GB1575845A

GB1575845A - Bag for containing beverage-making material

Info

Publication number: GB1575845A
Application number: GB1466177A
Authority: GB
Original assignee: RODIGUES ELY R
Current assignee: RODIGUES ELY R
Priority date: 1977-04-06
Filing date: 1977-04-06
Publication date: 1980-10-01

Description

(54) BAG FOR CONTAINING BEVERAGE-MAKING MATERIAL (71) 1, ROBERT RODRI UES-ELY, a Canadian citizen of 515 St. Laurent Boulevard, Apartment, 2011, Ottawa, Ontario, Canada, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following state ment :- This invention relates to a bag containing a beverage-making material, such as tea or coffee, and made of a porous and flexible material such as paper or other fabric (woven or non-woven) of the type conventionally used in so-called "tea bags", and to a method of making the bag.

While tea bags are widely used and have proved generally acceptable, there are a number of disadvantages in the use of tea bags as compared with the infusion of tea by using loose tea leaf material.

A disadvantage in the use of a tea bag is that the very hot infusing liquid is not able to mix as readily with the tea in the bag, as compared with loose tea leaf material in the bottom of a tea pot.

Furthermore, when using tea bags having paper walls, the action of boiling water on the bag can create deterioration in the properties of the bag, and also creates a very substantial and sudden increase in the volume of the material in the tea bag.

With a view to overcoming the above disadvantages, it is known to increase substantially the volume of tea bags, as compared with the volume of material contained therein. It is also known to divide the ingredient in a tea bag into two parts.

Furthermore, some manufacturers of nonwoven paper tea bags have provided a textured mesh in the walls of the bag with a view to promoting the circulation of water through the wall of the tea bag, and subsequent exit through the wall of the tea bag.

However, it has been found that these expedients do not always solve the problems referred to above. Furthermore, while the above described problems exist in connection with "tea bags", these problems are even more severe in connection with possible use of bags made of the same material as tea bags, but intended to contain coffee powder.

According to the invention there is provided a bag containing beverage-making material and made of porous and flexible material, said bag being unfoldable, prior to immersion in an infusion liquid, from a substantially flat profile suitable for storage of the bag to a substantially selfsustaining tetrahedral shape.

This may be achieved by providing strengthened regions in the bag for rigidity when unfolded, while the unstrengthened regions (relative to the general fabric of the bag) provide flexibility for folding purposes.

The bag may be formed from two pieces of paper or fabric (woven or unwoven), each piece being rectangular when unfolded.

The peripheral margins of the pieces may be secured together by adhesive or other convenient means such as heat sealing so as, when assembled, to provide the required tetrahedral structure. The connectedtogether marginal regions will constitute strengthened portions of the bag which provide rigidity for the bag in the unfolded condition i.e. they promote the selfsustaining three-dimensional profile provided by the bag. However, when the two pieces are connected together, there will be edges of the tetrahedral structure which are not strengthened i.e. they are constituted by part of the general fabric of the bag, and these unstrengthened portions will provide sufficient flexibility for the bag to enable the bag, when filled with beverage material, to be folded to a substantially flat profile suitable for storage or packaging of the bag.

When the bag contains beverage material, and is folded to the substantially flat profile, the bag will present a minimum volume, but when the bag is unfolded to the generally tetrahedral shape, the internal volume of the bag will be increased substantially, thereby permitting expansion of the beverage material without risk of tearing or rupture of the fabric of the bag.

Furthermore, by providing a substantially self-sustaining structure when unfolded, the bag can readily permit mixing of liquid with the beverage material when the bag is placed in a vessel containing liquid. When the bag is used as a tea bag, it can be used in the conventional manner of tea bags, and may be used to infuse the tea by suspending the bag in the liquid near the top, e:g. by means of a labelled string-suspension arrangement, or the bag may be combined with a flotation device of the type shown in the specification of British Patent No.

1,436,397. Alternatively, insofar as the bag provides four surfaces on which the bag can rest, when unfolded, the bag may be dropped into the bottom of a tea pot to rest on one of its surfaces, and then boiling water poured into the tea pot can readily mix with the contents of the bag.

The bag according to the invention can be fabricated relatively cheaply, using paper or other fabrics of the type conventionally employed in the manufacture of tea bags.

However, by virtue of the construction of the bag, which provides a tetrahedral struc ture when unfolded having a large free volume for expansion of the beverage material, the risk of bursting of the walls of the bag is substantially reduced as compared with conventional tea bags. Furthermore, the risk of the walls of the bag sticking together under the action of boiling water is minimised, the boiling water circulation is greater, and free expansion of the beverage ingredient is allowed as compared with conventional tea bags. Also admixture of liquid with the contents in the bag is promoted as compared with conventional tea bags.

