CN111315668A

CN111315668A - Soaking bag

Info

Publication number: CN111315668A
Application number: CN201880067151.5A
Authority: CN
Inventors: S·E·阿克斯; F·贝尼纳蒂; G·I·海
Original assignee: Unilever PLC
Current assignee: Ekatra Research And Development Uk Ltd
Priority date: 2017-08-16
Filing date: 2018-08-09
Publication date: 2020-06-19
Anticipated expiration: 2038-08-09
Also published as: EP3668804A1; JP7210546B2; EA038770B1; EP3668804B1; PL3668804T3; WO2019034531A1; EA202090188A1; JP2020531371A; CN111315668B

Abstract

The invention relates to an inflatable infusion bag containing a beverage precursor, wherein the infusion bag (1) is in a permanently compressed state in the absence of water and is transformed into an inflated state (5) in the presence of water.

Description

Soaking bag

Technical Field

The present invention relates to infusion bags. More particularly, the present invention relates to infusion bags (e.g., tea bags) that expand into a three-dimensional shape when immersed in water.

Background

Infusion bags (such as tea bags) have for many years been generally flat, made primarily of square or round layered porous filter material with infusible material (such as tea leaves) sandwiched between the layers. Such a package substantially restricts the movement of infusible material within the infusion bag to two dimensions. As a result, the soaking performance of such packages is limited.

Recently, mass-produced infusion bags have been developed that are more three-dimensional. Particularly successful are infusion bags of tetrahedral shape such as those described in WO 95/01907 (Unilever). Such infusion bags are believed to improve infusion performance by allowing more room for movement for infusible material.

Multiple infusion bags are often packaged together for sale in a carton. For example PG Tips pyramid shaped tea packs are sold in cartons containing 20, 40, 80, 160 or 240 tea packs. The disadvantage of providing a three-dimensional infusion bag is that it has a volume greater than the volume of a two-dimensional package and therefore cannot be packaged for sale efficiently.

Efforts have been made to provide three-dimensional infusion bags having a flat configuration for ease of packaging.

EP 0053204 (Unilever) discloses a tea bag having a generally tetrahedral shape which can be folded at least once to allow it to be folded into a flat configuration. The pulling device fixed to the bag may assist in the unfolding of the bag.

WO 2013/174710(Unilever) discloses an infusion bag comprising a gusset which is substantially flat prior to use and which expands when immersed in an infusion liquid to adopt a more three-dimensional shape.

EP 0846632 (Fuso Sangyo Kabushiki Kaisha) discloses a liquid-permeable flexible pouch that can be folded so as to be easily contained in an outer package and unfolded upon extraction so as to enlarge the inner space of the pouch.

The flat (or unexpanded) form of such infusion bags is achieved by folding the three-dimensional infusion bag in a defined manner. The three-dimensional shape to be taken by the infusion bag in use will inevitably affect the shape of its flat form. Furthermore, to facilitate mass production of such infusion bags, the flat form must be realized by a relatively simple folding pattern. The inflatable infusion bags described in the prior art therefore have only a very limited number of possible configurations in their unexpanded sheet form.

Accordingly, there remains a need to provide a soak bag form that can provide soak performance associated with three-dimensional packages and that can be packaged for sale in a more convenient and/or efficient manner than is currently the case.

Disclosure of Invention

In a first aspect, the present invention relates to an inflatable infusion bag containing a beverage precursor, wherein the infusion bag is in a permanently compressed state in the absence of water and is transformed into an inflated state in the presence of water, wherein the infusion bag has a density of at least 0.5g/cm when it is in the permanently compressed state³And said infusion bag being substantially rigid and having a Vickers hardness (H) when in a permanently compressed state_v) Is at least 0.2.

The compressive nature of such infusion bags means that they can be conveniently and efficiently packaged. This is advantageous from an environmental point of view, since less secondary packaging material is required to package a given number of infusion bags (e.g. when compared to a standard infusion bag having substantially the same inflated state).

In a second aspect, the present invention relates to a package comprising a plurality of inflatable infusion bags according to the first aspect of the invention.

Detailed Description

The present invention relates to an expandable infusion bag containing a beverage precursor, wherein the infusion bag is in a permanently compressed state in the absence of water and is transformed into an expanded state in the presence of water, wherein the infusion bag has a density of at least 0.5g/cm when it is in the permanently compressed state³。

As used herein, the term "permanently compressed state" refers to a form intended to remain stable for an indefinite period of time. The infusion bag itself is permanently compressed in form and does not transform into an expanded state in the absence of water. In other words, the infusion bag of the present invention does not rely on envelopes or similar secondary packaging to maintain its compressed form.

