Packaging Machine Safety: Keep it safe and productive
Safety in the packaging industry used to be a relatively simple matter, a matter of a few requirements and simple maintenance. However, this is changing rapidly. Consumers keep demanding new product choices and packaging styles. Therefore, the packaging industry is requiring modular packaging systems -cartoners, case and tray packers and palletizers with higher speeds, faster changeovers and reduced downtime.
With today’s more automated packaging lines, shutting down a machine isn’t just a minor inconvenience. It leads to productivity loss. It is impractical as well: If you shut the machine down when there is a product in it, before you get it up and running again you will have to clear the product from the machine. Additionally, bringing newer machines back online may in some cases be a more complex and time-consuming process than with older machines. This why the matter of safety cannot simply be reduced to an “emergency off switch”.
However, machines need maintaining and servicing, and we are challenged to find a way to perform safety-related work without stopping production. With a modular design approach, this can be accomplished. We can keep some of the machine running, for instance, slower or in a different mode of operation, so that we can keep downtime to a minimum while we keep the operator safe and get the machine back running faster.
What about safety standards?
It is true that no machine standards are enforced in the U.S. except for those of the Occupational Safety and Health Administration whose rules have the support of the law. On the other hand, multinational companies are increasingly demanding compliance. Noncompliance can even close the door for some markets, for example, Europe. The new standards go along with new technologies that can make packaging machines both safer and more productive.
The two most important standards in this area are ANSI/PMMI B155.1 2011 and EN ISO 13849-1. Other standards can refer to a specific aspect of a machine or system operation, such as robotics, but these two standards are the key drivers in redefining safety requirements for packaging machine manufacturers and users.
New approaches: zoning and optoelectronics
New safety technology uses the same Ethernet network as the machine control system. Switching from hardwired safety circuits and safety PLCs to a networked safety system enables packaging machines and lines to be zoned. It also provides additional diagnostic information, and replaces the wiring.
With the zoning approach, you can safely control speeds, torques and motion in specific sections of machines or lines without stopping the entire line, so the system can be safely slowed rather than e-stopped and restarted.
Robotics are playing an increasingly important role in packaging and the flexibility enabled by zoning is particularly relevant to robotics. A large percentage of robot-related injuries occur not during production but during maintenance and programming. To access the robot, workers must expose themselves to risk, because they have to turn off some or all of the old, binary on/off safety devices. Newer technology and new standards enable workers to access robots and still be protected. The Robotics Industry Association (www.robotics.org) has recently revised its ANSI/RIA R15.06 2012 Industrial Robot Standard according to the risk assessment methodology of EN ISO 13849-1 to adjust to this new reality and allow today’s advanced programmable safety devices to be used.
Devices such as light curtains, laser scanners, and safety cameras are becoming more and more reliable and when coupled with integrated controllers, they provide more flexibility as well.
Optoelectric devices such as safety light curtains have been decreasing in price while adding additional features making these devices more affordable to incorporate.
These and other devices are easier to incorporate into machines and systems thanks to the introduction of new safety technologies like safety controllers. Advanced communications and the flexibility of the safety controller reduce the machine downtime thus improving manufacturing efficiency. The safety controller is expendable, so it allows a customer to standardize on a single platform for all their machines.
As you can see, new technology brings new options, so when you set off on a hunt for a new packaging machine, be sure to ask for a machines safety specification and choose the machine that can meet your requirements in terms of safety and productivity. Start now, get a quote on Tishma Technologies’ cartoners, tray packers, case packers or palletizers.