GB2548013A

GB2548013A - Beverage capsule

Info

Publication number: GB2548013A
Application number: GB1703150.1A
Authority: GB
Inventors: Gort-Barten Leslie; Gort-Barten Alex
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-02-25
Filing date: 2017-02-27
Publication date: 2017-09-06
Also published as: GB201703150D0; GB201603318D0

Abstract

A frustoconical beverage capsule 1 for use in a coffee machine is made from a polyolefin with an active oxygen scavenging additive dispersed in the polymer matrix. The capsule has an upper surface 3 and a lower surface with an annular flange 7 with sealing means (8, fig. 2) on surface facing the upper surface. The capsule is further provided with a plurality of grooves 6 in an upper surface. The upper end maybe formed of a second frustroconical part 4 and an indent 5 and the grooves may be external, on the second frustroconical part and may extend from the indent towards the edge of the second frustoconical part. The capsule may have a foil seal (8, fig. 2) which is applied at a temperature of around 220 degrees C.

Description

Beverage Capsule

The invention relates to a capsule for making espresso coffee using an espresso machine.

Powered espresso machines are well known. The conventional espresso machine comprises a water chamber, a heating element adapted to heat the water to around 95-98 C, which is then pumped under high pressure of 15 to 19 bar to a filter holder or portafilter. Lower pressure systems also exist. The filter holder typically comprises a handle portion and a holder portion provided with two or three lugs that are adapted to engage in the installed position with the machine brewhead to where the water is pumped. The holder portion is adapted to receive a filter, which is usually a metal bowl with a number of perforations through its bottom. In use, the filter is filled with finely ground coffee and the water is forced through the coffee at the high pressure generated by the pump to produce the espresso coffee which is collected in a cup placed under the filter holder.

The classic coffee machine suffers from two potential drawbacks. The first drawback is that ground coffee starts to lose its freshness and flavour after a few days and so for the optimum espresso, the user will also need to have a coffee grinder. The other drawback is that the used espresso coffee has to be removed from the filter, which can lead to mess as the grinds are fine.

This lead to the development of ESE coffee pods, which can be used in many espresso machines. Coffee pods are generally individually wrapped to maintain freshness and consist of a small pod made of a perforated filter paper which contains the coffee. The pod is placed in the filter holder and then disposed of after use. Coffee pods are convenient but have to fit the filter holder and be placed correctly otherwise water can leak around the edge.

This in turn lead to the development of capsule machines. The coffee capsules for these machines are completely sealed. The capsule machines do not use the conventional filter holder. A capsule machine typically has a two part mechanism. The first part receives the capsule and is provided with an extraction surface upon which the capsule rests. The second part is provided with a locking lever which is used to make the first and second parts integral. In use, the second part cuts the upper surface of the capsule to allow water to enter the capsule and percolate down through the capsule, where it exits through the lower surface of the capsule at multiple locations determined by the geometry of the extraction surface. An example of such a machine is disclosed in EP 0870457 or W02005/004683. Capsules in the known capsule coffee machines are, in use, inserted into a capsule cage of the machine which holds the capsule in position so that it may be cut by a cutting member.

Capsule machines have proved to be commercially very successful as they are very convenient to use and produce a consistent product. However, each manufacturers coffee machines and capsules are designed to work with the manufacturers own brand. The most popular brand of capsule is Nespresso ®, which uses a sealed capsule made of aluminium. In use, the capsule is clamped into position in the machine with a capsule cage part holding the capsule so that it can be cut by typically three prongs to enable water under pressure to enter the coffee capsule.

Aluminium has the considerable advantage that it is oxygen and water impermeable, which means that the coffee in the capsules has a long shelf life. Aluminium however also suffers from several major drawbacks in that the aluminium is easily deformed during the filling and packing stage and it is difficult and expensive to produce a reliable seal on the capsule rim. The known solutions to these problems require an extremely high capital investment.

Most manufacturers have therefore adopted plastic capsules. Plastic capsules solve the problems of the ease of handling the capsule during the packing process but require other compromises. The plastic capsule needs to be able to be pierced by the blades in the capsule coffee machine without shattering the capsule or damaging the machine. The capsule also needs to be sealed at its open end with an aluminium foil which adheres to the plastic capsule in a reliable manner and at low enough temperatures that the quality of the coffee is not impaired.

Most capsules on the market are made from polypropylene which is not air or water impermeable so that the coffee becomes stale in a matter of days. Other plastics have been tried such as PET and PBT but these suffer from the problem that they shatter in use and require too high a temperature to seal the capsule. For this reason, polypropylene is used and the capsules are packaged in nitrogen filled pillow bags to enable the plastic capsule to match the shelf life of a sealed capsule. This results in significantly increased transport and packaging costs.

