Technical note - effects of seaming conditions on external and internal double-seam characteristics in round metal cans

Abstract

Canning is the major packaging technology for fully preserved food products. To obtain safe canned foods with extended shelf-life, the closed cans have to be hermetic. The consistency and quality of the seaming process are crucial to food safety. This note investigates the effects of different seaming conditions (base-plate pressure and seaming-roller pressure) on external (seam thickness, seam height) and internal (body hook length, overlap, lid hook length, seam gap and body hook butting) double-seam characteristics in round metal cans. External double-seam characteristics were significantly affected by the seaming-roller pressure during the final closure of the cans. Generally, there were small effects of base-plate pressure on the external double-seam characteristics. In contrast, all the investigated double-seam characteristics were affected significantly by the seaming-roller pressure, whereas only body hook length and seam gap were significantly affected by the base-plate pressure. This note illustrates the importance of close control and optimization of the seaming conditions during production of canned foods as a means to reduce the processing induced variability in double-seam characteristics, and subsequently to obtain safe and high-quality canned products. Copyright © 2005 John Wiley & Sons, Ltd.