Container and method for dispensing semi-solid substances

A container for semi-solid substances includes a releasable seal adapted to be opened by a user. Opening of the seal releases vacuum pressure inside the container to allow the semi-solid substance to be dispensed from the open end of the container as a unitary mass.

BACKGROUND OF THE INVENTION 
The present invention relates to containers with semi-solid substances and 
to methods of dispensing semi-solid substances from containers. 
Many semi-solid substances, particularly food products, are sold in 
disposable containers, such as cans. Examples include dog food, cream or 
condensed soups, frozen orange juice concentrate, and refried beans. These 
substances have a pasty or goopy consistency which makes it difficult to 
empty the contents of the container. Typically a utensil of some sort is 
needed to empty the container. 
Accordingly, there is a need in the art for a container and method which 
permits such semi-solid substances to be readily dispensed from their 
containers. 
SUMMARY OF THE INVENTION 
The present invention comprises a container having first and second ends. 
The container is filled with a semi-solid substance, and the first end is 
removable to provide a mouth thereat for dispensing the semi-solid 
substance along an axis of flow. The axis extends from one end of the 
semi-solid substance to another end, and the mouth of the container has a 
cross-sectional area which is at least as large as that of other portions 
of the container to permit the semi-solid substance to slide out of the 
container. The cross-sectional areas are taken through sections 
perpendicular to the axis of flow. 
The semi-solid substance is sufficiently viscous and cohesive to itself and 
to inner walls of the container to prevent air from readily flowing from 
the mouth to the second end, thereby in effect producing a vacuum 
retention force on the substance. The container additionally comprises a 
breakable seal at the second end, adjacent to the said another end of the 
axis of flow. The breakable seal, on release thereof, provides a vent area 
which allows air to enter between the second end and the semi-solid 
substance to break the vacuum retention force. The vent area is 
substantially smaller than the cross-sectional area of the mouth. 
The invention also includes a method of dispensing contents from a 
container. This method comprises opening a top of the container to provide 
a mouth for dispensing a semi-solid substance which is sufficiently 
cohesive and viscous to prevent the contents from readily pouring from the 
mouth. The method also includes the step of opening a breakable seal 
formed on the bottom of the container to provide a vent for allowing air 
to flow into the container from the bottom. The container is then 
positioned with the mouth facing downwardly to dispense the semi-solid 
contents. 
Another aspect of the invention includes a method of packaging utilizing a 
container having end surfaces and a breakable seal formed in one of the 
end surfaces. The method comprises introducing a product into the 
container such that the container is filled with a semi-solid substance.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
As shown in FIG. 1, the preferred embodiment of the present invention 
comprises a cylindrically-shaped, disposable container or can 10 having 
sides 12, and ends which form a top 14 and a bottom 16. The sides 12 
provide a uniform cross section for the can 10. The can 10 has a 
longitudinal axis 13 which is parallel to the sides 12. Preferably, the 
sides 12 are perpendicular to the top 14 and bottom 16. Although the can 
10 may be manufactured from a variety of rigid substances, including, 
heavy paper or cardboard, plastic, or metal, the particular can depicted 
is formed of metal and has a rim 18 at the juncture between the sides 12 
and top 14 of the type commonly found on canned food products. The rim is 
adapted to permit the can 10 to be opened with an ordinary can opener so 
as to remove the top 14 and thereby provide an open mouth 15, as shown in 
FIG. 2, for dispensing the contents of the can along an axis of flow 17, 
which extends from one end of the substance to the other. This axis 17 is 
parallel to and coincident with the can axis 13 (FIG. 1), and the 
direction of movement 19 of the substance as it slides out of the mouth 
15. In the preferred embodiment, the axes 13, 17 and direction 19 are 
parallel to the sides 12 and perpendicular to the top 14 and bottom 16. 
