Stable Micro System’s latest test could finally put an end to that frustrating moment when consumers are trying with all their might to open a can of pop or a tin of tuna, but they just can’t get it off.

The texture analysis experts at the company have developed a new rig to allow manufacturers of food tins and beverage cans to measure the force needed to lift the ring pull and open the container.

This new development could signal the end of consumer frustration with trying to open metal packaging that is too stiff, or where the ring pull detaches from the lid.

Understanding and quantifying the force needed to use a ring pull is vital for both packaging manufacturers and their customers to ensure safety, functionality and consumer experience. The force required to open tins and cans is dictated by the shape of the ring pull and lid, their materials and the depth of the groove in the lid. Until now, only subjective methods were available for assessing ‘force to pull,’ which made it difficult to identify the design that provided both ease of use and packaging integrity.

The new rig works by locking the product in place on the TA.XT plus texture analyser and attaching a hook adapter to its ring pull. The hook is pulled upwards, mimicking the action of a person opening the can, while measuring the force needed to lift the ring pull and finally break the seal.

The universal design of the Ring Pull Rig means non-circular shapes, such as meat or fish cans, can also be accurately analysed.

The flexibility of Exponent software has also allowed the development of a special test for tins that require a two-step pulling action. The rig first measures the force needed to break the seal before pausing and allowing the user to adjust the hook direction or rotate the tin. The second part of the test then measures the force required to peel and remove the metal lid completely.

“By understanding the force needed to open cans and tins, packaging designers and engineers can find the correct balance between safety and convenience for the consumer,” says Jo Smewing, applications manager at Stable Micro Systems.”  We have developed the Ring Pull Rig to give customers a detailed analysis of opening behaviors so they can optimise future product development.”

The Ring Pull rig can also be enhanced with the use of Stable Micro Systems’ Acoustic Envelope Detector, to capture and measure the ‘fizz’ sound of a carbonated drink, and the Video Capture and Synchronisation System, which allows the user to replay the data frame by frame for in-depth analysis. The rig is a Community Registered Design and is the latest in Stable Micro Systems’ ever increasing, innovative solutions for texture analysis.

For more information: Stable Micro Systems, Vienna Court, Lammas Road, Godalming, Surrey, GU7 1YL, UK. Tel: +44 (0)1483 427 345 Fax: +44 (0)1483 427 600. E-mail: or visit