the
right product to the right process, taking not only potential
machine hazards into consideration, but the task being per-
formed. It is also important that they look past the lack of
specific stretch wrap safety regulations when making equip-
ment decisions. Instead, we should consider the broader con-
text of OSHA language and guard “the point of operation of
machines, whose operation exposes an employee to injury.”
Clearly, automated and/or robotic stretch wrap operations fall
into this category. Given the recent advances in their design and
technology, automated barrier doors can be an excellent option
to guard these machines and protect operators, ultimately in-
creasing productivity and the level of safety for years to come. ■
DISCLAIMER: The information herein is provided as a general reference regarding the use of the applicable product(s)
in specific applications. This information is provided without
warranty. It is your responsibility to ensure that you are
using all mentioned products properly in your specific application and in accordance with all laws and regulations.
PHARMACEUTICAL PROCESSING | JULY/AUGUST 2014 35 ■
Most workers are happy to not “stoop and circle”
a pallet of product, but rather push a button and
allow a machine to take over the task.