The present invention therefore seeks to provide an improved coffee capsule.

According to the invention there is provided a capsule for use in a coffee machine having a generally frusto-conical form with an upper surface and a lower surface, an annular flange being provided at the lower surface, which annular flange is provided with sealing means on the surface facing towards the upper surface, wherein the capsule is made from a polyolefin with an active oxygen scavenging additive dispersed in the polymer matrix, the capsule being further provided with a plurality of grooves in an upper surface, which grooves are configured in use to be pierceable by a blade in the coffee machine.

Exemplary embodiments of the invention will now be described with reference to the drawings, in which:

Fig. 1 shows a perspective view of a first embodiment of the capsule Fig. 2 shows a cross section along the median line of the capsule Fig. 3 shows an alternative capsule

Figure 1 shows a perspective side section of capsule 1 having a generally frustoconical form for the main body 2. The upper end 3 of the capsule has a second frustoconical section 4 with a greater opening angle that the opening angle of the main body 2. The upper end of the cone frustrum therefore has a smaller diameter than the lower end. The upper end 3 is further provided with an additional frustoconical indent 5 at the centre of the upper end 3. The second frustoconical section 4 is provided with a plurality of radial grooves 6 with a reduced thickness. The grooves 6 extend from the periphery of the indent towards the edge of the second frustoconical section 4 ending about 2/3 the way to the edge. The capsule is provided with a flange 7 at the end of main body 2 remote from the upper end 3. The side of the flange facing towards the upper end is provided with a seal. The seal is shown schematically as a series of concentric upstanding rings but may take other forms such as having cut outs or internal members at an angle or potentially could comprises a silicone member.

Figure 2 shows a cross section through the capsule 1 shown in Figure 1 showing the main body 2, the upper end 3 and the flange 7. In use, a foil 8 will seal the open end of the capsule 1. The radial grooves 6 are circled on the upper end and are a thinned section on the surface. The groove may be in either side of the surface of the material but will generally be in the outer surface as this is technically easier to produce. The groove will generally reduce the thickness of the wall material by about 2/3. The capsule will be about 0.2mm thick elsewhere.

Figure 3 shows an alternative to the capsule shown in Figure 1 in which the grooves 16 alternate in length between extending to the edge of the second frustoconical section 4 and about two thirds of the way to the edge of the second fmstoconcial section 4.

The capsule is preferably made of a food grade material such as polypropylene with an oxygen scavenging additive dispersed in the polymer matrix and optionally a transition metal catalyst. Suitable oxygen scavenging additives are commercially available under the Cesa ® brand.

It has surprisingly been discovered that the arrangement of grooves has a weakening and strengthening effect on the capsule. The blunt blades of the coffee machine, originally designed to pierce aluminium capsules, cause capsules without a weakened zone made from polypropylene with the known additives or co-polymers to shatter in the coffee machine as the capsule is too brittle. The provision of the plurality of grooves provides a thinner area that can be pierced by the blade and imparts a flexibility to the remainder of the upper end of the capsule. This flexibility enables the upper end to flex slightly when the blunt blades of the machine impact the capsule so that it does not shatter. These ribs add strength to the capsule and therefore allow the blades to pierce softer material capsules.

The use of the oxygen scavenging additive in the polypropylene also surprisingly enables the foil seals 8 to adhere to the capsule at a temperature of around 220 °C, which increases the speed at which the seal can be applied and surprisingly the reliability of the seal compared to the application of the seal with standard food grade polypropylene, where a higher temperature of 280 °C has to be used.

The capsule of the invention has a significantly increase shelf life over the known capsules and does not require the use of a pillow bag. This significantly reduces the cost of production.

Although the capsule has been specifically described as being used to make espresso coffee, it would be possible to make other beverages such as tea or chocolate.

Claims

1. A capsule for use in a coffee machine having a generally frusto-conical form with an upper surface and a lower surface, an annular flange being provided at the lower surface, which annular flange is provided with sealing means on the surface facing towards the upper surface, wherein the capsule is made from a polyolefin with an active oxygen scavenging additive dispersed in the polymer matrix, the capsule being further provided with a plurality of grooves in an upper surface, which grooves are configured in use to be pierceable by a blade in the coffee machine.

2. A capsule according to Claim 1, wherein the grooves are formed on the outer surface of the capsule.

3. A capsule according to Claim 1 or Claim 2, wherein the capsule upper end is formed of a first frustoconical part and an indent, the grooves being formed on the frustoconical part.

4. A capsule according to Claim 3, wherein the grooves extend from the indent towards the edge of the frusto-conical part.

5. A capsule according to any one of Claims 1 to 4, wherein the capsule is provided with a foil seal, which foil seal is applied at a temperature of around 220 °C.