GB2567418A

GB2567418A - A biodegradable single-serve beverage cartridge

Info

Publication number: GB2567418A
Application number: GB1715748.8A
Authority: GB
Inventors: Khan Fuad; Khan Jalaluddin
Original assignee: Hpc Healthline UK Ltd
Current assignee: Hpc Healthline UK Ltd
Priority date: 2017-09-28
Filing date: 2017-09-28
Publication date: 2019-04-17
Anticipated expiration: 2037-09-28
Also published as: GB2567418B; GB201715748D0; GB2581442A; GB202004623D0; WO2019064017A1

Abstract

A biodegradable and compostable single-serve coffee cartridge 1 configured for use in a coffee brewing machine. The cartridge 1 comprises a hollow body 2 having at least one wall 6 and a cover 14, which may be a biodegradable plastic film attached to a flange. The body 2 is formed from a biodegradable and compostable pulp material and includes a biodegradable and compostable plastic layer that is provided on at least one of the inner and outer surfaces of the body. The body may be frusto-conical and may comprise a thermoformed pulp body (2, figure 12) surrounded by the inner and outer plastic layers (18 and 22, figure 12). The end wall may comprise a recessed annular channel 32 having contain apertures 38. Either the inner or the outer or both plastic layers may extend across the apertures to form a piercable membrane.

Description

The present invention relates to single-serve cartridge for use in a beverage brewing machine, and in particular a single serve capsule for a coffee brewing machine formed from a pulp material.

Single-serve coffee machines are an increasingly popular means of brewing coffee. A single-serve coffee capsule is provided that contains sufficient coffee to brew a single cup. The capsule is placed within a dedicated brewing machine that supplies heated water to the capsule under pressure. When the coffee has been brewed and dispensed, the singleserve capsule container is disposed of. The advantage of single-serve coffee machines is that they enable coffee to be brewed quickly and automatically, and enable the user to consistently brew coffee to their taste, in terms of strength and flavour, without the need to measure out portions or operate the brewing device in any complex manner; operation merely requires the user to insert the capsule and activate the device. Such is the popularity of single-serve coffee machines that sales of single-serve coffee capsules are expected to overtake sales of standard roast and ground coffee.

Single-serve coffee capsules, also referred to as coffee 'pods', are manufactured in a wide variety of shapes and sizes configured to fit a correspondingly wide range of dedicated coffee machines. However, all single-serve capsules have certain structural elements in common. The capsules all have a volume that contains the coffee grounds, a top that closes the capsule volume and an element which in use is pierced to allow pressurised hot water to enter the capsule. A filter element is provided that retains the used coffee grounds within the capsule. The capsule also includes some means for the filtered coffee to leave the capsule.

One of the most common forms of coffee capsule, the Nespresso pod as manufactured by Nestle ® is an aluminium capsule which contains the coffee grounds. The capsule includes a conical side wall, a tip at the small end of the conical wall, and an outwardly extending flange located at the periphery of the larger end. A foil membrane is secured to the outer surface of the flange to retain the coffee grounds within capsule. In use the capsule is placed within a 'brewing chamber' of the coffee machine. The chamber is closed and tip of the capsule is pierced when the chamber is closed. Heated water or steam is then forced under pressure through the holes and into the capsule. The brewed coffee passes out of the capsule through perforations created in the membrane while the used grounds are retained within the capsule.

A lever is operated to retract a rear part of the brewing chamber and expose an opening to the chamber into which the capsule is inserted. An interference fit between the flange and a pair of lugs projecting into the chamber prevents the capsule from falling through the chamber to the collection bin, and holds the capsule in position to be received with the rear part of the chamber. The lever is then operated to close the chamber and bring the rear part of the chamber forward into engagement with the capsule. The capsule is moved forward and the flange is forced past the holding lugs. The flange is clamped against a pressure plate by the rear part of the chamber. The rear part of the chamber continues to move forward until prongs arranged at the rear end of the chamber pierce the end wall of the capsule. The prongs are subsequently retracted to expose a series of holes in the end wall. The tapered wall of the rear part of the chamber engages and seals against an end region of the capsule. Pressurised steam is then passed into the rear end of the chamber. The seal between the rear part of the capsule and the chamber prevents the steam from passing around the sides of the capsule, and all of the steam is therefore directed into the capsule via the holes created by the prongs. The pressure within the capsule forces the membrane against raised regions on the pressure plate. The membrane bursts under pressure in the areas between the raised regions of the pressure plate, and the coffee passes out of the capsules into outlet apertures formed in the pressure plate between the raised regions.

