Method of manufacturing and providing lithography on metal closures

Abstract

The present invention relates generally to manufacturing metallic closures from a continuous coil of a pre-coated sheet metal material. More specifically, the present invention relates to manufacturing closures adapted for interconnection to a threaded neck of a container using a continuous coil of pre-coated aluminum sheet material. In one embodiment, marketing indicia or product information may be applied to the closures after formation of the closures.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61 / 856,352 filed Jul. 19, 2013, which is incorporated herein in its entirety by reference.FIELD OF THE INVENTION[0002]The present invention relates to a method for manufacturing metal closures. More specifically, the present invention relates to a method and apparatus which receives a continuous coil of pre-coated aluminum sheet material to form Roll On Pilfer Proof (ROPP) closures. The ROPP closures may optionally be decorated with marketing indicia or product information after the ROPP closures are formed.BACKGROUND[0003]Metal ROPP closures which are adapted for interconnection to a threaded neck of a container are well known in the metal container industry. The exterior top, sidewall, and interior top of ROPP closures are frequently decorated with brand names, logos, designs, product information, and / or other preferred indicia. The ...

AI Technical Summary

Benefits of technology

The present invention is a method and apparatus for manufacturing and forming a closure using uncoated, plain, or single colored aluminum coils. The apparatus receives a continuous sheet of aluminum from a coil and cuts blanks or discs from it, forms them into cups, trims them, and then forms them into ROPP closures. After manufacturing the ROPP closures, a printing method may be used to apply customer lithography and / or other desired indicia to the exterior and interior of the closure. The present invention reduces costs, improves efficiency, and reduces stored work-in-progress and completed work inventory.

Problems solved by technology

There are several disadvantages with the existing process.

First, the existing method results in a significant inventory of work-in-progress that must be stored while the closures are being decorated and formed.

Second, the process requires the use of cut sheets of metal as opposed to using a continuous roll or coil of metal material.

The manufacturer can purchase a coil of metal and cut it into sheets, but cutting the coil takes time and adds a step to the process.

Further, using the existing process, the manufacturer must cure the cut sheets in wicket ovens multiple times which further increases the production time and expense for the manufacturer.

In some instances, a large amount of scrap is created by the existing process.

However, in practice fewer than 210,000 cups are actually produced from each coil because greater than 2%, and sometimes as much as 10%, of process scrap is produced at several different points in the process.

First, a large amount of scrap is produced when a sheet printer / coater is set up and calibrated to apply a coating required to form a label or other indicia.

Calibrating colors and other coatings across a full length and width of the entire cut sheet is very difficult, and unfortunately one or more of the metal sheets must be passed through the sheet printer / coater to calibrate each coating.

Each cut sheet used to calibrate the sheet printer / coater becomes scrap metal and thus, each cut sheet used for calibration in this known process results in a loss of approximately 210 cups.

Because the final decoration may require five or more coatings, the sheet printer / coater may require five separate calibrations to produce the final decoration, resulting in a significant amount of scrap.

If a decorated sheet is not properly aligned and centered with the cupping press, or if the decorations on the sheet were not printed in the correct location on the sheet, the lithography will not be centered on the cup and all of the cups cut from the sheet will be defective.

Each cut sheet that is not properly aligned with the cupping press results in a loss of approximately 210 cups.

Because of the potential for misaligned decoration on the cups, the cups may require inspection after leaving the cupping press to ensure each decoration is properly centered or positioned on the cup.

The use of individual cut sheets in the existing process creates further scrap when the circular cups are cut from the individual sheets by the cupping press.

It is not possible for the cupping press to cut circular cups from the straight ends of the cut sheets, and thus scrap is left at each straight end.

Because there are up to 1,000 individual sheets per coil, there can be 2,000 cut ends resulting in a significant amount of end scrap for each coil of metal when the known process is used.

The existing process also produces a significant amount of edge scrap along the edges of the sheets because the cupping press of the known process can only accept a narrow sheet of metal.

In addition, the existing process requires a long production lead time and therefore manufacturers typically produce excess decorated sheets to account for expected process scrap to ensure on-time delivery of a customer's order.

Due to the numerous limitations associated with the existing manufacturing and decorating process for the metallic closures described above, there is an unmet need for a process and apparatus for manufacturing ROPP closures using standard coils of aluminum stock material which are optionally decorated after the ROPP closures are formed.

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