Method Of Forming Containers And Packages

Abstract

This disclosure relates to a method of forming containers and packages wherein either an unfilled container or a partially filled package may be formed. The method basically relates to the forming of a container or package having two faces from web material wherein the web material is formed into a tubular container with the two walls closed transversely at the bottom end and open at the top end, and a wide seam joins together double overlapping thicknesses of the web material to form a filling passage between the double thicknesses with the seam extending across the full width of the overlapping thicknesses and through which filling passage a substance or an additional substance can be added to the interior of the package, the entire filling passage being positioned within the wall of one package face which under pressure from contents within the package curves outwardly to hold the passage walls in mutual contact preventing the exit of the contents of the package through the passage and in the case of a partially formed package, introducing a first substance into the tubular container through the remaining open upper end of the tube walls, and thereafter placing a closing seal across the top end of the container.

Parent Case Text

This application is a continuation-in-part division of my copending application Ser. No. 39,375 entitled FLEXIBLE PACKAGE WITH SELF-CLOSING OPENING, filed May 21, 1970, now abandoned.

Description

This application is particularly directed to a method of forming containers and packages having valved passages whereby the container may be either readily filled or may have a product added to the product already contained therein.

BACKGROUND OF THE INVENTION

Many different types of products are now sold in a dry form and are to be mixed by the user with a liquid, such as water, as an initial step in the subsequent processing or use of the original material. Examples of such products requiring the addition thereto of a liquid for further processing include cake mixes, pie crust mixes, pancake mixes, and other food products which are sold in dry form and are to be mixed with milk or water by the user. Other examples of mixing requirements may be found among various non-food products such as plaster of paris, cement mixes, and various liquid plastics to which a liquid catalyst is to be added which causes the plastic to set or become hard.

One well-known manner of using products of this character involves emptying the contents of the package in dry form into a suitable mixing container, adding the desired liquid in the proper amount, and stirring or agitating the liquid and the dry mix together with a suitable implement. As a convenience to the user, such products are preferably sold in packages having flexible walls and into which the proper amount of added liquid may be placed, the liquid and the dry product being mixed in the package by flexing or kneeding the walls of the package to obtain the desired mixing action. After the desired mixture is secured, it is then ejected from the package through an opening in the package wall which is formed for that purpose. Many advantages accrue to the user from a package of this type, particularly the saving in time and trouble in cleaning up a second vessel in which the mixture would otherwise be prepared, since the original package constitutes a disposable mixing container when made according to the present invention.

One known type of container for this service is a sack-like container open at one end; but this has several objections. It is difficult to close. If one hand is employed to hold the original open end closed, only one hand is free to do the mixing.

Prior designs for packages of this type with varied inlet passages have not been entirely successful for various reasons. The chief problem has been to provide a one-way valve which remains securely closed during the mixing operation. In known designs of packages, the valve does not always remain securely closed, with the result that some of the contents escapes through the partially opened valve.

In an attempt to solve this problem, a one-way valve has been applied to the package with flexible walls comprising one or two additional pieces of flexible film added to the package in order to form the one-way valve. Examples of this structure are found in U.S. Pat. Nos. 3,282,412; 3,297,152; and 3,367,485; issued to A. P. Corella and W. S. Schneider.

A container having the same general appearance as the container of this application is found in British Patent No. 930,893 to David Victor Bonsor entitled "Improvements in or Relating to Containers for Holding Liquid" published July 10, 1963. However, as is quite apparent from that disclosure, the containers are individually formed from two blanks which are secured together by first overlapping end portions of the blanks and selectively sealing the same together to define a seal therebetween incorporating a valved passage, after which the uppermost blank is reversely folded upon itself and then sealed about the periphery thereof to the underlying blank. The only disclosed use of the Bonsor container is as a container for liquids and the valved passage is utilized both for the filling of the container and the dispensing of the liquid therefrom.

The Bonsor patent in no way suggests that a product be first placed in the container prior to the sealing thereof so that the container could be utilized with products other than liquids. Also, the Bonsor patent in no way suggests that the container could be mass produced in a manner which is economically feasible.