In the embodiment shown, the bottom 16 of the can 10 includes a rim 20, 
similar to the rim 18. The top 14 and bottom 16 are sealed to the sides 12 
to make the can 10 impermeable to air, and thereby seal the contents from 
the environment. Other types of openable tops may be used to permit 
opening without the need for a can opener. For example, the top 14 may be 
made with a tear string or plastic band seal, such as are commonly used on 
frozen juice concentrate containers, a foil "tear top" such as is commonly 
used on juice containers, a metal tear-off top of the type commonly used 
on sardine cans, or a metal band seal such as typically is found on cans 
of ham. Other examples include screw-off lids and pull-off lids. Further 
examples will be apparent to those skilled in the art. 
Preferably, the can 10 includes a label 22 designating its contents, as 
shown in FIG. 1. The label 22 has a top and bottom and is oriented such 
that the bottom of the label is adjacent the bottom 16 of the can 10. 
Although the container 10 of FIG. 1 is depicted as being cylindrical, other 
shapes such as a rectangular tube may be used. However, the dispensing end 
should be at least as large, cross-sectionally, as the remainder of the 
can for ease of dispensing. 
The container 10 is filled with a semi-solid substance, which, in the 
embodiment illustrated, is dog food. As used herein, the term semi-solid 
substance means a substance having a viscosity which is sufficiently high 
to prevent the substance from readily pouring from the container. The 
semi-solid substance fills at least a substantial portion of the 
container, substantially covering and contacting the bottom 16 and 
contacting at least a substantial portion of the sides 12 between the top 
and the bottom such that air from the top cannot flow to the bottom except 
through the semi-solid substance. Further, the semi-solid substance is 
relatively cohesive and gluey, and free of voids, such that it is 
substantially impermeable to air thus preventing air from the top of the 
container from readily flowing through the substance or along the sides 12 
of the can 10 to the bottom 16. Because air from the top 14 of the 
container cannot readily reach the bottom 16, any movement of the 
semi-solid substance out of the top of the can, will draw a vacuum at the 
bottom 16. This vacuum prevents the substance from easily dropping out of 
the container 10 when the container 10 is inverted. Assuming a can having 
a diameter of approximately three inches, and atmospheric pressure at 
about 15 pounds per square inch, there is about 100 pounds of vacuum force 
holding the semi-solid substance in the container. In contrast, the 
semi-solid contents of the container 10 may typically weigh, for example, 
no more than about a pound or so. It will thus be seen that the weight of 
the semi-solid substance is insufficient to overcome the vacuum force to 
permit the contents to readily flow out of the container of their own 
accord. 
In order to release the vacuum which holds the semi-solid substance in the 
container 10, and thereby permit the substance to flow out of the 
container 10, the present invention includes a breakable seal 30. The seal 
30 comprises a vent hole 31 on the bottom 16 at the center thereof and a 
peelable sealing strip 32, as shown in FIG. 2. In the embodiment depicted, 
the vent hole 31 is cleanly punched in the bottom surface 16, so that the 
edges of the hole 31 are flush with the surface and there are no metal 
spurs projecting into the can 10. The area of the hole 31 is substantially 
smaller than that of the top 14, bottom 16 and mouth 15. This vent hole 31 
is covered by the peelable strip 32 which provides an airtight closure for 
the hole 31, and thus, maintains the contents in a septic, aseptic or 
sterile condition, as required for the particular substance. In the 
preferred embodiment, the peelable strip 32 is formed from a thin film 
material. These seals are well known in the art and are commonly used on 
fruit juice cans. 
