Pressure testing and volume measurement – a new level of efficiency and accuracy

Agr International’s all-new Sampling Pressure Tester, the SPT2, offers a new level of testing capability for the glass container industry.  The SPT2 is the culmination of 40+ years of Agr’s experience in manufacturing pressure testers that are designed to help improve and protect packaging performance.  The all-new SPT2 builds upon Agr’s experience in pressure testing plus takes advantage of the latest technology to provide a tester that offers superior accuracy as well as a new level of efficiency. In addition to un-paralleled measuring and testing precision, the SPT2 can test up to 270 bottles per hour, offering a 35% throughput improvement over existing industry offerings. This capability is a key advantage of this system and can result in significant savings in testing and production efficiencies.

To achieve throughput at this rate, the SPT2 employs a two-station design with concurrent volume measurement and pressure testing operations.  A robotic handling system provides for optimal bottle travel and placement through the system. Closed-loop controls are in place to manage bottles throughout the system and dynamically monitor the testing process to maintain the most efficient bottle processing and throughput.

Multiple line compatibility is another added feature of this system.  The SPT2’s “intelligent management system” and universal bottle holders can automatically adjust for bottles of different sizes and finishes.  This capability combined with the high throughput rate makes it possible to test different bottles from multiple manufacturing lines, or hand-feed a set of bottles as required, without the need to stop and reconfigure the system.

With the increased throughput and the ability to accept bottles from multiple lines, the SPT2 provides users greater flexibility and savings in their testing program. Additionally, the increased throughput of the SPT2 offers glass bottle makers a way to sample ware on a more frequent basis, and as a result, proactively detect and correct pressure and volume-related problems before they become quality issues.

SPT2 Details

The Agr SPT2 is designed to provide a viable alternative to the hand selection and manual testing of bottles for volume and pressure performance.  When integrated into the production line, the SPT2 can be configured to receive bottles selected for sampling on a regular basis, throughout the production cycle.  Once bottles are received in the SPT2 station, they are automatically tested for pressure strength and volume performance. Data from tests can be uploaded in real-time to plant-wide data collection and process management systems.   Because the SPT2 can operate on a 24/7 basis without the need for operator intervention, testing can be performed on a defined schedule regardless of time of day or the availability of personnel.

At the heart of the SPT2 is an advanced pressure generation system that makes it possible to precisely pressurize containers at a constant ramp rate up to 69 bars (1 minute equivalent).  In addition to testing capabilities for high-strength containers, the SPT2 also tests low-pressure ware with a very high level of confidence.  The precise pressure control of the SPT2 facilitates the detection of low pressure leaks, and can distinguish them from low pressure breaks. This design provides extremely accurate and controlled pressurization throughout the testing process that meets the rigid testing requirements defined in ASTM C-147, Standard Test Method for Internal Pressure Strength of Glass Containers, and ISO 7458, where a constant-rate of increasing pressure must be applied to the bottle in a very precise and defined manner.  The SPT2 offers the choice of pressurizing bottles to a pre-defined pressure point (proof testing), or to destruction.

The optional volume measurement system on the SPT2 offers manufacturers a real alternative to the time consuming and labor intensive work required for laboratory volume measurements.   With the SPT2, volume measurements can be performed simultaneously with pressure tests capturing data for volume fill point, fill point at a given volume and overflow.

“The volume measurement system on the SPT2 is more precise and repeatable than any volume measurement product on the market,” cited Senior Process Leader, Sudha Christy.  “After extensive testing and research we determined that positive-displacement technology would provide the accuracy and repeatability necessary for the type of measurements that are needed for the glass container industry.  With this technology we have been able to achieve the necessary accuracy yet overcome the problems and inaccuracies associated with flow-meter based systems and the complexity and variability of gravimetric methods.   Furthermore, measurement precision is not affected by water quality or density of water.”

The SPT2 can be configured on a sampling line to provide a protocol to integrate easily with commercial process management systems.  The SPT2 is also designed to operate seamlessly with Agr’s OmniLab® automated measurement system.  When integrated with the OmniLab system, pressure and volume as well as dimension, weight and thickness data can be correlated into one report.

The SPT2 is the latest generation in a long line of automated pressure testing systems supplied by Agr for the glass container manufacturing industry. Agr’s automated pressure testing stations date back to 1979 when Agr first pioneered the concept of automatically sampling containers from the production line and testing them for pressure strength on a regularly scheduled basis.  This development made it possible to continuously monitor the pressure strength of bottles being produced and provide a statistically significant level of sampling that is not cost-effective or practical with laboratory-based testing. Over the past 40 years Agr has supplied over 2,100 pressure testing units to the global glass container industry. The SPT2 takes this one step further with its high throughput and its ability to provide precision volume measurements. According to Agr’s Chief Operating Officer, Bob Cowden, “Our product development team accepted and fulfilled a challenging product specification relative to pressure range, universal handling, volume measurement and precise on-board diagnostics.  We are very proud of their accomplishment and look forward to serving the global glass container industry with this dynamic new tool for many years to come.”

The SPT2™ and OmniLab® are part of Agr’s broad line of, on-line, laboratory testing and quality control devices for the glass container and filling industries. Agr’s headquarters and main manufacturing facility is located in Butler, PA, USA.