US3868056A - Protective containers and methods of making the same - Google Patents

Abstract

A cover sheet of paper or the like is laminated with a liner blanket of plastic material embodying closely spaced and hermetically sealed air cells. The composite sheet or mat is doubled upon either its longitudinal or its transverse center line to form a folder-shaped body with the cellular blanket inside. Two of the three open borders are heat sealed, hinged over upon and secured to the adjacent exterior surfaces of the body, thus completing a pressure cushioning and heat insulating container. The open border of the container is preferably crushed or compressed, to thin its walls for convenience in filling and subsequent closure.

Description

United States Patent Keren PROTECTIVE CONTAINERS AND METHODS OF MAKING THE SAME [75] Inventor: Eitan Keren, Bronx, N.Y.

[73] Assignee: Sealed Air Corporation, Fair Lawn,

[22] Filed: May 21, 1973 [21] Appl. No.: 362,169

Related U.S. Application Data [63] Continuation of Ser. No. 120,896, March 4, 1971,

abandoned.

[52] U.S. Cl. 229/55, 229/48 T [51] Int. Cl B65d 33/02 [58] Field of Search 229/55, 48 T [56] References Cited UNITED STATES PATENTS 1,944,613 l/l934 Rowe 229/55 3,349,990 10/1967 Woodford 229/55 3,494,457 2/1970 Titchenal 229/55 X FOREIGN PATENTS OR APPLICATIONS 1,029,870 5/1966 Great Britain 229/55 Primary Examiner-William 1. Price Assistant Examiner-Stephen P. Garbe [57] ABSTRACT A cover sheet of paper or the like is laminated with a liner blanket of plastic material embodying closely spaced and hermetically sealed air cells. The composite sheet or mat is doubled upon either its longitudinal or its transverse center line to form a folder-shaped body with the cellular blanket inside. Two of the three open borders are heat sealed, hinged over upon and secured to the adjacent exterior surfaces of the body, thus completing a pressure cushioning and heat insulating container. The open border of the container is preferably crushed or compressed, to thin its walls for convenience in filling and subsequent closure.

1 Claim, 15 Drawing Figures PATENIED P53251975 3,868,056

sum 1 9f 2 INVENTOR 57w A/EFEN PROTECTIVE CONTAINERS AND METHODS OF MAKING THE SAME This application is a Continuation of application Ser. No. 120,896 filed Mar. 4, 1971, now abandoned, entitled Protective Containers and Methods of Making Same.

The present invention pertains to improvements in protective containers and methods of making the same. In the progress of shipment, handling and storage of packaged goods such as books, small delicate machine parts, brittle food stuffs, and the like, the packages are frequently subjected to localized exterior pressures and shocks which tend to injure the contents. Further hazards in some instances are presented by exterior temperature and/or moisture conditions. However, success in minimizing the above hazards has been handicapped by certain characteristics existing either alone or in combination in the containing means hitherto available. Typically, such drawbacks include lack of inherent cushioning effect, both mechanical and thermal; undue bulk, weight and cost; lack of moisture repellant qualities; and undue complication in structure as well as in applicability to the particular goods to be packaged.

In view of the above and related considerations, an object of the present invention is to provide improved protective containers which are readily adaptable to a variety of packaging requirements.

A further object is to provide a packaging container having walls including built-in pneumatic cushioning means.

Another object is to provide containers in which the pneumatic means furnishes augmented insulating protection against exterior temperature changes.

A further object is to provide a container of the above nature in which the cushioning and insulating means includes a blanket of flexible plastic material in corporating closely spaced and hermetically sealed air cells.

Another object is to provide protective containers of the above type adapted to permit hermetically sealed enclosure of the material packaged therein.

Another object is to provide protective containers which are light, inexpensive, and of a form readily adaptable to standardization.

A still further object is to provide suitable methods or procedures for constructing the above types of containers.

Other objects and advantages of the invention will become evident during the course of the following description in connection with the accompanying drawings, in which FIG. 1 is a perspective view of typical matching cover and liner elements prior to being fastened together;

FIG. 2 is an enlarged fragmental cross-sectional view of the same in the general plane 2-2, FIG. 1;

FIG. 3 shows the outer and inner elements joined or laminated to form a composite wall sheet;

FIG. 4 is an enlarged fragmental section in the plane 4-4, FIG. 3;

FIG. 5 illustrates a long composite sheet doubled about its longitudinal center line to give it the shape of an elongated folder;

FIG. 6 illustrates sealing the long edge border of the folder of FIG. 5 to convert the latter to a tube;

FIG. 7 is an enlarged fragmental cross-section of the tube along the line 77 of FIG. 6;

FIG. 8 illustrates the longitudinal border lapping and the transverse end sealing of an individual container body length cut from the tube;

FIG. 9 is an enlarged fragmental section of the lapped longitudinal border in the plane 9-9 of FIG. 8;

FIG. 10 illustrates the lapping and securing of the sealed end border, the final sectional aspect of this detail also being shown by FIG. 9;

FIG. 11 illustrates the operation of local crushing or thinning the walls of the open or loading end of the completed container;

FIG. 12 is an enlarged sectional illustration of the thinned loading end walls, typically in the region 12-12 of FIG. 11;

FIG. 13 illustrates an alternative manner of forming a basic unitary container folder box by transverse axial bending of an individual composite blank;

FIG. 14 illustrates the simultaneous heat sealing of the two opposite side borders of the alternative folder body, and

FIG. 15 depicts the lapping over and securing of the sealed side borders to the adjacent outer surface zones of the container body.