When the lever is lifted again, which may be immediately following use or when the device is next used to brew coffee, the rear part of the chamber is retracted and a pair of projections engage the flange and prevent the capsule from being retracted with the rear party of the chamber. The unsupported capsule then falls downwards into a collection bin. However, if the flange is not sufficiently rigid it will deform, allowing it to be pulled past the projections by the rear part of the chamber and retained therein. It is therefore important, for both sealing and subsequent retraction, that the flange is able to maintain its integrity during use. It is also important that the capsule remains watertight and maintains its integrity sufficiently under the given operating temperature and pressure such that it is able to continue to enclose and retain the coffee grounds and prevent liquid from seeping through the walls of capsule following use. Liquid passing through the walls of the capsule will contaminate the interior of the chamber and allow mould and bacteria to grow within the chamber which presents a serious health hazard, particularly where capsules are allowed to remain within the chamber between uses as is often the case.

Single-serve containers formed from aluminium or plastic are able to suitably withstand the operational temperatures and pressures of a coffee machine. However, there is increasing concern surrounding the environmental impact of such containers. The use of aluminium, plastic, or a mixture of the two, together with the organic material in the form of the used coffee grounds, means that the capsules are very difficult to process in standard municipal recycling plants, and are therefore typically disposed of in landfill rather than being recycled, which is highly undesirable.

In view of the problems associated with recycling single-serve coffee containers, there have been several attempts to manufacture containers that are biodegradable in order to mitigate the environmental impact of the containers. Containers have been developed formed from biodegradable plastics such as polylactic acid (PLA). US2013/0045308 describes a single-serve coffee container having a base formed from a combination of paper and PLA. US 9,120,617 describes a coffee capsule formed from pressed paper or paperboard having a coating of biodegradable polyethylene. It is desirable that biodegradable containers are compostable to enable them to be broken down and reused in composted waste. Such containers may be deemed to be compostable if they meet European standard EN 13432 for packaging and packaging waste, which requires the constituents and components of the packaging to be recoverable by industrial composting. Industrial composting accelerates the composting processes using elevated temperature and oxygen levels, and requires large scale infrastructure and machinery to manage the compost. While this is preferable to a non-compostable capsule, it would be more preferable still to provide a single-serve coffee capsule that is able to be disposed of in a home composter or home food caddy so that a user may compost the capsules at home without the requirement for industrial composting and the requirement for collection and transport of the waste.

It is therefore desirable to provide an improved single-serve cartridge which addresses the above described problems and/or which offers improvements generally.

According to the present invention there is provided a single-serve cartridge for use in a beverage brewing machine as described in the accompanying claims.

In an embodiment of the invention there is provided a single-serve cartridge for use in a beverage brewing machine, the cartridge being biodegradable and compostable. The cartridge comprises a hollow body for containing a product for brewing a beverage. The hollow body comprises at least one wall. A cover is provided for closing and sealing the body. The body is formed from a biodegradable and compostable pulp material and includes a biodegradable and compostable plastic layer provided on at least one of the inner and outer surfaces of the body. The term 'compostable' means that the cartridge is able to biodegrade in a non-industrial composting process. The use of a moulded pulp material enables the cartridge to be formed in a wide range of shapes that cannot be achieved using press forming or other techniques that utilise a sheet substrate. The plastic layer is preferably formed from a bioplastic.

Preferably the pulp material is a thermoformed pulp. Thermoformed pulp is able to be formed to significantly greater tolerances than traditional moulded pulp, in forms that are not achievable in traditional pulp forming. Thermoforming also provides the pulp with a significantly improved surface finish. Providing a smooth finish to the sealing surface of the cartridge reduces friction between the cartridge and the brewing machine thereby assisting operation and release.

