US3559364A - Package with open ends and method of sealing wrapper thereon - Google Patents

Abstract

A PACKAGE FOR COMMODITIES COVERED WITH A SHEET OR FILM OF MATERIAL THAT PROTRUDES BEYOND OR EXTENDS BEYOND BOTH ENDS OF THE PACKAGE WITH THE FILM BEING FUSED AT THE BOTTOM OF THE PACKAGE. THE PACKAGE IN THIS CONDITION IS CONVEYED SO THAT THE TWO OPEN END EDGES OF THE OVERLAPPING FILM PASS UNDER TWO STREAMS OF HOT AIR WHICH CAUSES THE FILM TO SHRINK AND FOLD OVER AND CLING TO THE EDGES OF THE PACKAGE THEREBY MOLDING ITSELF TO THE PACKAGE AND FORMING A FIRM AND RIGID SEAL WHICH MAY EITHER COMPLETELY CLOSE EACH END OR LEAVE A CIRCULAR-TYPE OPENING THEREIN DEPENDING ON THE LENGTH OF THE OVERLAPPING FILM.

Description

Feb. 2, 1971 5. J. PETRELLA ETAL 3,559,364

PACKAGE WITH OPEN ENDS AND METHOD OF SEALING WRAPPER THEREON Filed July 25, 1968 2 Sheets-Sheet 1 00 3 M W r T I T N A eflw P J sa M h D a Y 3 1971 5. J. PETRELLA EI'AL 35 3 PACKAGE WITH OPEN ENDS AND METHOD OF SEALING WRAPPER THEREON Filed July 25, 1968 2 Sheets-Sheet z .Sebasfiano J Pefrel/a Salvatore J. Petra/la IN VENTOR$ Filed July 25, 1968, Ser. No. 747,620 Int. Cl. B65b 53/06 US. Cl. 53-33 2 Claims ABSTRACT OF THE DISCLOSURE A package for commodities covered with a sheet or film of material that protrudes beyond or extends beyond both ends of the package with the film being fused at the bottom of the package. The package in this condition is conveyed so that the two open end edges of the overlapping film pass under two streams of hot air which causes the film to shrink and fold over and cling to the edges of the package thereby molding itself to the package and forming a firm and rigid seal which may either completely close each end or leave a circular-type opening therein depending on the length of the overlapping film.

Wrappers have been provided on various types of commodities with the wrappers usually being wrapped around the commodity with the edges thereof sealed together either by fusing or by employing an adhesive depending upon the type of material used. With the use of plastic material, a hot plate frequently is used to seal the overlapping edges of a wrapper after which the ends of the wrapper are creased and folded and also sealed with a hot plate which serves to secure the wrapping material to itself. Certain commodities are frequently packaged in a skeleton-type framework such as a tray structure constructed of plastic, cardboard or the like. For example, tomatoes are frequently packaged in relatively shallow trays and provided with a transparent plastic wrapper which may be either as long as the tray with the ends thereof completely free or the ends may be wrapped around the end of the tray and sealed together with the conventional heat sealing process which employs a hot plate or the like. In this type of construction, there is no connection between the tray and the wrapper and due to handling of the packages, frequently, the end wall of the tray will break open or otherwise permit the commodity within the tray to be discharged from the end of the package or to exert pressure on the wrapper.

In order to overcome this problem, the present invention provides a package in which the Wrapper is heat sealed to the end of the tray which serves to reinforce and strengthen the tray and at the same time retain the wrapper securely in place in relation to the tray and commodity therein. This is accomplished by providing a wrapper of heat shrinkable plastic film with the end edges of the wrapper projecting beyond the ends of the tray and being passed under or through a stream of hot air which shrinks the film and causes it to fold over and cling to and seal to the edges of the tray or package thereby molding itself to the package and creating a firm and rigid seal.

It is another object of the present invention to provide a package in which the wrapper may be sealed to the end thereof so that the wrapper will completely close each edge or leave a circular type opening in the middle by selectively providing a desired length of overlapping film. By providing a short overlapping film, an air hole will be provided for enabling circulation of air through the package and/ or ventilation for the particular commodity United States Patent "Ice which is desirable in some instances. In other instances, by providing a relatively elongated overlapping film, the film may completely close the end of the package and be firmly and rigidly secured to the end of the package.

This particular package and the method of forming the same completely eliminates mechanical creases and folds and also eliminates the creases and folds formed thereby. Also, this invention eliminates the problem of disposing of wasted and surplus film which is normally trimmed off inasmuch as the excess film is merely shrunk into engagement with the package and sealed thereto to further rigidify the package. Further, the present invention eliminates the use of glues and adhesives and reduces the quantity of film required inasmuch as less film is required for this procedure than when using mechanical folding devices and hot plates.

Besides eliminating the problems set forth above, the present invention provides for a choice of a closed seal or an open seal which provides for ventilation and yet does not affect the rigidity produced by practicing this method in forming the package. Further, the molding of the film over the ends of the package makes a stronger and sturdier package which will hold the contents even when the container is lifted up endwise and it thus eliminates the likelihood-of the contents falling out through the ends. The tight seal at the ends of the package also secures the contents within the package thus greatly reducing the likelihood of bruising caused by the movement of the commodity within the container itself.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a side elevational view of an apparatus employed in carrying out the method of the present invention;

FIG. 2 is a view similar to FIG. 1 illustrating the manner of manipulating the package and wrapping film;

FIG. 3 is a view similar to FIGS. 1 and 2 illustrating the wrapping film being severed from a supply thereof;

FIG. 4 is a view similar to FIGS. 1-3 illustrating the step of fusing the overlapping edges of the wrapper film under the package;

FIG. 5 is a perspective view of the package illustrating the manner in which the hot air nozzles are directed goward the projecting ends of the heat shrinkable wrapping FIG. 6 is a fragmental perspective view illustrating the end seal formed by practicing the method illustrating its relationship to define a ventilation opening; and

FIG. 7 is a detailed sectional view, on an enlarged scale, taken substantially upon a plane passing along section line 7-7 of FIG. 6 illustrating the relationship of the plastic film to the end of the container or tray.