When the infusion bag of the present invention is in its permanently compressed state, it cannot be expanded simply by gently pulling or manipulating its constituent materials. This is in contrast to infusion bags which are folded to achieve a flat form, which easily adopt a more inflated form even when handled in this way in the absence of water.

The infusion bag has a density of at least 0.5g/cm when in a permanently compressed state³. The infusion bag preferably has a density of at least 0.55g/cm when in a permanently compressed state³More preferably at least 0.6g/cm³And still more preferably at least 0.65g/cm³. The infusion bag preferably has a density of less than 2g/cm when in a permanently compressed state³More preferably less than 1.6g/cm³And still more preferably less than 1.2g/cm³。

Thus, the density of the compressed infusion bag is typically greater than the bulk density of the beverage precursor. This is in contrast to the density of standard (uncompressed) infusion bags, which are typically less than or equal to the bulk density of the beverage precursor.

The bulk density of a beverage precursor in dry (i.e., non-infused) form is the mass of the beverage precursor divided by the total volume occupied. This bulk density is referred to herein as the "uncompressed bulk density" (or ρ)_{Is normal}) This can be measured by filling a known mass of beverage precursor into a measuring cylinder, tapping the cylinder several times, and then measuring the volume occupied by the beverage precursor. Uncompressed bulk density (p)_{Is normal}) Representing the bulk density of the beverage precursor in a standard infusion bag (i.e., an uncompressed infusion bag). For example uncompressed bulk density (p) of leaf tea in dry (un-infused) form_{Is normal}) About 0.4g/cm³。

It will be appreciated that the bulk density of the beverage precursor contained in the infusion bag will be different when the infusion bag is in a permanently compressed state. In fact, when the infusion bag is in this state, the bulk density of the beverage precursor will be significantly higher. In other words, a given mass of beverage precursor isThe infusion bag occupies a volume in the permanently compressed state that is less than the volume occupied by the infusion bag in the expanded state. The bulk density of the beverage precursor in the compressed infusion bag is referred to herein as the "compressed bulk density" (or ρ)_Compression). The compressed bulk density may be determined by applying the same pressure as the compressed infusion bag is made to a known mass of beverage precursor and then determining the volume of the beverage precursor after the pressure is applied (the compressed bulk density is the mass of the beverage precursor divided by the volume of the beverage precursor after the pressure is applied).

Compressed bulk density (ρ) of beverage precursor_Compression) Preferably the uncompressed bulk density (p) of the beverage precursor_{Is normal}) From 1.5 to 3 times greater, more preferably from 1.8 to 2.6 times greater, and most preferably from 2 to 2.4 times greater.

The infusion bag of the present invention is converted to an expanded state in the presence of water. Both hot and cold water will initiate this transition, although (all other parameters being equal) the time it takes for an infusion bag to adopt an expanded state in hot water is generally faster than it takes in cold water. The inflatable infusion bag is therefore suitable for preparing both hot and cold beverages.

The infusion bag of the present invention does not deform during handling when it is in its permanently compressed state and preferably has a substantially rigid structure. When it assumes its expanded state in the presence of water, it becomes deformable and preferably has a flexible structure (in other words, loses the rigidity it preferably has in its permanently compressed state).

The rigidity of the infusion bag in the permanently compressed state can be expressed in terms of the Vickers hardness (H)_v) And (4) showing. The vickers hardness number is a measure of the ability of a sample to resist plastic deformation.

The vickers hardness test is an indentation test that involves pressing a sample with an indenter. The geometry of the indenter used in the vickers hardness test was standardized (a 136 ° pyramidal diamond indenter forming a square indentation). The indenter is pressed into the sample by a precisely controlled test force and then removed, leaving an indentation in the sample that is square on the surface. By assuming that the impression has a pressure equal to the forming pressureThe same geometry of the indenter of the indentation determines the area (a) of the indentation and can be determined according to the following formula: a is 24.5h²Where h is the indentation depth (in mm).

Vickers hardness number (H)_v) Is a function of the test force divided by the surface area of the indentation and can be calculated using the following formula: h_vWhere F is the force applied to the indenter (in kgf) and a is the surface area of the resulting indentation (in mm)²Meter).

The infusion bag is substantially rigid and has a Vickers hardness (H)_v) Is at least 0.2, preferably at least 0.25, more preferably at least 0.3, most preferably at least 0.35. Vickers hardness (H) of the infusion bag in a compressed state_v) Preferably less than 1, more preferably less than 0.9, still more preferably less than 0.8, and most preferably less than 0.75.