A biodegradable and compostable plastic layer is preferably provided on the inner and outer surfaces of the body with the thermoformed pulp material being disposed between the inner and outer plastic layers. In this way the pulp material is protected at the interior of the cartridge from degradation due to liquid saturation both during and after brewing. The outer surface also benefits from liquid proofing. The outer plastic layer also provides the further advantage of reducing friction between the cartridge wall and the brewing chamber to improve release after use.

Preferably the biodegradable and compostable plastic layer surrounds and encapsulates the pulp body. The inner and outer layers combine to form a contiguous, continuous layer that extends entirely around the body such that none of the pulp material of the body is exposed.

The body may comprise a side wall and an end wall located at a first end of the side wall, the side wall and end wall defining a chamber for containing said product for brewing a beverage, and an opening located at an opposing second end of the side wall, the cover being configured to close and seal the opening. The cover preferably comprises a biodegradable compostable plastic film such that the entire cartridge is biodegradable and compostable.

The body preferably comprises a flange extending radially outwards from the second end of the side wall, which provides a surface to which the plastic film of the lid may be attached. The cover is bonded to the flange to close and seal the hollow body.

The plastic film may be adhered or thermally welded to the flange, or attached by any other suitable means. The biodegradable and compostable plastic layer may extend across both the upper and lower surfaces of the flange, and preferably also around the periphery of the flange such that the flange is entirely surrounded by the plastic layer.

The side wall is preferably substantially frusto-conical.

The end wall may include a plurality of pre-formed apertures configured to permit the ingress of water or steam into the cartridge. Preforming the apertures within the body obviates the requirement to pierce the cartridge with a barb, which is advantageous as the end wall therefore is not required to be sufficiently strong to receive a barb without buckling or otherwise failing.

The single-serve cartridge may further comprise a beverage precursor for brewing a beverage contained within the hollow body. The beverage precursor may be coffee, tea or any other brewable beverage.

The body may comprise a side wall and an end wall and the end wall comprises a recess having one or more preformed apertures formed therein. The recess preferably comprises a recessed annular channel. The recess strengthens the end wall of the container enabling the cartridge to better withstand the application of pressure from the rear of the brewing chamber, and preventing buckling which may compromise the seal between the end wall and the brewing chamber.

The apertures are preferably formed in a regularly spaced annular array within the channel.

The body may comprise a side wall and an end wall located at a first end of the side wall, the side wall and end wall defining a chamber for containing said product for brewing a beverage. Preferably an aperture is formed in the end wall and the aperture is covered and sealed by a piercable membrane. The piercable membrane is selected such that it is able to cover and seal the aperture while also being more readily piercable than the pulp material of the body.

Preferably the biodegradable and compostable plastic layer provided on at least one of the inner and outer surfaces of the body extends across the aperture and forms the piercable membrane. Therefore, advantageously the piercable membrane is formed in the same step as the addition of the biodegradable and compostable plastic layer, the same material forming and defining the piercable membrane.

The biodegradable and compostable plastic layer may comprise a biodegradable and compostable plastic layer provided on the inner surface of the body. The inner plastic layer simultaneously coats and seals the inner surface of the pulp to protect the pulp material from absorption of liquid from the beverage being brewed within the capsule and covers and seals the aperture.

The biodegradable and compostable plastic layer may comprise a biodegradable and compostable plastic layer provided on the outer surface of the body. In this arrangement the outer plastic layer simultaneously coats and seals the outer surface of the pulp to protect the pulp material from absorption of liquid from the beverage being brewed within the capsule and covers and seals the aperture.

The biodegradable and compostable plastic layer preferably comprises a biodegradable and compostable plastic layer provided on the inner surface of the body and a biodegradable and compostable plastic layer provided on the outer surface of the body. The inner and outer biodegradable and compostable plastic layers are bonded to each other in the region covering the aperture, such as by heat bonding, and the bonded inner and outer biodegradable and compostable plastic layers combine to form the piercable membrane. This arrangement advantageously protects both the inner and outer surfaces of the pulp body and also forms a piercable membrane having a thickness twice that of the inner and outer membranes.

