Converters have the uneasy task of taking a customer’s vision and bringing it to life – many times over. In order to ensure consistency (and, therefore, return customers), converters make use of various types of inspection equipment. Designed to ensure that color, shape, size and other details of a label remain steady from run-to-run, converters utilize everything from hand-held strobe lights to sophisticated, 100 percent inspection systems.
John Thome, vice president of marketing at BST International, which is headquartered in Bielefeld, Germany, says that the systems and capabilities have changed so much that 80 percent of everything the label printer knew about inspection three years ago is now obsolete.
“Converters are jockeying for competitive advantage, and using inspection as a means to help them optimize machine performance while improving customer satisfaction,” he says. “The movers and the shakers are equipping those new presses with state-of-the-art hybrid systems. Those that buy a new in-line press today with just a video system on it are simply falling further behind the curve.”
According to Jim Wright, division manager of print inspection at Erhardt + Leimer Inc. in Duncan, SC, USA, the biggest change in inspection equipment in recent years is their rapidly increasing popularity. “To see only a strobe on a new finishing machine is unusual unless it is a very basic machine. Now you see sensor-based inspection for matrix and missing label detection (MMLD) or print inspection systems.
“The press is changing, too,” he says. “Virtually every press installed has a web viewing system, but now, many are being equipped with 100 percent print inspection systems as well.”
Holly Poplawski, marketing manager at PC Industries in Gurnee, IL, USA, says that inspection equipment has not only become more popular, but more affordable. “Between the decreasing price of technology and increased hardware capabilities, such as higher resolution cameras and faster computers, we are seeing more powerful systems enter the marketplace.
“The ease-of-use of our systems has also dramatically increased, thanks to the feedback we receive from our users. Systems are designed with flexibility to meet the needs and fit into the changing production environment of today’s printers,” Poplawski says. “Some improvements that have been welcomed include the ability to provide remote diagnostics, install software revisions and provide training via the internet. These tools are being used by label printers to visually share information and to view production from a remote office or home.”
Kevin Gourlay, business director for Rotoflex, St. Louis, MO, USA, says that the popularity of inspection equipment with advanced technology has necessitated the integration of more sophisticated controls. “Gone are the days of clutch-driven units with individual devices controlling tension, count and inspection. Finishing machines today feature highly integrated control systems with fully synchronized electronic drives that can provide lower tensions at higher speeds than older, mechanically-driven units.
“In addition,” he says, “modern finishing machine operators are able to manage all aspects of a job, including tension settings, count and inspection and active devices all from a single user interface, while jobs can easily be saved as recipes for recall at a later date. This automation dramatically reduces the potential for human error and enhances the quality and consistency of the final roll.”
Wide range of options
The range of equipment available to converters today begins with strobe lights and bar code detection, and ends with 100 percent inspection equipment, designed to find even the most imperceptible flaws. Jonathan E. Ludlow, machine vision product manager at Microscan Systems Inc. in Renton, WA, USA, says that modern inspection includes “application-focused ID readers that either just read or check and verify 1D or 2D codes on labels; general-purpose machine vision systems that can read and verify human readable text in combination with auto-ID code reading; high-level label verification systems that can verify and validate labels for specific applications, such as the UID specification labels used by the military or GS1-compliant labels; and general purpose machine vision systems that can be programmed to inspect for specific defects and errors.”
“Line scan, because of its efficiency, is able to inspect 100 percent of the labels passing the camera, unlike area scan, which offers a limited field of view and only offers a small percentage of the entire label being inspected. However, area scan technology is effective in small area inspection points, for instance, OCR/OCV and single-lane brace grading application where the area of interest is small: 1" to 5" FOV,” Post says.
Unilux, a manufacturer of stroboscopic inspection lighting in Saddle Brook, NJ, USA, offers its customers products ranging from handheld units to fixed mount wide-width systems. According to the company’s president, Mike Simonis, the company “has developed both traditional, Xenon-based strobes and new LED strobes, which gives label converters a better opportunity to get the best strobe light for their needs.
“Strobe lights can work very well with video inspection/recording systems,” he says. “This enables operators to study specific still or video images to get a deeper understanding of recurring defects and figure out production-process modification to solve specific problems.”
Though some converters may feel that strobe lights aren’t the most technologically advanced type of inspection equipment, Simonis says that his company offers 100 percent inspection equipment, all based on strobe light technology.
“Strobe lights, essentially, freeze images of fast-moving materials. To the eye, these are like still pictures, and they make defects stand out. The ability to customize flash-rate and brightness settings have enabled operators to get the best possible viewing conditions to increase their ability to see defects with less eye fatigue. The development of LED strobe lights further allows operators to tailor viewing conditions to better match inspection needs. As LED lights develop, label converters will be able to use them for more applications.”
Erhardt + Leimer offers 100 percent inspection equipment systems for 100 percent print and surface inspection and print-to-PDF validation, says Wright.
“Accuracy has two different meanings,” he says. “First, it can mean how accurate is your system and how do you ensure it? Second, it can mean how accurate is the finished product?
