GB2053837A - Manufacture of herb-containing sachets - Google Patents

Abstract

A method of making herb- containing sachets, e.g. tea bags, from a web or webs of sachet forming material comprises forming an empty sachet having a herb-charging opening from the web(s), feeding the empty sachet to a herb-charging station whereat herbs are introduced into the sachet, closing the sachet with a closure that extends at a selected angle of from 0 DEG to 90 DEG relative to a bottom-forming fold or seam of the sachet, and separating the filled and closed sachet from the remainder of the web(s). An apparatus for performing the method includes a closing means which is adjustable to permit variation of said angle of closure. The method and apparatus afford the possibility of making sachets, e.g. of tetrahedral shape, wherein the problem of adhesion of the sachet walls when wetted is avoided.

Description

SPECIFICATION The manufacture of herb-containing sachets This invention relates generally to the manufacture of herb-containing sachets, and is concerned with providing improved infusion properties of such sachets, by the simultaneous control of the problem of adhesion of the walls of the sachets when wetted and of the volume of the expansion chambers of the sachets.

The term "herb-containing sachet" should be understood as referring to a sachet containing infusible herbs including teas such as Indian or China tea, and herbs of the type used as "herb teas", and also medicinal herbs.

This invention is concerned firstly with providing the herb industry with means to achieve the best possible infusion for a much greater variety of ingredients (qualitatively and quantitatively).

The superiority is well known of the infusion of tea and herb tea, when carried out loose in a tea pot, using ingredients of large size whereby the aromas are conserved and the active substances of the dry ingredients are used.

This invention is concerned secondly with the creation ofateabag or sachet in such mannerthat infusion can be comparable with that obtained with loose ingredients in a tea pot, and the creation of methods appropriate to forming webs into the form of the tea bags, and apparatus for carrying out the method.

As is well known, herb tea and teas are sold in different parts of the world in two distinctive manners as follows: 1. Conventional tea bags of three types are used, namely flat tea bags, semi-flat tea bags with enlarged bottoms, and double chamber tea bags.

These three types of tea bag use exclusively finely graded ingredients.

2. Tea and herb tea are used in loose form, the tea and herb tea being packaged in appropriate paper or plastics packaging. In this case, the ingre dientswhich are employed are of varied dimensions, but much greater than the finely graded ingredients used in tea bags.

It is well known that teas and herb teas conserve their aromas and their active substances much longer when the products are ground to large dimensions.

The conventional flat tea bags, with double chamber and enlarged bottom, do not provide a sufficient free volume of expansion chamber, whereby teas and herb teas ground to very large dimensions cannot be introduced therein. Furthermore, the walls of the conventional tea bag adhere together, regardless of the position adopted by the tea bag when it is plunged in boiling water.

Superior infusion of tea or herb teas is obtained when these products are used in loose form. The ingredients deposited in the bottom of a tea pot or in a perforated aluminium tea ball and immersed in boiling water are acknowledged to give superior infusion. The reasons for this are as follows: The problem of the adhesion of wetted sachet paper does not exist, and a large expansion chamber is provided for the ingredient.

The dimensions of the loose ingredients are much greater, so that it follows that the aroma and the active substances of the dried products are kept intact up to the moment of infusion, and this without regard to the losses of material which are practically nil.

The ingredients formed from fragile flowers and leaves, coarse roots, stems, barks, and other ingredients of herb teas, have greatly differing coefficients of expansion. However, deposited loose in the bottom of a tea pot or inside a perforated aluminium tea ball, none of these products are limited as to their expansion i.e. by the walls of a tea bag, and the flavour and aromas can freely be released by the ingredients.

It is known that the manufacturers of paper, for use as tea bags, have improved the product so as to improve the passage of liquid through the paper. It is known also that efforts have been made to enlarge the bottom of a tea bag, or to double the infusion chambers. These efforts have only given modest results, valid provisionally only for teas; but which could not be taken seriously by the herb tea industry, which requires that a hundred different products should be able to conserve their qualities for as long as possible, in order to release their properties at the appropriate moment.

As a result, customers who prefer to buy tea or herb teas, usually buy them in loose form. However, there are numerous disadvantages in the sale of herb tea in loose form. Quality control does not exist, but even if it did, the final point of consumption represents serious disadvantges of hygiene arising out of the manipulation of such products, to which should be added the necessity for fastidious attention to cleanliness.