The present invention will now be described by way of example only with reference to the following illustrative figures in which:

Figure 1 shows a single serve beverage cartridge according to an embodiment of the present invention;

Figure 2 is a side view of the single serve beverage cartridge of

Figure 1;

Figure 3 shows a single serve beverage cartridge according to another embodiment of the present invention;

Figure 4 shows a single serve beverage cartridge according to a further embodiment of the present invention;

Figure 5 shows a single serve beverage cartridge according to another embodiment of the present invention;

Figure 6 is a side view of the single serve beverage cartridge of

Figure 5; and

Figure 7 is a top view of the single serve beverage cartridge of

Figure 5.

Referring to Figure 1 there is provided a single-serve beverage brewing container in the form of a cartridge 1. The cartridge 1 includes a cup-shaped body 2 having a base 4, a side wall 6, an end wall 8 and a flange 10. The side wall 6 is substantially frusto conical and radially symmetrical, and tapers inwardly towards the end wall 8. The shape, relative position and dimensions of the end wall 8 and/or the shape, configuration and dimensions of the side wall 6 may vary depending on the dimensions and configuration of the brewing chamber of the coffee machine with which the container is intended for use.

The side wall 6 and end wall 8 form an enclosure having an internal cavity for containing coffee grounds or other beverage ingredients, with an opening 12 to the enclosure being defined at the base end. A membrane 14 defines a lid that is provided across the base 4 to close and seal the opening 12, and contain the coffee grounds within the enclosure of the container 1.

The flange 10 is annular and projects outwardly from the periphery of the opening 12 at the base 4. The annular flange 10 extends radially outwards and is co-planar with the opening 12. The base surface 15 of the flange 10 is the surface which faces outwardly away from the interior of the enclosure. The lid 14 is substantially circular and is secured to the base surface 15 of the annular flange 10 by an annular bonding region 16 at the periphery of the lid 14.

The body 2 is formed from a moulded pulp material, which may include paper, bamboo or any other suitable pulp fibre material. Moulding the body 2 from pulp material enables a rigid, stable three dimensional form to be created having well controlled tolerances and even wall thicknesses. It is known from the prior art to form coffee containers from sheet paper that is pressed to form. The problem with this process is that the paper is not ideally suited to press forming, particularly where a controlled form is required. A thinner paper stock is required to be able to effectively achieve a suitable three dimensional pressed form, which can lead to wrinkling and also does not provide the required wall strength. In contrast, moulding the body 2 from pulp fibre enables the shape and wall thickness to be closely controlled and suitable wall thickness and flange thickness to be achieved.

The flange 10 is preferably formed having a thickness that is greater than the wall thickness of the side wall 6 and end wall 8. This achievable due to the pulp moulding process and would not be possible if the body 2 were formed from sheet paper having a uniform thickness. The moulding process enables the thickness of the flange 10 to be varied relative to the wall thickness of the side wall 6 and end wall 8 to increase the strength of the flange while minimising material usage.

The body 2 is formed in a hot-press, thermoforming pulp moulding process. In one embodiment the body 2 is initially formed by placing a gauze mould into a slurry vat. A vacuum is applied to the gauze mould and the pulp fibres are drawn against the mould surface. The gauze mould may be a male orfemale mould. The gauze mould is withdrawn from the slurry and the continued application of a vacuum draws liquid from the pulp fibres. The de-watered body 2 is then transferred to a thermoforming mould comprising male and female hot press tools. The body 2 is placed within the smooth hot press mould tools which apply temperature and pressure to the body 2 to produce a smooth, even and highly toleranced surface finish and wall thickness. Alternatively, the body 2 may be retained on the original gauze mould or transferred to a second gauze mould to which is applied a corresponding hot press mould tool. The latter process results in a surface finish that is not as smooth on the gauze side as that achieved using a pair of smooth hot press tools, but the gauze surface has been found to promote a faster drying rate, which is advantageous for high volume production.