The time taken for the infusion bag to transition from the compressed state to the expanded state in the presence of hot water (e.g. at a temperature of 90 to 100 ℃) is generally relatively fast, typically only a few seconds. Thus, the inflatable infusion bag is particularly suitable for brewing beverages prepared with hot water, such as tea or herbal infusions. Consumers want to prepare such beverages as quickly and conveniently as possible, and the total brewing time is usually not more than 6 minutes. Thus, in the presence of hot water, the infusion bag preferably transitions from the compressed state to the expanded state in no more than 30 seconds, more preferably no more than 20 seconds, and most preferably no more than 10 seconds.

The inflatable infusion bag is also suitable for brewing beverages prepared with cold water (e.g. from

Cold tea brewed from coldbrow tea bags). The brewing time for such beverages is typically longer than the brewing time for hot beverages, and may be, for example, 5 minutes or longer. Thus, the rapid transition of the infusion bag from the compressed state to the expanded state is less important in terms of consumer acceptance of the product. In the presence of cold water (for example at a temperature of 15 to 25 ℃), the infusion bag preferably does not exceed 240 seconds, more preferably does not exceed 180 seconds, and still more preferably does not exceedThe transition from the compressed state to the expanded state takes 120 seconds, most preferably no more than 90 seconds.

The transition of the inflatable infusion bag from the permanently compressed state to the inflated state results in a "tumbling" motion. Without wishing to be bound by theory, the inventors believe that this movement improves the infusion performance of the infusion bag.

The inflatable infusion bag preferably contains a beverage precursor. As used herein, the term "beverage precursor" refers to a processed composition suitable for use in preparing a beverage. The beverage precursor can be contacted with an aqueous liquid, such as water, to provide a beverage (i.e., a drinkable composition that is substantially aqueous suitable for human consumption). This process is called brewing. During brewing, the beverage precursor typically releases certain soluble substances into the aqueous liquid, such as flavor and/or aroma molecules.

The beverage precursor preferably comprises plant material, particularly preferably tea and/or herbal plant material. As used herein, "tea plant material" refers to dry leaf and/or stem material (i.e., "leaf tea") derived from Camellia sinensis (Camellia sinensis). The term "herbal material" refers to materials commonly used as precursors for herbal infusions. Preferably, the herbal material is selected from the group consisting of chamomile, cinnamon, elderberry, ginger, hibiscus, jasmine, lavender, lemongrass, mint, ruyi (rooibos), rose hip, vanilla and verbena. The beverage precursor may additionally or alternatively include fruit pieces (e.g., apples, blackcurrants, mangoes, peaches, pineapples, raspberries, strawberries, etc.) and/or other taste ingredients (e.g., bergamots, citrus peels, synthetic taste particles, etc.). The beverage precursor preferably does not include plant material that requires pressure for optimal brewing. In particular, the beverage precursor preferably does not comprise plant material derived from coffee (in particular ground coffee).

The beverage precursor preferably has a mass of at least 1 gram because smaller quantities are difficult to dispense and meter accurately. More preferably, the mass is at least 1.2 grams, and most preferably at least 1.4 grams. It is further preferred that the mass of the beverage precursor is less than 4 grams, as larger amounts become inconvenient to store and/or handle. More preferably, the mass is less than 3.5 grams, and most preferably less than 3 grams.

The inflatable infusion bag preferably has a first geometry in its permanently compressed state and a second geometry in its inflated state. Although the second geometry may be an expanded form of the first geometry, it is preferred that the first and second geometries are different. In other words, the infusion bag preferably has a specific geometry in the permanently compressed state and is transformed into an expanded state in which a different geometry is adopted.

The infusion bag may for example have a substantially disc-shaped cylindrical configuration in the compressed state (i.e. the first geometry is a cylinder) and then transform with the addition of water to have a substantially tetrahedral configuration in the expanded state (i.e. the second geometry is a tetrahedron).

The first geometry preferably has a first face and a second face connected along a length (L), wherein a cross-section along the length (L) is constant and has the same shape as the first face and the second face. The first and second faces are preferably parallel to each other.

Preferably, the first geometric shape is a cylinder or a prism.

In the case where the first geometry is cylindrical, the first and second faces are circular or elliptical and are connected along the length (L) by a curved surface.

When the first geometry is a prism, the first and second faces are polygonal and connected along the length (L) by a plurality of joining faces, the plurality of joining faces being delimited from each other by a plurality of joining edges. The faying surface is preferably square or rectangular (i.e. the prism is preferably a right angle prism). However, it should be understood that in a configuration that is not very preferred, the faying surface may be a parallelogram (i.e., the prism may be an inclined prism).

The first and second faces may have any simple polygonal shape (i.e., the boundaries of the polygon do not intersect their own shape). Thus, the polygonal shape may be concave or convex. Non-limiting examples of suitable polygonal shapes include: triangular, quadrilateral, pentagonal, hexagonal, heptagonal, octagonal, nonagonal, decagonal, and the like.