It is envisaged that the main use of the bag according to the invention will be for containing beverage material to form tea and coffee. Particularly in the case of coffee, conventional bags have not proved satisfactory, since the application of boiling water to the beverage material results in the generation of substantial volumes of gas which has two disadvantages, namely (1) the risk of rupture of the wall of the bag, and (2) the generation of the gas tends to inhibit satisfactory circulation taking place between the boiling liquid and the beverage material. However, in a bag according to the invention, the bag when unfolded provides a substantial free volume for expansion of the beverage material and for containing generated gas, thereby minimising the risk of rupture of the walls of the bag, and yet permitting satisfactory mixing of the liquid with the beverage material.

The invention also provides a method of making a porous bag containing beveragemaking material, comprising forming a sheet or sheets of porous and flexible material into a planar bag-like shape having an opening for access to the interior thereof, inserting beverage-making material into said bag-like shape through said opening, and closing said opening along a plane perpendicular to the plane of the bag-like shape so as to form a generally tetrahedral shaped bag.

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawing in which: Figure 1 is a diagrammatic illustration of a conventional tea bag after being immersed for a short period in boiling water; Figure 2 is a view, similar to Figure 1, of the conventional tea bag after a further period of time; Figure 3 is a perspective view of one embodiment of bag according to the invention, for containing a beverage material; Figure 4 is an exploded view of the bag shown in Figure 3; Figure 5 is a side elevational view of the bag shown in Figures 3 and 4; Figure 6 is a front view corresponding to Figure 3; Figure 7 is a perspective view of a floatable bar for use with the bag shown in Figures 3 to 6; Figure 8 is a diagrammatic illustration of one method of making the bag according to the invention; and Figure 9 is a diagrammatic illustration of a further method of making a bag according to the invention.

Referring now to Figures 1 and 2 of the drawings, a conventional tea bag is designated generally by reference numeral 10 and comprises an opposed pair of walls 11 and 12 which contain beverage 13 for making tea. The tea bag shown in Figure 1 illustrates the expansion of the beverage material 13 after immersion of the tea bag in boiling water for about 15 seconds, and it will be noted that a substantial portion 14 of the tea bag 10 has the walls 11 and 12 sticking together by virtue of the boiling liquid which has impregnated the walls 11 and 12. Also, as seen in Figure 1, the remaining portion 15 of the tea bag 10 has the materal 13 trapped therein, since the portion 14 will resist the tendency of the material 13 to separate the walls 11 and 12.

Figure 2 illustrates a typical crosssection of the tea bag after immersion for about 40 seconds in boiling water. There is now very little room left for further expansion of the material 13 and, it beng understood that a typical time of 90 seconds is required in order to brew a good cup of tea, any further expansion of the material 13 will be opposed by the adhering resistance of the parts of the walls 11 and 12 which are stuck together. Consequently, after about 50 seconds, further circulation of water through the walls 11 and 12 of the tea bag and over the material 13 will be impeded, with consequent ioss of strength imparted to the tea.

The problem of loss of strength with a conventional tea bag as illustrated in Figures 1 and 2 is even greater when a similar type of bag is employed to contain coffee.

Referring now to Figures 3 to 6, there is illustrated one embodiment of a bag according to the invention. The bag is designated generally by reference numeral 20 and may be made of any conventional porous paper or other fabric (woven or non-woven) currently used with tea bags. However, the construction of the bag 20 is quite different. Thus, as will be evident from Figure 3, the bag 20 is generally tetrahedral in shape, i.e. a structure having four plane surfaces each triangular in shape i.e. a triangular pyramid. As will be seen from Figure 4, the bag 20 its made up from two identical pieces 21 and 22 which are each rectangular in the flat condition, but are relatively foldable to occupy the shapes illustrated in Figure 3, and are subsequently adhered together along their marginal regions.Thus, taking the piece 21 by way of example only, it is folded into a form so as to provide triangular mating edges 23, 24 and 25 for adherence to corresponding edges of the piece 22, whereas it has an edge 26 which is folded on itself to provide two adjacent edge portions which are adhered together. The edge portions of the piece 22 corresponding to the edge portions 23 to 26 for the piece 21 are designated by the same reference numerals.

Prior to the assembly of the pieces 21 and 22, an appropriate quantity of the required beverage material is placed into one of the pieces, and then the pieces are assembled by adhering together the respective edge portions 23 to 25 of the pieces 21 and 22. This adherence may be by means of any conventional techniques currently employed in the manufacture of tea bags.

