Safety is a major topic with automated machines and automation components exploding in popularity in today’s manufacturing environment. The goal is to have reliable, repeatable manufacturing processes while also keeping your labor force safe and providing a rewarding work environment. It seems like not a day goes by without a new safety regulation, safety product, or safety feature being blasted into your email inbox. Safety regulations from OSHA or other organizations governing machine safety can be daunting and typically deal with the physical or mechanical safety of machinery. The list of new safety products with integrated safety features seems to be endless. These products include a myriad of safety terms and considerations from safe torque off (STO) to safety integrity level (SIL) to collaborative workspace to functional safety to even dual safe torque off?! This all makes navigating the safety environment difficult at best.
Top 3 Machine Design Guidelines for Hard Guarding:
1) Always Include Hard Guarding if Possible
The default stance for machine designs should be to include mechanical or hard guarding, such as fencing, extrusion assemblies with appropriate panels, doors with locks, or other physical barriers to prevent moving machine elements from contacting human operators. Not only is this design stance the most safe, it can also simplify the overall machine design by limiting the amount of electrical safety automation components and the associated expense. To be clear, electrical safety components will be required for an overall safe machine design, but the safest approach and best practice (if space is available) is to utilize physical hard guarding in most situations.
2) Limit Options to Override Safety Guards
According to OSHA, one of the most common causes of injuries with machinery was failure to use a safety guard. In these cases, the safety guard was removed or disabled from a door or other access point to the machine due to “inconvenience” or for routine maintenance and then was never properly put back in place. Incorporating a procedure such as Lock Out, Tag Out (LOTO) can minimize or eliminate this from happening because the machine will not be able to start back up because this involves isolating power sources. In addition, limiting access to safety keys, training employees, and having appropriate oversight can also significantly reduce the probability that machine safety guards are overridden or removed.
3) Use Adequate Materials for the Environment
First and foremost, machine hard guarding materials should stand up to the physical demands (collisions, vibrations, etc.) to eliminate fatigue and eventual failure. Additionally, other environmental considerations must also be factored in to the hard guarding design. For example, in a welding or laser processing environment that creates dangerous light conditions, the appropriate glass panels, door materials, and fence materials must be utilized to block or filter harmful rays. In environments with potentially harmful chemicals (cutting fluids, washdowns, pharma, etc.), care must be taken to prevent spills and splashing, but also to make sure the material will not corrode or deteriorate over time from constant exposure. In the end, always know your environment and make sure the structural design and material selection are appropriate for the long term.
Examples of Machine Hard Guarding Built by Mechatronic Solutions:
(Left- Aluminum extrusion assembly w/ doors, panels, and venting)
(Right- Fencing structure w/ visual protection for robotic welding cell)
Mechatronic Solutions is a high-tech automation distributor with mechanical and electrical design engineers to help create machine safeguarding solutions, including aluminum extrusion assemblies and safety fences. With its mechanical and electrical value-added assembly shop, Mechatronic Solutions can also assemble a large variety of complex machine guarding structures including robotics, safety light curtains, UL 508A electrical panels, motion control, actuators, pneumatic components, and more.
Contact us to have a Mechatronic Solutions' design engineer help design an appropriate and safe hard guarding solution for your machine.