The geometry and dimensions of the infusion bag in its permanently compressed state will determine how many such infusion bags can be packaged efficiently.

The first geometry preferably has a width (W), wherein the width (W) is greater than or equal to the length (L).

The width (W) is the widest dimension of the first or second face in a plane perpendicular to the length (L). For example, for a cylinder with a circular cross-section, the width (W) is the diameter of the circular cross-section, while for a cylinder with an elliptical cross-section, the width (W) represents the major axis of the elliptical cross-section. Similarly, for a prism having a square cross-section, the width (W) represents the diagonal of the square cross-section.

The length (L) of the cylindrical or prismatic infusion bag in a permanently compressed state is preferably greater than 2mm, more preferably greater than 3mm, most preferably greater than 4 mm. The length (L) is preferably not more than 20mm, more preferably not more than 18mm, most preferably not more than 16 mm.

The width (W) of the cylindrical or prismatic infusion bag in a permanently compressed state is preferably greater than 14mm, more preferably greater than 17mm, most preferably greater than 20 mm. The width (W) is preferably not more than 45mm, more preferably not more than 40mm, most preferably not more than 35 mm.

The inflatable infusion bag preferably has a second geometry in its inflated state. As mentioned above, the second geometry is preferably a different shape than the first geometry.

Embodiments are not excluded in which the second geometry is substantially flat (e.g. infusion bags comprising infusible material sandwiched between square or circular sheets of porous material). However, such an embodiment is less preferred, as it is believed that this type of infusion bag restricts the movement of the infusible material substantially in two dimensions, thereby limiting its infusion performance. Moreover, packaging a plurality of infusion packets of this type has been relatively efficient due to their substantially flat nature.

Therefore, it is preferred that the second geometric shape is a three-dimensional shape. There is no particular limitation as to the second geometry, which may be any three-dimensional shape. However, it is desirable to be able to easily mass produce infusion bags having the second geometry. Thus, preferred examples of the second geometric shape include shapes such as tetrahedrons, pyramids, hemispheres, spheres, cubes, and the like. Particularly preferably, the second geometry is spherical, hemispherical, tetrahedral or pyramidal.

The present invention contemplates compressing a conventional infusion bag to obtain a form in which the infusion bag is in a permanently compressed state. Non-limiting examples of conventional infusion bags include spherical or semi-spherical infusion bags such as those described in EP 0811562 (Unilever), WO 2012/095247(Unilever) or WO 2005/051797(Tetley), and tetrahedral infusion bags such as those described in WO 95/01907(Unilever), WO 2004/033303(i.m. a. spa) or WO 2012/004169 (Unilever).

The inflatable infusion bag preferably has a first geometry in its permanently compressed state and a second geometry in its inflated state. Although the second geometry may be an expanded form of the first geometry, it is preferred that the first and second geometries are different. In other words, the infusion bag preferably has a specific geometry in the permanently compressed state and transforms into an expanded state, which has a different geometry.

The inflatable infusion bag has a volume V in a permanently compressed state_CAnd has a volume V in the expanded state_E. In order to significantly reduce the packaging space occupied by each compressed infusion bag without affecting the infusion performance, the volume is significantly increased when the infusion bag is transformed from its permanently compressed state to its expanded state with the addition of water. Thus, V_EPreferably at least 2V_CMore preferably at least 2.5V_CMost preferably at least 3V_C. The expandable infusion bag should be capable of transforming from its permanently compressed state to its expanded state in an efficient manner when water is added. Thus, V_EPreferably not more than 10V_CIs more excellentIs selected to be not more than 8V_CMost preferably not more than 6V_C。

The inflatable infusion bag of the present invention may be made of any suitable material. Nonwoven materials are particularly preferred because these materials generally have relatively little "memory" in the fibers and therefore tend to transition from a compressed state to an expanded state upon the addition of water. Non-limiting examples of nonwoven materials include nonwoven materials made from continuous filaments (e.g., PET, PLA, PP) and wet laid nonwoven materials (e.g., cellulose/polymer blends comprising cellulose and a polymer such as PP, PE, or PLA).

As noted above, the geometry of the inflatable infusion bag in its permanently compressed state will determine how many such infusion bags may be efficiently packaged. However, the infusion bag of the present invention will require less storage space in its compressed state than in its expanded state, regardless of the particular geometry selected.

There is no limitation on the form of the package. For cost reasons it is preferred that the manufacture of the selected packages is not overly complicated. From a simple point of view, the package is preferably a tube or carton. Another benefit of such packaging schemes is that the packaged product requires only a small amount of storage space in the consumer's home. Indeed, it is preferred that the secondary package be sufficiently compact that the infusion bag can be conveniently carried by a consumer or stored at work.

