US3240394A - Pressurized dispensing container - Google Patents

Description

March 15, 1966 J. P. MODDERNO PRESSURIZED DISPENSING CONTAINER Filed Aug. 26, 1959 POLYESTER POL VOA [Fl/V INVENTOR Jolm/ Pa/a/ flladdelw A ORNEYS United States Patent 3,240,394 PRESSURIZED DISPENSING CONTAINER John P. Modderno, Gambrills, Md., assignor to Modern- Lab., Incorporated, Baltimore, Md., a corporation of Maryland Filed Aug. 26, 1959, Ser. No. 836,216 1 Claim. (Cl. 222-95) This application is a continuation-in-part of my application for Letters Patent Serial No. 673,395, filed July 22, 1957, now abandoned.

This invention relates to a pressurized dispensing device for keeping material to be dispensed separate from the dispensing medium. More particularly, this invention relates to a pressurized container for dispensing a composition which must be kept free of dispensing medium during storage and dispensing by providing a preformed collapsible plastic inner container and an outer plastic container, each having a plurality of plastic surfaces so that the inner surface of the outer container can be heat sealed to the outer surface of the inner container along the top marginal edge thereof with a dispensible gas forming material therebetween.

It will be appreciated that there are many compositions which cannot be marketed for dispensing under pressurized conditions because propellant gases used in dispensing the material (for example, freon, carbon dioxide, etc.) become soluble in the composition and cause corrosion, toxicity, and the like, thereby making the dispensedproduct unacceptable. Catsup, mayonnaise, and the like, in the food field, are typical examples of such materials. In addition, when the propellant gas is soluble in the composition to be dispensed, the dispensed product becomes foamy and is presented in an unusable condition. Many attempts have been made to adapt compositions which are incompatible with gas propellents to pressurized dispensing, but the problem has resisted a simple and practical solution. Also sealing a dispensing gas in one of the compartments of a compartmentalized container separate from the product to be dispensed requires the proper clinching pressure so that no breaks or cracks occur at the point where the seal takes place. In such a device, expensive containers, such as tin containers, must be used. When the dispensing head is attached there is a tendency for leaks to occur by the cracking of the plastic material or by the inability of the plastic to form a seal.

The present invention is directed to a dispensing device for dispensing all types of compositions which are incompatible with the dispensing medium by employing a double plastic container, one disposed in the other, heat sealed around the top marginal edge so that a sealed compartment is presented therebetween. In this device the gas producing medium can be placed between the inner and outer containers before heat sealing so that the pressure producing medium is hermetically sealed and available to dispense the product from the inner container when a discharge head is attached in sealed relationship to the heat seal marginal edge of the double plastic container.

The inner container can be formed by taking a sheet of film of two or more integrally bonded plastic materials, such as a polyolefinic and a polyester, and deep drawing the film with a heat sealable polyolefinic surface as the outside of the container and the outer container can be reversed so that the polyolefinic side is inward. Such drawing is accomplished by progressively thinning out the side of the container as it is "ice container which will have, in addition to tough expansible film characteristics, a pressure sealable outer surface and a wall of varied thickness which forces the inner container to crush in a telescoping manner as it is crushed upwardly by the discharge of product therefrom. Also, the thin bottom is sensitively responsive to the pressure exerted in the container, thereby producing substantially total evacuation of the product from the inner container as the sides of the inner container are maintained substantially against the inner side wall of the outer container.

The double container can then be placed in an outer jacket, box or can with the heat sealed edge resting on an outer flange member so that a dispensing head can be clamped thereto with the heat sealed edge therebetween. Also, a dispensing head can be attached by clamping or the like to the heat sealed edge of the double container to provide direct dispensing without encasement.

Additional objects of the invention will become apparent from an examination of the drawings, specification, and appended claim.

The invention will be described further in connection with the accompanying drawings, which are to be considered an exemplificati-on of the invention and do not constitute limitation thereof.

In the drawings:

FIGURE 1 is a cross-sectional view showing a compartmentalized container with the preformed double plastic containers positioned therein with the heat sealed lip thereof between the closure and an outer container body;

FIGURE 2 is an exploded view showing the containers positioned prior to heat sealing with a gas producing material therebetween;

FIGURE 3 is a fragmentary cross-sectional view of the heat sealed edge of the two containers; and

FIGURE 4 is a fragmentary section of the Wall of FIGURE 3 showing the film formed from two different types of plastic.

Referring to the drawings, FIGURE 1 illustrates a form of the pressurized dispensing device of the present invention. The device consists of an open-top outer jacket or container 10 having a bottom portion 11 and outwardly extending lip 12. Positioned closely within the side wall of container 10 is a double plastic container 13 having an inner container 14 and an outer container 15. The two plastic containers are heat sealed along their marginal edges to form a seal 16 which is in the form of an extended lip 17 which rests upon the lip 12 of outer jacket 10. Clamped to lip 12 and resting against plastic lip 17 is a dispensing head 18 which is adapted to clamp lip 17 in sealed relationship with lip 12 and the marginal edge of the top of the dispensing head. Positioned in head 18 is a dispensing valve 19 which communicates with the interior of the inner plastic container 14. In the compartment formed between containers 13 and 14 is positioned a gas producing medium 20 which, after the two containers are sealed together, is permitted to volatilize to form the pressure producing medium.