Referring to FIG. 1, the numeral 20 denotes an elongated web of wrapping or cover material, typically pa per, but which may alternatively be of other materials such as sheet fabric or plastic to meet particular requirements. Numeral 21 generally denotes a cellular cushioning blanket or liner, which may be of the nature shown in US. Pat. No. 3,142,599. A typical enlarged detail section of such a blanket appears in FIG. 2. Referring to the latter Figure, the blanket 21 includes a flat plastic sheet 22 and an embossed plastic sheet 23 secured thereto by heat sealing throughout the narrow areas between the embossments 24, thus forming a pattern of closely spaced and hermetically sealed air cells 25.

In describing the construction of containers according to the present invention, the process or method may best be set forth in the customary manner of describing a number of individual operations or steps. However, it will be best understood that the inference of successive time periods refers simply to a preferred order in which various operations take effect on any assumed unitary component as it passes through the production line; for example, operations such as those of steps 1, 2 and 3 are adapted to simultaneous application on successive units in a continuously moving system. With these considerations borne in mind, a typical set of operations is as follows:

1. The cover sheet 20 and blanket 21 are laminated or secured together by means of any suitable flexible adhesive in the relation illustrated in FIGS. 3 and 4, producing a composite web or mat which is designated collectively by the numeral 26 for convenience in reference to the diagrammatic illustrations.

2. The composite mat 26 is bent or doubled along its longitudinal center line 27, as indicated in FIG. 5, thus converting 11 to the general shape of an elongated folder with the cellular blanket 21 forming the interior lining thereof.

3. The longitudinal border strips 28 of the elongated folder are heat sealed together, as by pressing them between heated rolls 29 which raise the temperature of the engaged components to or slightly above the point of surface fusion of the plastic material embodied in the blanket 21. By this means, the engaged portions of the liner 21 are pressed and fused together, while the cover sheet also is heat sealed to the liner elements within the border 28, illustrated in FIG. 7. It will of course be understood that the thicknesses of the sheet elements of the combinations thereof involved in the sealing of the assembly are necessarily shown magnified in order to render the relationships clearly discernable in the patent drawings.

1. The sealed border portion 28 is lapped over and cemented to the cover sheet 20, as shown in FIG. 9, thus converting the elongated folder to the form of a flattened tube.

5. The tube is cut into lengths or container units 30, such as that shown in FIG. 8.

6. The bottom end borders 31 of each unit 30 are heat sealed by means such as heated rolls 32, FIG. 8, the local effect being the same as that illustrated in FIG. 7.

7. The sealed end borders are lapped over and cemented or glued to the bodies of the units 30, as shown in FIG. 10.

8. The foregoing operations having completed the formation of a container permanently closed on three of its four edges, the fourth or open loading end is preferably processed as shown in FIG. 11. This operation consists in subjecting the border 82 of the open end to crushing pressure, indicated by application of cold rollers 33 and preferably subsequent to a preheating operation. The effect is to compress the walls of the open end to minimal thickness, as illustrated in FIG. 12. The thinness in zone 32 not only facilitates loading of material into the container, but also provides convenience in final closure, the latter ranging from border folding with local retention, (as in instance of shipments required by postal law to be openable for inspection) to applications wherein hermetic scaling in of the content is advantageous, in which case the zone 32 is readily adapted to heat sealing, or in cases precluding the use of heat, to effective plastic cementing.

The alternative version of the method of making a protective container, while basically the same as that described above, differs in certain procedural details which render it particularly applicable in cases wherein it is desirable that the bottom of the container be of seamless nature rather than cross sealed. The manner in which this result is accomplished is illustrated in FIGS. 13, 14, and 15. The first operation in the process, namely, formation of the elongated composite sheet or mat, remains the same as set forth. However, instead of doubling the elongated mat on its longitudinal center line, it is next cut into individual blanks having lengths substantially double the depth of the desired containers. Each such blank 34, as shown in FIG. 13, is next doubled about its transverse center line 35, to convert it to a folder conformation 36, with the cellular blanket 2] inside as previously set forth. The two opposite side borders 37 are heat sealed by means illustrated as heated rollers 38. Finally the sealed borders 37 are folded over and secured as shown in FIG. 15, and the open end 39 of the container may be thinned or compressed in the manner previously explained in respect to FIGS. 11 and 12.