SUMMARY OF THE INVENTION

In view of the foregoing, it is proposed to form containers each incorporating a wall portion of a double thickness having a valved passage formed therein, the containers being formed from web material and in a manner wherein the containers may be economically mass produced. It is also an object of the invention to provide a simple package or container which can be easily produced by existing types of machinery by simple modification of such a machine in order to promote its use.

A primary feature of the invention is the forming of containers, either filled or empty, on a continuous basis utilizing web material in strip form by shaping the same about a mandrel and forming the same first into a tube by a series of side seam seals which incorporate valved passages, and thereafter performing such transverse sealing and severing operations on the tube as is necessary to divide the same into a plurality of containers.

How the above, as well as other, objects and advantages of the present invention are achieved will be more easily understood by reference to a filled package formed by wrapping film about a hollow mandrel to form a tube with a wide overlap of the two parallel, longitudinal edges, incorporating in the overlap area transversely thereof a filling funnel and one-way valve, closing the end of the plastic film tube below the end of the mandrel, introducing a quantity of a product through the mandrel into the package above the closing seal, and placing a second transverse seal that is spaced above the first seal. The package can now be severed at the second seal from the following web. The overlapping area has a passage between the two mutually overlying layers of film and which are held in closed position by the outwardly convex curvature of the package wall produced by the quantity of contents inside the package. The shape of this passage preferably is curved or angular so that a straight wrinkle forming in the outer layer of the film cannot form at any location where it will extend from the entrance to the exit of the passage.

According to an alternative form of the invention, the film may be employed to produce an empty container which is filled through the one-way valve passage, after which the passage may be closed and hermetically sealed, if so desired.

BRIEF DESCRIPTION OF THE DRAWING

How the above and other objects and advantages of the invention are attained will be more easily understood by reference to the following description and to the accompanying drawing, in which:

FIG. 1 is a front elevation of heat sealing web showing various steps in the sequence of operations in making a package according to the present invention;

FIG. 2 is a side elevation of a portion of FIG. 1 at a reduced scale;

FIG. 3 is a side view of a package produced by the invention; and

FIGS. 4 and 5 are side views of modified forms of packages embodying the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT

By referring to FIG. 1 it will be seen that the package 10 is formed by initially wrapping web 12 around a hollow mandrel 14 open at its lower end at 14a and subsequently discharging a measured quantity of a product 16 into a package through the open end of the tube formed by the film which has been wrapped around the mandrel. This tube is first closed at its lower end by transverse seal 24.

The package 10 is preferably and typically made from thin sheet material that is heat sealable on both sides of the web. As will become evident, the web material may be heat sealed on only a strip on the outside surface. Other materials may be used and the invention is not limited to any specific material for the film or web material used to make the package; but materials which are heat sealing on one or both sides are currently in widespread use for production of packages and have many advantages therefor. However, other materials can be used since an adhesive can be employed instead of the heat sealing characteristic in order to form the transverse seals and the wide longitudinal seal in which the valve passage is located.

Web 12 feeds from a supply roll (not illustrated) over a guide or former 18 of any suitable shape. The former directs the web to wrap it around the hollow mandrel 14 to produce the tubular configuration of the web as shown in the central portion of FIG. 1. Former 18 produces an unconventionally wide overlap above the two longitudinal margins of the web as shown by the unusually wide spacing between web edges 12a and 12b. If the entire outer surface of the web is not heat sealed, it may be heat sealed along a strip parallel to edge 12a of the width of sealed area 22.

The transverse seal 24 is applied by a pair of heated sealing heads 28. The two heads are mounted on opposite sides of the tube and when they are brought together they grasp the tube together and seal opposing faces of the external wall of the tube below the mandrel. The heads can also be used as a means for advancing the web by moving them downwardly, from the position shown in FIG. 2, for the length of the package to a position indicated at seal 24a.

Prior to engaging the film in order to produce the transverse seal, the single sealing head 26 is moved inwardly against hollow mandrel 14 and engages the web at the wide overlap area 22 where two layers of the film are in face-to-face contact. It will be noticed that the size of sealing head 26 is relatively larger than is true of most heads for making the longitudinal seal the width of overlap 22.