The conventional packaging machines which make flat, semi-flat and double chamber tea bags utilise only finely graded ingredients. Conventional machines to make flat tea bags run at speeds of production of about 1500 tea bags per minute. These speeds of production depend entirely on the fineness of the ingredients. In fact, small regular heaps of ingredients are deposited on a sheet which is moved regularly in one direction. This sheet is then covered by a second sheet, before the necessary joining operations are carried out. It should be understood, therefore, that the speed of production depends entirely on the regularity of these small heaps, which depend in turn on the fineness of the ingredients.

The machines which manufacture double chamber tea bags manufacture the tea bags virtually one by one. This principle, and also the examination of a double chamber tea bag, allows one to conclude that a fineness of ingredient is necessary to the good functioning of a machine of which the speed of production is, in any case, reduced to about 180 tea bags per minute.

The machines which manufacture semi-flat tea bags, for the same reasons, require finely graded ingredients.

The present invention has been developed primar ill with a view to enabling the production of a sachet which can have its internal volume and also the problems of adhesion of the walls of the sacket controlled simultaneously, whilst still providing a sachet which is sufficiently felxible for most requirements and which can be filled with ingredients of different properties and dimensions. In particular, regard should be had to the requirements of both country and town regions of all countries, and taking account of the diversity of herbs and teas as to the following factors.

The invention has the following objectives: 1. To re-create firstly, within a new sachet, the four conditions which give the superiority of an infusion created in a pot; large volume of expansion chamber, no adhesion problems, and as large size and density of ingredients as is possible.

2. The ground or milled dimensions of teas and herb teas having a considerable influence on the conservation of the aroma and active substance of these products, the second object is the creation of a method of manufacture of sachets which allows them to be filled with ground ingredients with very large dimensions.

3. Given the qualitative and quantitative diversity of teas and herb teas and their coefficients of expansion, another object is to creat a variability in the capacity of the bag, the sealing of its walls and its flexibility.

4. Another object is to creat a control of these three quantities which vary to allow the deduction of the choice of a grinding dimension or of the type of filter paper to be used.

5. Another object is to implement this method of controlled variability of the three main characteristics of a bag, at the very heart of the method of manufacture of bags that is defined in the first object.

6. Another object allows, thanks to the implementation of the system of controlled variability, the creation of a common method of manufacture of conventional bags and of controlled volume tea bag.

A variable volume tea bag should be sufficiently flexible when containing finely graded ingredients and ingredients having individual dimensions of up to 0.20 cm2, to enable easy handling and packaging ofthe tea bags.

Also, a sufficient expansion volume with minimum adhesion of the paper walls should be allowed in the sachet to take into account the variability of the medicinal herb properties so that there is: (a) improvement in the infusions to render them comparable with those obtained by infusion of loose tea or herbs; (b) the aroma can be conserved and the active substances of the medicinal herbs can remain for a longer period than those of loose medicinal herbs and of finely graded tea; (c) allowing new and precise method to the manufacturers of paper (for the sachets) to establish the correct pattern automatically; (d) avoiding losses of material; (e) allowing appreciable economies in paper filters; (f) opening a new clean market of loose herb teas and giving in the meantime to the current consumer of loose herbs the opportunity to retain the advantages of loose herbs while avoiding the inconveniences of the use of loose herb teas; (g) by providing a central extension on a sachet with appropriate labelling, the avoidance of possible mistakes by the user of medicinal herbs.

According to one aspect, the invention provides a method of making herb-containing sachets from a web of sachet-forming material comprising; forming the web into a plurality of successive sachets contained in the general plane of the web and each having a herb-charging opening, each sachet having a given internal volume when it forms part of the web; feeding the sachets to a herb-charging station; charging each sachet with a charge of herbs through the respective charging opening; closing said opening of each sacket; and separating each charged and closed sachet from the web; in which the manner of closing each sachet is controlled in such a way as to provide the sachet with a selected internal volume which may be varied between said given internal volume and a predetermined maximum internal volume.

Thus, there is provided in simple manner a means of increasing the internal volume of the sachet to allow expansion of the herbs and improve circulation of infusion liquid within the sachet, but also simultaneously there is provided a means of holding a variable and convenient separation of the walls of the sachet so as to avoid, or at least mitigate, the problem of adhesion of the walls, when wetted.