Examples of such tubular packages include cardboard, plastic or metal tubes with a suitably shaped cross-section. For example, if the compressed shape of the inflatable infusion bag has a triangular cross-section, a hollow tube having a triangular cross-section may effectively package a plurality of such infusion bags. It is also contemplated that a tubular wrapper may be formed around the compressed infusion bag. For example, a plurality of compressed infusion bags may be stacked and packaged in a tubular manner by wrapping a sheet of flexible packaging material (e.g., paper or plastic) around the stacked infusion bags in a circumferential manner and sealing the location where the edges of the sheet meet (i.e., in a longitudinal direction such that the seal is substantially parallel to the length (L) of the compressed infusion bags).

In a preferred embodiment, the package is a tube and the first geometry is a cylinder (i.e., the inflatable infusion bag has a substantially disc-shaped cylindrical configuration in a permanently compressed state).

The tube need not have the same cross-section as the inflatable infusion bag. Thus, in embodiments where the package is a tube and the first geometry is a cylinder, the tube may have a circular or elliptical cross-section and thus match the cross-section of the first geometry.

Alternatively, the tube may have a cross-section that does not match the cross-section of the first geometry. It is believed that in such embodiments, the space between the infusion bag and the tube facilitates removal of the infusion bag from the carton (by allowing the consumer to easily grasp the curved surface of the infusion bag). Tubes having a square or rectangular cross-section are particularly preferred because such cartons are easy to manufacture.

It will be appreciated that similar effects may be achieved with infusion bags of other shapes. For example, an expandable infusion bag having a first geometry of a hexagonal prism may be packaged in a tube having a square cross-section or the like.

As mentioned above, the second package may be a carton. The tubular form described above relates to a stacked packaging solution for compressed infusion bags. In contrast, cartons provide a solution for packaging layers or rows of compressed infusion packets (where each layer or row includes two or more compressed infusion packets). The compressed infusion bag can be packed in this way independently of the first geometry of this infusion bag. For maximum packaging efficiency, it is preferred that the first geometry be completely nested. However, this is not a necessary requirement and the non-interlocking shape may also be more efficiently packaged than a conventional uncompressed infusion bag. Furthermore, the spaces between the rows of compressed infusion packets having a non-nesting shape may facilitate convenient removal of individual infusion packets from the carton by a consumer.

In a preferred embodiment, the package is a carton and the first geometry is square or rectangular prismatic (i.e., the inflatable infusion bag has a prismatic configuration of square or rectangular cross-section in a permanently compressed state).

In another preferred embodiment, the package is a carton and the first geometry is a cylinder (i.e., the inflatable infusion bag has a substantially disc-shaped cylindrical configuration in a permanently compressed state). Cartons having a square or rectangular cross-section are particularly preferred because of the ease of manufacture of such cartons. The space between the row of infusion bags and the carton is believed to facilitate removal of the infusion bags from the carton (by allowing the consumer to easily grasp the curved surface of the infusion bag).

As already discussed, the present invention contemplates compressing a conventional infusion bag, thereby obtaining a form in which the infusion bag is in a permanently compressed state. This may be achieved by a method comprising the steps of: (a) providing an infusion bag in an expanded state; (b) inserting the infusion bag into a mold; and (c) applying pressure to transition the infusion bag to a permanently compressed state. The infusion bag provided in step (a) is preferably a conventional infusion bag and may be manufactured by any known method. Tetrahedral infusion bags are particularly preferred.

Inserting the infusion bag provided in step (a) into a mould. Preferably the mould is metallic, for example may conveniently be made of steel.

The pressure applied in step (c) is preferably applied by means of a piston fitted in the mould. Preferably, the piston is metallic, which may conveniently be made of aluminium, for example. The mold and the piston are preferably made of different metals. Factors that influence the appropriate pressure applied in step (c) include the area of the cross-section of the mould used in step (b), the type of material from which the infusion bag is made and the size/weight of the infusion bag. The pressure applied in step (c) is generally higher where a greater degree of compression is required and lower where a lesser degree of compression is required.

It will be appreciated that the amount of infusible material contained in the infusion bag has a given volume (e.g., a volume occupied by 3 grams of infusible material is greater than a volume occupied by 2 grams of infusible material). Generally, the more infusible material contained in the infusion bag, the greater the volume occupied by the infusible material. Thus, infusion bags containing higher amounts of infusible material are typically compressed to a lesser extent than infusion bags containing lower amounts of infusible material.