Referring now to Figures 3 and 5 to 6, the assembled form of the bag 20 is illustrated, with the edges 23, 24 and 25 of the pieces 21 and 22 adhering together.

This provides three strengthened regions of the bag 20, and a fourth strengthened region is provided by means of the assembledtogether edges 26 of the pieces 21 and 22, which unite to form a continuous edge 27 for the bag 20.

As will be evident from Figures 3 and 5 to 6, the edge portions 24 and 25 are united with a middle portion 28 of the edge 27.

While the bag 20 is provided with strengthened portions which provide a selfsustaining capability to the bag 20 when unfolded, the bag 20 also has edge and/or surface portions which are unstrengthened relative to the remainder of the bag 20, so as to provide flexibility and to enable the bag 20 to be folded into a substantially flat profile for storage or packaging purposes. In the flat profile (not illustrated), the volume of the bag will be only slightly in excess of the volume required to store the beverage material therein. By way of example, the flexibility of the bag may be ascertained by gripping the edge 23 with one hand, and manipulating the edge 27 so as to pivot about the middle portion 28.

When the bag 20 is unfolded to the tetrahedral structure illustrated in the drawing, a large free volume (relative to the volume of the beverage material) is provided within the bag, which will permit substantial expansion of the material upon the application of hot liquid thereto. This means that the problem of possible rupture of the bag 20 is overcome, or at least substantially minimised. Furthermore, external hot liquid can readily pass through the walls of the bag 20 to mix with the beverage material, and then exit through the walls of the bag, whereby good circulation can exist between the external liquid and the material within the bag.

The bag 20 is particularly suitable for containing material for making tea or coffee, though evidently it can be employed to contain any other beverage material, as desired.

In the case of coffee, as is well known there is substantial generation of gas during the applicaion of hot water to the coffee, but this gas can be allowed to escape by the provision of suitable small holes in the walls of the bag.

As is well known, in connection with the formation of coffee, it is necessary to provide different filter systems which are both expensive and time consuming to clean.

While the illustrated embodiment of bag is considered to be suitable for coffee as well as tea, the use of coffee does increase the risk of rupture of the bag occurring, and for this reason it is preferred that the bag should be strengthened by means of cellulose and/or synthetic fibres which may be applied in parallel bands spaced apart e.g.

at two centimetre spacings. The thickness of each fibre need not exceed a few hundredths of a millimetre, and the width of each band may be about two millimetres.

The positioning of the bands will depend upon the regions in which increased strength is required.

By providing a tetrahedral structure, in the unfolded state, the bag 20 can move about in boiling water with ease and, when not used in suspended manner e.g. from a string or from a float, the bag can be selfsupporting on one of its four supporting surfaces, and provides substantial space for expansion of the beverage material and which also promotes the circulation of the liquid through the walls of the bag -to contact the material, and then to exit through the walls of the bag.

Example A conventional tea bag was made in conventional paper material, and the total area of the bag was 72 cm2. In the empty state, the volume of the conventional tea bag was substantially zero. Using the same material, a tetrahedral bag was made using approximately 25% less paper. The total surface area of the tetrahedral bag was 55 cm2, and contrasting with the volume of the empty conventional tea bag, the tetrahedral bag had an empty volume of 40 cm3. The same quantity and quality of tea was then introduced into the conventional bag and also into the tetrahedral bag. The two bags were then inserted into respective cups filled with boiling water.

After 90 seconds, the two tea bags were taken out of the cups, and it was noted that the conventional tea bag was on the point of bursting having an unoccupied internal volume of only 1 mm3, whereas the tetrahedral bag still had an unoccupied internal volume of 7 cm3 permitting further expansion of the tea and providing free water circulation. Therefore, using 25% less paper material, the tetrahedral bag was available to provide more aroma, having more room for expansion, and leaving 7 cm3 unoccupied volume even after expansion of the tea.

The tetrahedral structure shown in Figures 3 to 6 is provided with strengthened regions constituted by the edges 23, 24, 25 and 27. Evidently, two of these edges, namely the edges 23 and 27, constitute edges proper of the tetrahedral structure, whereas the edges 24 and 25 extend from opposite ends of the edge 23 to a middle portion of the edge 27. Furthermore, the tetrahedral structure will be constituted by four generally triangular planar external surfaces, and the edges 24 and 25 will substantially bisect the respective planar surface in which it is contained.

