More Confident Bottle Filling

Electronic counters and vision systems address efficiency on bottle filling lines.
Recalls due to wrong or defective pharmaceutical tablets and capsules found in bottles are not an uncommon occurrence. Evidence of wrong-strength tablets in bottles has forced several pharmaceutical companies to call back product lots in recent years.
Novartis Consumer Healthcare last year notably suspended operations at its Lincoln, Nebraska, plant in recalling lots of Excedrin and NoDoz after reported incidents of bottles with stray tablets from other products, and tablets broken or chipped.
Companies that may have relied on product inspection upstream from the filling line, or on cGMP cleaning and line and room clearance SOPS, are showing greater interest in automated tablet/capsule inspection just previous to filling.
“One of the most common FDA citations recently have been foreign products found on the machine or in the bottling suite. Industry is very focused on this; it is driving the interest in automated inspection at the point of bottle filling,” says Mark Laroche, vp sales, NJM Packaging (www.njmpackaging.com).
Yet the promise of more efficient inspection needs to be weighed against the potential for reduced production output. Solutions need to be evaluated for the application, based on factors such as pill shapes and speed requirements.
“Electronic counters are very efficient machines. Introducing vision on electronic counters is becoming requested by our customers more and more and is a good option to offer for inspection of individual tablets and capsules during the counting process. With vision, you have inspection capabilities, but you introduce some complexity and the possibility of false rejects,” says Stewart Harvey, president, IMA North America Inc. (www.ima-na.com).
“You have product moving randomly on trays such that it is hard to track the exact position of the product, which equates to some number of bottles being rejected. Additionally, you are stopping the machine, which slows down the process. At end of day, you can handcuff yourself into producing at a very inefficient rate, depending on the level of inspection you are trying to achieve,” Harvey adds.
Vendors of electronic tablet counters and camera vision inspection have advanced the precision and speed of their respective technologies for improving quality in bottle filling and production efficiency.
At Interphex this year in New York City in April, NJM Packaging featured Optel Vision’s Count Safe vision system for electronic counters integrated with a new Cremer CF-622 tablet counter module. IMA showcased its Swiftpack SwiftPharm electric tablet counter with integrated Antares AFC (Antares Foreign Checker) camera solution.
SERVO CONTROL
In Cremer’s modular design system, the packager adds the number of modules needed to a standard frame to get the desired bottle filling speed/capacity. The CF-622 filling head-with-vibratory tray module system features a mechanical vibrator driven by a servo-controlled cam shaft in lieu of an electromechanical vibrator. The electromechanical technology is subject to wear and electric coil temperature variability that cause product to jump around more in the tray channels, Laroche says.
“The rotary servo-driven system gives you much better vibratory control, enabling a smoother flow of the product, which makes it easier for the vision system inspection,” he adds.
The CF-622 replaces pneumatic cylinders with linear servos for controlling the memory flaps that separate pill count volume from one bottle to next. The module’s six-channel vibration plate can be anodized in different colors to provide contrast for inspection.
The Optel Vision Count Safe camera inspects the product as it flows on the vibratory plate to the counting area, looking for wrong color, length, and shape and for broken tabs or capsules. The system includes Windows software for recipe management, with a touch screen image of defective pills.
Customers always want the vision system to stop the vibratory plate when wrong color tabs are found to allow for manual removal. When partial or damaged product is identified, the Optel Vision software sends a signal to the Cremer tracking system for bottle ejection.  Two or more bottles can be ejected to ensure removal of the bottle with the defective tab.
The IMA Swiftpack SwiftPharm electronic tablet counter shown at the show uses a rotary pre-count gate driven by stepper motor to increase output in the same foot print.
With its Swiftpack Swiftvision electronic tablet counter, different options are provided for product counting and verification. The basic unit uses the standard optical counting deployed in most electronic tablet counters. “This really isn’t any form of inspection. A sliver of a product that meets the set minimum and maximum dimensions will be counted as a product,” Harvey says.
Electrostatic field sensing (EFS) is a different option for counting offered with the Swiftpack Swiftvision and SwiftPharm machines. With EFS, a product falling through an electrostatic field creates a disturbance that is roughly equal to the mass or the density of the product. The disturbance is measured and compared against a verified value. As EFS is measuring mass or density, it can detect and correctly count products that overlap as they fall to the bottle.
EFS detects broken products—up to the size of half of a tablet. EFS also identifies into what bottle a defective tablet falls. “With EFS, we can see where the defective tablet is in the stream and track the broken piece to the individual bottle. With a camera system, you are rejecting two or three bottles because it is difficult for the system to track the product on the tray,” Harvey says.
In using the EFS option, the packager can limit the functions required of the camera—then the camera can inspect for only color, for example—which minimizes the need to slow down the tray to get product separation for camera inspection and lessens the chance of camera-prompted false rejects, Harvey says.
Tablets of certain shapes and sizes that inhibit a smooth presentation on the tray can impact production speeds. “If you get above a 1% rejection mark, the system becomes useless. You can’t throw that much product away,” Laroche says.
“People will get excited about the technology and dive into it without really understanding what the end result will be. We always say our toughest job as salesmen is to make sure our customers’ expectations are low enough,” he adds.
NEW ALGORITHM
Optel Vision has released a new version of its electronic counter inspection that allows for better detection of broken tablets. The new software algorithm minimizes false rejects and production slowdowns, says Charles Belzile, product manager, Optel Vision.
It is ten times faster, with real time tracking of the tablets on the vibrating plates, in addition to being easier to use than the previous version, Belzile says.
“With the current system, if we see a product that, for example, looks smaller due to its orientation, when the product position changes, we stop the vibratory plate and take a second image. The stop is less than 200 milliseconds, but that can have an impact on production speeds with some products,” Belzile says.
“The new algorithm runs at least ten times faster. Instead of taking two images as the tabs flow into the camera view, we may take as many as 20 images. We are following all the tablets as they flow on the plate like a movie, so we are continuously reinspecting as the tablets move and change orientation,” he adds.
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