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.

Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example, with reference to the accompanying schematic drawings, in which

Fig. 1 is a perspective view of a package.

Fig. 2A and 2B illustrate a cap and a shoulder of the package of Fig. 1.

Fig. 3A is a cross-sectional view of the cap and the neck in a pre-sealed state.

Fig. 3B is a cross-sectional view of the cap and the neck in a sealed state.

Fig. 4A and 4B illustrate part of the cross-sectional view illustrated in fig. 3A in further detail.

Fig. 5 is a flow chart illustrating a method for applying the cap onto the package.

Fig. 6 is a flow chart illustrating a method for producing the package. Fig. 7 is a schematic view of a filling machine for producing the package.

Detailed Description

Fig. 1 illustrates by way of example a package 100, more particularly a so- called carton bottle package.

The package 100 is provided with a cap 102. The cap 102 may be made of polypropylene (PP), but other materials are also possible. The cap 102 can be connected to a neck 200, as illustrated in fig. 2A and 2B, and the neck 200 can in turn be connected to a shoulder 104. When producing the package 100, the neck and shoulder 104 may 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 shoulder 104 in the filling machine. When moulding the neck and shoulder 104, or only shoulder in case the neck is pre-made, the shoulder can be connected to a cartonbased main body 106. The main body 106 may be formed from a sheet of packaging material that is folded and longitudinally sealed. In an interior 108 of the package 100, a food product 110 can be held.

Fig. 2A and 2B illustrate the cap 102 and the shoulder 104 in further detail and separated from one another. Fig. 2A provides a perspective view from above and fig. 2B provides a perspective view from below.

The neck 200 is, as illustrated, connected to the shoulder 104 via a connection rim 202. In case the neck 200 and shoulder 104 are molded in one piece, as is the case in the illustrated neck and should in fig. 2A and 2B, the connection rim 202 may be a thickened section assuring rigidity when screwing and unscrewing the cap 102 from the neck 200. Further, the cap 102 may be provided with a tamper and/or tether band 204, i.e. a ring, placed at a lower part of the cap 102, that remains with the neck 200 once the cap is unscrewed for the first time. In the example illustrated in fig. 2A and 2B, the cap 102 is to be applied to the package 100, i.e. screwed onto the package 100 for the first time, and for this reason the tamper and/or tether band 204 is attached to the cap 102.

The cap 102, illustrated by way of example, comprises a top portion 205 having an outer top surface 206, facing outwards when the cap 102 is applied, and an inner top surface 207, facing inwards when the cap 102 is applied. The cap 102 has a cylindrical side wall portion 209 having an outer side wall surface 208 and an inner side wall surface 216. The outer side wall surface 208 may be provided with vertical grooves, as illustrated, to provide improved gripping for consumers. The neck 200 has a cylindrical side wall portion 217 that is connected to the shoulder 104 and comprises an outer neck surface 210 and an inner neck surface 212.

To provide for that the cap 102 and the neck 200 can interact with one another, the neck 200 is provided with an outer thread 214 facing radially R outwards, and the inner side wall surface 216 of the cap 102 is provided with an inner thread 218 facing radially R inwards.

Fig. 3A and 3B illustrate cross-sectional views of the cap 102, neck 200 and shoulder 104 in a pre-sealed state and a sealed state, respectively. Fig. 3A illustrates a state in which the cap 102 is placed on the neck 200, but not fully applied, i.e. screwed onto the neck 200, while fig. 3B illustrates a state in which the cap 102 is fully applied onto the neck 200.

As illustrated in fig. 3A and 3B, as well as fig. 2B, the cap 102 is provided with an inner cylindrical body 300 extending from the inner top surface 207 of the cap 102. A peripheral end 306 of the inner cylindrical body 300, is used for guiding, or directing, the cap 102 correctly with respect to the neck 200 during the cap application in the filling machine. As explained more in detail below, the peripheral end 306 may be tapered to provide for more reliable guiding during the cap application.

To provide for that the package 100 is adequately sealed when the cap 102 is applied onto the neck 200, either in the cap application process in the filling machine or when being re-closed by the consumer, an annular sealing protrusion 304 may be provided. As illustrated, the annular sealing protrusion 304 may extend radially R outwards from the inner cylindrical body 300. Between the peripheral end 306 and the annular sealing protrusion 304, a transition portion 308 is provided. Since the cap 102 may be molded in one piece, the transition portion 308 may constitute a continuous transition from the peripheral end 306 to the annular sealing protrusion 304. 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 band 204, i.e. a ring for assuring that the package has not been tampered and/or for tethering the ring to the package 100, may comprise a spring element 312 providing for that the cap 102 with the tamper and/or tether band 204 can be applied onto the neck 200, but that the tamper and/or tether band 204 remains, due to interaction between the spring element 312 and a protrusion of the neck 200, with the neck 200 once the package 100 is opened for the first time by the consumer. To provide for that the tamper and/or tether band 204 can be wholly or partly separated from the cap 102, perforations may be provided in the cap 102. Having the annular sealing protrusion 304 is advantageous in that a risk of having surrounding air entering the interior 108 of the package 100 can be reduced. Since microorganisms, such as spores and bacteria, that may risk deteriorating the food product 110 may be present in the surrounding air, reducing an inflow of the surrounding air is advantageous. It also prevents leakage from the package. As illustrated in fig. 3A, having the annular sealing protrusion 304 provides for that even if not having the cap 102 fully applied, the annular sealing protrusion 304 may reduce such inflow. Once the cap 102 is applied fully, as illustrated in fig. 3B, the annular sealing protrusion 304 abuts the inner neck surface 212 in combination with that the neck 200 abut the inner top surface 207 of the cap 102 such that two closures are achieved. Generally, having caps and necks providing two closures provides a more reliable sealing of the package 100 compared to caps and necks only providing one closure.