Head 26 is preferably substantially the same width as the overlap area 22, as may be seen in FIG. 1. This is because the two layers of the web in the area 22 are sealed together for the full width of the overlap. The length of head 26 is substantially equal to the length of the completed package, or it may be even longer, if desired. The face of sealing head 26 conforms to the external shape of mandrel 14; hence, the face is substantially the same radius as the external radius of mandrel 14, or both surfaces can be flat or oval. Sealing head 26 is mounted on post 27 which moves the sealing head towards and away from the mandrel. When the web is drawn downward by the transverse sealing heads the sealing head is away from the web.

The cylindrical surface of sealing head 26 seals together the two overlapping portions of the web in zone 22, except where the face of the sealing head is centrally recessed thereby maintaining selected areas of the two overlapping portions in an unsealed relationship in order to provide filling passage 30 in overlap 22. The shape of this passage may be quite different from that shown in FIG. 3, although the shape illustrated in FIG. 3 is preferred. Passage 30 is generally funnel shaped, having its greatest width adjacent the outer edge 12b of the web. A short distance inwardly from the edge 12b, the funnel narrows to a more or less constant width.

Sealing head 26 is located a short distance above the open lower end 14a of mandrel 14 and a package length above the top most portion of transverse sealers 24. The web is formed preferably into a hollow cylinder and is maintained in that shape by the sealed area which joins the two overlying portions of the web in the zone 22. Because of strength and simplicity, it is preferable that the heat seal area of the overlying marginal areas on the web are sealed together except at filling passageway 30. However, it is not necessary to do this, and, accordingly, it may be desired not to seal together the entire area on either side of passageway 30 and within zone 22.

In FIG. 1 there is shown a completed package 10 which is partially filled with contents 16. The lower end of package 10 is closed by the transverse seal 24a while the upper end of the package is closed by a transverse seal 24 which is being made by the pair of transverse sealing heads 28. These two heads are brought together to apply heat and pressure to the film or web which is preferably heat sealable on its entire inner face and on at least an area on the outer face.

A simple method of advancing the web is to reciprocate vertically the transverse sealing heads 28. While they are applying the transverse seal 24, the two heads can move downwardly by a length of a package, thereby moving a previously made seal 24 to the lower position 24a. On the next vertical travel the seal 24a is pulled down to the position 24b. After the sealing heads have been separated from the film and moved upwardly, then a pair of blades 32 can be brought together to cut off the completed package 10a at 24b from the following web at the lower station. Alternatively, it is known to locate blades 32 in the sealing heads. Of course, the invention is not limited to this means for advancing the web lengthwise of mandrel 14, and any other means for advancing the web may be used equally well.

While the web is being advanced by the two sealing heads 28, the contents 16 are introduced into the package through the interior of mandrel 14 by any type of feed mechanism, not shown in the drawing. The dry powder is thus in place at the bottom of the tubular configuration of the web by the time that the transverse sealing heads approach one another to close the upper end of the package.

The width of the overlapping zone 22 is preferably sufficient to hold the two walls in contact as a result of the curvature introduced into them by the contents 16. The width of the neck of filling passage 30 is likewise kept narrow, although no minimum is set and is in part a function of the width of the overlap.

The width of the overlap zone 22, measured circumferentially of mandrel 14, is preferably of the general order of magnitude of one-half to two-thirds of the package width dimension parallel thereto of the completed package, as may be seen in FIG. 3. A width within this range is satisfactory under most circumstances, although the exact dimension chosen will depend upon various matters, for example the amount of contents 16, the size of the package, its shape, and other factors.

When the package is turned to bring in seals 24a at the right and left hand ends as in FIG. 3, the filling passage 30 is substantially vertical. In this position, the edge 12a of the film more or less closely limits the amount of liquids which can be added to the original partially filled package. It will be apparent that this is the case because of the fact that as the liquid is placed into the package and reaches edge 12a, it traps air in the upper portion of the package and thereby limits the quantity of liquid that can be added. If the quantity of liquid is below the edge 12a, then this level of liquid to be added can be marked by printing a fill line 32 on the package at a suitable location, as is shown in FIG. 3.

