Manufacturing process of metal spiral cover

Abstract

The invention discloses a manufacturing process of a metal spiral cover, and particularly relates to a manufacturing process of a tinplate spiral cover. The manufacturing process sequentially comprises the following steps of selecting tinplate, carrying out tinplate painting and printing, cutting tinplate subjected to painting and printing into small sheets / stretching, cutting stretched left material, carrying out opening end inward pre-curling, carrying out opening end inward edge curling, carrying out curled edge pressing, carrying out thread pressing, carrying out expansion one or more times according to the final shape structure of the cover, and installing a sealing rubber gasket in the cover. According to the manufacturing process, when the cover structure is formed, when the sheetmaterial is stretched into a circular barrel shape, the transition part between the cover bottom and the cover body forms a large circular angle to play a role in buffering subsequent forming processes, meanwhile, the follow-up cover structure is formed according to the final shape of the cover through one-time or multiple-time step-by-step molding, so that corresponding appearance defects are avoided, meanwhile, the defects that the subsequent deformation degree is relatively large and the edge of the cover is cracked are avoided, in the forming process of a screw thread, the four proceduresof edge pre-curling, edge curling, curled edge pressing and screw thread pressing are adopted, the edge of the cover opening is smooth and tidy after screw thread is formed, the shape of the screw thread is uniform, the sealing performance is good, and the matching degree is high.

Description

technical field [0001] The invention relates to the technical field of metal can lids, in particular to a metal screw lid manufacturing process. Background technique [0002] Metal screw caps are widely used in the field of metal packaging because of their good sealing performance and easy opening. At present, in the manufacture of tinplate screw caps, due to the limitations of the manufacturing process level and the tinplate material itself, there are many differences in shape and function of tinplate screw caps. Limitations, for example, after the screw teeth are formed, the edge of the cover mouth is uneven, which seriously affects the appearance quality of the entire package, and there will be large differences in the shape and size of the multi-channel screw teeth in the cover, resulting in poor sealing of the cover and difficulty in screwing the cover In and out, the operability of repeated opening of the cover is poor, which affects the use function of the cover; in a...

AI Technical Summary

Problems solved by technology

[0002] Metal screw caps are widely used in the field of metal packaging because of their good sealing performance and easy opening. At present, in the manufacture of tinplate screw caps, due to the limitations of the manufacturing process level and the tinplate material itself, there are many differences in shape and function of tinplate screw caps. Limitations, for example, after the screw teeth are formed, the edge of the cover mouth is uneven, which seriously affects the appearance quality of the entire package, and there will be large differences in the shape and size of the multi-channel screw teeth in the cover, resulting in poor sealing of the cover and difficulty in screwing the cover In and out, the operability of repeated opening of the cover is poor, which affects the use function of the cover; in addition, the ductility of tinplate is limited. When the structure of the cover is complex and the degree of deformation is large, it is easy to have appearance defects such as uneven cover surface and cover surface indentation. There may even be cracking of the tinplate during the forming process

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