CAP FOR SEALING A PACKAGE

A cap for sealing a package by applying the cap onto a neck of the package, the cap comprising an inner thread arranged on an inner side wall surface of the cap, and an inner cylindrical body extending from an inner top surface of the cap, wherein the inner cylindrical body comprises a peripheral end arranged to guide the inner cylindrical body into the neck, an annular sealing protrusion extending radially outwards from the inner cylindrical body towards the inner side wall surface, and a concavely shaped transition portion located between the annular sealing protrusion and the peripheral end.

TECHNICAL FIELD

The invention relates to the field of food packaging. More particularly, it is related to a cap for sealing a package, an arrangement comprising the cap and a neck of the package, the package, and a method for applying the cap onto the package. The cap has an inner cylindrical body extending from an inner top surface of the cap, where a peripheral end of the cylindrical body is arranged to guide the inner cylindrical body into the neck of the package.

BACKGROUND ART

Today, many consumers prefer packages provided with caps. One reason for this is that the package can conveniently and reliably be re-closed such that the package with its remaining food content can be stored safely in e.g. a refrigerator even if the package is laid down, i.e. in a non-upright position. Another advantage with caps is that they can be provided with tamper bands, also sometimes referred to as tamper rings. By having a tamper band forming part of the cap, the consumer can easily detect if the package has been opened or not. By unscrewing the cap from the package, the tamper band is, as an effect, separated from the rest of the cap.

Having packages provided with caps come with a number of challenges from a production perspective. First, to assure that the environmental food print and cost are kept at low levels, the cap as well as a neck of the package made to interact with the cap should be made of materials that can provide reliable functionality at a reasonable cos. Also, the amount of material used for producing the cap and the neck should be kept as low as possible. To reduce the amount of material used for producing caps the cap should be shaped wisely to ensure that its functionality is not compromised.

Cap application in a food product filling machine is often made at very high speeds. Since failed cap application is likely to result in unwanted secondary effects, such as filling machine downtime or increased food waste, the cap should also be shaped such that the filling machine, sometimes referred as packaging machine, can reliably apply the cap onto a package.

Even though packages and caps currently available provide high reliability in terms of opening and closing functionality for consumers and cap application functionality for food producers, there is still a need for improving how the cap is shaped to achieve even better functionality, but also to reduce the amount of material needed for producing the caps.

SUMMARY

It is an object of the invention to at least partly overcome one or more of the above-identified limitations of the prior art. In particular, it is an object to provide a cap that provides proper closing functionality for a consumer as well as offers reliable cap application in a filling machine.

According to a first aspect it is provided a cap for sealing a package by applying the cap onto a neck of the package. The cap comprises a top portion having an outer top surface and an inner top surface, a cylindrical side wall portion having an outer side wall surface and an inner side wall surface, an inner thread arranged on the inner side wall surface, wherein the inner thread is arranged to interact with an outer thread of the neck of the package, and an inner cylindrical body extending from the inner top surface. The inner cylindrical body comprises a peripheral end arranged to guide the inner cylindrical body into the neck of the package, for positioning the cap with the inner cylindrical body radially inside the neck and the inner tread radially outside the neck, an annular sealing protrusion extending radially outwards from the inner cylindrical body towards the inner side wall surface, and a transition portion located between the annular sealing protrusion and the peripheral end, wherein the transition portion is concavely shaped.

An advantage with having the transition portion concavely shaped, i.e. shaped with an inward curvature, is that it gives room for positioning cylindrical body in the neck prior to the thread of the cap engaging the thread of the neck. This allows for efficient alignment of the cap relative the neck, prior to rotating the cap for screwing it onto the neck. This may allow for making the cap more compact, which may be needed if, for example, an existing cap shall be fitted with a tether band.

The transition portion may comprises a first transition sub-portion having a first inclination angle, and a second transition sub-portion having a second inclination angle, wherein the first and second inclination angles are measured with respect to an axial direction of the cap, wherein the first transition sub-portion is adjacent the peripheral end and the second transition sub-portion is adjacent the sealing protrusion, and the second inclination angle is greater than the first inclination angle.

The first inclination angle may be less than 45° and the second inclination angle may be greater than 45°. The first inclination angle may be within a range of 10-20°. The second inclination angle may be within a range of 55-60°.

A height of the transition portion may be, as seen in an axial direction of the cap, within a range of 80-120% of a height of the annular sealing protrusion.

An average width of the transition portion may be, as seen in a radial direction of the cap, within a range of 30-70% of a greatest width of the annular sealing protrusion.

