This invention relates to packaging for fluids, especially viscous liquids.

Numerous attempts have been made over the past 30 years to develop a form of plastic packaging suitable for liquids which does not require a separate cap to be applied. A cap, especially if it is to be resealable, is generally expensive both to manufacture and to apply to the container during a packaging operation. Also, if it is lost, the contents are left open to the air, deteriorate rapidly, and are subject to accidental spillage.

Current methods of packaging, for instance, shampoo, detergent and hair gel, usually involve filling a moulded plastic bottle and subsequently attaching a cap bottle. Any printing on the bottle must be done using a relatively expensive printer working around the entire outside of a comparatively fragile bottle. Further, large amounts of storage space are taken up by unfilled bottles in the factory.

Most attempts to develop a soft form of packaging for liquids have fallen into three categories. The first category provides a package which must be pierced, with a sharp instrument or a straw which is provided, to release the contents. This type of package is not resealable, does not allow any real control over the volume of contents dispensed, and is virtually impossible to file so that the whole available volume is used, resulting in wasted materials.

The second category comprises packages which resealed to some extent, but which require external means, such as a straw, to extract the contents. Such containers have a disadvantage in that it is necessary to provide these external means and affix them to the package. Secondly, such packages do not usually allow all the contents to be extracted, so that waste occurs. Further, such packages generally require elaborate manufacturing techniques and cannot be made simply from sheets of plastic material.

The third category includes pressure releasable containers. Such containers allow the discharge of fluid upon sufficient pressure being applied to the fluid through the container by, for example, squeezing. Upon release, the discharge opening seals either of its own accord or upon being mechanically forced shut. The major disadvantage inherent in such a container is that any sudden impact, during storage or use, causes leakage of the contents. Also, such containers cannot be filled tightly, as this causes leakage if the release pressure is in any normal range.

It is an object of the present invention to provide a container which overcomes the defects of the prior art. It is a further object of the present invention to provide a container which is suitable for filling in a tight manner in a production line, and a method of producing tightly filled containers. A still further object is to provide a resealable container which is simple to manufacture and which does not release its contents under pressure alone.

The present invention comprises according to one aspect a container formed from two pieces of flexible material. The container has a body portion and a nozzle portion. The nozzle portion includes restrictions on each side, which narrow the available passage for fluid from.the body of the container. The container and restrictions are so configured that fluid cannot be released by pressure alone - the nozzle portion must be simultaneously pulled outward to release the contents. When pulling ceases, the container reseals at the base of the nozzle.

A further preferred aspect of the present invention is that the container discharges initially into the nozzle region, which can contain only a discrete volume of the liquid contents. The container can therefore be used to discharge a predetermined quantity of liquid.

A container according to the present invention may be formed by using a single high-frequency (RF) welding die to produce edge seams, the restrictions, and optionally an

additional weak seal near the opening in the nozzle. The whole container may therefore be formed in a single operation.

The present invention also relates to a container which is especially useful for a filling process. This container provides, in addition to the features described above, a further pair of restrictions at the base of the body of the container, which during a rear filling of the container prevent fluid loss. After filling the container tightly, the bottom of the container may be sealed up.

The present invention further encompasses a method of producing tightly filled containers, wherein the container is provided with a pair of restrictions at the rear end of the body to prevent spillage. Fluid is injected from the rear through an injection nozzle, after which the nozzle is removed, and the tightly filled container is sealed while excess material at the rear end is simultaneously removed. This method is useful even for containers without the novel nozzle portion of the instant invention.

The present invention has many advantages over containers currently in use. It does not require a separate cap, so that considerably complexity in manufacture and associated expense are eliminated. The container stores flat until filled, greatly simplifying storage in transport. Energy savings due to easier transport of the empty packages are considerable. Also, the filled containers are flexible and can be packed relatively tightly. The flat containers can be printed flat, which is a considerably easier process than printing on an actual filled or empty expanded container.

Further, the container has considerable functional advantages over conventional plastic bottles. The nozzle can be used as a volumetric measure, so that extra spoons or cups are not required. This is especially useful, for example, for gels or pastes for medical use, for dispensing a concentrate of some sort, or viscous chemicals. The

material of which the container is formed must, of course, be compatible with the contents.

Further, the container will not release fluid solely under pressure, so that the risk of leakage during storage and transport, and of accidental spillage in use, are minimal. Fluid is released by simply pulling on the nozzle, and if necessary squeezing the container if insufficient fluid remains. Upon release of the nozzle, the container is self sealing.

10 The instant container can also be very tightly filled, if desired, to a pillow shape, with one or both sides of the container being formed from transparent material. This creates a very attractive package for display, in which the contents are clearly visible.

15 The invention will now be described with reference to the accompanying drawings.

Figure 1 shows a cross-sectional view of one embodiment of the container. The container is formed from two pieces of flat plastic material, joined by high

20 frequency (RF) welding along the periphery 2. The container has a nozzle region 1, which has provided therein restrictions 4 and 5. These restrictions are preferably formed by high frequency (RF) welding, but could be heat sealed or ultrasonicly welded (as could periphery weld 2). _2ς There is also provided, for additional security of containment during transport, an additional heat seal 3. The latter heat seal 3 is broken before use by simply forcing fluid out of the nozzle.

