EP0806352A1 - Twin-compartment infusion bag, especially for tea, and process for its manufactue - Google Patents

Abstract

A tea bag (1) has two chambers (2,3) joined at their base (4) by a folding flap (5) and at the apex by a hot seal. During manufacture, two webs of tea filter paper advance at the same speed towards a hot-sealing assembly. The lower web receives a measured quantity of e.g. tea (26) at intervals. Four rows of tea leaves are dosed onto the lower web, before passing between a pair of hot-seal rollers (31,30). The rollers join the two webs together, by hot-sealing the top, base and sides of the bag, forming four rows of tea bags which are then cut from the web as strings. Individual bags are then cut from the strip, each with two chambers and are folded to shape with the head of each chamber hot sealed (15) to the other. Each unfolded bag forms a triangle in side-elevation.

Description

The invention relates to a process for the continuous production, filling and sealing of double-chamber infusion bags for a substance to be leached out by an infusion liquid, in particular tea, with two chambers lying side by side, each containing a quantity of substance, which are connected to one another at the bottom via a transverse fold and the head ends of which are attached to one another by a connection, a uniform, forwardly moving, flat web of heat-sealable material, in particular filter paper material, being provided with a series of identical substance quanta at uniform intervals. The invention further relates to the double-chamber infusion bag produced by such a method.

Tea infusion bags are used in various forms. In particular, the use of double-chamber infusion bags has established itself, which have two adjacent, side-by-side chambers, each containing a quantity of dried and ground tea leaves. The two chambers are connected to one another at the bottom by a transverse fold, also called bottom fold, and are closed together at their head end by a connection to which a thread is attached with a label. For this purpose, a top seal rebate is usually formed in two steps, by folding the corners of the infusion bag in a first step and folding the trapezoidal part that remains at the tip in a second step, whereupon the folded parts are closed by a locking clamp can be attached to each other while fastening one thread end. The double chamber infusion bag constructed in this way consists of a slightly permeable material, which enables the infusion liquid to digest the substance to be leached out, in particular the tea, and to dissolve the substances contained therein. In particular, filter paper material is used for this.

Such a double-chamber infusion bag is known from the German patent application 1 001 944. To produce it, a uniformly moving filter paper web is bulged at its edges, equal quanta of the substance to be leached are applied to the fabric web at regular intervals and a continuous tube is formed by folding the longitudinal edges of the fabric web. A piece of the tube containing two substance quanta is then cut off and this piece is folded over, so that the transverse folding creates two chambers, each containing a substance quantum, which are placed side by side. The ends of the hose section or the two chambers that were still open until then are folded together and, as described above, connected together by means of the metal locking clamp. The disadvantage here is that by folding the longitudinal edges of the fabric web into a continuous tube and the formation of the head connection, a simple, multi-lane procedure with a high number of cycles in a practical way is not feasible, since many operations would be required in mechanically difficult technology.

The automatic device described in DE 38 07 795 C2 for the continuous production of filter bags for infusion products also works with a continuously advanced filter material band, which is folded into a tube shape after the application of a number of substance quanta, a longitudinal seam being formed. Subsequently, chambers are formed successively by transverse heat seals, each containing a quantity of substance, double tube infusion bags then being folded from tube pieces with two chambers each, the chambers of which are not connected to one another via the bottom region. A multi-lane production method is also not possible with this device.

Finally, from DE 691 00 244 T2 a double-chamber infusion bag is known, the two chambers of which - unlike the embodiment described above according to DE 1 001 944, but corresponding to that of DE 38 07 792 - are sealed off from one another at the bottom fold. For this purpose, a pair of tubular webs, each of which is divided along its length into a series of individual chambers, are arranged in an overlapping relationship, their chambers being aligned with one another and the webs being connected at the partitions between the chambers. The double chamber infusion bag therefore has edge seals on its long sides and profile end seals on the bottom and at the head end, the head seal having a convex profile, while the bottom seal is carried out with a concave profile to form side extensions, which are folded accordingly by a W -shaped bottom fold. In the process for producing such a double-chamber infusion bag, two pairs of single-layer webs, that is a total of four webs, made of heat-sealable filter paper material are overlapped in order to form the two tubular webs by means of longitudinal heat seals at the edges (edge seals). Before that, tea portions are placed on the bottom lane of each pair at spaced intervals. The chambers are formed and sealed with transverse heat seals between the tea portions after the sealing of the longitudinal edges. The two tubular sheets are then cut with the chambers aligned with the existing cross seals to separate pairs of chambers and the chambers are welded together at the lower extensions while their upper ends are still left unconnected.

