US3855026A - Method of manufacturing container end with protective bead - Google Patents

Abstract

A container having a body and at least one open end with the container end secured to the body and closing the opening, wherein the container end includes a removable panel portion, the removal of which produces an inner edge in the container end defining an access opening through which the contents of the container may be removed and a protective bead operatively associated with the container end and the removable panel portion for guarding the hazardous edges of said removable panel portion and said inner edge for allowing the removal of the contents of the container through the access opening by the consumer without injury from the edge of the container end or the removed panel portion thereby produced.

Description

United States Patent [191 Fox et al. Dec. 17, 1974 METHOD OF MANUFACTURING 3,527,377 9/1970 Colby et a1. 220/906 x CONTAINER END WITH PROTECTIVE 3,671,356 6/1972 Keinanen 156/69 X HEAD 3,744,668 7/1973 Bartels 220/54 Inventors: James D. Fox, Darlington; Earl P.

Norman, Jr.; Jerry F. Sansbury, both of Hartsville, all of S.C.

Sonoco Products Company, Hartsville, S.C.

Filed: Feb. 26, 1973 Appl. No.: 335,992

Related US. Application Data Division of Ser. No. 162,379, July 14, 1971, Pat. No. 3,754,678.

Assignee:

References Cited UNITED STATES PATENTS 5/1970 Heller 220/906 X Primary Examiner-Edward G. Whitby Attorney, Agent, or Firm-C. Gordon McBride 5 7] ABSTRACT A container having a body and at least one open end with the container end secured to the body and closing the opening, wherein the container end includes a removable panel portion, the removal of which produces an inner edge in the container end defining an access opening through which the contents of the container may be removed and a protective bead operatively associated with the container end and the removable panel portion for guarding the hazardous edges of said removable panel portion and said inner edge for allowing the removal of the contents of the container through the access opening by the consumer Without injury from the edge of the container end or the removed panel portion thereby produced.

4 Claims, 5 Drawing Figures PATEHIED DEC I 7 I974 FIG. 2

FIG.

FIG.

FIG. 5

METHOD OF MANUFACTURING CONTAINER END WITH PROTECTIVE BEAD This application is a division of Ser. No. 162,379 filed July 14, 1971, now US. Pat. No. 3,754,678.

This invention relates to a container for storing food and the like and more particularly to an improved container end of the easy open type for hermetically storing food or any desired contents.

Recent developments in the production of sealed containers have introduced the use of container ends fabricated from relatively thin gauge metal, particularly aluminum and alloys thereof, for the purpose of economy and ease in opening. While these container ends are easy to open with the conventional punch-type container openers, additional developments have provided container ends of this type with a removable panel portion which typically includes a score line formed around the outer periphery of the removable panel portion in the container end and a device for fracturing the container end along the score line for removal of the panel portion. However, the full panel E-Z open metal ends are opened by tearing the metal panel along the pre-scored line. Such tearing leaves a sharp edge on the panel that has been removed and the residual lip remaining on the can body, which upon removal of the contents of the container by the consumer and especially when removed by hand, oftentimes injures the consumer through contact with the remaining sharp edge or the edge of the removed panel portion may cause injury during pening..Thus it is seen these sharp edges are hazardous and can easily cut fingers or hands during the handling, opening or removal of the contents.

Accordingly, it is an object of this invention to provide a container end eliminating the cutting hazard by shielding the raw and sharp metal edges during and after removal of the center panel portion.

Another object of the instant invention is to provide a sealed container having a removable central panel portion in the container end, the removal of which produces an inner edge in the container end defining an access opening which is guarded so as to allow removal of the contents of the container by the consumer without injury from said inner edge produced in the container end and guarding the edge of the removed central panel portion to prevent injury from the sharp edge thereof also.

Still another object of the instant invention is to provide a container end which protects against cuts being received from the sharp metal edges of the removable center panel of an E-Z open end or from the sharp inner residual lip remaining on the container after opening Yet another object of the instant invention is to provide protection against the hazards encountered on the removal of a central panel of an easy open container end, as well as protecting against injury from the portion remaining on the can body.

A further object of this invention is to provide a method of producing substantially hazard-free easy open container ends.

In accordance with the above objects. the container of the present invention comprises a container end for a container body which includes a central removable panel-portion, the removal of which produces an access opening through which the contents of the container may be removed. A bead of plastic material is positioned on the end directly over and bonded on both sides of the score line such that rupture and removal of the central panel portion results in rupture of the plastic material directly over the score line and leaves a portion of the material on the raw edge of both the removable panel and the residual lip edge; thereby permitting the plastic material to function as an obstacle to any cutting action by the exposed sharp edges on both the residual lip and the panel portions. The container end is produced by sequential operation of a making press, a compounder, a converting press, a coating station and a sleeve packer.

