GB548274A - Improved manufacture of sheet metal containers - Google Patents

Abstract

548,274. Making cans. CROWN CORK & SEAL CO., Inc. Aug. 13, 1940, No. 12940. Convention date, March 26. Drawings to Specification. [Class 83 (ii)] Cans of the kind having an integral conical top terminating in a neck having a closed bead or lip that forms a locking ring for receiving a closure are manufactured by a process that is continuous and automatic from the stamping out of the blank from strip steel to the final packaging for transport. The production line starts with means for uncoiling strip for the supply at a machine for blanking out shells which pass to the body forming machine lines squared and parallel. Each of these lines may end in a trimming machine beyond which the lines merge to a single flanging machine. A single combined trimming and flanging machine may be employed. After cleaning to remove lubricating oil used on the preliminary neck curling and in the cutting operation, the blanks pass through two curling machines and are then tested for pin holes, cracks and other flaws. The inside is sprayed for example with an aluminium paint and then the outside at the conical part and neck and the flanged bottom end that is tucked up during seaming on the bottom. The two sprayings may be combined in one machine. After drying and bottom seaming the complete container is tested for fluid tightness and coated material for the rest of the body is rubbed on and dried. This drying may take place in an upper tier of the previous drying oven. Printing in an air conditioned room with means for preventing the rollers being overheated is followed by drying, outside varnish spraying and further drying, these two dryings may also be in the same oven. Preheating for tinning is followed by spraying molten wax into the interior of the inverted cans, draining, wiping of the lip, rolling to distribute the wax evenly, standing on end to allow wax to settle in the bottom seam, and finally packing and carton sealing. In modifications the order of certain operations is varied. Specifications 488,628 and 544,040 are referred to.