US2225810A - Packaging method - Google Patents

Description

Dec. 24, 1940. H. F. WATERS PACKAGING METHOD INVENTOR. 545/ E 1444755;

ATTORNEY.

Filed May 15, 1937 Patented Dec. 24, 1940 UNITED STATES PATENT OFFICE 6 Claims.

This invention relates to improvements in the packagingv of commodities which deteriorate rapidly when exposed to the atmosphere, and more particularly to an improved method for the packaging of such materials in bags, preferably utilizing vacuum packagr' .ig principles.

In the packaging of those commodities which deteriorate when exposed to the atmosphere for any length of time it is essential that the package be air-tight and/or gas-tight. The formation of a suitable package becomes even more important if the commodity to be packaged is coffee. In the following description my improved method of packaging materials will be explained with reference to the packaging of coifee, although it is to be understood that it is applicable to the packaging of those materials which generate or which are capable of generating gas. Sauerkraut may be cited as another example.

Coffee has very definite characteristics not possessed by other food commodities. Coffee in the bean form must be roasted, and before it is used it must be ground to that fineness required by the particular method used in preparing the beverage.

The coffee bean is essentially fibrous in character, containing a plurality of cells, and when roasted, carbon dioxide gas is formed in the cells. Moreover, during the roasting operations there are developed aromatic and vegetable or fixed oils. The aromatic oils are volatile sothat they will pass very quickly into the atmosphere unless some means are provided to prevent such evaporation. The vegetable and fixed oils readily become rancid when exposed to the oxygen of the atmosphere, and indeed, coffee in bean form after being roasted will not retain much of its desirable properties if exposed to the atmosphere much longer than thirty days. Ground coffee will lose the greater part of its desirable characteristics in a much shorter time; in a majority of cases in about a week or ten days. When the carbon dioxide is lost, the rapid deterioration of the coiiee becomes inevitable.

In order to reduce the loss of these essential oils and the carbon dioxide, it has been proposed to package ground coffee under vacuum, using rigid containers for the purpose. However, since a space is usually left between the cover of the container or can and the top of the coffee, the carbon dioxide generated by the coffee will soon pass into this space. The coffee is loosely, confined in the container and makes it possible for each particle to give off the gas very readily.

The vacuum created also accelerates the rate at which the carbon dioxide is evolved so that instead of the coffee being in fact packaged under vacuum, it is only sotpackaged for a very short time. When the cover is removed from a can containing cofl'ee originally packaged under vacuum, 'the carbon dioxide will quickly become dissipated in the air., Once the cover has been removed it is impossible as a practical matter to retain the volatile, aromatic oils in the coffee so that it soon becomes stale and rancid.

In accordance with the present invention I propose to package coffee, utilizing vacuum principles of packaging but employing a fiexible container made of some suitable material, as for example that product sold under the trade-named Pliofilm, or paper coated with some'suitable material which will render the paper air-tight. Preferably I employ a thermoplastic coating possessing the above characteristics such as, for example, a rubber hydrochloride coating, since in closing the package it is highly essential that no small openings occur in the closure; otherwise the advantage of my packaging method will be lost. Other thermoplastic coatings possessing the same necessary characteristics may be used if desired. 7

Accordingly, one of the many objects of my present invention is to provide a method for the packaging of materials which generate a gas such as, for example, coffee, sauerkraut and the like, wherein the material is first placed in a bag made of flexible gas-tight material and the walls of the bag are then collapsed against the material to confine the latter in a compact, comparatively rigid mass. Since the material is in effect packaged under pressure, the rate at which thegas will be evolved will be lower than the rate at which the gas would be evolved if the material were packaged in a vacuum or according to the usual methods of packaging materials.

