Foil/Fiber Can and Drum Production
Aluminum foil/fiber can and drum design and manufacture have been developed to provide complete liquid tight integrity at high production rates. Depending upon the product to be packaged, the physical and merchandising requirements generally are met with one to two plies of foil (.00035" thickness is typical), and two plies of kraft board.
Powdered fruit drink mixes, snacks, refrigerated and dehydrated foods are often packaged in foil/fiber cans. One type, which is used for snacks and other products containing shortening, has a foil/kraft liner, two plies of kraft, and a label ply of foil/kraft printed in color on the foil side and coated to resist dirt and oil encountered in handling. The interior foil surface of the can is sometimes coated to help assure flavor and freshness retention over an indefinite storage or shelf life. A full range of appropriate laminating and coating materials is employed in producing various types of foil/fiber cans and drums. Can ends frequently are also aluminum.
Practically all foil/fiber cans and most of the larger foil/fiber drums or barrels are spiral wound, although some convolute winding is also employed.
The continuous spiral winding process is versatile and permits high production rates. Strips of body wall materials are aligned and wound around a steel mandrel to form the container. As the strips of paperboard, foil and/or films are unrolled, adhesive is applied to facing surfaces and the materials are combined in an overlapping spiral pattern around the revolving mandrel. A continuous tube of the several laminated plies is thus formed and individual can bodies are cut off at line speed. Can body ends are flanged, and the bottom end closure is applied and seamed prior to casing and palletizing for shipment.
The plies of foil/fiber cans may be altered by using various gauges and arrangements of foil, foil coatings and other materials to fit specific product needs.
The outer surface usually consists of a web of pre-printed foil/kraft stock, designed so that the printed surface is registered to form the can label as it is wound. Often this label stock is rotogravure printed for excellent reproduction using four to six colors and or a print over coating. The outer foil surface offers unlimited possibilities for striking label designs. This label also can be constructed to form a primary water vapor barrier to protect the contents during long periods of indoor or outdoor storage.