Containers and blanks with a curled edge and method of making same

• US 5,184,995 A
• Filed: 02/21/1992
• Issued: 02/09/1993
• Est. Priority Date: 12/31/1990
• Status: Expired due to Term

• Current Assignee: Graphic Packaging International Incorporated
• Original Assignee: James River Corporation of Virginia (KOCH Industries Incorporated)
• Inventors: Kuchenbecker, Morris W.
• Primary Examiner(s): Kisliuk, Bruce M.
• Assistant Examiner(s): MARLOTT, JOHN
• Application Number:
  US07/839,674
• Time in Patent Office: 354 Days
• Field of Search: 493/62, 493/74, 493/79, 493/80, 493/102, 493/104, 493/108, 493/109, 493/140, 493/156-159, 229/126, 229/132, 229/135, 229/198.2, 229/905
• US Class Current: 493/79
• CPC Class Codes: B26D 7/27 Means for performing other operations combined with cutting B26D9/00 takes precedence
• CPC Class Codes: B26F 1/40 using a press, e.g. of the ram type presses in general B30B
• CPC Class Codes: B26F 1/44 Cutters therefor; Dies therefor
• CPC Class Codes: B31F 1/0087 Rim-rolling

Abstract

A blank cutting technique in a process for manufacturing containers such as paperboard cups, canisters and cartons provides a flaired edge which, in one embodiment, forms a precurl to facilitate the formation of a completed brim curl and in another embodiment, is used to provide a flaired edge on a lid flap of a carton. In the latter case, the flaired edge which is created assists in insertion of the lid flap into the carton opening and creates an improved seal. In the blank cutting technique, stock material is positioned on a die cutting bed across a stepped portion. The stock material is cut along a cutting line offset from and substantially parallel to the stepped portion and against a lower surface of the die cutting bed defined by the stepped portion during the cutting operation, whereby the flaired edge is formed.

Claims

1. A method of forming an unclosed container with an opening defined by an edge having a brim curl, comprising the steps of:

cutting from stock material a blank for the container in a manner so as to create a precurled portion along at least one edge thereof which will define the container opening;

forming the container from said blank to cause said precurl to be directed radially outwardly from said container opening; and

performing a final curling operation on said precurled portion of the unclosed container to form a brim curl on said at least one edge along the container opening in a manner to leave the opening unclosed when the final curling operation is complete thereby forming the unclosed container.

2. A method of forming a container according to claim 1, wherein said stock material comprises paper.

3. A method of forming a container according to claim 2, wherein said container opening has a circular edge upon which the final curling is performed.

4. A method of forming a container according to claim 2, wherein said container opening comprises at least one linear edge portion upon which the final curling is performed.

5. A method of forming a container according to claim 4, wherein said container opening further comprises at least one arcuate edge portion and the final curling is also performed thereon.

6. A method of forming a container according to claim 1, wherein said cutting step is performed by:

creating a stepped portion on a die cutting bed;

positioning said stock material on the die cutting bed so that it extends across said stepped portion; and

cutting the stock material with a cutting tool along a cutting line substantially parallel to said stepped portion and against a lower surface of the die cutting bed defined by the stepped portion, whereby a precurl is formed along an edge of the blank as the blank is cut.

7. A method of forming a container according to claim 6, wherein said stock material comprises paper.

8. A method of forming a container according to claim 7, wherein said cutting line is spaced from said stepped portion a distance not greater than a thickness of the stock material.

9. A method of forming a container according to claim 7, wherein said stepped portion comprises an edge surface extending perpendicularly between said lower surface of the die cutting bed and an upper counter surface of the die cutting bed, said edge surface having a height in the range of 30 to 40/1000ths of an inch.

10. A method of forming a container according to claim 6, wherein said stepped portion is created by placing at least one counter sheet of a predetermined thickness on said die cutting bed.

11. A method of making a blank for a closable paperboard carton having an opening, a closable lid and a flared edge formed on the closable lid, comprising the steps of:

cutting stock material to form a blank including a closable lid, said cutting step creating the flared edge along at least one edge portion of the blank; and

forming fold lines in the blank for allowing the blank to be folded in such a manner to create the closable paperboard carton wherein said flared edge of said edge portion is integral with one edge of said closable lid and extends outwardly away from the carton interior when said closable lid is closed.

12. A method of making a blank according to claim 11, wherein the cutting step is performed by:

creating a stepped portion on a die cutting bed;

positioning said stock material on the die cutting bed so that it extends across said stepped portion; and

cutting the stock material with a cutting tool along a cutting line substantially parallel to said stepped portion and against a lower surface of the die cutting bed defined by the stepped portion, whereby the outwardly flaired edge is formed as the blank is cut.