As will be described in more detail below with reference to Figure 3, a generally similar shape of tetrahedral bag may be obtained to that illustrated in Figures 3 to 6, and provided with the edges 23 and 27 which constitute edges proper of the tetrahedral structure. However, by virtue of the method of construction described below with reference to Figure 8, one of the edges 24 or 25 is dispensed with.

Referring now to Figure 7 of the drawings, a floatable bar is designated generally by reference numeral 29, and this may be secured to the bag whereby, in use, the bag will be suspended therefrom when the bag is immersed in liquid. Conveniently, the bar 29 may be secured along the edge 27, and may have a length substantially equal to the length of edge 27. If desired, one or more surfaces of the bar 29 may provide a vehicle for advertising or other information e.g. along the surface 30. The bar 29 will be made of any convenient material which will not have an adverse affect on the required beverage, and one convenient material is expanded polystyrene.

When the floatable bar 29 is provided on a bag according to the invention, the bag when folded may have a surface area of half S, when a conventional tea bag made from the same amount of material may have a surface area S.

Reference will now be made to Figures 8 and 9 of the drawings, which illustrate diagrammatically two methods of making a bag according to the invention.

Referring first to Figure 8, there is illustrated a method in which a tetrahedral bag is obtained from a sheet which is made into generally flattened tubular form. A sheet 31 is folded-over into tubular form, and opposite edges of the sheet are secured together to form a longitudinal marginal region 32- e.g. by a heat sealing process.

One end of the tubular form is closed by flattening the peripheral edge of the sheet 31 at that end so as to provide a second marginal region 33 which extends perpendicular to the first marginal region 32.

This leaves an opening 34 at the opposite end of the tubular form, and beveragemaking material e.g. tea may then be inserted into the bag-like shape so-formed as indicated at 35. After the insertion of the beverage-making material, the opening 34 is closed by flattening the peripheral edge 36 at that end in a plane perpendicular to the marginal edge region 33. Thus, a third marginal region is provided which extends perpendicular to marginal region 32, and also to marginal region 33. Thereby, a bag of generally tetrahedral construction will be obtained, whereby marginal region 33 will be equivalent to edge 23 and the marginal region formed to close the opening 34 will be equivalent to edge 27 in the bag shown in Figures 3 to 6. The marginal region 32 will provide a strengthened region equivalent to edge 24 or 25.

Tetrahedral bags may be formed on a continuous basis according to Figure 8 in simple manner, so as to achieve economies in the manufacturing process. Thus, by way of example, a single long sheet may be folded into tubular form, and then separated-off into individual bags by the marginal regions 33.

Referring now to Figure 9 of the drawings, there is illustrated diagrammatically a method of obtaining a tetrahedral bag as shown in Figures 3 to 6. Just as, in the arrangement illustrated in Figure 8, bags may be produced on a substantially continuous basis. Description will be made however of the formation of a single bag.

Two rectangular sheets are secured together along adjacent edges to provide marginal regions 37 and 38. One end of the bag hke form so obtained is closed by securement of adjacent edges at that end of the two sheets to form a further marginal region 39. This leaves an opening at the opposite end through which beverage making material can be inserted as indicated at 40. Thereafter, the opening can be closed by flattening the edges 41 and 42 of the respective sheets in a plane perpendicular to the plane of the drawing, so as to provide a marginal region which extends perpendicular to marginal regions 37 and 38, and also perpendicular to marginal region 39.

Upon the formation of the marginal region by the securement together of the edges 41 and 42, the tetrahedral construction shown in Figures 3 to 6 can be obtained. The marginal regions 37, 38, 39 and the marginal region formed by the securement together of edges 41 and 42 will then correspond to the edges 23, 24, 25 and 27 shown in Figures 3 to 6.

Evidently, the arrangement illustrated in Figure 9 can be carrned out on a substantially continuous basis, either by providing a pair of individual sheets to form each bag in succession, or by providing a pair of lengthy sheets which can form a plurality of bags throughout the length of the sheets, with successive marginal regions of securement 37 and 38 being formed throughout the lengths of the sheets.

WHAT I CLAIM IS:- 1. A bag containing beverage-making material and made of porous and flexible material, said bag being unfoldable, prior to immersion in an infusion liquid, from a substantially flat profile suitable for storage of the bag to a substantially self-sustaining tetrahedral shape.

2. A bag according to claim 1, in which strengthened regions are provided in said material to provide rigidity for the bag when unfolded.

3. A bag according to claim 2, in which two of the edges of said tetrahedral structure constitute said strengthened regions.