Some of the objects of the invention have been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which:

FIG. 1 is a fragmentary perspective view of a container incorporating a conventional easy open container end to which the instant invention applies;

FIG. 2 is a fragmentary perspective view of a container wherein the central removable panel portion of the container end has been removed;

FIG. 3 is an enlarged fragmentary sectional view taken substantially along the line 33 of FIG. 1;

FIG. 4 is an enlarged fragmentary sectional view taken substantially along the line 4-4 of FIG. 2; and

FIG. 5 is a diagrammatic representation of the method of producing the container ends.

Referring now to the drawings wherein like reference characters are used to indicate like parts, there is illustrated in FIGS. 1 and 3 a container 10 which comprises a substantially cylindrical container body 11 having at least one end thereof sealed and closed by an improved container end 12, in accordance with the instant invention, secured to the end of container body 11 by conventional double-folded seam 13. In addition to the double folded seam 13, container end 12 includes chuck wall 14 and end panel 15 which are joined by chuck radius 16. Chuck wall 14 serves to reinforce folded seam 13 against radial and outward expension of container end 12. It is to be noted that chuck wall 14 would normally include recess 17 against which a conventional sealing chuck could operate for seaming of container end 12 to container body 11.

End panel 15 includes a removable central panel portion 18 formed by score line 21 disposed around the outer periphery thereof. Although score line 21 is shown as located near the periphery of end panel 15, it is to be understood that score line 2'] may be of any planar configuration for removal of all or a portion of panel 18. A suitable pull or tear tab 22 is secured to removable central panel portion 18 for removing panel portion 18 by fracturing or tearing along score line 21. Such action produces inner edge 23 in container end 12 (FIGS. 2 and 4) to define an access opening in container end 12 through which the contents of the container maybe removed by the consumer.

As normally is the case, container end 12 of the present invention is constructed of a relatively thin gauge metal, such as aluminum or alloys thereof, and, thus, inner edge 23 produced upon removal. of central panel portion 1 8 is sharp, irregular and is very likely to injure the consumer if not handled properly when removing the contents of container 10. Similarly, removed central panel portion 18 has sharp, irregular edge 24 that is extremely hazardous to the consumer if not handled properly.

In accordance with the present invention, there is provided protective bead or shield 25 for guarding inner edge 23 produced in container end 12 and outer edge 24 of central panel portion 18 upon removal of central panel portion 18 from container end 12. More particularly, protective bead 25 is preferably formed from a plastic material, such as a hot melt adhesive which is a mixture of suitable thermoplastic resins and wax, but which could be any suitable plastic-like or rubber-like protective material. Bead 25 is operatively associated with container end 12 and adhesively attached to the exterior surface of container end 12 adja cent chuck radius 16 and chuck recess 17. Bead 25 extends radially inwardly of chuck wall 14 to at least slightly beyond score line 21 so as to guard the inner edge 23 produced in the container end 12 upon removal of central removable panel portion 18, as well as outer edge 24 of central panel portion 18, and prevent injury to a consumer removing the panel or contents from the container. in the event score line 21 is of a configuration and location other than the periphery of end panel 15, such for example as ofa spiral configuration, bead 25 would be applied over score line 21 regardless of the location.

Referring now to FIGS. 2 and 4, there is illustrated container wherein central panel portion 18 has been removed. The relative relation of inner edge 23 produced in container end 12 and outer edge 24 on central panel portion 18 with bead 25 of plastic material is to be particularly noted in the enlarged fragmentary sectional view, FIG. 4. Bead 25 extends inwardly of chuck wall 14 slightly past score line 21 and, therefore, past inner edge 23 and into the access opening adjacent the inside surface of container end 12 to serve as a protective shield for the consumer against contact with the sharp inner edge 23. Furthermore, bead 25 extends outwardly of removable central panel portion 18 beyond outer edge 24 and serves as a protective guard for the consumer against contact with sharp outer edge 24.

Protective bead 25 comprises a coating of pliable material, such as a thermoplastic material, applied to container end 12 in such a manner that the coating extends from the inside rim. chuck wall 14, over score line 21 where the metal will be torn and onto central panel portion 18 which is to be removed.

It has been found that a coating of thermoplastic material, commonly referred to as a hot melt which'may be composed of combinations of the following materials: a plastic type resin such as ethylene vinyl acetate, polyethylene, or polypropylene; waxes such as paraffin and/or micro-crystalline; tackifying resins such as wood resin, hydrocarbon, polyterpine, or synthetic; plasticizers; extenders; fillers; colorants; antioxidants and preservatives. This hot melt material is so formulated that it adheres to the metal and when center panel 18 is removed, the hot melt material tears along score line 21 of removable central panel portion 18, leaving a protective shield or coating extending over the metal edges on removed central panel 18 and on residual lip portion 26 which remains on container body 11. it is to be understood that the material from which bead 25 is made should have greater adhesion for end 12 than the tear strength of the material from itself.