In one preferred arrangement, each sachet is closed along a closure line which is inclined selectively at an angle greater than 0 and up to +90" relative to the general plane of the web.

When the closure line is substantially parallel to the plane of the web, a conventional shape of sachet or tea bag is obtained which is substantially flat, and provides a minimum internal volume of tea bag.

When the closure line extends perpendicular to the plane of the web, i.e. inclined at +90 relative thereto, a triangular prism shape of tea bag is obtained which has maximum internal volume.

Thus, for a given charge of tea, there will be a greater internal free space in the triangular prism than in the flattea bag, in orderto allowforexpansion ofthetea and also to promote, within the tea bag, the circulation and contact between the infusion liquid and the tea.

The tea bag of minimum internal volume is satisfactory for teas such as China tea or Indian tea, but is less satisfactory for use with herb teas which tend to be provided in larger individual sizes.

Therefore, the ability to vary the internal volume of the tea bag is particularly advantageous when herb teas are involved. As is well known, herb teas undergo greater expansion on contact with infusion liquid and also require better contact with the liquid and for a longer period in order to obtain a satisfactory beverage. The maximum internal volume, or triangular prism tea bag, is therefore particularly suitable for use with herb teas.

However, an irregular triangular prism-shaped tea bag having the closure line inclined at +20to 30 is superior to a conventional flat tea bag for finely ground teas and herb teas, while maintaining satisfactory flexibility for the bag, accompanied by a diminished tendency for the walls of the bag to stick together when wetted. When the closure line is inclined at +30 to 60 , the tea bag is suitable for herb teas of larger dimension, when paper is used forthe bag which permits as ready circulation of liquid as is provided by the holes of a conventional perforated aluminium tea ball.

If desired, each tea bag will be provided with a floatation member, from which the bag will be suspended when placed in an infusion liquid. Conveniently, the floatation member may be applied to each pocket simultaneously with the closure of the tea-charging opening. The floatation member may be made of wood or plastics material, preferably foamed plastics.

Additionally, each tea bag may be provided with a support which may bear advertising or other matter, and also a handle by which the tea bag may be manipulated manually.

In a further preferred arrangement, each sachet is convertible to have a greater internal volume by providing an extension adapted to the two types of sachet, one of conventional form for clients who prefer to retain the traditional form, and the other having a triangular prism shape. A large opening permits each type of sachet to be filled with herb ingredients of mean dimensions between 12 and 20 mm2. Furthermore, the two type of sachet benefit from the advantages of the extension.

The main portion of the extension may include a float.

According to a further aspect, the invention provides an apparatus for making herb-containing sachets from a web of sachet-forming material, the apparatus comprising: means for forming the web into a plurality of successive sachets containing in the general plane of the web and each having a herb-charging opening, each sachet having a given internal volume when it forms part of the web; means for feeding the sachets to a herb-charging station; feed means provided at said station for introducing a predetermined charge of herbs through the opening of each sachet; closure means for closing the opening of each sachet; and means for separating each closed sachet from the web;; in which the closure means is selectively adjustable so as to vary the angle of the closure of said opening of each sachet between 0 and +90 relative to the plane of the web whereby a selected internal volume of the sachet so formed is obtainable which is variable between said given internal volume and a predetermined maximum internal volume.

Thus, the selected internal volume of each sachet may be increased simultaneously with the increase in the distance separating the walls of the sachet for the purposes of avoiding adhesion of the walls when wetted.

When the closure line is parallel to the plane of the web, a conventional tea bag is obtained, whereas a triangular prism tea bag is obtained having a maximum internal volume and a maximum separation of the walls when the closure line is inclined at +90" relative to the plane of the web.

The invention is also concerned with tea bags as made by the methods and apparatus as defined above.

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which: Figure lisa schematic illustration of the various stages of a tea bag forming apparatus according to the invention; Figures2a to 2e are diagrammatic illustrations of different modes of forming a web of bag-forming material into a number of tea bags bythe apparatus of Figure 1; Figures 3a to 3d are illustrations of four different types of tea bag which can be obtained from the webs illustrated in Figures 2a to 2d; Figures 4, 5and 6 are graphs of variation in characteristics of a tea bag with variation in the angle of inclination of the closure plane of the bag;; Figure 7 illustrates diagrammatically automatic means for closing the end of a sachet formed from a web provided with an extension; and Figures 7a and 7b illustrate further types of tea bags which may be made by the means of Figure 7.