The peelable strip 32 of the preferred embodiment is shown more clearly in 
FIG. 3, and includes a tongue portion 34 and a tab portion 36. The tongue 
portion 34 covers the vent hole 31 and has an adhesive on the underside 
thereof such that it adheres to the outer surface of the bottom 16 to seal 
the vent hole 31 from the atmosphere. The tab portion 36 has no adhesive 
and is sized to be grasped between the thumb and forefinger of a user. By 
pulling the tab portion 36 away from the surface 16, the tongue portion 34 
is pulled back, thereby exposing the hole 31, and allowing air to enter 
therethrough and pass through the bottom 16 into the interior of the 
container 10. This process releases the vacuum pressure which holds the 
semi-solid substance in the can, and thereby permits the semi-solid 
substance to drop out of the can by its own weight when the can is 
inverted, as shown in FIG. 2. The contents of the can are thus dispensed 
cleanly as a unitary mass, such that substantially no product is left 
within the can. In the event that the contents of the container 10 are of 
a light weight nature, or have high adhesive bonding to the container 
walls, such that they do not have sufficient weight to drop out of the 
container of their own accord, the user may blow air through the vent hole 
31 (e.g., by mouth) to create a positive pressure to force the contents to 
slide out of the container. 
Referring to FIG. 3, the peelable strip 32 of the preferred embodiment is 
adapted for reclosure. With some food products, it is sometimes necessary 
to use the can as a measuring device for adding milk or water. For 
example, soups typically call for the addition of a can or half can of 
milk or water to the dispensed contents of the can. The hole 31 can be 
resealed by pressing the adhesive of the tongue portion 34 against the 
surface of the bottom 16, thereby permitting use of the container 10 for 
fluid measurement. Alternatively, the hole 31 may be resealed by means of 
a plug (not shown) or by placing the user's finger over the hole. 
To ensure that the peelable strip 32 is not completely removed from the can 
10 during the dispensing of the contents, the tongue portion 34 of the 
peelable strip 32 includes a stop portion 38 and a release portion 40. The 
release portion 40 includes an inner area 42 which has no adhesive on the 
underside thereof. This area 42 covers the hole 31, and may be somewhat 
larger than the hole 31. The non-adhesive area 42 is spaced from the 
marginal edges of the release portion 40, so as to provide marginal strip 
portions 44(a) to (c) which, with the stop portion 38, serve to surround 
the non-adhesive area 42, and thereby provide adhesive surfaces which 
completely seal the nonadhesive area 42 from the environment. The purpose 
of the nonadhesive area 42 is to reduce the amount of adhesive area in the 
release portion 40, and thereby make it relatively easy to peel back. The 
stop portion 38, on the other hand, is designed to provide high resistance 
to peeling by providing an adhesive area having a width w which is 
substantially greater than that of the release portion 40. Accordingly, 
when the release portion 40 is pulled back, the resistance to pulling will 
suddenly increase when the stop portion 38 is reached. This prevents or at 
least inhibits a user from completely peeling off the strip 32 from the 
container bottom 16, and thereby allows easy reclosure of the hole 31 by 
pressing the peeled-back release portion 40 onto the surface 16 to reseal 
the hole 31. The above-described differential resistance to pulling may 
also be accomplished by using a differential adhesive in which the 
sticking power of the adhesive on the stop portion 38 is greater than that 
of the release portion 40. As noted above, after resealing, the container 
can be filled with the desired amount of fluid, e.g., water or milk. Note 
that the water or milk can be dispensed through the hole 31, by releasing 
the seal a second time. Because the hole 31 is relatively small compared 
to the bottom 16, the water or milk will drain therethrough relatively 
slowly allowing controlled dispensing of the fluid, solvent or dilutant to 
the original dispensed contents. 
In FIG. 4, a modified version of the breakable seal 30 of FIG. 2 is shown. 
The breakable seal 30 includes an adhesive portion 46 which covers the 
vent hole 31, and a tab portion 48. The adhesive portion 46 has an 
adhesive on the underside thereof, while the tab portion 48 has no 
adhesive on the underside thereof. Attached to the tab portion 48 is a 
spike and a plug assembly 50. The spike and plug assembly 50 comprises a 
conically-shaped spike 52 suitable for piercing a thin film material, and 
a plug 54 sized and shaped to fit snugly within the vent hole 31. In this 
embodiment, the tab portion 48 may be lifted away from the surface 16 and 
folded over the adhesive portion 46, such that the spike 52 pierces the 
adhesive portion 46 covering the vent hole 31. The spike 48 is then 
removed from the hole 31, thus allowing air to enter therethrough which, 
in turn, releases the vacuum pressure and permits the semi-solid substance 
to drop out of the can 10. The hole 31 in the bottom surface 16 can then 
be resealed by securely pressing the plug 54 into the hole 31. 