FIG. 4 also discloses a variational form of package 10b which is the seam as previously described but with the addition of a heat seal of the narrow bar type at the end of the wide mouth of the funnel. Heat seal 36 closes the fill passage 38 which in this embodiment of the invention is made tortuous rather than straight. This heat seal is a narrow and is applied by sealing head 26 at the same time that passage 38 is made. Seal 36 should be narrow and weak in order that it can easily be broken without rupturing the web from which the package is made, and particularly without breaking the web at the passage walls. For this reason and for this same purpose, a pressure-sensitive seal is an ideal material for closing the fill passage 38. Alternatives in seal 36 may be made as disclosed in my co-pending application Ser. No. 856,099, filed Sept. 2, 1969 and now U.S. Pat. No. 3,608,709. Seal 36 is located near the entrance or inlet end of the portion of fill passage 38 that is of substantially constant width so that it can be ruptured by the user in order to admit fluent material into the package.

It is also to be noted that the filling passage 30 of FIG. 3 may be formed with the seal 36 and such a seal has been illustrated therein. In other words, the seal 36 is not a species modification limited to the container of FIG. 4.

Handling the package and setting it down in different positions, especially after liquid has been added or the package is partially empty, can cause the package to leak contents through passage 30. The presence of the bar seal 36 prevents any leakage as it insures 100 percent closure of the filling passage. While the closed passage might normally resist leakage, it in combination with the relatively weak bar seal stops all passage through passage 38 that might also result from changes in barometric pressure change or vapor penetration. Thus shelf life of the packaged product is increased and quality maintained.

FIG. 5 discloses another variation of the invention in which the fill passage 40, while extending across the seam 22, actually has its inlet end at a position proximate one end seal 24c. Fill passage 40 has a curve throughout its length and opens at its inner end to the interior of the package, as in the packages previously described.

When the fill passage of the type 40 is utilized, it becomes necessary to prevent the outer layer of web in zone 22 from being heat sealed to the opposite wall in face to face relation when the tube is clamped between sealing heads 28. Various expedients may be utilized to prevent this. One that is well known is to print on the outer surface of web 12 the adhesive which renders the web heat sealing; and in so doing omitting all or part of the area on the overlap 22 which forms fill passage 40. As another way of leaving the end of the fill passage open, openings may be die cut in the web in registration with the printing at such a location that the die cut opening indicated at 41 in FIG. 5 is subsantially the width of fill passage 40 and slightly greater than the width of the transverse seal area 24c. This shortens a portion of the fill passage but provides the advantage of leaving a free edge to the fill passage which can be grasped to open the passage.

It is to be understood that each of the packages may be provided with means for facilitating the opening thereof when it is desired to dispense the product contained therein. Such an opening device has been illustrated in FIG. 3. as a perforated tear line 42 although the opening device is in no way limited to the illustrated example and the opening device may be utilized in each of the various package modifications.

The packages illustrated in the drawings are all of the familiar pillow shape, that is, when the package is empty it is rectangular but when partially filled the shortening of the web to provide the outwardly convex curvature of the sidewalls draws in the two opposite sides of the package between the end seals 24. Ordinarily the pillow package is made longer between end seals than the width of the package transversely to this dimension. However, there may be an advantage in a particular design in all three forms of the invention illustrated herein in making the shorter dimension of the package the distance between end seals 24. This utilizes the ability of the package to receive only a limited amount of added fluent material so that the designer of the package can by controlling the size of the package control the total amount of material that can be added to the contents already in the package.

From the above it will be understood that various changes may be made in the present invention by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, the foregoing description is considered to be illustrative of, rather than limitative upon, the invention as defined by the appended claims.

Claims

I claim:

1. The method of forming a valved package from continuous flexible web material and partially filling it with a first substance and closing it, said package having two faces, that comprises the steps of: forming said web material into a tubular container with the tube walls closed transversely at the bottom end and open at the top end, and a wide seam joining double overlapping thicknesses of said web material, sealing together said overlapped thicknesses along said seam and forming a filling passage of predetermined size and shape between said thicknesses and extending across the full width of said overlapping thicknesses and through which an additional substance can be added to the interior of the package by maintaining selected areas of said overlapped thicknesses along said seam in an unsealed relationship, positioning the entire filling passage within the wall of said one package face which when under pressure from the package contents curves outwardly to hold the passage walls in mutual contact preventing the exit of the contents through said passage, introducing said first substance into the tubular container through said open end of said tube walls, and placing a package closing seal across said top end of the container.