Drawings

The invention is illustrated by way of example and with reference to the following drawings, in which:

FIG. 1a is a perspective view of an inflatable infusion bag in a permanently compressed state;

FIG. 1b is a perspective view of the inflatable infusion bag of FIG. 1a in an inflated condition;

FIG. 2a is a perspective view of a compressed infusion bag according to the invention, which has been placed in a receptacle ready for brewing;

FIG. 2b is a schematic view of the infusion bag of FIG. 2a as water is added to the container to prepare a beverage;

FIG. 3a is a perspective view showing the arrangement of a plurality of compressed infusion bags;

FIG. 3b is a perspective view showing one embodiment of a package comprising a plurality of compressed infusion bags; FIG. 3c is a perspective view showing an alternative embodiment of a package comprising a plurality of compressed infusion bags;

fig. 4 is a series of perspective views showing possible shapes of an inflatable infusion bag according to the invention in its permanently compressed state.

FIG. 5a is a perspective view of an infusion bag having a hemispherical expanded state;

FIG. 5b is a perspective view of the infusion bag having a cubical expanded state;

FIG. 6 is a perspective view showing a carton containing a plurality of compressed infusion bags;

FIG. 7 shows a different arrangement of a plurality of compressed infusion bags;

figure 8 is a perspective view showing a carton containing a plurality of compressed infusion bags.

Detailed Description

Figure 1a shows an inflatable infusion bag according to the invention in its permanently compressed state. The compressed infusion bag (1) is cylindrical and has a circular cross-section. In this form, the infusion bag has a first face (2) of circular shape and a second face of circular shape (opposite the first face and therefore not visible in fig. 1 a) connected along the length (L) by a curved surface (4). The cross-section along the length (L) is constant and the same shape as the first and second faces (i.e. circular). In the embodiment shown, the width (W) is the diameter of the circular cross-section.

Fig. 1b shows the infusion bag of fig. 1a in its inflated state. The inflated infusion bag (5) takes the shape of a three-dimensional tetrahedron. Thus, the infusion bag has a different shape in its expanded state than in its compressed state. This three-dimensional expanded state allows the infusible material (6) to have space to move within the infusion bag (5), which is believed to improve infusion performance.

Fig. 2 shows the transition of an inflatable infusion bag according to the invention from its permanently compressed state to its inflated state. This transition occurs under conditions that consumers typically use to prepare for infusion from conventional infusion bags.

Figure 2a shows the infusion bag before brewing commences. The compressed infusion bag (1) has been placed in a container (7) suitable for receiving a quantity of hot water (in this case a mug). To prepare a beverage from a compressed infusion bag, the consumer adds hot water to the container. The infusion bag is transformed into an expanded state in the presence of water (8). The volume of water used by consumers to prepare beverages from conventional infusion bags varies and is not constant from one region to another. Thus, the volume of water that preferably causes the infusion bag to transition from its permanently compressed state to its expanded state is not so great, it being understood that this volume is typically greater than V_E(100ml of water is usually sufficient). Figure 2b shows the infusion bag during infusion. The infusion bag is now in its expanded state (5) and adopts a three-dimensional tetrahedral shape.

The compressed infusion bag of the present invention may be conveniently packaged as shown in figure 3.

Figure 3a shows a plurality of compressed infusion bags (1) stacked on top of each other. Since the infusion bag has a regular shape in the compressed state, this arrangement results in a form with a constant cross-section (in this case a circular cross-section).

Fig. 3b shows a possible way of packaging a plurality of compressed infusion bags (1). The stack of inflatable infusion bags is held together by a secondary packaging (9). In fig. 3b, the secondary package (9) is tubular and in the form of a sheet (e.g. formed of paper or plastic) which extends circumferentially around the infusion bag and is sealed where its edges meet.

Fig. 3c shows an alternative way of packaging a plurality of compressed infusion bags (1). In fig. 3c, the secondary package (9) is a cardboard tube with a square cross-section. The carton has the form of a square prism. Although the compressed infusion bag does not fill the entire volume of the carton, packaging efficiency is still improved (i.e., a carton designed to hold the same number of conventional infusion bags in expanded form has a significantly greater volume).

Although not shown, it will be appreciated that still more secondary packaging forms are possible (e.g. cardboard or plastic tubing, etc.).

The shape of the inflatable infusion bag in its permanently compressed state may be prismatic. Fig. 4 shows some possible prismatic configurations.

In fig. 4a, the compressed infusion bag has the form of a triangular prism. In this form, the first and second faces of the infusion bag are triangular and connected along the length (L) by three rectangular engagement faces (11) which are delimited from each other by three engagement edges (12). In this embodiment, the width (W) is the distance between two adjacent vertices of the triangular cross-section.

