The customer manufactures closures for the beverage industry. These include tamper-evident caps used on mineral waters and other soft drinks. The company wished to perform a compression test on the tamper evident ring, which could measure the maximum force used to ‘push it off‘ the cap. As the tamper-evident closures are fitted onto bottles using a compressive action, this test would provide the company with valuable information relating to the correct application of force throughout production.
A MultiTest 1-d motorised test stand, rated to 1000 N, an AFG 500 N digital gauge and special accessory were supplied, by Mecmesin, to perform this test. The special accessory comprises a tapered spigot (in varying diameters to accommodate different cap sizes), push tube, tube cap and cap base pillar. Together, this forms a simple solution, in which a compressive force is applied, to, in essence, ‘push off‘ the ring, thereby separating the tamper-evident element from the cap. With a tamper-evident closure securely fitted onto the tapered spigot, the compression plate, fixed to the digital gauge, is lowered to a pre-defined distance, detaching the tamper-evident ring from the cap. The AFG records the peak force measurement and transmits the reading to a PC hosting the customers SPC monitoring software. Using the constant speed of the motorised test stand ensures optimum repeatability for the test helping the customer to check that their manufacturing practices are correct and product quality is being maintained.