A sizing agent is provided within the pulp slurry to provide the thermoformed pulp body with a water resistance. In addition, a surface layer of biodegradable plastic is provided to protect the pulp material from the high temperature and pressure of the brewing process.

In one embodiment a layer of biodegradable plastic 18 is provided on the inner surface 20 of the body 2. The biodegradable plastic layer 18 may also be provided on the base surface 15 of the flange 10. The biodegradable plastic may be any suitable plastic that is biodegradable and capable of being home composted or composted in a non-industrial process. Preferably the biodegradable plastic is a bioplastic.

The biodegradable plastic is selected to be able to withstand temperatures of between 80-120°C. The biodegradable plastic layer 18 on the inner surface 20 of the body 2 lines the pulp material and provides a direct, water proof barrier between the contents of the cartridge 1 and the side wall 6 and base 8 ensuring that the pulp maintains its integrity during and after use. The biodegradable plastic layer 18 at the base surface 15 of the flange 10 also advantageously improves sealing between the flange 10 and the pressure plate of the coffee machine. The biodegradable plastic layer 18 at the annular base surface 15 of the flange 10 also works to improve the strength of the flange 10, and may be thickened in this region to further enhance the flange strength. The biodegradable plastic layer 18 on the inner surface of the body 2 is in direct contact with the coffee grounds or other beverage precursor contained within the cartridge 1. Therefore, the biodegradable plastic layer 18 is selected from a range of food grade biodegradable plastics, and is preferably a food grade bioplastic.

In a second embodiment the biodegradable plastic layer 22 is applied to the outer surface 24 of the body 2. The outer biodegradable plastic layer 22 surrounds the side wall 6 and the end wall 8, and may also line the upper surface 18 of the flange 10. An additional annular layer of biodegradable plastic 26 may be applied to the base surface 15 of the flange 10 to strengthen the flange 10 and improve sealing. The biodegradable plastic layer 22 provides a watertight barrier at the outer surface 24 of the body 2 and prevents liquid from escaping the cartridge 1 in use, and prevents liquid from penetrating the cartridge 1 at the outer surface. Unlike the first embodiment, the pulp is exposed at the inner surface 20 of the cartridge 1 to the heated liquid during brewing. Although the pulp becomes saturated to a certain degree the outer biodegradable plastic layer 22 maintains the shape and integrity of the pulp. The outer layer biodegradable plastic layer 22 reduces the coefficient of friction of the outer surface, and the flange 10, which reduces friction between the cartridge 1 and the brewing chamber of the coffee machine enabling a smoother release of the cartridge 1 from the brewing chamber and hence a more positive ejection of the cartridge 1 following use. The outer layer of biodegradable plastic 22 also improves the outer surface finish of the container 1, which allows the container to be decorated to resemble existing plastic or aluminium containers, as well as maintaining the integrity of the pulp during transit and storage. As the outer layer 22 is not in contact with the coffee grounds or other beverage precursor, it is not necessary for the biodegradable plastic layer 22 to be formed from a food grade biodegradable plastic.

In a third embodiment the container is provided with both an inner layer of biodegradable plastic 18 and an outer layer 22. The inner layer 18 provides a direct water proof barrier to protect the pulp, while the outer layer 22 provides the improved surface finish with the associated advantages as described above. At least the inner layer 18 is formed from a food grade bioplastic.

The biodegradable plastic layer 18 and/or biodegradable plastic layer 22 may be applied as a coating, a laminate layer, surface film or any other suitable means. In one embodiment the inner layer 18 and outer layer 22 are pre-formed in a prior moulding or vacuum forming operation to have a shape corresponding to the inner 20 and outer 24 surfaces of the body 2 respectively. Following the thermoforming of the body 2 the inner 18 and outer 22 layers are placed into and over the inner 20 and outer 24 surfaces of the body 2 respectively to create a sandwich of three layers with the thermoformed pulp body 2 disposed in the middle. The three layers are then pressed together in a hot press forming machine at a temperature suitable to cause the three layers to bond together. In an alternative embodiment, the inner layer 18 may be formed into the inner cavity of the capsule 1 by a vacuum forming operation. A preformed outer layer 22 may then be applied where such an outer layer is required and bonded to the container in a hot press operation.

