Critical features measured with non-contact back end gauges

Sencon has introduced an automatic Finished Can Master and benchtop Finished Can Gauge, which measure dimensional features on finished (necked) cans. Both gauges make all of their measurements using solid-state optical metrology that is wear-free and has proven its reliability on Sencon’s widely used End Progression Gauge over the last 12 years.

Using non-contact optical devices instead of mechanical contact transducers (LVDTs) enables a scan of over 30,000 measurements on each can. This returns true maximum and minimum dimensions, an improvement on the more limited data provided by contact systems that tend to measure in four fixed positions. The actual shape of any feature is also revealed, including any anomalies which are easily missed by contact systems.

The significant advantage of optical measurement is that more features can be measured, taking no extra time to do so. These additional measurements include seaming clearance,  flange angle, neck angle and ovality – all critical for good can performance at the filler. This comprehensive data is stored for subsequent recall and analysis. So if a can filler reports a seaming problem for cans made five days ago, for example, the precise dimensions of these features can be checked and detailed can images reconstructed on screen. These gauges also have a Dome Reform Option which works simultaneously while scanning the neck area. Reform diameter, reform height, stand diameter, and other base reform characteristics – such as eccentricity – are optically measured with the same high degree of accuracy.

Non-contact metrology offers increased accuracy and repeatability because the can is not deformed while being measured. A wider range of can body diameters, neck diameters and can heights can also be measured with no need for adjustments or change parts. This means that Sencon’s back end gauges will be able to accommodate future needs as can sizes, shapes and weights continue to evolve.

All these advantages, together with built-in monitoring of gauge stability and self calibration to national standards, result in improved confidence and better ability to tightly control the can-making process. Eliminating wear parts like mechanical transducers means less downtime with negligible maintenance and significantly lower lifetime costs.