In fig. 4b, the compressed infusion bag is a square prism. In this form, the first and second faces of the infusion bag are square and are connected along the length (L) by four rectangular engagement faces (11) which are delimited from each other by four engagement edges (12). In this embodiment, the width (W) is the diagonal of the square cross-section.

Figures 4c and 4d show two possible hexagonal prism configurations for the compressed infusion bag. In both cases, the first and second faces of the infusion bag are hexagonal and are connected along the length (L) by six rectangular engagement faces (11) delimited from each other by six engagement edges (12). The compressed infusion bag of fig. 4c has a convex hexagonal cross-section, whereas the compressed infusion bag of fig. 4d has an L-shaped concave hexagonal cross-section.

The shape of the inflatable infusion bag in its inflated state is not limited and may be any geometric shape. Fig. 5 shows some possible configurations.

In fig. 5a, the inflated infusion bag (5) has a three-dimensional hemispherical shape, whereas in fig. 5b it has a cubic shape in its inflated form.

It will be appreciated that there is no particular relationship between the shape of the inflatable infusion bag in its compressed state and its inflated shape. In particular, infusion packets having any of the expanded shapes shown in figures 1b, 5a and 5b may be compressed to have any of the configurations shown in figures 1a, 4b, 4c and 4 d.

The shape of the infusion bag in its compressed state may be used as a code to assist the consumer in identifying the appropriate product. For example, a range of products (e.g., green tea, black tea, fruit and herbal infusions, etc.) are often sold by a particular manufacturer. Typically, each member of the range uses infusion bags of the same shape (e.g., tetrahedrons). Each type of product is sold in a separate package (e.g., a carton containing a number of infusion bags), and information provided on the package identifies the particular product type. The present invention allows each product within this range to have a different shape in the permanently compressed state (although maintaining the same shape in the expanded state). For example, infusion bags containing black tea may have the form of a cylinder, whereas infusion bags containing green tea may have the form of a hexagonal prism, etc. In this way, the consumer is still able to visually identify each product within the range even though the compressed infusion bag has been removed from the package for sale.

Figure 6 shows a possible way of packaging a plurality of compressed infusion bags. In this figure, a plurality of compressed infusion bags (1) are arranged inside the carton (15). The square cross-section of the infusion bag (1) means that they are completely engaged, so that the internal space inside the carton can be used very efficiently.

Figure 7 shows a different arrangement of a plurality of compressed infusion bags. Figure 7a shows a plurality of compressed infusion bags (1) of hexagonal cross-section stacked on top of each other. The regular shape of these infusion bags in a compressed state means that the stack of infusion bags has a constant cross section. A stack of inflatable infusion bags may be packaged to maintain this arrangement (e.g. in a similar manner to that shown in figure 3 b).

Fig. 7b shows an alternative arrangement of a compressed infusion bag (1) having a hexagonal cross-section. In this arrangement, the compressed infusion packets are arranged in a single layer. The regular hexagonal cross-section of the infusion bag (1) means that they are fully engaged. The layers of the inflatable infusion bag may be packaged to maintain this arrangement (e.g. by packaging it in a carton).

Fig. 8 shows one possible way of packaging a plurality of compressed infusion bags. In this figure, a plurality of compressed infusion bags (1) are arranged inside the carton (15). The circular cross-section of the infusion bag (1) means that they do not engage with each other. However, the compressed infusion packets can still be packed very efficiently, while the small amount of space around the compressed infusion packets allows the consumer to easily remove the individual infusion packets by grasping their curved surfaces.

Although not shown, it should be understood that the final packaging arrangement may include a multi-layer compressed infusion bag. Indeed, it is also contemplated that each layer of the infusion bag may have a differently shaped compressed form. For example, the first layer may consist of infusion bags having a hexagonal cross-section and the second layer may consist of infusion bags having a square cross-section.

Examples

Commercially available PG Tips pyramid tea bags (bag weight 2.9 grams) were provided. The tea bag is substantially tetrahedral in shape (edges) in the expanded stateRim length 65 mm). Volume (V) of tea bag in expanded state_E) Is 32365mm³。

The tea bag was inserted into a steel mould having the form of a hollow cylinder and was converted to a permanently compressed state by compressing the tea bag by applying a pressure of 4200kPa to an aluminium piston sliding within the cylindrical mould. The tea bag is substantially cylindrical in shape (having a circular cross-section) in the permanently compressed state. The tea bag has a width (W) of compressed cylinder form of 32mm and a length (L) of 5 mm. Volume (V) of tea bag in permanently compressed state_C) Is 4021mm³. The density of the tea bag in the permanent compression state is calculated to be 0.72g/cm³。

