SEALED CONTAINER

Abstract: A blow-moulded capsular container has a localised line of weakness at which the container may be split open by digital pressure applied to the container adjacent the line of pressure. The line of weakness coincides with the floor of an external groove (7) in the surface of the container whereby contact of the line by external bodies is largely prevented. Also disclosed is a method of making and filling a capsular container comprising the steps of placing a plastics parison within a mould space and expanding the parison to conform it to the mould space, characterised by the further steps of feeding a charge of filling material into the parison, sealing the expanded and charged parison and removing it from the mould space.

Description: SEALED CONTAINER FIELD OF THE INVENTION This invention relates to sealed, single use containers for the storage and transport of predetermined quantities of fluent filling materials. DESCRIPTION OF THE PRIOR ART It has become commonplace at to-day's restaurants, fast food outlets, at sports venues, in planes and trains or wherever pre-prepared meals are supplied or sold, for adjuvants to the main courses, such as sauces, spreads, syrups, granulated sugar, milk and the like to be furnished in hermetically sealed, single serve packages which are discarded after use. A widely used package of the kind in question comprises a rigid plastics tub with a metal or other foil diaphragm sealing the mouth of the tub. The diaphragm has to be peeled back to gain access to the contents. Other containers of the kind in question may be in the form of foil sachets openable by means of tear strips or the like. Still others, used frequently for small quantities of toothpaste for use by travellers, comprise a collapsible tube with a screw neck (and cap) sealed by an integral plug which has to be pierced to enable the contents to be dispensed. Many people, especially elderly people who may be suffering from arthritis or poor eyesight, find it difficult to open such containers and extract or dispense the contents as needed. Those difficulties are compounded in situations where normal table facilities are not available. Notwithstanding the foregoing the usage of such containers is widespread and growing because of- their perceived convenience and cheapness; by comparison with possible alternative solutions to the problem of furnishing small quantities of materials to individual consumers. Specific proposals to simplify such containers and overcome the above indicated difficulties include the containers of U.S Patents 3825157 and 4252257 (A.M.Herzig) . Those containers are single component containers which are openable merely by being squeezed, but they depend for their sealing on pressure between two resilient lips defining an outlet. Such a seal is scarcely hermetic and renders the containers unsuitable for foodstuffs and prone to leakage during transport. British patent 797720 (B.F.Gassaway) addresses the problem inherent in the Herzig container by uniting the two resilient lips by an external rupturable bead, described as a "thin membrane". The bead of the Gassaway container, being the outermost part of the container surface and being of soft elastic material, is subject to abrasion and damage during transport. Australian patent specification 15538/66 (Vynol Paints Pty. Ltd) discloses a one piece hermetically sealed container but in its case scissors or the like are needed to cut off a portion of the container to open it. SUMMARY OF THE INVENTION An object of the present invention is to provide a hermetically sealed, preferably capsular, container adapted for the above discussed usage which ameliorates the general difficulties met with heretofore in that it is openable by one hand and is robust enough to withstand normal transport and handling shocks without damage. The invention consists in a sealed container of the kind having a line of weakness along which the container may be split open by digital pressure applied to a zone of the container adjacent said line, characterised in that said line coincides with the floor of a groove formed in the external surface of the container. Because the line of weakness in containers according to the invention is at the bottom of a groove and because the groove is surrounded by a relatively thick, and therefore relatively unyielding, material, the line of weakness is shielded from abrasive contacts or physically destructive blows apt to occur during normal transport and handling operations. Leaving aside the simplicity and unitary nature of preferred capsular embodiments of the invention, this is the major factor distinguishing containers according to the invention in principle and in practical utility from the Gassaway container referred to above. Containers according to the invention are preferably capsular, that is to say formed as a unitary, imperforate hollow body. In that event they may be conveniently manufactured as a plastics moulding, and for preference a one piece blow-moulding. Furthermore, in such a capsular container it is preferred that the line of weakness and the groove in the container wall be not only of limited extent, so that the split in the container wall is of a predetermined size, but also positioned and sized relative to the body of the container so that the digital pressures applied by the user to deform the zone adjacent the groove and effect the splitting of the container wall along the floor of the groove have little or no effect on the shape of, and therefore the pressure within, the container as a whole. To that end, in preferred embodiments of the invention, the groove is situated at or near the free end or tip of a nozzle-like extension of the body of a capsular container. A The invention also consists in a method of making and filling a capsular container comprising the steps of placing a plastics parison within a.' mould space and expanding the parison to conform it to the mould space, characterised by the further steps of feeding a charge of filling material into the parison, sealing the expanded and charged parison and removing it from the mould space. For preference the expansion of the parison is effected in conventional manner by inserting a gas supply needle into the parison within the mould space, feeding gas in through the needle, withdrawing the needle and sealing the needle hole in the inflated parison without allowing gas to escape. Likewise, in accordance with the method of the invention, the charge of fluent filling material to be contained may be fed into the inflated parison in the mould through the same or a second such needle. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of a container according to the invention, drawn to an enlarged scale. Fig. 2 is a side elevation of the container of fig. 1. Fig. 3 is a rear elevation of the container of fig. 1. Fig. 4. is a sectional view taken on line 4--4- of fig- 1 drawn to a still larger scale. Fig. 5 is a sectional view taken on line 5-5 of fig. 2 drawn to the still larger scale. DESCRIPTION OF THE PREFERRED EMBODIMENT The illustrated container is a capsular container intended to store a charge of a fluent material such as a food adjuvant, for example tomato sauce. It is a unitary blow-moulding made from a resilient, thermoplastic material suitable for the blow-moulding process, for example, a food grade polyethylene. The moulding has a relatively thick wall so that the container is self-supporting as distinguished from a pliant sachet type container. It may be described as resilient but nevertheless stiffly yielding so that relatively small strains or deformations are accompanied by substantial internal stresses. The container comprises a bulbous body portion 5 and a tapering nozzle-like extension 6. An external groove 7 extends about the tip of the extension 6 to create a thin wall portion underlying the groove and constituting a line of weakness in the edge wall of the tip of the extension 6. Thus the line of weakness coincides with the floor of the groove 7. The extension 6, at least near its tip, is preferably of oval or elliptical cross-section and the splitting of the container wall along the floor of the groove 7 is effected by squeezing the end of the extension 6 along the longer axis of the ellipse. This tends to deform the extension tip into a circular cross-section to thereby increase the volume of the extension tip and if anything reduce the internal pressure in the container so that at the instant of splitting there is a tendency for air to enter the container rather than for its contents to be expressed. Thus, the tip of the extension 6 may be squeezed between the thumb and first finger at the place indicated by the arrows in fig.1 to deform the tip and effect a split in the wall along the line of weakness, but with virtually no effect on the charge of sauce (not shown) or the like in the body portion • Once the splitting has occurred it is merely necessary to similarly squeeze the body portion 5 where indicated by the arrows in fig. 2 to express the contents of the container in a readily controllable manner. The illustrated container may be blow-moulded and filled utilising gas and material supply needles in the manner described earlier. That is to say, except for the additional step of introducing a charge of filling material into the container through a needle during its formation in the mould, the method of the invention is essentially a conventional method for making a sealed, hollow, blow- moulded article and calls for little further description. In particular, the step of sealing the or each needle hole as the needles are withdrawn may be performed by conventional closure elements which come together in the mould to pressure weld together the margins of the still active plastics material of the moulding surrounding the hole, in well known manner. Those closure elements may be shaped to press form the characteristic external groove in the container wall if the needle insertion point coincides therewith. If that is not so, the mould space is shaped to produce the required groove elsewhere. According to another embodiment of the invention generally similar to the illustrated embodiment, the line of weakness and the groove lie in a cross-sectional plane of the tip of the extension near but spaced from the free end of that tip. They may extend from about one end to the other end of the longer axis of the ellipse of the cross- section, that is to say about half of the elliptical circumference or a little more. Alternatively, they ay extend from the same end points but lie in an inclined transverse plane in which the longer axis lies. For preference, to enable conventional blow-moulding apparatus to be used with a minimum of modification, two needles are used, one for inflation and the other for filling, disposed coaxially one within the other. They may then be moved in and out of the mould as one with either the gas or filling material entering by way of the inner needle and the other by way of the annular space between the needles. In a somewhat different version of the method of the invention, where the nature of the filling material permits, it alone is relied upon to expand the parison into conformity with the mould space. That is to say no air or other inflation gas is used. Alternatively, where the filling material is not inherently suitable, it may sometimes be made so by subjecting it to a preparatory aerating step; following which the aerated material may be fed into the parison by way of a single needle. In other embodiments one needle may be used which is used sequentially to inflate and then to fill. Although the method of the invention is applicable to blow-moulding it should be emphasised that containers according to the invention are not restricted to blow- mouldings. They may, for example, be formed from two or more injection moulded component parts welded together to form the fully sealed hollow container. Furthermore, containers according to the invention are not necessarily capsular. They may comprise a conventional squeeze bottle type container with a separate closure means in which the characteristic line of weakness and groove is formed.