Referring to Figure 1 of the drawings, there is shown, by way of example, a schematic illustration of the various stages of tea bag forming apparatus.

However, it should be understood that the method and apparatus is applicable generally to the formation of herb-containing sachets. Aweb 10 of bagforming material, such as paper or other permeable material conventionally used in the manufacture of tea bags, is fed to pocket-forming apparatus 11 in which the web is formed with a successive arrangement of rectangular pockets each having a teacharging opening. The web 10 is then fed by a web feeding device 12 to a tea-charging station 13 at which feed means is provided to introduce predetermined charges of tea through the charging opening of each pocket as it arrives at the station 13.

Thereafter, the charged pockets are fed to a pocket closing apparatus 14 at which the charging opening of each pocket is closed and sealed. Thereafter, the charged and sealed pockets are fed to a tea bag separation device 15 at which individual tea bags are separated from the web 10.

Referring now to Figures 2a to 2e, there is illustrated a number of different ways whereby a web can be first formed into a plurality of successive pockets. Each pocket is provided with a tea-charging opening through which a charge of tea can be introduced at the tea-charging station 13 of Figure 1.

Figures 2a to 2e also show the manner by which the opening of each pocket can be closed after a charge of tea has been introduced into the pockets.

Referring to Figure 2a, a web 10a is fed in a vertical direction as indicated by the arrow X and is formed from a single sheet of material which is folded-over to form a longitudinal margin 16. Also, the web 10a is divided-up into a succession of pockets 17. Thus far, the conversion of the web 10a of Figure 2a into pockets may take place in any suitable one of the conventional methods.

Referring now to Figure 2b, there is shown a web 1 Ob which is fed horizontally in the direction of the arrow X, and, like the web 1 Oa, is formed from a single sheet of material. In this arrangement, the web lOb is formed into a plurality of successive pockets 17 which are bounded laterally by margins 18.

Referring to Figure 2c, there is shown a web 10c which, like the web 1 Oa, is fed vertically, but is formed from two sheets of material which are joined along longitudinal margins 19.

Referring to Figure 2d, a web 10d is fed horizontally and also is formed from two sheets of material, but manipulated to provide a longitudinal margin 21, in addition to the laterally spacing margins 18.

In all of the arrangements shown in Figures 2a to 2d, it will be noticed that each pocket 17 is provided with a tea-charging opening 22 through which a charge of tea can be introduced when the pocket reaches the tea-charging station 13. After the pocket 17 has received a predetermined charge of tea, the pocket then passes to the closing apparatus 14 of Figure 1 so that the pocket can be closed. In Figure 2e, there is shown diagrammatically a closure means for closing the charging opening of each pocket. Figure 2e is a diagrammatic plan view of a pocket 17, and the plane Y-Y represents the general plane of the web 10. The opening 22 of the pocket 17 is closed along a closure line which is inclined selectively at any angle between 0 and up to +90" relative to the plane Y-Y.The internal volume of the tea bag formed from each pocket 17 can be controlled by careful selection of the angle of the closure plane of each opening 22.

For illustration purposes only, there is shown diagrammatically in Figure 2e a bar 23 which can take up any desired angle relative to the plane Y-Y between 0" and +90 , and the edge of the pocket 17 which defines the opening 22 is adhered or attached in any convenient manner along both longitudinal sides of the bar 23 in order to close the opening 22.

Conveniently, the bar 23 may be a floatation mem ber fo a tea bag and, to this end, may be made of wood or foamed plastics material. Evidently, variation in the angle of inclination of the bar 23 relative to the plane Y-Y will result in considerable variation in shape of tea bag which is obtained.

Thus, when the conventional and flat shape of tea bag is square and when the bar 23 extends perpendiocular to the plane Y-Y, a tetrahedral shape of tea bag may be obtained.

The tetrahedral and triangular prism shape of tea bags have particular advantage over the conventional flat shape of tea bag, in that, for a given charge of tea, a tetrahedral or triangular prism teabag provides a greater free internal volume which allows for expansion of the tea and also promotes better circulation and contact within the tea bag between the infusion liquid and the tea. However, in some circumstances, the tetrahedral or triangular prism tea bag may not be sufficiently flexible from the point of view of packaging and storing, so that other angles of inclination, between 0 and +90 , of the closure line of the opening of each pocket may be selected.While an angle of inclination less than +90" will have a lesser internal free volume than the +90 arrangement, it will still have a greater free internal volume than the conventional flat tea bag. Furthermore, the intermediate arrangement will have greater flexibility than the f90" or tetrahedral or triangular prism tea bag arrangement.