Another object of my present invention is to provide an improved method of packaging commodities of the type above described, particularly coifee, in which the cofiee is placed in an airtight and/or gas-tight container or bag made of flexible material of the type above described, subjected to a vacuum, and thereafter sealed. By this method the walls of the bag are collapsed, due to atmospheric pressure, against the coffee, and the coffee is retained in a compact condition. I have found that by utilizing atmospheric pressure to exert a force on the packaged oofiee, the amount of carbon dioxide gas liberated by the coifee will be reduced to a minimum so that the aromatic and volatile oils will not become dissipated over a considerable length of time. This is particularly important when the package is opened since, due to the slowness of the liberotion of the carbon dioxide, the amount of aromatic oils lost when the package is opened will 5 be practically negligible. In order to prevent the breaking ofthe container due to the pressure gradually built up by the liberation of the carbon dioxide gas, I also contemplate the provision of an excess of material in the bag which will permit the formation of a space above the coffee into which the carbon dioxide may fiow as it is being liberated. It is to be understood in this connection that this space is not analogous to the space now provided in coffee packages of the rigid type since, when the package is formed, the wall portions of. the bag forming the top thereof are pressed against the coffee due to the vacuum packaging operation. The excess of material permitting the formation of such a space is created by sealing the bag some distance from the top of the coffee. This space is only brought into existence upon the formation of the carbon dioxide gas.

Another object of my present invention is to provide in a method and package of the type above described, a suitably constructed outer container to which the bag or flexible container mayv be secured by spaced lines of adhesive. Preferably these lines of adhesive are so arranged as to- 30 assist in holding the bag opening as it is being filled with coffee and during the time when the vacuum is being applied thereto so that complicated handling machinery will not be needed.

These and other objects of my present invention will become more apparent from a study of the following description taken in connection with the accompanying drawing, in which like numerals indicate like parts, and in which:

Fig. 1 is a view, in perspective, of a bag filled 40 with coffee and packaged under a vacuum in accordance with my present invention, certain parts being broken away to show the contents;

Fig. 2 is a view, in perspective, of the completed package, the inner bag being shown in 45 dotted outline;

Fig. 3 is a view, in perspective, of a modified form of package showing the method of forming the closure thereof, the inner bag and adhesive lines being shown in dotted outline;

50 Fig. 4 is a vertical sectional view through the modified form of package illustrated in Fig. 3.

Referring now to the drawing and more particularly to the modifications disclosed in Figs. 1 and 2, there is shown a bag l provided with 55 gussets II. The bag is filled with roasted coffee l2 either ground or in the bean and the walls of the bag are collapsed against the coffee. From an inspection of Fig. 1 it will be noted that the bag walls are also collapsed against the top of 60 the coffee so that the latter is confined under pressure in a compact mass. Preferably the walls of the bag are collapsed by evacuating the container. In this way the atmospheric pressure is utilized to force the bag walls against the cofiee.

65 While the vacuum is still being applied the bag is sealed along seal line [3. In order that the bag may be suitably secured to a vacuum packaging apparatus, I have provided an extension of the bag I4 extending above the seal-line I3.- Al- 70 though any form of vacuum packaging mechanism may be employed, I prefer to use the type of apparatus disclosed and claimed in my copending application Serial No. 180,591, filed December 18, 1937, which is a continuation of my 75 application Serial No. 20,371, filed May 8, 1935,

for Machine and method for packing commodities." Similarly, although the bag may be made of any material which will prevent the seepage of air through the bag seams and through the material itself, I prefer either to use a bag made of rubber hydrochloride such as that material sold under the trade name Pliofilm" or a bag made of paper coated with air-tight and thermoplastic adhesive.

Similarly, although the bag may be constructed in accordance with standard bag making methods, it is essential that the seams of the bag be so formed as to prevent any possible leakage. As will be appreciated, small pinholes will destroy the utility of the package.

When vacuum is applied to remove air from the bag, the latter, being made of flexible material, will be collapsed to the differential in pressures in the inside and outside of the bag. Moreover, that portion of the bag between the top of the contents and the seal-line l3 will be in part collapsed against the contents and against each other as is clearly illustrated in broken outline in Fig. 1 designated generally by the numeral IS. The contents will, therefore, be retained in an extremely compact condition with the result that the carbon dioxide will be liberated very slowly and its protective character will consequently be retained. Breakage of the container, due to the slow liberation of the carbon dioxide, will be prevented since it will be collected between the top of the contents and the seal-line I3. In fact, tests of my package have shown that the rapidity with which the carbon dioxide given oil by the coiIee is decreased to one-fifth of the rate at which it is given off by the so-called vacuum tin type of packages. The outer container I5 is provided with conventional closure flaps I! which are sealed to each other in any conventional manner.

