Special Report: Bottle, container inspection units see technological gains
Technologies for the inspection and measurement of bottles and containers are making blow molding operations even more efficient.
Equipment can provide a range of quality-control checks, including thickness measurement and detection of leaks, contaminants, defects and stress. Many of the systems include rejection or alert systems and can be integrated directly into the production line.
Manufacturers can improve quality and reduce bottle weight by maintaining tight controls over thickness; to do so, though, some use tests that require cutting samples, which can be wasteful and ineffective.
To meet this need, TeTechS, Waterloo, Ontario, teamed with IMD Ltd., Brügg, Switzerland, to devise a new testing system: IMDvista Layer, which uses the movement of terahertz waves to calculate material thickness. Together, they demonstrated the new system in October at the K show in the Milacron booth.
“Terahertz radiation is on a wavelength between microwaves and infrared,” said Matthias Hermle, the CEO of IMD and founder of TeTechS. In a statement provided by IMD, he said technology using the waves shows promise for testing applications in the plastics industry. “So, for example, as opposed to X-ray technology, terahertz is not at all dangerous, and, compared with infrared technology, not dependent on emission factors. Therefore, measurements and analyses are feasible much more directly and quintessentially easier to trace.”
TeTechS’ TeraGauge — a nondestructive testing instrument that measures the time it takes for terahertz waves to move through opaque and translucent bottles, preforms or packaging — is at the heart of the Layer. Kelly Hall, TeTechS public relations and marketing manager, said the system “is capable of locating and measuring the barrier layer within these structures.”
With the push of a button, and in a matter of seconds, the Layer can make accurate thickness measurements of base and barrier layers ranging from 0.01mm to 5mm. It can be used to measure bottles as tall as about 12 inches, with a maximum diameter of about 6 inches and neck diameters of between 0.4 inch and 4 inches.
GP Resources LLC, Cumming, Ga., also exhibited new thickness-measurement equipment at the K show. Installed on a conveyor downstream from blow molding operations, its Wall Thickness System (WTS) uses high-speed optical technology to automatically measure the thickness of several locations on each container. It can be set to automatically reject off-spec containers.
“Our system can measure each wall of the bottle independently,” said Juha Saily, the company’s sales and marketing manager. “Other [inline] thickness systems use light through the entire bottle, combining the thicknesses of both walls in a single thickness value. Knowing [the] thickness of each wall is critical for many bottle blowing processes and bottle designs.”
Besides reducing the need for manual quality-
control checks, the WTS allows manufacturers to optimize bottle weight and provides access to production data. It can work with a wide range of containers, sizes, shapes, colors and materials.
Mettler-Toledo LLC, Columbus, Ohio, recently released the X3710 X-ray inspection machine. Its energy-saving 20-watt X-ray generator provides the same detection ability as a 100-watt X-ray generator. The X3710 can inspect up to 1,200 parts per minute for contamination such as glass, metal and stone, as well as perform product-integrity checks. Several optional reject mechanisms are available. For easy maintenance and cleaning, the machine is equipped with easy-access hatches and in-tunnel lighting. Like the company’s other new X-ray systems, the X3710 has an IP 69 certification for harsh wash-down environments and easy cleaning and maintenance.
X-ray technology can also be used for other inspection applications. The X3710 can simultaneously perform a wide range of inline integrity checks, including measuring zoned and gross mass, as well as length; counting components; identifying missing or broken products; and inspecting seals.
Air Logic Power Systems LLC
At the K show, Air Logic Power Systems LLC (ALPS), Oak Creek, Wis., exhibited its SC Linear leak testers, which are suited for many injection stretch blow molding systems, and its Speed-Glider and NexGen Rotary lines for higher-speed reheat stretch blow molding systems.
“Over the past several years, we’ve seen an increase in leak testing of PET bottles,” said Andrew Steiner, the company’s technical services manager. “The increase of recycled content, especially from the postconsumer stream, increases the potential for contamination and material issues to cause a random defect, making leak testing an essential part of any quality-control program.”
ALPS bottle and container measurement systems include:
• The SC Linear, a general-purpose, single-station leak tester with an integrated tabletop conveyor, which handles a variety of containers. Leak inspection speeds can range from 10 containers per minute (CPM) for larger containers up to 200 CPM for very small pharmaceutical containers. An optional vacuum conveyor enhances handling at higher speeds.
• The Speed-Glider, a multiple-station, continuous-motion, linear leak-test system for empty containers, which is available in different sizes with two to eight test heads. It is designed for inspection speeds of up to 500 CPM.
• The NexGen Rotary, in sizes from four to 30 test stations, which handles high-speed applications of up to 1,200 CPM. Quick-change tooling allows for changeovers in as little as 10 minutes. All station-specific test data is available for review through the controller touch screen.
Intravis Inc., Norcross, Ga., continues to enhance its vision inspection systems. At the K show, it exhibited several products, including the SpotWatcher for inspecting bottles, the IntraWatcher for inspecting label orientation, and the PreWatcher III system for inspecting preforms.
Intravis’ products use its proprietary Intra-
Visualizer software, which provides extensive quality-control tools to enable true process monitoring, rather than just rejecting bad parts, said Intravis CEO Andreas Mueller. To provide even more information to users, Intravis recently upgraded the software to allow operators to monitor all Intravis-system-equipped lines at a glance; IntraVisualizer now can also convert data into simple and easy-to-understand graphics.
The software is customized to the application so the systems provide alerts when process trends indicate that deviations from set parameters could occur. “The warning is displayed in the user interface and signal tower, in addition to being sent digitally to the production control office,” Mueller said. The inspection software also minimizes false rejects.
Polaritek Systems Inc.
Polaritek Systems Inc., Atlanta, provides equipment that can spot stresses in plastic bottles and containers that can result in cracks and breakage. Its WLP-2 stress measurement system has a light source, polarization optics and camera to perform testing of translucent solids, such as plastic bottles.
An included computer generates and analyzes the images, determines changes in refracted light and computes the stresses using proprietary data.
The resulting stress maps can show where cracks are likely to occur, explained Polaritek President and CEO Steven Danyluk.
“By utilizing Polaritek stress maps, users can quickly realize the stress magnitude and variations across a part and check the stresses at critical locations,” Danyluk said. He said the stress measurement system tool provides an easy, simple, repeatable and quick way to monitor the blow molding process.
Lisa Jo Lupo, correspondent
Air Logic Power Systems LLC,
GP Resources LLC,
Polaritek Systems Inc.,