It is only in recent years that there has been a substantial increase in their use for food cans. When the ring pull was introduced in the late 1950s, the concept had an immediate impact on the development of the beverage can. But despite the success of the concept, the canned food industry was slow to benefit from the advantages of the easy open end.
Nonethless, the food packaging industry is making up for lost time. "After the steel easy opening end made its première in the market for pet food cans in the early 1990s, it was quickly adopted throughout the whole food market," said Arcelor Packaging's food project leader Barbara Martin.
"In due course, major brand owners in the human food business such as Heinz, Unilever, Campbell, Bonduelle and many others began to switch to this new technology. Since then, the use of steel easy opening ends has doubled in the last five years and continues to grow.
Arcelor Packaging International is launching Maleïs, a new generation of steel, which the company claims will improve the manufacture and performance of ring pulls for the food packaging industry. Arcelor's Maleïs product leader Pierre Damiani describes the difficulty in developing the concept.
"It is not an easy task to attach the pull tab effectively to the easy opening end and ensure that it does not break off before opening. Intensive research carried out in our R&D centre in Florange on the easy opening end mechanism has shown that the properties of the tinplate used are very critical for the production of steel for easy opening ends.
"In particular, the ductility of tinplate is a critical factor in achieving the delicate forming operation of the rivet to attach the pull tab on the end and was one of our main concerns. By changing the parameters of the continuous annealing process we were able to influence the mechanical properties of the material and reach the specifications we had targeted for this new grade of tinplate."
Arcelor says that Maleïs tinplate offers considerably lower opening forces than materials currently used. A decrease of 15 to 30 per cent depending on the thickness of the Maleïs grade has been achieved during extensive trials with several canmakers whilst maintaining the same performance levels.
The Luxembourg-based company claims that consumer tests show that this difference in opening ability is highly appreciable. "We believe that the improved properties of Maleïs offer potential for a multitude of end uses in steel for packaging," said Damiani.
Arcelor director of marketing and development Luc Neuville said: "Maleïs has, without doubt, a great potential for a wide range of applications in the future. Investment of more than €15 million has been made in our Basse-Indre plant, which is evidence of Arcelor Packaging International's commitment to the steel packaging industry."