After the coffee has been packaged in the manner just described, the bag may be placed in an outer countainer or carton l5 made of relatively rigid material which may carry the usual form of advertising matter and dress. Since the extension of the bag I4 is no longer needed, it may be cut off just above the seal-line l3 and the remainder folded over against the body of the bag.

Referring now to the modification illustrated in Figs. 3 and 4, I have shown a bag I0 provided with gussets II and containing coffee l2. Instead of filling the bag and applying vacuum before it is placed in an outer container, I have found that in some cases it is desirable to secure the bag in the outer container before the filling, vacuum and sealing operations. Accordingly, either the bag or the outer container, in the embodiment shown, the bag, is provided along two opposite walls and adjacent .the bottom thereof with adhesive lines l8. Similar lines of adhesive l9 are located at the bottom of the outer container. When the bag is inserted in the outer container these adhesive lines cause an adherence of the bag to the outer container. In order to hold the bag mouth open, lines of adhesive 20 are provided along the inner surface of the two opposite side flaps 2| so that when these flaps areopened thebag mouth will also be opened, due to the adhesion of the walls of the bag to these adhesive lines 20. After the bag has been filled into operative position. This extension I4 is then folded back upon itself and thereafter the end flaps 22 are folded into position in the conventional manner. When the wall portions forming the bag mouth are brought together there will be provided an excess of material 23 which normally would extend beyond the area of the container proper and against the flaps 22.

However, this portion will not prevent the closing of the closure flaps of the outer container, since it may readily be folded upon itself and against one of the flaps 2|. When the package is opened a portion of the excess material 23, including a section of the seal, may be cut so that when the extension I4 is opened up a pouring spout may be provided.

It will be appreciated by those skilled in the art to which this invention pertains that many alterations and changes may be made in constructional details and forms of package without departing from either the spirit or scope of the invention. It is therefore to be understood that the invention is to be limited only by the appended claims which are to be broadly construed.

I claim:

1. In a method for the packaging of roasted coffee, the steps of filling a gas-tight flexible bag with the coffee, removing air from said bag while the outer surfaces of the bag are subjected to atmospheric pressure to collapse it against the coffee to hold the latter confined in a compact mass, sealing the collapsed mouth of the bag at a distance above the top of the coffee whereby as gas is evolved from the coffee the pressure of the gas will be dissipated through the expansion of the bag between the top of the coffee and the sealed section of the bag.

2. In a method for. the packaging of roasted coffee, the steps of filling a gas-tight flexible bag with coffee, removing air from said bag while the outer surfaces of the bag are subjected to atmospheric pressure to collapse the walls of the bag under atmospheric pressure against the coffee in all directions and to collapse the walls of the bag above the coffee against each other, sealing the mouth of the bag above the top of the cofiee to leave a section of the bag between the seal and the coffee, whereby to provide an area which may be opened by the gas evolved by the coffee without destroying the seal or breaking the bag.

3. A method of sealing bags whereby space is provided for internal expansion after final sealing which consists in collapsing the bag mouth and applying heat thereto in a zone located above the initial contact of the mouth walls a distance sufficient to accommodate fluid expansion within the bag, said steps being carried out while the bag is exposed to atmospheric pressure.

4. A method of providing space for atmospheric expansion within the interior of an hermetically sealed bag which consists of flattening the walls of said open mouth of bag after same has been fllled with contents, thus causing a lessening of atmospheric volume within the interior of said bag, and when in flattened position sealing the upper portion only of said flattened walls, said steps being carried out while the bag is exposed to atmospheric pressure.

5. A method of sealing the open mouth of a material containing bag consisting of bringing together in flattened relationship the two opposite walls of said mouth, and thereafter uniting the interior surfaces of said two opposite walls by means of heat over a predetermined limited portion of said flattened area spaced away from the initial line of contact of the walls so as to provide a substantial expansion zone in the bag above the material therein, said steps being carried out while the bag is exposed to atmospheric pressure.

6. A method of closing the mouth of a bag made of substantially impervious material having contents therein, which consists of bringing together in flattened position two opposite walls of said mouth and while in flattened position effecting an air tight seal above the base of the flattened portion, sufficiently to permit the subsequent expansion within the sealed bag, said steps being carried out while the bag is exposed to atmospheric pressure.

HARRY F. WATERS.

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