4. A bag according to claim 3, in which said two edges are interconnected by a strengthened region which extends from the end of one of said two edges to a centre region of the other of said two edges.

5. A bag according to claim 4, in which said two edges are interconnected by a further strengthened region which extends from an opposite end of said one edge to the centre region of said other edge.

6. A bag according to any one of the preceding claims and made of porous paper material.

7. A bag according to any one of the preceding claims and having a bar of floatable material connected thereto.

8. A bag according to claim 7, in which said bar is secured to one of the edges of the tetrahedral shape.

9. A bag according to claim 1 and sub stantially as hereinbefore described with reference to and as shown in the accompanying drawings.

10. A method of making a porous bag containing beverage-making material, comprising forming a sheet or sheets of porous and flexible material into a planar bag-like shape having an opening for access to the interior thereof, inserting beverage-making material into said bag-like shape through said opening, and closing said opening along a plane perpendicular to the plane of the bag-like shape so as to form a generally tetrahedral shaped bag.

11. A method according to claim 10, in which the planar bag-like shape is obtained by forming a sheet into generally flattened tubular form having one end closed and an opposite end open to provide said opening.

12. A method according to claim 11, in which the tubular form is obtained by securing together opposite edges of the sheet to form a first marginal region extending longitudinally along the periphery of the tubular form, said one end is closed by flattening the peripheral edge of the tubular form at said one end to provide a second marginal region extending perpendicular to said first marginal region, and said other end is closed by flattening the peripheral edge of the tubular form at said opposite end to provide a third marginal region extending perpendicular to said first marginal region and to said second marginal region thereby to form a substantially tetrahedralshaped bag.

13. A method according to claim 11 or 12, in which a plurality of bags are formed on a successive basis from a tubular formation of flexible and porous material.

14. A method according to claim 10, in which two opposed edges of one rectangular sheet are secured to respective edges of a similar second sheet to form said bag-like

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. continuous basis according to Figure 8 in simple manner, so as to achieve economies in the manufacturing process. Thus, by way of example, a single long sheet may be folded into tubular form, and then separated-off into individual bags by the marginal regions 33. Referring now to Figure 9 of the drawings, there is illustrated diagrammatically a method of obtaining a tetrahedral bag as shown in Figures 3 to 6. Just as, in the arrangement illustrated in Figure 8, bags may be produced on a substantially continuous basis. Description will be made however of the formation of a single bag. Two rectangular sheets are secured together along adjacent edges to provide marginal regions 37 and 38. One end of the bag hke form so obtained is closed by securement of adjacent edges at that end of the two sheets to form a further marginal region 39. This leaves an opening at the opposite end through which beverage making material can be inserted as indicated at 40. Thereafter, the opening can be closed by flattening the edges 41 and 42 of the respective sheets in a plane perpendicular to the plane of the drawing, so as to provide a marginal region which extends perpendicular to marginal regions 37 and 38, and also perpendicular to marginal region 39. Upon the formation of the marginal region by the securement together of the edges 41 and 42, the tetrahedral construction shown in Figures 3 to 6 can be obtained. The marginal regions 37, 38, 39 and the marginal region formed by the securement together of edges 41 and 42 will then correspond to the edges 23, 24, 25 and 27 shown in Figures 3 to 6. Evidently, the arrangement illustrated in Figure 9 can be carrned out on a substantially continuous basis, either by providing a pair of individual sheets to form each bag in succession, or by providing a pair of lengthy sheets which can form a plurality of bags throughout the length of the sheets, with successive marginal regions of securement 37 and 38 being formed throughout the lengths of the sheets. WHAT I CLAIM IS:-

1. A bag containing beverage-making material and made of porous and flexible material, said bag being unfoldable, prior to immersion in an infusion liquid, from a substantially flat profile suitable for storage of the bag to a substantially self-sustaining tetrahedral shape.

shape having two coplanar marginal regions, and one end of the bag-like shape is closed by securing together adjacent edges of the sheets at said one end to provide a further marginal region which extends coplanar with but perpendicular to said first-mentioned marginal regions, and an opposite end of the bag-like shape is closed by securing together adjacent edges of the sheets at said opposite end to provide another marginal region which extends perpendicular to said first-mentioned marginal regions and perpendicular to said further marginal region thereby to form a subtsantially tetrahedral-shaped bag.

15. A method according to claim 14, in which a plurality of bags are formed on a successive basis.

16. A method according to any one of claims 10 to 15, in which a bar of floatable material is secured to the bag.

17. A method according to claim 10 and substantially as hereinbefore described with reference to and as shown in Figure 8 or Figure 9 of the accompanying drawings.