As indicated above, the shape of a tetrahedral tea bag, i.e. closure plane at 90" to the plane Y-Y, is described and illustrated in more detail in the specification of my British Application No. 14661/77.

However, Figures 3a to 3d illustrate some other arrangements of tea bag which can be obtained with the method and apparatus of this invention. Figure 3a shows a conventional flat rectangular tea bag 24 which can be obtained from the single sheet web 1 Oa or 10b of Figures 2a and 2b respectively, the bag 24 being formed when the closure plane of the opening 22 of a pocket 17 is parallel to the general plane Y-Y of the web. Figure 3b shows a flat conventional tea bag 25 which can be formed from the double sheet webs 10c and 10d of Figures 2c and 2d respectively, again when the closure plane is parallel to the plane Y-Y.

Figure 3c shows a tea bag 26 which can be formed from the webs 10a and 10b, but in the case in which the closure plane is inclined at an angle between 0 and ~90 , preferably in the range +20" to 300, or +30" to 60 , to the plane Y-Y. Similarly, Figure 3d shows another polyhedral tea bag 27 which is formed from the webs 10c and 1 Od, when the closure plane is similarly inclined to the plane Y-Y.

The triangular prism tea bags 26 and 27 are particularly advantageous embodiments in that there remains an adequately greater free internal volume than in the case of the conventional tea bag, while still providing sufficient flexibility for the tea bag and considerably reduced tendency of the walls of the tea bag to adhere together when wetted.

The arrangement of the closure plane at an angle of inclination of +20" to 300 to the plane Y-Y is particularly advantageous for finely ground teas and herb teas, while maintaining satisfactory flexibility for the bag, accompanied by a diminished tendency for the walls of the bag to stick together when wetted.

Inclination of the closure plane at +30 to 600 is particularly advantageous for herb teas of larger dimensions when a paper is used for the bag which permits as ready circulation of liquid as is provided by the holes of a conventional perforated aluminium tea ball.

Inclination of the closure plane in the range +20" to 60 provides for satisfactory internal volume of an expansion chamber in a tea bag, while maintaining satisfactory flexibility and reducing substantially the tendency for the walls of the bag to adhere together when wetted. In the range +20 to 600, a suitable design of controlled volume tea bag can be chosen according to the ingredients to be inserted therein.

Thus, a tea bag can be designed readily not only for finely ground teas, but also for herb teas having dimensions between 12 mm2 and 20 mm2 surface area.

Figures 4, 5 and 6 show graphs of variation of characteristics of a tea bag against variation in angle of inclination (A) of the closure plane. Figure 4 shows the variation in internal volume (Vl) with change in A; Figure 5 shows the adhesion (A) of the walls of a tea bag with change in A; and Figure 6 shows the variation in flexibility (F) of a tea bag with change in A.

Referring to Figure 7, there is shown a part of apparatus for forming a web of herb-containing material into a succession of sachets. The web comprises a flattened tube A of bag-forming material which is provided with a longitudinal extension D and which is guided to a herb-charging station Y. A guide block J guides the main part of the tube A and a guide G guides the extension D. At the charging station Y, a releasable holding device is provided having fingers H which are movable towards and away from each other in order respectively to grip and to release the extension D.

The motion of the flattened tube A is stopped when the fingers H grip the extension D, and then any suitable means is employed in order to open the leading end of the tube as shown at E. By way of example, suction may be applied to the side B of the flattened tube, though other means may be adopted including the insertion of a magnetic element or ball into the tube A, which is then drawn upwardly by magnetic action in order to open the tube fully.

A charge of herbs is then introduced through the open end E, and thereafter the end E is closed by means (not shown). The bottom end Cofthesachet is closed by line contact and engagement at C with the two sides of the flattened tube, or the flattened tube may be provided initially with a series of preformed closed ends of each sachet.

Depending upon the angle of closure of the end of each sachet relative to the general plane of the web, there will be produced different shapes of sachet as described above with reference to Figures 2 and 3.