In a further embodiment shown in Figure 5, the end wall 8 includes an annular recessed channel 26, which projects inwardly into the cavity of the hollow body 2. A rim 28 is arranged at the peripheral edge of the end wall 8. A first outer annular wall 30 extends axially downwardly from the rim 28 in an axial direction. The terms 'upwards' and 'downwards' are relative terms and here the term downwards is used relative to the upwardly facing end wall as shown in Figure 5. The annular base 32 of the channel 26 is substantially horizontal as shown in Figure 6. A second inner annular wall 34 extends upwardly from the radially inner edge of the base 32 of the channel 26 and is radially spaced from the outer annular wall 30 by the base 32. A substantially disc shaped horizontal central region 36 is located at the upper edge of the inner annular wall 34. The height of the inner wall 34 is substantially equal to the height of the first outer annular wall 32 such that the central region 36 and the rim 28 are coplanar.

A plurality of apertures 38 are formed in the base 32 of the channel 26 in an annular array, as shown in Figure 7. The apertures 38 may be formed as part of the moulding process, but are preferably punched or otherwise mechanically formed in the pulp postmoulding. The apertures may extend entirely through the base 32 of the channel. Alternatively, the apertures 38 may be formed such that they partially extend through the base 32, forming a weakened region that is initially closed. The weakened region of the apertures 38 are designed to fail under the pressure of the incoming steam to fully open the apertures 38 to permit the passage of water or steam into the capsule 1. In the arrangement of Figure 7 the annular array of apertures 38 comprises 8 apertures. Alternatively the channel 26 may comprise one or more apertures.

In a further embodiment shown in Figure 8 the cartridge 100 includes a body 102 having a base 104, a side wall 106, an end wall 108 and a flange 110. The end wall 108 includes an aperture 109 formed centrally within the end wall 108. The end wall 108 is annular in form, and surrounds the aperture 109. A piercable membrane 112 covers and seals the aperture 109. The piercable membrane 112 is formed of a bioplastic film. The material properties of pulp are not conducive to effective piercing by the barbs of a coffee brewing machine. It has been found that the pulp material deforms when engaged by a barb, rather than allowing the barb to pierce the pulp material, such that an attempt to pierce the end wall compresses and damages the cartridge. A thicker and or more rigid pulp material is not able to be pierced without excessive force and is therefore not suitable. The piercable membrane is more readily pierced by a barb. The combination of the pulp body 102 with a piercable membrane 112 in the end wall 108 allows the walls of the body 102 to be formed from pulp material of sufficient strength to maintain its structural integrity during use, while the membrane 112 allows the cartridge to be easily pierced.

A layer of biodegradable plastic 118 is provided on the inner surface 120 of the body 102. The biodegradable plastic layer 118 lines the inner surface 20 of the body 102. The biodegradable plastic layer 118 is formed such that it extends across the aperture 109 to form the piercable membrane 112, as can be seen from Figure 9. The biodegradable plastic layer 118 is bonded to the inner surface of the body 102, including the inner surface of the end wall 108. The bonding between the biodegradable plastic layer 118 and the end wall 108 extends to the periphery 114 of the end wall 108 that defines the aperture 109. The biodegradable plastic layer 118 therefore provides both a water proof barrier on the inner surface of the body 102, and also forms the piercable membrane 112.

The biodegradable plastic layer 118 may be vacuum formed onto the inner surface 120 of the body 102. Alternatively, the biodegradable plastic layer 118 may be pre-formed having a shape that conforms to the inner surface 120 of the body 102. The pre-formed biodegradable plastic layer 118 may then be heat bonded or otherwise bonded or adhered to the inner surface of the body 102. The biodegradable plastic layer 118 may be formed having a wall section having a first thickness and a base having a second thickness that is greater than the wall thickness. The base of the biodegradable plastic layer 118 forms the piercable membrane 112. The piercable membrane section 112 of the biodegradable plastic layer 118 extends across the aperture 109 and providing this section with a greater thickness to mitigate the risk of damage and the membrane 118 becoming accidentally pierced prior to use in transit or storage.