The transition portion may be concavely shaped with an interior angle that is greater than 180° or greater than 200°. The interior angle may be smaller than 270°.

The transition portion may be concavely shaped with a depth, wherein the depth has a magnitude that is within a range of 5-50% of the distance from the peripheral end to the widest part of the annular sealing protrusion. The widest part of the annular sealing protrusion is the part that is widest as seen in the radial direction of the cap.

The annular sealing protrusion may be asymmetrical, as seen in plane that is parallel to the radial direction or the cap.

The cap may comprise a rim protrusion anvil having a rim protrusion anvil surface located at the inner top surface of the cap and arranged to abut, when the cap is applied onto the neck of a package, an outer top surface of the neck. A difference between an inclination angle of the outer top surface and an inclination angle of the rim protrusion anvil surface may be between 5 and 20°.

An advantage with this is that surrounding air is hindered in two steps from entering an interior of the package, both via the interaction between the rim protrusion anvil and the neck and via the annular sealing protrusion and the neck. As an effect, the risk of having unwanted microorganisms entering into the package is reduced.

According to a second aspect it is provided an arrangement for sealing a package comprising a cap according to the first aspect, and a neck having an outer thread arranged to interact with the inner thread of the cap, wherein the sealing protrusion abuts an inner neck surface of the neck when the cap is applied on the neck.

The cap may further comprise a tamper and/or tether band, and a ratio of a height of the cap without the tamper and/or tether band to a height of the neck may be less than 70%.

The second inclination angle of the second transition sub-portion of the inner cylindrical body of the cap may be arranged to substantially coincide with an inclination angle of a top surface of the neck. By substantially coincide means that the inclination angles do not deviate from each other by more than 5°.

According to a third aspect it is provided a package for holding a food product, the package comprising an arrangement for sealing according to the second aspect, and a carton-based main body to which the arrangement for sealing is connected.

According to a fourth aspect it is provided a method for applying a cap according to the first aspect onto a neck having the outer thread arranged to interact with the inner thread of the cap. The method comprises guiding the inner cylindrical body of the cap into the neck by using the peripheral end of the inner cylindrical body, gripping the cap to the neck by using the inner thread of the cap and the outer thread of the neck, and sealing the package by rotating the cap relative the neck such that the sealing protrusion of the inner cylindrical body is pressed towards an surface of the neck. This fourth aspect has the same advantages as the first aspect.

The step of guiding may further comprise the sub-step of sliding a second transition sub-portion of a transition portion of the inner cylindrical body of the cap along a rim protrusion top surface of the neck.

The step of sealing may further comprise the sub-step of blocking surrounding air from passing by pressing a rim protrusion side surface of the neck towards a rim protrusion anvil surface of a rim protrusion anvil placed on an inner top surface of the cap.

According to a fifth aspect it is provided a method for producing a package filled with a food product. The method comprises forming a carton-based main body with an open top end and an open bottom end in a sleeve forming station in a filling machine, moulding a shoulder and a neck of the package in the moulding station such that the shoulder is connected to the open top end of the carton-based main body and the open top end is closed, applying a cap onto the neck according to the fourth aspect, filling the package with a food product via an open bottom of the carton-based main body in a filling station in the filling machine, and closing the open bottom in a bottom forming station of the filling machine.

Still other objectives, features, aspects and advantages of the invention will appear from the following detailed description as well as from the drawings.

DETAILED DESCRIPTION

FIG.1illustrates by way of example a package100, more particularly a so-called carton bottle package.

The package100is provided with a cap102. The cap102may be made of polypropylene (PP), but other materials are also possible. The cap102can be connected to a neck200, as illustrated inFIGS.2A and2B, and the neck200can in turn be connected to a shoulder104. When producing the package100, the neck and shoulder104may be molded at the same time and in this way constitute one and the same element. Another alternative is to have the neck pre-made and only mould the shoulder104in the filling machine. When moulding the neck and shoulder104, or only shoulder in case the neck is pre-made, the shoulder can be connected to a carton-based main body106. The main body106may be formed from a sheet of packaging material that is folded and longitudinally sealed. In an interior108of the package100, a food product110can be held.

FIGS.2A and2Billustrate the cap102and the shoulder104in further detail and separated from one another.FIG.2Aprovides a perspective view from above andFIG.2Bprovides a perspective view from below.

