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Safer Palletizing and Automated Stretch Wrap Machines

September 2, 2014

As manufacturing processes become ever more sophisticated, industrial safety standards are constantly being overhauled and updated to keep up with them. The past three years have been a particularly intense period of change, with many forward-thinking companies beginning to implement safer practices even before regulatory bodies mandate them.
    In today’s technologically complex plants, highly trained employees are more valuable than ever. Safety-minded managers are implementing best practices that go beyond current regulations to embrace the reality of these highly automated industrial workplaces – and the dangers inherent in them.

Automated Stretch Wrap Machines: Unprotected Danger
Automated stretch wrap machines are one area of plant operation in which new regulations have not kept pace with new technology. As ubiquitous as they are in loading dock areas where palletizing occurs, there still aren’t specific OSHA guidelines regarding proper guarding of stretch wrap machinery.
    Currently, these safety regulations for these machines default to the general requirements for all machines per OSHA 29 CFR 1910.212 (a) (3) (ii) which states 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 essentially stipulates that employers provide employees with safe working conditions and that those employees comply with occupational safety and health standards under this act.
    As with most other industrial processes, what began as a manual operation (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 the machine to take over the task.
    However, this particular aspect of plant operation has long been overlooked as a hazard. With suppliers 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.

Options for Point-of-Interaction Safety
Certainly, presence-sensing devices such as light curtains and laser scanners are potential solutions for point-of-interaction safety, whether it’s in a robotic cell, on the assembly line, or at a stretch wrap machine. 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 help 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 motion – even after it has been shut down. Additionally, an automated barrier door can be located closer to the process, allowing for a much smaller footprint in the facility.
    The most advanced roll-up automated barrier doors offer high-speed, high-cycle technology, as well as PLe hold-down mechanisms and safety rated non-contact interlock 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.

Safety in the Future
It’s 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 performed. It is also important to look past the lack of specific regulations and consider the broader context of OSHA language and guard “the point of operation of machines, whose operation exposes an employee to injury.”
    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 increasing productivity and the level of safety for years to come.
    Eric Esson is national sales manager at Rite-Hite Machine Guarding (Milwaukee, WI). For more information, call 888-841-4283 or visit www.ritehite.com.

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