Referring now to Figures 7a and 7b, there are shown further types of sachet or tea bag which may be made by the method and apparatus according to the invention. Figure 7a shows a conventional shape of tea bag, having a central extension which may be formed, and filled with herb or tea ingredients, by the means as shown diagrammatically in Figure 7.

Figure 7b shows a sachet of triangular prism shape having an extension, which also may be formed and filled by the means shown in Figure 7.

The two types of sachets shown in Figure 7a and 7b are the preferred shapes corresponding to the new needs of two types of consumers, namely the ones preferring the conventional forms with tea or herb teas having large dimensions, and the others preferring the new shapes with larger sizes of ingredients. In any event, these two types of consumers benefit, furthermore, from a number of advantages arising out of the provision of the extensions on the sachet. First of all, the extensions may serve to inform the user, by provision of information, e.g. a number placed on the most central and visible part of the extension, so that the consumers of medical herbs may avoid any case of error.Also, thanks to the provision of the extensions, the following other advantages can be obtained: Superior infusion by the variability of the volume or, according to the case, by the increase in the possible dimensions of the ingredients; superior infusion by the provision of a float on the extension; and consumers of medical herbs are well informed.

Accordingly, the various embodiments of the invention described above enable manufacturers to select the optimum shape of sachet, from an infusion point of view, to suit the particular herbs to be inserted in the sachet. The sachets are readily manufactured on suitable machinery, and will have the dual advantage of increasing the internal volume ofthesachetto allow for expansion of the herbs, and also overcome or mitigate the problem of adhesion of the walls (when wetted) of the sachet. This is achieved by suitable selection of the closure line of each sachet between 0 and i90" relative to the general plane of the web.

While the preferred shape for the sachets is square or rectangular, it is within the scope of this invention for irregular shapes of sachets to be obtained e.g. in which the opposite edges of each sachet do not extend parallel to each other

Claims (12)

1. A method of making herb-containing sachets from a web of sachet-forming material comprising: forming the web into a plurality of successive sachets contained in the general plane of the web and each having a herb-charging opening, each sachet having a given internal volume when it forms part of the web; feeding the sachets to a herb-charging station; charging each sachet with a charge of herbs through the respective charging opening; closing said opening of each sachet; and separating each charged and closed sachet from the web; in which the manner of closing each sachet is controlled in such a way as to provide the sachet with a selected internal volume which may be varied between said given internal volume and a predetermined maximum internal volume.

2. A method according to claim 1, in which each sachet is closed along a closure line which is inclined at a selected angle between 0" and +90 relative to the general plane of the web.

3. A method according to claim 2, in which each sachet is closed along a closure line which is inclined at +20 and 30 relative to the plane of the web.

4. A method according to claim 2, in which each sachet is closed along a closure line which is inclined at +30 to +60 relative to the general plane of the web.

5. A method according to claim 1, in which each sachet is provided with a floatation member from which the sachet can be suspended when placed in an infusion liquid.

6. A method according to claim 5, in which the floatation member is applied to each sachet simul taneouslywith the closure of the herb charging opening.

7. A method according to claim 5, in which the floatation member is made of wood or foamed plastics material.

8. A method according to claim 1, in which each sachet is provided with a support for bearing advertising material, and a handle by which the sachet may be manipulated manually.

9. A method according to claim 1, in which the web is provided with an extension which serves for guidance of the web during the formation of each sachet, and which remains attached to each formed sachet so as to bear information.

10. A method according to claim 9, in which the extension includes a float

11. A method according to claim 1, in which the web is formed into a plurality of successive rectangular sachets contained in the general plane of the web.

12. An apparatus for making herb-containing sachets from a web of sachet-forming material, the apparatus comprising: means for forming the web into a plurality of successive sachets contained in the general plane of the web and each having a herb-charging opening, each sachet having a given internal volume when it forms part of the web; means for feeding the sachets to a herb-charging station; feed means provided at said station for introducing a predetermined charge of herbs through the opening of each sachet; closure means for closing the opening of each sachet; and means for separating each closed sachet from the web; ; in which the closure means is selectively adjustable so as to vary the angle of the closure of said opening of each sachet between 0" and +90 relative to the plane of the web whereby a selected internal volume of the sachet so-formed is obtainable which is variable between said given internal volume and a predetermined maximum internal volume.