The neck200is, as illustrated, connected to the shoulder104via a connection rim202. In case the neck200and shoulder104are molded in one piece, as is the case in the illustrated neck and should inFIGS.2A and2B, the connection rim202may be a thickened section assuring rigidity when screwing and unscrewing the cap102from the neck200. Further, the cap102may be provided with a tamper and/or tether band204, i.e. a ring, placed at a lower part of the cap102, that remains with the neck200once the cap is unscrewed for the first time. In the example illustrated inFIGS.2A and2B, the cap102is to be applied to the package100, i.e. screwed onto the package100for the first time, and for this reason the tamper and/or tether band204is attached to the cap102.

The cap102, illustrated by way of example, comprises a top portion205having an outer top surface206, facing outwards when the cap102is applied, and an inner top surface207, facing inwards when the cap102is applied. The cap102has a cylindrical side wall portion209having an outer side wall surface208and an inner side wall surface216. The outer side wall surface208may be provided with vertical grooves, as illustrated, to provide improved gripping for consumers.

The neck200has a cylindrical side wall portion217that is connected to the shoulder104and comprises an outer neck surface210and an inner neck surface212.

To provide for that the cap102and the neck200can interact with one another, the neck200is provided with an outer thread214facing radially R outwards, and the inner side wall surface216of the cap102is provided with an inner thread218facing radially R inwards.

FIGS.3A and3Billustrate cross-sectional views of the cap102, neck200and shoulder104in a pre-sealed state and a sealed state, respectively.FIG.3Aillustrates a state in which the cap102is placed on the neck200, but not fully applied, i.e. screwed onto the neck200, whileFIG.3Billustrates a state in which the cap102is fully applied onto the neck200.

As illustrated inFIGS.3A and3B, as well asFIG.2B, the cap102is provided with an inner cylindrical body300extending from the inner top surface207of the cap102. A peripheral end306of the inner cylindrical body300, is used for guiding, or directing, the cap102correctly with respect to the neck200during the cap application in the filling machine. As explained more in detail below, the peripheral end306may be tapered to provide for more reliable guiding during the cap application.

To provide for that the package100is adequately sealed when the cap102is applied onto the neck200, either in the cap application process in the filling machine or when being re-closed by the consumer, an annular sealing protrusion304may be provided. As illustrated, the annular sealing protrusion304may extend radially R outwards from the inner cylindrical body300. Between the peripheral end306and the annular sealing protrusion304, a transition portion308is provided. Since the cap102may be molded in one piece, the transition portion308may constitute a continuous transition from the peripheral end306to the annular sealing protrusion304. Having such continuous transition, i.e. having no sharp edges, may be advantageous in that a risk of having food residues stuck can be reduced, which in turn improves food safety.

The tamper and/or tether band204, i.e. a ring for assuring that the package has not been tampered and/or for tethering the ring to the package100, may comprise a spring element312providing for that the cap102with the tamper and/or tether band204can be applied onto the neck200, but that the tamper and/or tether band204remains, due to interaction between the spring element312and a protrusion of the neck200, with the neck200once the package100is opened for the first time by the consumer. To provide for that the tamper and/or tether band204can be wholly or partly separated from the cap102, perforations may be provided in the cap102.

Having the annular sealing protrusion304is advantageous in that a risk of having surrounding air entering the interior108of the package100can be reduced. Since microorganisms, such as spores and bacteria, that may risk deteriorating the food product110may be present in the surrounding air, reducing an inflow of the surrounding air is advantageous. It also prevents leakage from the package. As illustrated inFIG.3A, having the annular sealing protrusion304provides for that even if not having the cap102fully applied, the annular sealing protrusion304may reduce such inflow. Once the cap102is applied fully, as illustrated inFIG.3B, the annular sealing protrusion304abuts the inner neck surface212in combination with that the neck200abut the inner top surface207of the cap102such that two closures are achieved. Generally, having caps and necks providing two closures provides a more reliable sealing of the package100compared to caps and necks only providing one closure.

As illustrated, a height HNECKof the neck200may greater than a height HCAPof the cap102. Further, a height HCAP′of the cap102with the tamper and/or tether band204removed is less that the height HCAPof the cap102with the tamper and/or tether band204.

FIGS.4A and4Billustrate the pre-sealed state shown inFIG.3Ain further detail. As can be seen, the transition portion308may be divided in a first transition sub-portion400located adjacent to the peripheral end306and a second transition sub-portion402located adjacent to the annular sealing protrusion304. The first transition sub-portion400may be inclined with a first inclination angle a that is less than 45°, more particularly in the range of 10° to 20° measured with respect to an axial direction A of the cap102. The second transition sub-portion402may be inclined with a second inclination angle b that is greater than 45°, more particularly in the range of 55° to 60° also measured with respect to the axial direction A. Having the first inclination angle a greater than the second inclination angle b is advantageous in that a lowermost part of the inner cylindrical body300may more easily be fitted into the neck200during the cap application in the filling machine, but still have the possibility to block out the surrounding air efficiently by the annular sealing protrusion304.