In a second embodiment as shown in Figure 9 a biodegradable plastic layer 122 is applied to the outer surface 124 of the body 102. The outer biodegradable plastic layer 118 surrounds the side wall 106 and the end wall 108, extending across the aperture 109. In this embodiment the outer biodegradable plastic layer 122 forms the piercable membrane section 112. The biodegradable plastic layer 122 is bonded to the outer surface 124 of the body 102, including the outer surface of the end wall 108. The outer biodegradable plastic layer 122 provides a complete impermeable outer layer that covers and protects the outer surface of the body 102. The biodegradable plastic layer 122 has the advantage of ensuring that the integrity of the pulp is protected from brewing from heated water and steam within the brewing chamber.

The outer biodegradable plastic layer 120 may be vacuum formed about the outer surface 124 of the body 102. Alternatively, the outer biodegradable plastic layer 120 may be preformed having a shape that conforms to the outer surface 124 of the body 102. The pre formed outer biodegradable plastic layer 120 may be heat bonded or otherwise bonded or adhered to the inner surface of the body 102. Similarly to the inner biodegradable plastic layer 118. In this embodiment the outer biodegradable plastic layer 120 may be formed having a wall section having a first thickness and a base having a second thickness that is greater than the first wall thickness.

In a yet further embodiment as shown in Figure 11 the body 102 is coated with both an inner biodegradable plastic layer 118 and an outer biodegradable plastic layer 122. The inner 118 and outer 122 biodegradable plastic layers may be bonded to the body 102 in any suitable manner, including those methods described above. In one arrangement the inner 118 and outer 122 biodegradable plastic layers are preformed and are placed over the inner 120 and outer 124 surfaces of the body 102. The inner 118 and outer 122 biodegradable plastic layers are then heat bonded to the body 102. During the heat bonding process the region of the inner 118 and outer 122 biodegradable plastic layers spanning the aperture 109 are bonded together to form a common membrane layer 125 that defines the piercable membrane. In this way, both the inner 120 and outer 124 surfaces of the body 102 are coated and protected. In addition, the inner 118 and outer 122 biodegradable plastic layer form a double thickness piercable membrane layer 112 in the region of the aperture 109.

In a further embodiment shown in Figure 12 the capsule 1 includes an inner layer 18 and outer layer 22 of biodegradable plastic. The inner layer 18 and outer layer 22 are bonded to the inner 20 and outer 24 surfaces of the body respectively, as described in relation to the embodiment of Figure 4. The inner layer 18 and outer layer 22 combine to encapsulate the pulp body 2 such that the pulp body 2 is completely surrounded and encased by biodegradable plastic. In the enlarged view of Figure 12 the thin inner layer 18 and outer layer 22 have been exaggerated in thickness for illustrative purposes. The inner layer 18 lines the inner surface 20 and a flange portion 40 extends over the base surface 15 of the flange 10. The flange portion 40 extends outwardly past the peripheral edge 42 of the flange 10 defining an outer rim section 44. The outer layer 22 lines the outer surface 24 and a flange portion 46 extends over the underside 48 of the flange 10. The flange portion 46 also extends outwardly past the peripheral edge 42 of the flange 10 defining an outer rim section 50.

The rim section 44 of the inner layer 18 and the rim section 50 of the outer layer bond to each other in the region of overlap outwardly of the peripheral edge of the flange 10. This region of bonding seals the peripheral edge 42 of the flange 10 and the inner layer 18 and outer layer 22 form a continuous plastic layer via the bonding region 52 that extends entirely around the body 2 of the capsule 1. Preferably the inner layer 18 and outer layer 22 are applied to the body 2 as the body 2 is held on a jig. The inner 18 and outer 22 layers are bonded to the body 2 and to each other. The rim sections 44 and 50 may extend outwardly to a greater diameter and may be part of a continuous sheet of plastic film which is subsequently die cut to release the capsule. The steps of encapsulating the body 2 in bioplastic are undertaken prior to application of the lid membrane. By covering the flange 10 in a plastic layer, the lid membrane 12 may be more readily bonded to the flange, and may be bonded by heat welding the membrane to the plastic layer coating the flange 10.