“Our 100 percent print inspection system, NYSCAN Web:Inspector, ensures accuracy through system configuration which includes our patented lighting method – TubeLight – and the appropriate selection of cameras to provide the needed system resolution. The configuration is then validated by inspecting a running web containing defects of known sizes, multiple times. The results of each run are then reviewed to ensure the required size of defects have been reported and that they have been reported in each run.”
Wright adds that lighting is an essential component of any inspection equipment. “Without the correct lighting, the system can’t see the defects to report on them. Our standard illumination is TubeLight, which provides a fully-diffused light to the web surface. The quality of the light makes it possible for us to inspect a wide range of substrates, including holograms, without the operator having to make lighting system adjustments.”
Thome, of BST International, agrees with Wright that lighting can make-or-break an inspection system. “We have used LED lighting for quite some time now. LED lighting is more effective because it is even and non-pulsating, has an extremely long life, and is suitable for a wide range of different substrates. Equally important,” he says, “is ease of use. Operators have to be able to do a job set-up very quickly and easily. Our system uses a ‘job wizard’ for precisely this reason. Our next generation systems, to be shown at drupa, will do job set-up automatically.”
Born out of necessity
Sophisticated inspection systems were born out of necessity, largely due to regulations imposed on the pharmaceutical industry. Though, as Scott Stevens, president of Lake Image Systems Inc. in Henrietta, NY, USA, points out: “The pharmaceutical requirements are stringent and well-known, but the same quality is everyone’s goal. With the evolution and implementation of digital print technology driving shorter runs and significant variable data content with high quality graphics, much of the demands associated with the pharmaceutical industry will become commonplace,” he says.
Jane Adams, account manager for direct sales at Ryeco, Marietta, GA, USA, says that its not just consumer safety, but operator safety that can necessitate the need for inspection equipment. “Safety requirements, either dictated by individual corporate policies or other entities such as OSHA, are a common cause for installing an automated marking system,” she says.
“Commonly, Ryeco’s Defect Marking Systems are installed to replace the unsafe practice on operators hand-flagging defects and process upsets.”
Regulations on pharmaceutical labels are typically implemented by the US-based Food and Drug Administration. However, products designed for global distribution must comply with regulations of multiple nations. According to Sharon Azoulay, marketing communications and IR manager at Israel-based Advanced Vision Technology (AVT), points out that those regulations can pose significant challenges for converters.
“In Europe, the new European Union legislation on Braille requires all pharmaceutical companies to include Braille writing on their labels,” she says. “The converters’ challenge is to ensure the Braille writing and dots are correct and according to the corresponding standards. Systems such as AVT’s PrintVision/Helios Sense platform is designed to simultaneously inspect and verify both printing and Braille faults. The system is able to decode the Braille test in order to verify correctness and to detect defects in the Braille dots during production.”
Though the pharmaceutical industry may be responsible for introducing high-tech inspection equipment into converters’ inventory out of necessity, other industries have followed suit simply because of the excellent results.
“Inspection equipment has become popular in all forms of printing, including roll-to-roll, roll-to-sheet, and sheet inspection,” says Poplawski of PC Industries. “100 percent inspection for digital printing presses has also been gaining momentum. Folding box and carton applications, and converting applications are also very active. We have seen an increase in the presence of inspection systems prepress, where offline inspection allows file-to-file, file-to-scan, and scan-to-scan comparison, along with first article inspection,” says Poplawski.
Gourlay, of Rotoflex, adds: “While pharma was originally the most popular market for inspection, we have received requests from converters to integrate inspection into finishing equipment for cosmetic, health and beauty, and beverage labels and packaging.”
AVT has seen converters in other markets adopt inspection equipment, including those who need to scan the surface of paper, metal, laminates, glass and other materials. “Most of the large format, high-speed packaging presses are sold with inspection systems as default equipment. Whether these are gravure or flexo presses, printing wide web flexible packaging applications in high speeds, vision-based press controls and process control inspection systems are used regularly,” says Azoulay.
As more sectors of the printing industry seek the aid of inspection equipment to ensure quality and consistency, the technologies available to them will undoubtedly increase. Ludlow, of Microscan Systems, says that a large part of inspection technology’s evolution has to do with improved press technology. “Speeds are increasing, so inspection equipment capability will have to continue to increase,” he says.
Stevens, of Lake Image Systems, believes that camera and computer technology will continue to improve – to the benefit of converters. “As these technologies continue to get faster and more powerful, the detail level and speed of inspection will continue to increase,” he says.
Wright agrees with Stevens’s prediction, and believes that it will be cost-effective for both customers and end-users. “As technology advances, look to see improvement in camera technology that will increase the use of 100 percent print inspection in wider web applications.
As computer technology advances, the cost to implement systems will continue to decline, thus increasing use of, as well as the ROI, on inspection systems.”
As inspection equipment advances, label press operators and converters will not only have peace of mind, but the time to focus on other aspects of the converting process. According to Gourlay of Rotoflex, “improved quality of the product coming off the press and increasingly shorter run lengths will allow converters to focus less on the actual act of inspection within the finishing department, and more on overall throughput.”