Referring now specifically to the drawings, the wrapping apparatus is generally designated by the numeral 10 and includes a supporting platform 12 mounted on a suitable support such as a table, bench or the like 14 by a plurality of supporting legs 16. At the end of the platform 12 is a depending support bracket 18 having a shelf member 20 secured thereto in an adjustable manner by the provision of fastener bolts 22 which enable variation in the height of the shelf 20. The shelf 20 may be in alignment with a conveyor or other apparatus for delivering tray-like containers 24 with produce or commodities 26 therein such as tomatoes or the like. The shelf 20 has a notch therein to enable the free end of a heat shrinkable plastic wrapping film 28 to be grasped by the hand 30 and inserted under the shelf 20 and engaged with the bottom of the container 24 through the notch in 3 the shelf 20 thus enabling the tray 24 with the film 28 thereon to be lifted upwardly and outwardly as illustrated in FIG. 2.

The transparent film 28 is wrapped around the package as it is lifted and then passed over a cutting element 32 supported by adjustable supports 34 on bracket members 36. The cutting element may be in the form of a heated wire, sharp edged member or the like for severing the film 28 as it is moved upwardly and inwardly of the cutting element as illustrated in FIG. 3, so that the downwardly hanging portion of the cut film will engage a sealing plate 40 supported on the brackets 36 as illustrated in FIG. 4 so that the edge of the film held by the fingers and the overlapping edge of the film cut by the cutting element 32 will be heat sealed together to form a package in which the ends are free. From the hot plate 40, the package is moved onto a conveyor belt 42 of conventional construction as illustrated in FIG. 5. The specific construction described heretofore is substantially the same as that disclosed in prior Pat. No. 3,263,392, issued Aug. 2, 1966.

As illustrated in FIG. 5, the partially completed package moves with the conveyor belt 42 with the ends 44 of the wrapping film 28 projecting beyond the end members 46 of the tray or container 24 which may be straight or slightly outwardly inclined as illustrated in FIG. 7 to facilitate reception of tomatoes or other produce 26 therein. Disposed in the path of movement of the projecting ends 44 of the heat shrinkable plastic wrapping film 28 is a plurality of hot air nozzles 48 which are directed in a vertical and inclined manner in relation to the projecting ends 44 so that the hot air when it engages and impinges upon the wrapper 28 will cause the projecting ends 44 to fold inwardly and seal to the end members 46 forming the tray 24 as illustrated in FIGS. 6 and 7. Depending upon the length of the projecting end portion 44 of the wrapper 28, the end seal formed by the end portion 44 may leave an opening 50 therein to enable ventilation of the interior of the package. If the end portion 44 is made longer, then it will completely close the end of the package thus providing a selectively closed or ventilated package.

The position of the hot air nozzles 48 may be varied by providing suitable supports and controls therefor to impinge the air in a particular direction for facilitating closure of the plastic film in relation to the container or tray. The conveyor belt 42 may be of a width less than the container tray or it may be greater than the width thereof or it may be constructed of a mesh material so that the hot air may pass upwardly therethrough to cause the heat shrinkable film to be forced toward the end members 46 of the tray or container 24 by the impingement of the air thereon in a particular direction. As illustrated in FIG. 7, the end portion 44 of the film will seal and adhere to and partially wrap around the end members 46 of the container or tray 24 thereby forming a rigid connection and seal therewith.

At least two air nozzles, one for each end of the package, are necessary with the position of such nozzles being variable and adjustable depending upon the particular size and shape characteristics of the package. The heat shrinking not only causes the film to partially wrap around the end wall of the tray, it also seals the plastic film to the tray or container thus providing a positive connection thereto for reinforcing the tray and preventing the commodity within the tray from being accidentally discharged from the tray in the event the package is lifted from either end in an endwise manner which frequently occurs during normal handling of such items.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. The method of forming a package with a heat sealable and shrinkable wrapping film consisting of the steps of placing the wrapping film in enclosed relation to an elongated shallow tray of the type having a skeleton framework including end members defined by a skeleton framework including a peripheral frame with the end edges of the filmprojecting beyond the end members of the tray, and subjecting the projecting end edges of the wrapping film to a stream of hot air for folding and heat shrinking the film partially around the peripheral frame of the end members and sealing the film thereto thereby connecting the film to the tray.

2. The method as defined in claim 1 wherein the end edges of the film project a distance less than one-half of the transverse dimension of the end members so that when it is heat shrunk, a centrally disposed opening is formed for enabling ventilation of the package.

References Cited UNITED STATES PATENTS 3,085,375 4/1963 Harrison 20645.33X 3,270,482 9/1966 Kraut 5330 3,331,503 7/1967 Brown 206- 3,263,392 8/1966 Petrella et al. 53390X THERON E. 'CONDON, Primary Examiner E. F. DESMOND, Assistant Examiner U.'S. Cl. X.R. 533 0

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