As illustrated, a height HNECK of the neck 200 may greater than a height HCAP of the cap 102. Further, a height HCAP’ of the cap 102 with the tamper and/or tether band 204 removed is less that the height HCAP of the cap 102 with the tamper and/or tether band 204.

Fig. 4A and 4B illustrate the pre-sealed state shown in fig. 3A in further detail. As can be seen, the transition portion 308 may be divided in a first transition subportion 400 located adjacent to the peripheral end 306 and a second transition subportion 402 located adjacent to the annular sealing protrusion 304. The first transition sub-portion 400 may 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 cap 102. The second transition sub-portion 402 may 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 body 300 may more easily be fitted into the neck 200 during the cap application in the filling machine, but still have the possibility to block out the surrounding air efficiently by the annular sealing protrusion 304.

A rim protrusion 404 may be provided on the outer neck surface 210. This protrusion can have a rim protrusion top surface 406 inclined radially inwards and a rim protrusion side surface 408 inclined radially outwards. More specifically, the rim protrusion top surface 406 may 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-portion 402 parallel to the rim protrusion top surface 406, is beneficial in that the cap 102 is more easily applied on the neck 200. The rim protrusion side surface 408 may 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 surface 207 of the cap 102, a rim protrusion anvil 410 is provided. This anvil 410 may 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 anvil 410 and the rim protrusion side surface 408 can be achieved once the cap 102 is screwed onto the neck 200.

As illustrated, a height hi of the transition portion 308 may be 100-150% of a height h2 of the annular sealing protrusion 304, as seen in the axial direction A. Further, an average width w1 of the transition portion 308 may be 30% to 60% of an average width w2 of the annular sealing protrusion 304.

The transition portion 308 may be concavely shaped, or with other words, be concave. Having the transition portion 308 concaved gives rise to a depth d2. The depth d2 may be within a range of 5-50% of the distance I from the peripheral end 306 to the widest part of the annular sealing protrusion 304. The transition portion 308 may be concavely shaped with an interior angle e that is greater than 180°, or is greater than 200°.

An advantage with having the transition portion 308 concavely shaped is that the cap 112 can be made more compact height wise. This advantageous in that more room can be provided to the tamper and/or tether band 204. For instance, this may provide for that the neck 200 can remain the same even if the cap 102 is 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 cap 102 can be reduced, which is beneficial from cost as well as from an environmental perspective.

Fig. 5 is a flowchart presenting steps of a method 500 for applying the cap 102 onto the package 100. In a first step 502, the inner cylindrical body 300 is guided into the neck 200 by using the peripheral end 306 of the inner cylindrical body 300. In a second step 504, the cap 102 is gripping to the neck 200 by using the inner thread 218 of the cap 102 and the outer thread 214 of the neck 200. In a third step 506, the package 100 is sealed by screwing the cap onto the neck, which results in pressing the sealing protrusion 304 of the inner cylindrical body 300 towards the neck 200. Optionally, in a fourth step 508, the second transition sub-portion 402 of the transition portion 308 of the inner cylindrical body 300 of the cap 102 is slid along a rim protrusion top surface 406 of the neck 200. Optionally, in a sixth step 510, surrounding air is blocked from passing by pressing the rim protrusion side surface 408 of the neck 200 towards a rim protrusion anvil surface 412 of the rim protrusion anvil 410 placed on the inner top surface 207 of the cap 102.

Fig. 6 is a flowchart presenting steps of a method 600 for producing the package 100 filled with the food product 110. In a first step 602, with further reference to Fig. 7, the carton-based main body 106 with an open top end and an open bottom end in a sleeve forming station 702 is formed in a filling machine 700. In a second step 604, the shoulder 104 and the neck 200 of the package 100 is molded in a moulding station 704 such that the shoulder 104 is connected to the open top end of the cartonbased main body 106 and the open top end is closed. In a third step 606, the cap 102 is applied onto the neck 200 according to the method illustrated in fig. 5. In a fourth step 608, the package 100 is filled with the food product 110 via the open bottom of the carton-based main body 106 in a filling station 706 in the filling machine 700. In a fifth step 610, the open bottom is closed in a bottom forming station 708 of the filling machine 700.

Fig. 7 generally illustrates the filling machine 700 referred to above. As illustrated, the sleeve forming station 702 may be provided for forming the cartonbased main body 106. The moulding station 704, which may be a plastic injection moulding station, may be used for forming the neck 200 and the shoulder 104 and may include a cap applicator for applying the cap 102 on the shoulder 104. In the filing station 706, the food product 110 may be filled into the package 100. Finally, in the bottom forming station 708, the open bottom of the carton-based main body 106 may 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.