BEVERAGE CUP

Field of the invention

The present invention relates to a beverage cup of the type containing a single serving of a beverage concentrate which is packaged and sealed within the cup.

Background of the invention

Such a beverage cup is described in US 3,870,220. In the latter patent, a large drinking cup made of polystyrene includes a smaller cup-shaped insert that is held in place in the bottom of the polystyrene cup by an undercut. A concentrate placed within the insert is covered by means of a foil that seals around the rim of the insert. The foil and the material of the insert are impervious to air so that the concentrate remains fresh until the foil is removed by pulling on a tab of the foil. After removal of the foil, water is added into the cup to prepare the beverage in the cup from which it is to be drunk.

Another cup made of a foamed plastics material that has an internal cavity for receiving a beverage concentrate is described in US 3,407,922.

It is generally preferred to make such cups from paper rather than polystyrene and there are cups currently available in which a plastics insert is retained within a paper cup. The term "paper" is used herein in its commonly understood sense in the present context, to include boards of different weights both with and without a plastics coating.

Hitherto, paper cups have been made which have a plastics insert for receiving a beverage concentrate, the insert having an upper lip to which a foil can be sealed. In

most such cases, the paper cup had a paper bottom that serves to retain liquid within the cup and the insert is bonded to the cup to prevent it from falling out while the beverage is being drunk.

In one of the embodiments described in the Applicant's earlier PCT publication No. WO2004/074111 there is shown a paper cup which does not have a paper bottom and relies instead on the insert to close off the bottom of the cup. In that case, the sealing between the plastics insert and the paper side wall of the cup is effected by turning over the lower edge of the paper side wall to wrap its lower edge about cylindrical projection on the underside of the insert, the paper then being bonded to the inside surface of the projection.

Summary of the invention

According to the present invention, there is provided a beverage cup comprising a paper side wall and a plastics base having the form of a shallow cup, the upper rim of the base defining a surface for bonding to a foil to form within the base a hermetically sealed compartment for receiving a beverage concentrate, characterised in that the paper side wall of the cup is joined to the base by bonding the inner surface of the paper side wall to the outer surface of the side wall of the base.

While, in principle, both the paper side wall and the base may be cylindrical, it is preferred for stacking purposes for them to be frustoconical, to enable cups to he stacked. The paper side wall may suitably be made, in a conventional manner, of a folded blank of which the edges are overlapped and bonded to one another.

In the present invention, the cup is formed using a paper wall but instead of using paper to form the bottom of

the cup, as in normal paper cups, a plastics base is used to close off the bottom of the cup. The under surface of the base is conveniently flat, thus providing a stable support for the cup.

Using a plastics base to close off the bottom of the cup yields several advantages, amongst them:

• A cost reduction because there is no paper required to form a base. • A cost reduction as compared with paper cups having a plastics insert, as there is no need to weld the plastics insert separately to the paper bottom the cup.

• A reduction in wastage resulting from an insert not adhering to the paper base of a cup. • A reduction in wastage resulting from the bottom of a cup not being properly sealed and leaking when the cup is filled with water.

• A strengthening of the lower edge of the paper side wall on account of its being welded to the plastics base. • An increase in the volume of product that can be packaged in the base without loss of stacking height on account of the outer wall of the base being parallel to the paper side wall of the cup. This is to be contrasted with the cup described in US 3,407,922 where the bottom does not allow space for the modern dry powders that contain foaming agents.

Unlike the cup described in WO2004/074111, as long as the paper side wall in the present invention overlaps the side wall of the plastics cup, though it may do so, it need not necessarily extend as far down as the bottom of the cup (i.e. the surface on which on which it rests when placed on a flat support), let alone beyond it. In addition to the advantages listed above, this makes for more economical use of the paper. Furthermore, the height of the cup is reduced for a given capacity and the pitch of the cups is reduced

when cups are stacked one inside the other, both these improvements serving to increase the packing density.

The paper side wall of the cup may be bonded to the plastics base using an applied adhesive or welding. When welding, it is important to ensure that there is sufficient plastics material present at the join between the paper side wall and the plastics base to form a strong bond while at the same time filling any voids near the step formed by the overlapping edges of the paper blank from which the side wall is formed.

