By Miles Kroner, Business Manager, Vision Inspection & Serialization at Mettler-Toledo Product Inspection
In recent years, as ensuring food safety has grown in importance as a priority among consumers and regulators, food manufacturers and processors have been asked to conduct more inspections of their products and their packaging. As a result of this increased emphasis, inspection systems have evolved to become both more precise and more complex to meet increasing inspection demands. Vision inspection systems, for instance, which originally consisted of lights, a camera and software to display and analyze images, today can include such options as smart cameras, liquid lenses, 360-degree imaging, sophisticated data collection capability and participation in sophisticated connectivity networks, among other features.
This evolution has led to two results: first, today we talk in terms of vision inspection programs, rather than individual systems, because of the complexity of these operations and their interconnectivity with the user’s overall operation; and second, many production lines are almost continually being upgraded as inspection equipment featuring more and better capabilities becomes available.
This means that evaluating a new inspection system before purchasing it has become a more complex task. Companies today recognize that, in addition to evaluating the system itself, the evaluation process must include evaluating the part it will play in the inspection program: weighing where on the line the system will be used, what it will be specifically inspecting for, what the customer will do with that data, and what optional capabilities these factors may require. It also involves evaluating the company that will provide the new program.
The ideal location?
This question is closely tied to what the buyer intends the inspection system to inspect for. For example, productivity and profitability both demand that physically defective containers be removed from production before adding value by filling and labeling them. A vision system at the head of the production line will quickly identify defective bottle and jar neck threads, malformed bodies, unsightly contamination or other defects that can cause leaks or damage a company brand. Similarly, it will detect and reject incorrect printed cartons and printed flexible pouches prior to filling, as well as those with unreadable graphics and codes.
Vision systems also excel at confirming the condition of filled and finished packaging. A system positioned downstream from filling, capping and labeling and prior to case packaging will identify and reject rigid containers with cocked or missing caps, low fill levels and incorrect, skewed or unreadable labels and codes before they can leave the facility. They will also detect unsealed carton flaps and open flexible pouch seals that expose product to leaking and/or oxygen ingress.
Something as simple as detecting a wrinkle in a label covering an ingredients list that includes an allergen will avoid a recall that can cause severe financial loss and damage to brand reputation.
What are the location conditions?
The question of where to most effectively locate an inspection in turn raises other questions. What are the light conditions at the point where each inspection will take place? Is the area so bright that an enclosure will be needed around the inspection area to block ambient light that can interfere with accurate results? Or is the area dark, which might require more or stronger lighting?
Is there enough space around the product or package target inspection area to install cameras in positions that will produce acceptable images? Will the line speed at the inspection point require high-speed cameras? Will there be moisture droplets on bottles and jars at the location that might require special software that can override the resulting distortion, or dust in the air that can affect the clarity of images? Is the production line at the point of the projected inspection stable? Mounting a camera on a vibrating conveyor frame will be counter productive.
As vision systems have involved in recent years, camera, lighting and software technology has developed solutions for all of these–and many more–challenges. A highly experienced manufacturer of vision programs will be thoroughly versed in the latest technology and how it is most effectively applied. This is why evaluating a vision program also includes carefully evaluating the company that developed it and that stands behind it.
What capabilities do I need?
The design and shape of the product and/or packaging to be inspected, including its labeling configuration, will affect the required number and type of cameras and the number and type of lights needed to achieve acceptable inspection results. The physical format and configuration of the product and/or package can even affect the way in which the vision system software will process the inspection images.
Most people, including packaging professionals, see packages and products in simple visual formats: a package is a package. Vision systems do not “see” in the same way and are looking for critical dimensions and features that we as humans cannot recognize and measure. That is why human inspectors were replaced years ago by vision systems.
It is also why most vision system providers will require manufacturers to send samples of their products and packaging to be evaluated so that the best specific vision system configuration can be developed.
The big questions
When evaluating a new inspection system, the two basic questions for food producers are: What inspection capabilities do I need to reliably ensure the safety of my products, and how can I get the greatest benefit from that system? The bigger question is: how do I know what to ask for in a new system when I don’t know what is available in today’s latest technology?
A critical part of benefiting from a new system is ensuring that the new solution is one that operators can own and manage. An overly complex system may wind up being bypassed. This is another area where the system manufacturer can be extremely helpful, both with the system design and operator training.
The first step in evaluating a new inspection system has to be exploring what the major vision system manufacturers have to offer. From web site searches to virtual trade show visits (and live shows as they return), that exploration should be as wide and deep as possible, followed up by direct contact for information that applies to your unique needs. Only an exhaustive search will lead to the ideal solution.