A rim protrusion404may be provided on the outer neck surface210. This protrusion can have a rim protrusion top surface406inclined radially inwards and a rim protrusion side surface408inclined radially outwards. More specifically, the rim protrusion top surface406may be inclined by a third inclination angle c, which may be in the range of 55° to 60° with respect to the axial direction A. Having the second and third inclination angle b, c about the same, i.e. having a surface of the second transition sub-portion402parallel to the rim protrusion top surface406, is beneficial in that the cap102is more easily applied on the neck200. The rim protrusion side surface408may be inclined by a fourth inclination angle d, which may be in the range 140° to 150° with respect to the axial direction A.

On the inner top surface207of the cap102, a rim protrusion anvil410is provided. This anvil410may be inclined by a fifth inclination angle e, which may be in the range 130° to 140° with respect to the axial direction A. A difference between the fourth and fifth inclination angle d-e may be 5° to 20°. A tight fit between the anvil410and the rim protrusion side surface408can be achieved once the cap102is screwed onto the neck200.

As illustrated, a height h1of the transition portion308may be 100-150% of a height h2of the annular sealing protrusion304, as seen in the axial direction A. Further, an average width w1of the transition portion308may be 30% to 60% of an average width w2of the annular sealing protrusion304.

The transition portion308may be concavely shaped, or with other words, be concave. Having the transition portion308concaved gives rise to a depth d2. The depth d2may be within a range of 5-50% of the distance I from the peripheral end306to the widest part of the annular sealing protrusion304. The transition portion308may be concavely shaped with an interior angle e that is greater than 180°, or is greater than 200°.

An advantage with having the transition portion308concavely shaped is that the cap112can be made more compact height wise. This advantageous in that more room can be provided to the tamper and/or tether band204. For instance, this may provide for that the neck200can remain the same even if the cap102is redesigned to include not only a tamper band, but a combined tamper and tether ring that requires more room height wise. Another advantage linked to the more compact cap height is that the amount of material needed for producing the cap102can be reduced, which is beneficial from cost as well as from an environmental perspective.

FIG.5is a flowchart presenting steps of a method500for applying the cap102onto the package100. In a first step502, the inner cylindrical body300is guided into the neck200by using the peripheral end306of the inner cylindrical body300. In a second step504, the cap102is gripping to the neck200by using the inner thread218of the cap102and the outer thread214of the neck200. In a third step506, the package100is sealed by screwing the cap onto the neck, which results in pressing the sealing protrusion304of the inner cylindrical body300towards the neck200. Optionally, in a fourth step508, the second transition sub-portion402of the transition portion308of the inner cylindrical body300of the cap102is slid along a rim protrusion top surface406of the neck200. Optionally, in a sixth step510, surrounding air is blocked from passing by pressing the rim protrusion side surface408of the neck200towards a rim protrusion anvil surface412of the rim protrusion anvil410placed on the inner top surface207of the cap102.

FIG.6is a flowchart presenting steps of a method600for producing the package100filled with the food product110. In a first step602, with further reference toFIG.7, the carton-based main body106with an open top end and an open bottom end in a sleeve forming station702is formed in a filling machine700. In a second step604, the shoulder104and the neck200of the package100is molded in a moulding station704such that the shoulder104is connected to the open top end of the carton-based main body106and the open top end is closed. In a third step606, the cap102is applied onto the neck200according to the method illustrated inFIG.5. In a fourth step608, the package100is filled with the food product110via the open bottom of the carton-based main body106in a filling station706in the filling machine700. In a fifth step610, the open bottom is closed in a bottom forming station708of the filling machine700.

FIG.7generally illustrates the filling machine700referred to above. As illustrated, the sleeve forming station702may be provided for forming the carton-based main body106. The moulding station704, which may be a plastic injection moulding station, may be used for forming the neck200and the shoulder104and may include a cap applicator for applying the cap102on the shoulder104. In the filing station706, the food product110may be filled into the package100. Finally, in the bottom forming station708, the open bottom of the carton-based main body106may be closed. The filling machine may be any suitable, conventional filing machine. The cap itself may be premanufactured prior to being applied on the neck. The manufacturing of the cap can per se be accomplished by using conventional techniques for plastic moulding and/or injection.

From the description above follows that, although various embodiments of the invention have been described and shown, the invention is not restricted thereto, but may also be embodied in other ways within the scope of the subject-matter defined in the following claims.