The present invention relates to closures for containers and, more particularly to plastic caps provided with coloured imagery for bottles.

BACKGROUND

Plastic bottles and other plastic containers are produced in huge numbers. Typically plastic bottles are provided with screw caps, frequently with some form of tamper indicating skirt.

The upper surface of such caps, provides space for Indicia and imagery, either for the purpose of promoting a brand name or providing useful information to a consumer. Imagery to make the purchase of the bottle more attractive may also be embossed on the cap surface. A disadvantage of the manufacturing process of known plastic caps is that the imagery is restricted to the colour of the plastic material in which the cap is moulded.

It is an object of the present invention to address or at least ameliorate some of the above disadvantages.

Notes

1. The term "comprising" ^' (and grammatical variations thereof) is used in this specification in the inclusive sense of "having" or "including", and not in the exclusive sense of "consisting only of . 2. The above discussion of the prior art in the Background of the invention, is not an admission tha any information discussed therein is citable prior art or part of the common general knowledge of persons skilled in the art in any country.

BRIEF DESCRIPTION OF INVENTION

Accordingly, in a first broad form of the invention, there is provided a method of providing imagery on an injection moulded cap for a container; said method including the steps of:

(a) printing a multi-coloured image onto a substrate,

(b) placing said substrate into an injection moulding die,

(c) injection moulding said cap, and

wherei an upper surface of said cap fuses with said substrate.

Preferably, said injection moulding die is provided with a substrate supporting feature cap forming cavity of said injection moulding die for retaining said substrate prior to said injection moulding.

Preferably, said substrate supporting feature comprises a substrate holding cavity.

Preferably, said substrate supporting feature comprises an area provided with a vacuum source for retaining said substrate. Preferably, said- substrate supporting feature is is provided in that portion of each cap forming cavity defining said upper surface of Baid cap.

.Preferably, said multi-coloured image is at least a four colour image.

Preferably, said multi-coloured image is at least a four colour lenticular image.

Preferably, said substrate holding cavity is shaped so as to form a three dimensional structure on said upper surface of said cap; said three dimensional structure coloured corresponding to colours of said substrate.

In another broad form of the invention, there is provided a closure for a container; said closure displaying a multicoloured image on an upper surface of said closure; said multi-coloured image comprising a substrate fused to said upper surface.

Preferably, said closure comprises a plastic cap for a beverage container.

Preferably, said multi-colou image is a four colour lenticular image.

Preferably, said image is formed on a three dimensional structure projecting from said upper surface.

Preferably, said image is formed on said upper surface by an injection moulding process.

Preferably, said substrate is located in line with a cavity forming said closure in a plastic injection die. In still another broad form of the invention, there is provided a plastic cap for a beverage bottle; said plastic cap including an upper surface provided with a multicoloured image; said multi-coloured image fused to said uppe surface.

Preferably, said multi-coloured image is printed on a polymer substrate; said substrate fused to said upper surface in an injectio moulding process.

Preferably, said upper surface is a flat surface; said multi-coloured image forming a two-dimensional image.

Preferably, said substrate is printed with a lenticular multi-colour image.

Preferably, a cavity retaining said substrate in said injection moulding process is shaped so as to form a three- dimensional projection from said upper surface; said image forming a three-dimensional representation on said plastic cap.

Preferably said cap is formed in an automated injection moulding process.

Preferably said automated injection moulding process utilises a robotic arm for picking and placing substrates into an injection mould cavity, said substrates incorporated into said substrate forming feature. BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the present invention will now be described with reference to the accompanying drawings wherein:

Figure 1 is a top view of a plastic cap for a beverage · container according to a first preferred embodiment of the invention, showing a four-colour two-dimensional image on an upper surface of the cap,

Figure 2 is a side view of a plastic cap for a beverage container according to a second preferred embodiment in which the cap has been provided with a four- colour three-dimensional representation projecting from the upper surface of the cap,

Figure 3 is a perspective view of the cap of Figure 2 showing the projected representation of a promotional figure.

Figure 4 illustrates diagrammatically an automated process for production of the cap described with reference to previous figures .

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Firat Preferred Embodiment

The invention resides in the provision on the upper surface of a losure or cap for a container, a multi- coloured, preferably at least a four colour image. In a preliminary process, a desired image is printed onto a transparent substrate of polymer material. This material may be the same polymer as that used for the cap, for example polypropylene, polyethylene terephthalate (PET) , polystyrene (PS) or at least a compatible polymer. Pref rably, the substrate is trimmed to the extents of the printed image.

In a first preferred embodiment of the invention with reference to Figure 1, a plastic cap 10 for a container (not shown), in this instance a beverage container, is formed in an injection moulding operation. Typically the die used for moulding will be a multi-cavity die, possibly with unscrewing mechanisms for screw caps depending on the thread and material characteristics.

In one arrangement, in which the injection die gating is central to the cap, the pre-printed substrate is prepared with a small, typically 1mm diameter hole which coincides with the injection die gate when the substrate is positioned prior to the injection cycle.

In a more preferable arrangement, the caps are injection moulded with a side gating system, thereby obviating the need to inject through the image bearing substrate.

For the purposes of the invention, an otherwise conventional injection moulding die is modified in that the part of the cap-forming cavities which define the upper - Ί - surface of the cap, are provided with substrate supporting features.