A modified container 10 is shown in FIG. 5. This container 10 may, for 
example, be used with the breakable seal 30 of either FIG. 3 or 4. This 
modified container is particularly suitable for use with semi-solid 
substances that are vacuum-packed during the canning process, and which 
have a residual vacuum in the container after canning is completed. In 
this embodiment, the bottom surface 16 of the container 10 has a generally 
convex curvature prior to being filled with the semi-solid substance. 
During the filling process, a force is applied to the bottom surface 16, 
such that the bottom surface 16 becomes concave, or at least less convex. 
This transformation of the surface 16 may be achieved by application of a 
mechanical force to the bottom of the can, or by application of a vacuum 
force during the canning process. Regardless of the manner in which the 
surface 16 is forced toward concavity, the container 10 is sealed with the 
surface 16 in a deformed condition, so that the surface 16 is retained in 
the deformed condition by residual vacuum retention forces within the 
container 10. When the breakable seal 30 is released, the bottom surface 
16 springs back to its original convex shape, thus breaking the adhesion 
between the bottom 16 of the container 10 and the semi-solid substance, as 
shown in FIG. 6. 
Although the preferred embodiment utilizes a peelable seal, those skilled 
in the art will recognize that other types of releasable seals 30 may be 
utilized alternatively, including, but not limited to, the various types 
of "pop top" openers used on soft drink and beer cans. Such pop top seals 
typically comprise a scored portion which preferentially breaks or tears 
along score lines, thereby providing an opening. A lever portion, commonly 
in the shape of a ring or tab, is attached to the scored portion such 
that, by lifting the lever portion, the user may break or tear the scored 
portion to provide the opening. 
In the embodiments disclosed, the hole 31 is located near the center of the 
bottom 16. It is believed that a center location is more effective in 
releasing the vacuum pressure than a hole located near the periphery of 
the bottom 16. The center location permits the vacuum to be released more 
uniformly due to its equidistant location relative to the sides of the 
container 10. While a round hole has been illustrated in the drawings, 
other shapes may be utilized. For example, a star pattern having multiple 
rays radiating from its center may be desirable for some substances. 
The present invention is appropriate for use with a wide variety of 
semi-solid substances. Examples include pasty substances, such as tomato 
paste, gelatinous substances, such as cream soups and cranberry sauce, wet 
solids, such as canned meats, frozen concentrates, such as juices, and 
other highly viscous substances such as refried beans and heavy 
consistency stews. These food products contain a mixture of moisture and 
solids which make them quite difficult to dispense from a can. The 
container of the present invention may also be used for highly viscous 
non-food items. 
As discussed above, the present invention permits dispensing the semi-solid 
contents as a unitary mass. In some cases, however, it may be desirable to 
dispense only a portion of the contents (e.g., dog food). Advantageously, 
the vent hole 31 can be covered, for example, with a finger of the user, 
or by resealing the seal 30, to stop the flow of material out of the can 
and thereby limit the amount of product dispensed. Alternatively, the flow 
can be stopped by turning the can on its side. If necessary, the dispensed 
portion can be separated from the portion remaining in the can by manual 
force. For example, the dispensed end might be cut off with a knife or 
broken off by shaking the can or forcing it against a surface. 
The walls of the can 10 may be coated with a lubricating substance, such as 
an oil or other non-stick substance prior to filling the can. Such coating 
inhibits adhesion of the contents to the walls of the can 10, and provides 
lubrication which allows the contents to easily slide out of the can. The 
use of lubricating coatings may be particularly advantageous for 
relatively lightweight substances and for substances which exhibit a high 
degree of adhesive bonding to the inner walls of the container.