The paper side wall normally has a plastics coating to render it waterproof and one way of ensuring that there is sufficient plastics material available to form a watertight joint between the paper side wall and the base is to increase the thickness of the coating.

It is however preferred to provide the outer surface of the base with at least one projecting annular bead.

A weld can be formed between the plastics base and the paper side wall in any suitable manner, for example by application of heat, but it is preferred to employ ultrasonic welding.

The cup of the invention can be manufactured more simply than prior art paper cups with plastics inserts because of the need for fewer folding steps. After a cut flat blank has been folded over and its edges bonded to one another to form a cone, it is only necessary, for the purpose of joining it to the base, to place the cone around the base and weld the two to one another. The base can be lowered into the paper cone while the cone is held in a former, and energy applied to effect the bonding while pressure is applied to urge the base and the paper side wall against one another.

Brief description of the drawings

The invention will now be described further, by way of example, with reference to the accompanying drawings, in which:

Figure 1 shows a section through a plastics base, Figure 2 is a section through a paper side wall, Figure 3 is a plan view of a foil for sealing the compartment in the base after a beverage concentrate has been placed within it,

Figure 4 is a section through a cup of the invention assembled from the three components shown in Figures 1 to 3, and

Figure 5 is a section of through three cup when stacked one inside the other.

Detailed description of the preferred embodiment

Figure 1 shows a base 10 made of a plastics material, such as polyethylene, which has a frustoconical side wall

12, a bead 14 projecting from the side wall 12 and a top rim 16 to which a foil can be attached to form within the base 10 a hermetically sealed compartment for receiving a beverage concentrate.

Figure 2 shows a frustoconical paper side formed by folding over a flat blank having the shape of a section of an annulus and overlapping and bonding the opposite edges of the blank, the overlap region being designated 22 in Figure 2. The blank is preferably formed from a plastics coated paper, the plastics coating being arranged on the inner surface of the cone. After forming of the cone, the upper edge is rolled over to strengthen the mouth of the cup and form a drinking lip 24.

Figure 3 shows the foil for forming a hermetically sealed compartment in the base 10. The foil 10, normally

made of aluminium, has a disc 30 shaped and dimensioned to fit over the rim 16 of the base 10 and a strip 32 which is use to release the foil from the base 10 prior to pouring liquid into the cup.

The three components of Figures 1 to 3 are assembled to form the cup shown in Figure 4. The base 10 is inserted from above into the conical paper side wall 20. This is preferably carried out by holding the base 10 and raising the side wall 20 to fit over it. With the two held in correct alignment, heat or more preferably ultrasound radiation is applied to cause the bead 14 to melt and bond the paper side wall 20 to the base 10. Instead of the bead 14, a paper having a plastics coating of increased thickness can be used to ensure that there is sufficient molten plastics material at the join not only to effect a strong bond but also to fill in the step resulting from the overlapping of the edges of the paper blank.

Because of the frustoconical configuration of the paper side wall and the base, variations in the dimensions of the paper side walls within a permitted tolerance will not affect the quality of the joint as the base will merely sit a little lower or higher relative to the paper side wall, as can be seen in the stacked cups shown in Figure 5.

A beverage concentrate 40 is then placed within the inner compartment of the base 10 and the disk 30 of the aluminium foil is bonded to the rim 16 of the base 10 to seal the compartment. The strip 32 extends up the side wall of the cup and acts as a pull tab by means of which the foil can be released from the base 10 when a beverage is to be made .

When the cups of Figure 4 are stacked one inside the other, the pitch of the stack, that is the distance between like parts of adjacent cups, is only the height of the

concentrate compartment. Because of the flat bottoms of the cups, the volume of the stack exceeds the volume of a single cup only by the volume needed to accommodating the beverage concentrate of the remaining cups in the stack. Unlike paper cups in the prior art, there is no increase in the height of the stack on account of hollows in the bottoms of the cups.

Normally, the beverage concentrate will be a fully soluble powder, such as chocolate or instant coffee powder. This need however always be the case as one could, for example, use tea leaves. If a tea bag is placed within the base, then a string attached to the tea bag can be used to remove the tea leaves after the tea has been allowed to brew. The term concentrate should therefore be construed to include any material from which a beverage can be made, regardless of whether it is fully soluble or leaves behind a residue .