Determination of Vickers hardness (H) of permanently compressed tea bags_v). In operation Bluehill2^TMMeasurements were performed on an Instron universal tester (model 5500R) of the software (version 2.17). The sample was placed on the base plate and the indenter was manually lowered until it was close to the sample surface. The pre-load cycle is run at a displacement of 1mm/min until a load of 0.1N is measured, at which time an automatic calibration of the displacement and load is performed. The force (in kgf) and displacement (in mm) were measured in the indentation loading cycle and the unloading cycle. The loading cycle was run at a displacement of 2mm/min until the tip of the indenter was pushed into the sample to a depth of 2.5 mm. The unloading cycle was run at a displacement of 2mm/min until the load returned to zero. Vickers hardness H of permanently compressed tea bags_vIs 0.46.

The permanently compressed tea bag was placed in an empty cup and 200ml of hot water was added. The tea bag is converted into its expanded form in a few seconds. In addition, this transition causes the tea bag to "tumble". This movement helps to quickly brew the tea leaves contained in the tea bag without the need to stir or agitate the tea bag.

For comparison, an uncompressed commercially available PG Tips pyramid-shaped tea bag (bag weight 2.9 grams) was placed in an empty cup and 200ml of hot water was added. The addition of water caused the tea bag to temporarily flatten. Furthermore, although the tea bag floats when the addition of water is complete, it does not "tumble" and is substantially static during the brewing process. The lack of movement means that the tea leaves contained in the tea bag do not brew as quickly.

The bulk density of the leaf tea mixture contained in the PG Tips pyramid shaped tea bag in the expanded (or uncompressed) state was determined to be 0.46g/cm³. The bulk density of the leaf tea mixture in the compressed state was estimated to be 0.97g/cm³. This was determined by placing a known mass of leaf tea blend in the same steel mould used to make compressed tea bags, applying a pressure of 4200kPa to the leaf tea blend and then calculating the volume of leaf tea after applying the pressure. It can be seen that the bulk density of the leaf tea in the compressed tea bag is significantly higher than the bulk density of the leaf tea in the expanded (uncompressed) tea bag.

Claims

1. An inflatable infusion bag containing a beverage precursor, wherein the infusion bag is in a permanently compressed state in the absence of water and is converted to an inflated state in the presence of water, wherein the infusion bag has a density of at least 0.5g/cm when in its permanently compressed state³And said infusion bag being substantially rigid and having a Vickers hardness (H) when it is in a permanently compressed state_v) Is at least 0.2.

2. The expandable infusion bag of claim 1 wherein the infusion bag has a density of at least 0.6g/cm when in its permanently compressed state³。

3. The inflatable infusion bag of one of claims 1 to 4 wherein the infusion bag is substantially rigid when it is in a permanently compressed state and has a Vickers hardness (H)_v) Is at least 0.25.

4. The expandable infusion bag of claim 5 wherein the infusion bag has a Vickers hardness (H) when in its permanently compressed state_v) Is 0.3 to 0.8.

5. The expandable infusion bag of one of claims 1 to 4 wherein the beverage precursor has an uncompressed bulk density (p ™)_{Is normal}) Pressure and pressureReduced bulk density (. rho.)_Compression) And the compressed bulk density (p) of the beverage precursor_Compression) An uncompressed bulk density (p) of the beverage precursor_{Is normal}) 1.5 to 3 times larger.

6. The expandable infusion bag of claim 5 wherein the compressed bulk density (p) of the beverage precursor_Compression) An uncompressed bulk density (p) of the beverage precursor_{Is normal}) 1.8 to 2.6 times larger.

7. The expandable infusion bag of any one of claims 1 to 6 wherein the beverage precursor comprises leaf tea.

8. Inflatable infusion bag as claimed in one of the claims 1 to 7, wherein the infusion bag has a volume V in a permanently compressed state_CAnd has a volume V in the expanded state_EIn which V is_EIs 2V_CTo 10V_C。

9. The expandable infusion bag of one of claims 1 to 8 wherein the infusion bag has a first geometry in its permanently compressed state and a second geometry in its expanded state, wherein the first and second geometries are different.

10. The expandable infusion bag of claim 9 wherein the first geometric shape is a cylinder.

11. The expandable infusion bag of claim 9 wherein said first geometric shape is a prism.

12. The expandable infusion bag of one of claims 9 to 11 wherein the second geometry is spherical, hemispherical, tetrahedral or pyramidal.

13. The inflatable infusion bag of any one of claims 1 to 12 wherein the infusion bag is made of a non-woven material.

14. A package comprising a plurality of inflatable infusion bags according to any of claims 1 to 13.

15. The package of claim 14, wherein the package is a tube or carton.