2. The method of making a partially filled package as in claim 1 that includes the further step of positioning fill level identifying means on said package for visually indicating the volume of said second substance to be added.

3. The method of making a partially filled package as in claim 1 in which one edge of said package comprises a fold and said method includes forming said filling passage with an open end adjacent to said folded edge and the other end open to the interior.

4. The method of making a partially filled package as in claim 1 in which one edge of said package comprises a seal and said method includes forming the filling passage with an open end adjacent to said sealed edge and the other end open to the interior.

5. The method of making a partially filled package as in claim 1 together with the forming of a ruptureable closure across said filling passage.

6. The method of making a partially filled package as in claim 5 wherein the seal of said ruptureable closure is one that can be opened without rupturing the passage walls.

7. The method of making a partially filled package as in claim 1 that includes the further step of forming an exit channel of predetermined size and location through which the package contents can be expelled.

8. The method of making and filling a valved package that comprises the steps of: wrapping continuous flexible web material around a mandrel to form a tube with a wide overlapping seam extending axially of the mandrel, sealing together the overlapped portions of said web along said seam to form a seal while maintaining selected areas of said portions unsealed to thereby defined a filing passage of predetermined size and shape extending across the area and through which a fluent material can be added to the interior of the passage, closing the lower end of the wrapping below the mandrel with a transverse seal, introducing a quantity of product into the package through said mandrel, and placing a transverse seal above the level of product previously introduced.

9. The method of making and filling a valved package according to claim 8, in which the filling passage is centrally located between and extends generally parallel to said transverse seals.

10. The method of making and filling a valved package according to claim 8, in which an outwardly convex curvature of the package produced by the contents therein holds the passage walls in mutual contact.

11. A method of forming a container comprising the steps of providing a flat pliable web in strip form, wrapping said web around a mandrel with edge portions of said web being disposed in overlapping relation, sealing together said overlapping edge portions to form a tube, forming predefined valved passages at container intervals directly between said overlapped edge portions by maintaining selected areas of said overlapped portions in an unsealed relationship, and severing said tube at container intervals in a predetermined relation to said valved passages.

12. The method of claim 11 wherein said tube is advanced in a step-by-step manner and said sealing together of said overlapped edge portions is also effected in a step-by-step manner.

13. The method of claim 11 wherein said tube is advanced in a step-by-step manner and said sealing together of said overlapped edge portions is also effected in a step-by-step manner in timed relation to the advancing of said tube.

14. The method of claim 11 wherein said sealing together of said overlapped edge portions is effected utilizing said mandrel as a back-up member in cooperation with an external sealing mechanism.

15. The method of claim 11 wherein prior to severing said tube, said tube is first flattened and transversely sealed to form both a temporary tube bottom and a sealed container edge.

16. The method of claim 15 wherein prior to severing said tube, said tube is further flattened and transversely sealed to form both a closed container and an additional sealed container edge.

17. The method of claim 16 wherein prior to said further flattening and transverse sealing, a product is deposited into said tube with downward flow of the product in the tube being limited by the then temporary tube bottom.

18. The method of claim 17 wherein the product is deposited into said tube through the mandrel.

19. The method of claim 11 together with the forming of a rupturable seal across and closing said valved passage.

20. The method of claim 19 wherein said rupturable seal is formed simultaneously with said forming of said valved passage.

21. The method of claim 11 wherein prior to severing said tube, said tube is first flattened and transversely sealed to form both a temporary tube bottom and a sealed container edge, said overlapped edge portions being oriented relative to said tube flattening and transverse sealing with said sealed together overlapping edge portions being disposed along one side edge of the flattened tube.

22. The method of claim 11 wherein said valved passages are formed simultaneously with said sealing together of said overlapping edge portions.

23. The method of claim 1 wherein one edge of said package is defined by a fold adjacent a free edge of said web material, and said free edge is disposed innermost providing a direct access into the interior of the package through said filling passage.

24. The method of claim 8 wherein one edge of said package is defined by a fold adjacent a free edge of said web material, and said free edge is disposed innermost providing a direct access into the interior of the package through said filling passage.