It should be appreciated that- the container could __ be formed from lengths of tubular material if desired, with corresponding alterations to the manufacturing process. The valve mechanism is applicable to many different shapes of containers, not only those illustrated.

The dimensions of the restrictions 4 and 5 and, _ _ς therefore, the necessary gap between them are dependent chiefly on the viscosity of the fluid to be contained and also to some extent on the dimensions of the container.

Less viscous fluids require a narrower aperture to be effectively contained. Ideally, the fluid contained is of the consistency of shampoo, or of even greater viscosity. However, container will function effectively with fluid of almost any viscosity, with suitable adaptations to the restrictions.

The container may be formed from a flexible plastic material, such as PVC plastic sheeting. However, the choice of material and the thickness of such material necessarily depends ^" on the fluid to be contained, and the volume of fluid to be contained. Particularly for applications involving volatile contents, such as the perfume components of shampoo, it is preferred to form the container from foil laminate materials, with corresponding minor alterations to production techniques. The material selected must be necessarily chemically compatable with the contents.

The actual closure mechanism is a result of the internal fluid distending the plastic film so as to produce a rounded V-shaped bulge with its apex at the bottom of or between the passage between the restrictions. This bulge occurs on both sides of the container, that is on both sheets of material. Best closures result when the restrictions are substantially flat, so that ^* the passage formed between the bulges and the restrictions has a minimum volume. The smaller that this volume, is, the more effective the closure. The restrictions may be formed as complete curves back onto the periphery of the container as illustrated, or may be configured so as to not actually reach the periphery at either end, so long as the gaps left are consistent with the maintenance of the function „of the container. Further, these restrictions may protrude to some extent into the body of the container.

As an additional measure to enhance containment during transport, the nozzle may be folded back onto the body of the container, to make any leakage virtually impossible. If the container is formed from UV plastic with a very fine surface, the nozzle will loosely adhere of its

own accord when folded back. If desired, some additional fixing means could be provided.

Fluid is removed from the container by pulling outwardly on the nozzle, and if necessary, squeezing the package. The fluid will not come out of the nozzle under the influence of pressure alone. This is an important advantage over prior attempts to produce such an article. Fluid ^' passes through the restrictions into the nozzle region, as shown by arrow 6. Upon release of the nozzle,

10 the V-shaped bulge forms once again, thus resealing the container.

An additional feature of this invention is that a discrete volume of contents is held in the nozzle region before it is squeezed completely out. The container can j. - therefore be used to dispense a predetermined volume of fluid. This is especially useful in containers for dispensing, for example, pastes and gels where only a particular quantity is required.

The embodiment described above may be filled by, for instance, injection on a filling line of known type.

20 However, it is desirable that the container be filled to its maximum volume, both from a materials economy perspective and from a marketing perspective. A piliow-shaped container, especially with a transparent side to display the contents, produces a particularly desirable container.

25

Turning now to Figure 2, there is shown therein a cross-sectional view of a further embodiment of the present invention. The container shown therein generally designated 10, is especially desirable as it can be readily filled tightly. The container is forjπed, once again, by high

30 frequency welding of two sheets of plastic film. Restrictions 12 and 13 are also formed at this time. The releasable heat seals 17 are formed in the same operation, by having a die element in the welding die set further back from the surface of the plastic and the rest of the (strong)

35 welds, so that only a weak seal is formed. Opening 18 is formed in this single process also. The nozzle or dosage

compartment 11 is thus formed between the opening 18 and the restrictions 12 and 13. For storage, the whole nozzle area can be folded back along line 22 onto the body of the container, so that a pillow-shaped package is presented for sale. There is also therefore no possibility of spillage, with three distinct points of closure.

This embodiment 10 is also formed with restrictions 19 and 20 at the base by high frequency welding, in the same process as the other features. The restrictions function to form a valve-like closure in the same way as the restrictions at the nozzle end. With filling through the neck, it is difficult or impossible to tightly fill the container. Using this form of container, the fluid is injected from the rear. Restrictions 19, 20 form a tight closure around the injection nozzle 21, which is withdrawn after filling, and said restrictions then form a closure at the base of the container. The container is then sealed along line 23. Preferably, the excess plastic material is cut off simultaneously with a strong heat seal being applied to the base. Sealing could alternatively be made by means of an ultrasonic weld. RF welding cannot be used due to the proximity of liquid.

It will be appreciated that rear filling enables a much greater rate of fluid injection, as the aperture is larger, and that the instant invention includes a means of providing very tight, rapid filling.

It should be appreciated that the present invention is useful for a wide range of products, including shampoo and similar hair care products, food products including condensed milk and food pastes, pharmaceutical products, disinfectants, toiletries and cosmetics.