As to the open end 39, in some applications it may be desired that the extreme outer edges consist only of the cover sheet, with the edges of the liner blanket spaced inwardly therefrom. This result may readily be accomplished by making the strips of cover sheet 20 and cellular liner blanket 21, FIG. 1, of width encompassing the total length of the blank used in the folder 36, FIG. 13, but with the cover web 20 of sufficiently greater width than the liner 21 to allow for the desired edgewise overlap; in this arrangement the spaced cutting of the laminated or composite strip determines the width rather than the length of the blank, so that when the blank is bent as shown in FIG. 13, the protrusion of the cover sheet at the open edge 39 is provided as indicated at 20a, FIG. 12.

From the foregoing description, it will be seen that the invention provides containers affording improved protection to their content against harmful exterior influences, whether these influences be mechanical, thermal, or a combination thereof; the mechanical protec tion being due to the inherent and persistent flexible cushioning effect of the sealed air or gas cells 25 in the blanket 21, while the augmented thermal protection is lodged in the heat insulating quality also inherent in such cells, as well as in the sealed interstices between them.

In the preceding explanation the outer cover sheet 20 has been mentioned as typically of paper, which material of course is desirable in a large number of packaging requirements. The thickness of the paper may be varied to meet particular service needs. For instance, flat articles such as books may best be served by a form having relatively thick covers functioning as shipping envelopes in which the contents are pneumatically cushioned, while in the case of bulkier or irregularly shaped content a thinner and hence more flexible outer covering may be advantageous in allowing the container to act as a bag which readily accommodates itself to the general contours of the enclosed articles, but still maintaining its protective pneumatic cushioning throughout. In the production of thick or thin covered containers, either of the methods previously described may be employed; in the steps involving heat sealing of the composite folder a higher temperature of the heat application is provided in the case of thicker paper covers, in order to compensate for the somewhat higher heat insulating properties of such papers. In uses wherein the containers are to be expanded to relatively wide bag shape, the seamless bottom bend 35, shown in FIGS. l3, l4, and 15, may be of advantage in point of maximum flattening adaptability to upright or closely packed storage.

While, as previously mentioned, the cover sheet 20 has been exemplified as paper, other sheet materials may be employed where best suited to particular uses. Thus, when maximum strength and durability are important, as in shopping bags and the like which are intended for repeated use, the cover sheet may be of a suitable fabric. Similarly, where complete exterior water-proofing is important, an appropriate plastic cover sheet may be embodied. Finally, in the field of food packaging, the inherent characteristics of shock resistance and heat insulation, either in combination or sinvgly, also present obvious advantages.

1 In the interest of clarity and brevity, the methods of forming the containers have been set forth largely in terms of the operational combinations involved, rather than by undue detail showing and recapitulation of various mechanical devices by which the individual operations may be carried out, since such devices per se are well known in various forms which may be optionally employed. Thus the heat sealing represented by the hot rolls 29 and 32 in FIGS. 6 and 8 may be accomplished by other means such as wide jaw heaters. Similarly, the proportions of the containers as to depth and extent of filler opening obviously may be varied from those shown in accordance with particular requirements. In other words, while the invention has been set forth in preferred simple state, it is not limited to the particular forms illustrated, as various modifications may be made without departing from the scope of the appended claims.

What is claimed is:

l. A protective container comprising an outer covering folded upon itself to form two layers disposed in overlying relationship and a seamless edge, a sheet of cellular material adhered to the inner facing surfaces of said outer covering, said cellular material having a first plastic sheet including a plurality of closely spaced embossments extending from one side thereof and a second plastic sheet secured to the other side of said first sheet, at least two opposing, substantially parallel marginal hermetically sealed edge zones and at least one open edge zone, the cellular material disposed within said marginal hermetically sealed edge zones and said open edge zone being crushed to collapse the cells in said cellular material and said hermetically sealed edge zones being folded and sealed to the adjoining surfaces of the container whereby said hermetically sealed edge zones impart a relatively high degree of stiffness to said container and thereby enhance the protective qualities thereof.

Claims (1)

1. A protective container comprising an outer covering folded upon itself to form two layers disposed in overlying relationship and a seamless edge, a sheet of cellular material adhered to the inner facing surfaces of said outer covering, said cellular material having a first plastic sheet including a plurality of closely spaced embossments extending from one side thereof and a second plastic sheet secured to the other side of said first sheet, at least two opposing, substantially parallel marginal hermetically sealed edge zones and at least one open edge zone, the cellular material disposed within said marginal hermetically sealed edge zones and said open edge zone being crushed to collapse the cells in said cellular material and said hermetically sealed edge zones being folded and sealed to the adjoining surfaces of the contaIner whereby said hermetically sealed edge zones impart a relatively high degree of stiffness to said container and thereby enhance the protective qualities thereof.

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