In one preferred arrangement, the substrate supporting feature is a shallow cavity, of a shape and configuration to confine the perimeter of the substrate, centred in the end of the cap forming cavity.

In another arrangement, a substrate in the form of a relatively thin foil of the polymer material _/ may be retained in position in the cavity by provision of a vacuum source in communication with small orifices in the cap upper surface forming end of the die cavity.

The multi-colour image printed on the substrate may be a simple flat, colour image. Alternately the image may be printed in lenticular form so as to present the illusion of

^■ ■ v

a three-dimensional image on the cap's upper surface. In at least some forms of the preparation of the substrate, the lenticular technologies incorporated may include "two phase lenticular", Ultra 3D Lenticular, as well as multiphase, morph and zoom lenticular. The image printed on the substrate may further include holographic images.

Othe possible forms for the substrate may include the use of UV reactive, thermochromatic and hydrchromatic inks.

In still a further variation, the image may be printed onto a ferrous metal substrate so as to make the moulded cap reactive to a magnetic field. The cap may be moulded from a transparent polymer. In this case, the substrate may be printed on the reverse side (that is the side facing the cap surface) with such information as a promotional alphanumeric code or a "smart phone" readable bar or QR code for example.

Once the die cavities have been prepared by the insertion of the substrates, a normal injection cycle follows in which polymer is injected into the cap-forming cavities. The injected polymer, which initially flows into the cavities in fluid form at elevated temperature and pressure, readily fuses with the polymer of the substrate. By this means, the image 12 becomes an inseparable part, of the cap 10 displaying the image 12 in at least four colours.

Seoond Preferred Embodiment

In a second preferred embodiment, a substrate with a multi-colour printed image is similarly prepared. In this instance however _/ the end of the cap forming cavities of an injection die are prepared with a three dimensional shape 14, such as that shown on the surface of the cap in Figures 2 and 3.

In one preferred arrangement, the printed substrate is thermoformed to assume a desired three dimensional shape prior to the injection moulding of the cap.

This three dimensional shape may represent some hero character or action figure, for example attractive to children. I this embodiment also, a prepared substrate, which is configured in size to allow for its deformation in the cavity/ is placed in each of the cavities as described above, followed by an injection cycle.

In this embodiment the injected polymer forms not only the cap 10 but flows into the three-dimensional cavity defining the shape 14 of the printed figure. As before, the substrate, which now conforms to the three-dimensional shape, becomes an inseparable part of the injection moulded cap, with the three dimensional image projecting from the upper surface of the cap.

Automated assembly

With reference to figure 4 there is illustrated a process for automation of production of any of the caps 10 described in previous embodiments . In this instance in a first stage of an injection moulding process there is provided a mould 20 having at least one cavity 21. The cavity is adapted to form at least part of the exterior of a cap 14.

In stage 2 as illustrated in figure 4 a substrate 22 incorporating a multicolour image in any of the forms as previously described is picked up by an automated arm 23 of a robotic device 24 and the substrate 22 inserted into interior 21 of mould 20 as illustrated. The substrate 22 can include specific identifying indicia 25 unique to each substrate and therefore ultimately unique to each cap produced with the substrate.

In stage three the mould is closed by insertion of a second mould 26 which includes exterior parts which conform to the insides of cap 10. Having closed the mould the injection step takes place wherein plastics material is injected into the cavity 27 defined between the first mould 20 and the second mould 26. Injection can take place via an appropriate entry channel into the cavity 27. In one instance the path to the cavity passes through the centre of substrate 22. In the course of heating the injected material in the cavity as part of the injection moulding process and as previously described the substrate 22 conforms to the walls of the cavity and becomes fused with the injected material forming the cap 10.

At the completion of the injection and fusing step the second mould assembly 26 is removed from the die assembly and the cap 10 is ejected. In this instance the cap 10 has formed integrally in its top external surface a three- dimensional image 14 as described in previous embodiments and, in this instance, also a unique identifier 25 which is associated visually therewith. In particular embodiments there will be many cavities for injection in one mould assembly. In one instance, for example, there may be 24 cavities which will therefore allow simultaneous production of 24 caps at the one time.

A typical expected injection cycle is two seconds.

Base materials which can be used include plastics materials including but not limited to HDPE/PP/LDPE and PP.

The automated process provides a 3D image result. However the process can be utilised to produce ID images fused to the cap as described in earlier embodiments. Lenticular is one form of 1 dimensional image but a 3D image can be produced in fused form as well by a process of pre forming of a thermoformed 3D carcass that is then placed into the cavity to form a 3D image to the top of the cap or other closure for a bottle or container.

In Uao

The caps according to the invention may be used in game play. For example, a cap may be flicked between thumb and forefinger to roll along a surface in a competition for the furthest or most accurate trajectory. In the case of a ferrous metal based substrate, a game may include the player attempts to piqk the cap up with a magnet.

Caps may be prepared with a form of sequential imagery, for example the players in a favoured .football team, or all the models of a particular brand of vehicle or product, so as to make the caps collectable. Collectability would allow promotional applications, as would the provision of unique codes included on the substrate.

Finally, caps could become a form of ^currency" with different caps having different values for the redemption of discounts on beverages or other products.

The above describes only some embodiments of the present invention and modifications, obvious to those skilled in the art, can be made thereto without departing from the scope of the present invention.