Claims: CLAIMS 1 . A s e-aled c ontainer of the kind having a line of weakness along which the container may be split open by- digital pre s sure applied to a zone of the container adj acent said line , chara ct e ri s ed in that said line coincides with the floor of a groove (7) formed in the external surface of the container . 2. A container according to claim 1 further characterised in that it is a capsular container . 3. A container according to claim 2 further characterised in that it i s a r e s ili ent , s el f -supporting plastic s moulding . A. A container according to claim 3 comprising a bulbous body portion (5) and a nozzle-like extension (6) further characterised in that said line of weakness is disposed at or near the tip of said extension. 5. A container according to claim 4. further characterised in that said tip is of elliptical or oval cross-section. 6. A method of making and filling a capsular container comprising the steps of placing a plastics parison within a mould space and expanding the parison to conform it to the mould space, characterised by the further steps of feeding a charge of filling material into the parison, sealing the expanded and charged parison and removing it from the mould space. 7. A method according to claim 6 wherein the parison is expanded by inserting a gas supply needle into the parison within the mould space, feeding gas in through the needle to inflate the parison and withdrawing the needle and sealing the needle hole in the inflated parison without allowing gas to escape, characterised in that the parison is charged by inserting a second needle into the parison within the mould space, feeding filling material in through said second needle and withdrawing said second needle without allowing gas or filling material to escape. 8. A method according to claim 7 further characterised in that said needles are disposed with one within the bore of the other. 9. A method according to claim 8 further characterised in that the expansion of the parison is effected by the incoming charge of filling material. 10. A method according to claim 9 further characterised by the step of aerating the filling material before it is fed into the parison.

Inventors: EVANS GEOFFREY WALTER, EVANS, GEOFFREY, WALTER
Applicants: EVANS DAVID G ASS PTY, DAVID G. EVANS AND ASSOCIATES PTY. LTD.
Application year: 1988
Main classification: B65D35
IPC codes: B65B3, B65D1, B65D17