By completely encapsulating the capsule in bioplastic the capsule is able to resist damage from water and steam during use. This also prevents the capsule from absorbing liquid over time if it is left in the coffee machine following use, which can otherwise result in the capsule swelling and softening, leading to jamming or fouling of the coffee machine and prevent capsule release.

Claims

1. A single-serve cartridge for use in a beverage brewing machine, the cartridge being biodegradable and compostable and comprising;

a hollow body for containing a product for brewing a beverage, the body comprising at least one wall; and a cover for closing and sealing the body;

wherein the body is formed from a biodegradable and compostable pulp material and includes a biodegradable and compostable plastic layer provided on at least one of the inner and outer surfaces of the body.

2. A single-serve cartridge according to claim 1 wherein the pulp material is a thermoformed pulp.

3. A single-serve cartridge according to claim 1 or 2 wherein a biodegradable and compostable plastic layer is provided on the inner and outer surfaces of the body with the thermoformed pulp material being disposed between the inner and outer plastic layers.

4. A single-serve cartridge according to claim 3 wherein the biodegradable and compostable plastic layer surrounds and encapsulates the pulp body.

5. A single-serve cartridge according to any preceding claim wherein the body comprises a side wall and an end wall located at a first end of the side wall, the side wall and end wall defining a chamber for containing said product for brewing a beverage, and an opening located at an opposing second end of the side wall, the cover being configured to close and seal the opening.

6. A single-serve cartridge according to claim 5 wherein the cover comprises a biodegradable compostable plastic film.

7. A single-serve cartridge according to claim 5 or 6 wherein the body further comprises a flange extending radially outwards from the second end of the side wall.

8. A single-serve cartridge according to claim 7 wherein the cover is bonded to the flange to close and seal the hollow body.

9. A single-serve cartridge according to claim 8 wherein the side wall is substantially frusto-conical.

10. A single-serve cartridge according to any one of claims 5 to 9 wherein the end wall includes a plurality of apertures configured to permit the ingress of water or steam into the cartridge.

11. A single-serve cartridge according to any preceding claim further comprising a beverage precursor for brewing a beverage contained within the hollow body.

12. A single-serve cartridge according to any preceding claim wherein the body comprises a side wall and an end wall and the end wall comprises a recess having one or more preformed apertures formed therein.

13. A single-serve cartridge according to claim 11 wherein the recess comprises a recessed annular channel.

14. A single-serve cartridge according to claim 11 or 12 wherein the apertures are formed in an annular array within the channel.

15. A single-serve cartridge according to any preceding claim wherein the body comprises a side wall and an end wall located at a first end of the side wall, the side wall and end wall defining a chamber for containing said product for brewing a beverage, an aperture is formed in the end wall and the aperture is covered and sealed by a piercable membrane.

16. A single-serve cartridge according to claim 15 wherein the biodegradable and compostable plastic layer provided on at least one of the inner and outer surfaces of the body extends across the aperture and forms the piercable membrane.

17. A single-serve cartridge according to claim 15or 16 wherein the biodegradable and compostable plastic layer comprises a biodegradable and compostable plastic layer provided on the inner surface of the body.

18. A single-serve cartridge according to claim 15 or 16 wherein the biodegradable and compostable plastic layer comprises a biodegradable and compostable plastic layer provided on the outer surface of the body.

19. A single-serve cartridge according to any one of claims 15 to 18 wherein the biodegradable and compostable plastic layer comprises a biodegradable and compostable plastic layer provided on the inner surface of the body and a biodegradable and compostable plastic layer provided on the outer surface of the body.

20. A single-serve cartridge according to claim 19 wherein the inner and outer biodegradable and compostable plastic layers are bonded to each other in the region covering the aperture, the bonded inner and outer biodegradable and compostable plastic layers combining to form the piercable membrane.