As shown in FIGURE 2, the inner container 14 snugly fits in outer container 15 with the lips of each container superimposed on each other so that heat sealing aroundthe marginal edge produces a hermetic seal. (See FIG- URE 3.) The bottom of inner container 14 is positioned above the bottom of outer container 15 to form the space for the gas producing medium.

It will be appreciated that many types of discharge nozzle arrangements can be used with the dispensing device of this invention as long as the orifice to the valve dispensing means is positioned so that it communicates one or both sides.

with the inner container and is not restricted when the container is collapsed as the pressure exerted in the bottom space between containers when the valve is released, forces the inner container upwards guided by the inner walls of the outer jacket to effect dispensing of the material in the collapsible inner container. Also, the plastic lip 17 of the double container 13 may be sealed to the 'a multi-layer or coated film having a tough expansible polyester base material 20, united, coated, or the like, with polyethylene 21, which is capable of heat sealing. The base film also can be coated or united on both sides thereof so that the polyester base is coated or united to a covering layer of a polyethylene. It will be appreciated that the coating or layering can be multiple in nature andv may vary from 0.001" to 0.020" in thickness. Also, the coating or layer has a bonded or fused interface so that the film is integral in construction and does not separate during deep drawing or use.

Exemplary of the composite film is polymerized ethylene glycol-terephthalic acid plastic (Mylar) coated or united with a layer of polyethylene or polypropylene on Also, Scotchpack brand polyester film SLP 50,461, produced and sold under the above designation by the Minnesota Mining and Manufacturing Company, can be used. This film has a polyester base with a. polyethylene surface capable of heat sealing.

The container 14 can be formed from material from 0.001 to 0.020" in thickness with the sides tapering to a thinned bottom. A top wall of from 0.01" to 0.02 tapered to 0.001" to 0.005" was found to function in a satisfactory manner. The outer container can be formed in the same manner with the polyolefinic surface on the inside of the container or, where the outer container is .to be supported, can be of a heat scalable plastic which will form the heat seal with the inner container at the marginal edge thereof.

, The dispensing device, as illustrated in FIGURE 1, is assembled by first placing in container 15 a gas producing material, such as a liquid or solid, then placing container 14 therein until the marginal edges of both containers form an annular lip. The annular lip is then heat sealed around the periphery so that it forms a double container assembly having the gas producing medium between the containers. The assembly is then placed in an outer jacket or container 10 with the heat sealed flange resting on lip 12 of the container. Product to be dispensed is placed in the container and closure head 18is clamped to lip 12, sealing the heat sealed marginal edge between the inner surface of the .closure head and the lip 12.

At this point, the container is assembled ready for storage. The liquid or the solid gas producing material is then free to exert its full pressure within the container to form a pressurized dispensing device. This container permits storage of materials for long periods of time that could not be stored in a pressurized dispensing device in combination with a propellant gas without detrimentally affecting the material. I In addition, where the double plastic container is to be used without a supporting jacket, a dispensing head can be clamped to the heat sealed lip 17 in hermetically sealed relationship. In this condition, the double plastic container is ready for use.

It has been found that pressures between Band 80 p.s.i. give very good results, but higher or lower pressures can be used, depending upon the nature and physical properties of the material to be dispensed. When using high pressures, the thickness and bursting strength of the container must be taken into consideration. It has also been found that the range of pressure is somewhat dependent upon the physical conditions of the material to be dispensed and the thickness of the film forming the pliant container.

Since the gas to produce the pressure does not come in contact with the material to be dispensed, a variety of vaporizable materials may be used to produce the gas. Both liquid and solid vaporizable materials have been found satisfactory, or two or more ingredients which chemically react to produce a gas may be employed. An example of a liquid propellant is Freon. When such a propellant is used, assembly of the container must be carried out under low-temperature conditions or the assembly must be accomplished rapidly. Dry Ice (solid CO has been found to perform very satisfactorily under normal conditions and is an excellent example of a solid gas producing material. For example, it is a known fact that one pound of Dry Ice at 70 F. exerts a pressure of 15 p.s.i. in an cu. ft. container. Thus, a pellet of Dry Ice weighing 4 grams is sufficient to produce the necessary pressure to evacuate a 6-ounce container. The amount of propellant used, of course (that is, the size of the Dry Ice pellet or the amount of liquid propellant), depends upon the volume of the container and the viscosity and specific gravity of the material to be dispensed. When the resistance to dispensing is high, that is, when dispensing a material of high viscosity, more propellant must be used in order to provide the necessary pressure within the container or a higher pressure producing propellant must be employed.

Although the present invention has been shown and described in terms of preferred embodiments, nevertheless various changes and modifications such as are obvious to one skilled'in the art are deemed to be within the purview of the invention.

What is claimed is:

A pressurized dispensing device for discharging a composition therefrom under pressure comprising a unit formed of a flexible plastic outer container and a flexible plastic inner container, each of said containers having corresponding open ends with their marginal edges heat sealed together to form a hermetically sealed compartment between said containers, a pressure-producing medium in said hermetically sealed compartment and a discharge closure head having valve means therein hermetically attached to said sealed marginal edges to form a second hermetically sealed inner compartment, said containers formed from film having a tough, ex-

pansible plastic surface on one side thereof and a heat scalable polyolefinic surface at the area of contact forming the seal, and in which the side wall of said inner plastic container uniformly diminishes in thickness from the top to the bottom thereof and in which the inner container is substantially circular in cross-section.

References Cited by the Examiner LOUIS J. DEMBO, Primary Examiner. LAVERNE D. GEIGER, Examiner.

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