The material for protective bead 25 may be of any plastic or rubber-like material which adheres to container end 12 and is of proper tensile and tear strength to permit tearing above score line 21. A material which has been found to perform extremely well as a protective bead is hot melt material CHM 6380 manufactured by Sonoco Products Company, Hartsville, South Carolina 29550.

Container 10 is generally constructed in accordance with various conventional techniques with a slight modification in preparation of container end 12 incorporating the present invention and briefly described hereinafter. Container body 11 is provided with a conventional flange 27 for cooperation with the suitably curled container end 12 which is prefabricated to include removable central panel portion 18. Prior to application of container end 12 and formation of the conventional folded seam 13, bead 25 of hot melt adhesive is applied to the outside wall of container end 12 adjacent rim or chuck wall 14.

It has been found that container end 12 should be prepared in a special manner for applying hot melt bead 25 in order to obtain optimum results. The conventional technique of forming container ends is utilized at the initial stages of making press 30, compounder 32 and converting press 34, FIG. 5. The conventional technique of forming container end 12 would thus proceed with draw-forming container end 12, including the formation of the integral rivet, tab 22 and score line 21 through conipounder 32 and converting press station 34. In the novel processing technique of the invention, container ends 12 are then conveyed to coating station 40 which includes pre-heater 36 and hot melt applicator 38. The temperature of end 12 would be raised in preheater 36 to a temperature in the range of to 225 with approximately 200 F. preferable. Container ends 12 are then passed to hot melt applicator 38 at which the plastic material forming bead 25 is applied at a temperature in the range of 300 to 375 F. or approximately 340 F. for CHM 6380 such that the hot melt material forms a bead adjacent that flows over score line 21 and onto center panel portion 18. After application of hot melt bead 25, container end 12 is conveyed to sleeve packer 42 for packaging into sleeve 44 which is handled conventionally prior to end 12 being sealed to container body 11. It is to be observed that chuck recess 17 permits the sealing of container end 12 to body 11 without contact of the chuck with hot melt bead 25. This provision against contact of the chuck with bead 25 insures a reasonable curing time to permit bead 25 to properly cure and obtain the desired tensile strength and tearing properties.

Thus, it is seen that proper positioning of head 25 in sufficient quantities permits the hot melt material to flow inwardly of container body 11 and rim l4 slightly beyond score line 21. Thereafter, the hot melt material provides a resilient protective shield for the inner edge 23 produced in container end 12 and outer edge 24 on central panel portion 18 upon removal of panel portion 18 as previously indicated.

It is to be understood that although bead 25 of hot melt material is preferably applied prior to application of container end 12 to container body 11, head 25 could be applied after the sealing of end 12 to the container body and after completion of construction and the filling of container 10, especially in situations in which foodstuffs are being packaged and end 12 may have been preheated in the filling operation.

Thus, it is seen that the instant invention provides a container end wherein the sharp, hazardous edges of both the residual lip and the removed central panel portion of an easy open end for a container have been eliminated while permitting utilization of continued relatively simple production techniques. It is to be understood that the embodiment of the invention shown in the drawings is representative only and all types of easy open ends are contemplated as being within the scope of the appended claims. Accordingly, protection is provided on the removable panel portion, as well as the portion which remains on the can body, to thereby protect the consumer not only during opening of the container, but during removal of the goods from within the container. The protective bead is attractive and may be colored or otherwise modified for aesthetic appeal.

In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

What is claimed is:

1.-The method of making a container comprising: forming a container end of the easy opening type; applying a compound to said end for sealing thereof to a container body; pressing said end to form the tab and score line; preheating said end; applying hot melt material across said score line; building a container body; and seaming said end to said body; whereby a container is provided which has a protective shield on both the sharp edge of the removed portion and the residual lip portion remaining after removal of the removable portion.

2. The method of claim 1 wherein said end is preheated to a temperature in the range of F. to 225 F.; and said hot melt material applied at a temperature in the range of 300 F. to 375 F.

3. The method of claim 1 wherein said step of applying hot melt material occurs subsequent to the seaming of said end to said body.

4. The method of claim 1 additionally comprising the step of packaging said ends prior to the seaming thereof to said container body.

Claims (4)

1. The method of making a container comprising: forming a container end of the easy opening type; applying a compound to said end for sealing thereof to a container body; pressing said end to form the tab and score line; preheating said end; applying hot melt material across said score line; building a container body; and seaming said end to said body; whereby a container is provided which has a protective shield on both the sharp edge of the removed portion and the residual lip portion remaining after removal of the removable portion.

2. The method of claim 1 wherein said end is preheated to a temperature in the range of 175* F. to 225* F.; and said hot melt material applied at a temperature in the range of 300* F. to 375* F.

3. The method of claim 1 wherein said step of applying hot melt material occurs subsequent to the seaming of said end to said body.

4. The method of claim 1 additionally comprising the step of packaging said ends prior to the seaming thereof to said container body.

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