Today’s Checkweighers’ Expanded Capabilities Are Making Them Essential Productivity Tools
Modern checkweighers have evolved far beyond being simply weighing devices to also being interactive productivity control devices able to monitor their own and other systems’ performance.
By Keri Klein, Checkweighing Product Manager at Mettler-Toledo Product Inspection
Many years ago, product inspections were carried out by employees who viewed packaged products as they passed by on the production line and removed those with gross errors like cocked caps, missing labels, etc. It was a start, but notably inefficient. Today, the work of inspection is done by sophisticated systems that have replaced eyes with cameras and hands with automated reject devices.
The earliest of these modern inspection systems that were introduced were checkweighers, devices that weighed each packaged product to ensure that its weight matched what was stated on the package label. Today, it is a rare processing or packaging production line that does not include at least one checkweigher, but the functions those systems perform have greatly increased.
Modern dynamic checkweighers are best known for their ability to instantly weigh a package moving at production line speed to an accuracy level of within 2 grams. What is less well known is that the days are long gone in which the sole purpose of a checkweigher was to determine the weight deviation of a product. Today, a checkweighing program matched to the production process it is part of plays a comprehensive function that includes both protection and safety, but can also directly affect productivity–and therefore has huge commercial significance.
By weighing 100 percent of filled packages accurately, even on a fast-moving production line, a checkweigher provides a quality assurance control over the performance of an upstream filling system. If packages are detected to be underfilled by even a few grams, regulations are being violated, putting the company at risk; if the filler is overfilling by a even few grams, it is giving away valuable product. The checkweigher provides necessary and reliable confirmation of the filler’s real time performance.
As checkweighers evolved, they acquired the ability to be programmed to alert line operators when they detected a preset number of sequential over- or under-fills, so the filler could be quickly adjusted and further risks or losses controlled. Today, in state-of-the-art IIoT integrated production lines, more of which are coming online every day, the checkweigher delivers even greater efficiency, communicating directly with the filler’s controls to adjust the filling rate to compensate for the results it is measuring.
Self-evaluation, guided maintenance and data collection
As measuring technologies have evolved, digitization has become a core element of innovation. For example, many businesses have made the shift from analog signal transmission to end-to-end digital data transfer. As a result, an intelligent checkweighing device provides more than just accurate measuring values. It provides qualified real-time status information about the manufacturing process, including its own operational status.
The data the device provides enables the initiation of preventive maintenance actions before problems due to wear or strain begin to occur. This keeps production
running smoothly, avoids downtime and enables needed repairs to be done when it will least interfere with production. Checkweighers today are built more future-proof, providing a modular design that enables upgrading. If a replacement checkweigher is required, current technology makes the integration of new or replacement checkweighers automatically into both production line control systems and company data collection systems simple and efficient.
Checkweighers also collect data on the packages they are weighing and inspecting–total inspections, number of rejects, number of over- and under-weights, etc.–and transmit it to a central data storage location. From there it can be recalled when needed during an FDA facility visit, or to be analyzed to support the user’s Continuous Improvement program.
Maximizing the advantages
As a result of these new expanded capabilities, and the significant effect they have in minimizing downtime and maximizing productivity, checkweighers today are having as important an impact on packaging productivity as they did when they were first introduced into production lines to replace human inspectors. Manufacturers of weight-sensitive products such as packaged foods should evolve as well, to take advantage of the new capabilities.
As checkweighers have evolved from being solely dynamic weighing devices to being interconnected inspection systems, they have also become subject to what all technological systems face: the likelihood of being outperformed by a newer version. The launch of IIoT and Industry 4.0 operations have accelerated that, as all systems in an integrated production line face more demands on their performance and communication capabilities.
For those companies using today’s expanded checkweighers, the result is expanded line integration, information sharing and greater value from what was once a simple weighing system. It also means, however, that those companies need to remain informed about other expanded capabilities that newer checkweighers can offer, to be able to continue to take full advantage of what those new capabilities offer.
About the Author
By Keri Klein is the checkweighing product manager at Mettler-Toledo Product Inspection.