Finally, the two chambers forming the infusion bag are moved around each other by 180 ° so that the upper ends of each pair of chambers can be brought together and sealed together. The disadvantage here is that no leaching of the tea can take place over the bottom area of the chambers, since these are completely separated from one another by a heat seal. The permeable bag areas available for leaching, ie the passage of liquid, are greatly reduced by the bottom seal. In addition, the method of manufacture is technically complicated and time-consuming, so that production on a high-speed machine is not possible. Especially but it is disadvantageous that a total of four webs of filter paper material have to be processed one above the other in order to form a double-chamber bag and that, in addition, duplication is not possible.

In view of this prior art, the invention is based on the task , while avoiding the above-mentioned disadvantages, of developing a production method of the type described at the outset, in particular for tea, which produces a single- or multi-lane production of double-chamber infusion bags with chambers connected on the bottom side by side in any number of lanes technically simple at high speed, especially on a machine with more than 500 pcs / min. enables.

The object is achieved in that several rows of substance quanta are placed symmetrically to one another on the correspondingly widened web, over which a second upper web of heat-sealable material, in particular filter paper material, of the same width is guided, that the lower and upper web are brought together and by means of heat seals running in the longitudinal direction at the edges of the web and in the middle between the rows of substance quanta to form continuous single tubes, which are subjected to heat seals in the transverse direction at regular intervals, each covering two substance quanta of the rows - corresponding to the length dimensions of the double-chamber infusion bags to be produced, that the longitudinal sealing seams and transverse sealing seams are then each cut at the center lines and tubular parts are formed in this way, the two chambers containing a substance quantum n have that in a further process step, preferably simultaneously and parallel to each other, the adjacent tube parts are folded to form a bottom fold, and the two chambers of each tube piece are placed side by side in such a way that the head ends of the chambers are adjacent to one another, and that a head seal is applied all tracks are carried out synchronously together or branched differentially.

The lower web is preferably widened to a width which is the sum of the widths of the prey to be produced parallel to one another plus the widths corresponds to the longitudinal edge seals to be created and the upper web is formed with congruent dimensions and fed synchronously to the lower web at the same speed. In the subsequent heat sealing process step, the longitudinal seals for producing the longitudinal seal seams and the transverse seals for producing the transverse seal seams can be carried out simultaneously using a combined tool, in particular heat sealing rollers, in order to simplify the process, to be able to use shorter-construction machines and to increase the process speed can.

The longitudinal seal seams and the transverse seal seams can each be cut on the center lines in succession in two separate process steps. It is preferred to first cut the longitudinal seal seams on their center lines, then fold in the longitudinal edge seals on all the individual hoses produced in this way, then carry out the cutting of the transverse seal seams and finally carry out the transverse folding to form the bottom fold such that the folded longitudinal edge seals in the interior be arranged between the two chambers of the double-chamber infusion bag. As a result, the width of the double-chamber infusion bag is not only made smaller, but the longitudinal seam is given an increase in strength due to the folding, which significantly improves the durability of the seam.

Since the double-chamber infusion bags are usually provided with a thread and a label, in particular when used as a tea bag, it is proposed in an expedient embodiment of the invention to arrange the thread in the longitudinal direction above each tube part in such a way before the transverse folding step to form the bottom fold, that the thread is arranged after the formation of the bag chambers and this side by side in the form of a loop in the interior between the chambers, with the final head sealing at least one strand, preferably both strands of the thread loop with their free ends protruding outside and by means of a roof-shaped folded labels are connected together.

The double-chamber infusion bag produced in particular with the above method of the invention has two side-by-side chambers, each containing a quantity of substance, which are connected to one another at the bottom by means of a transverse fold and whose head ends are connected to one another by a connection. According to the invention, the double-chamber infusion bag is characterized in that the longitudinal edges of each chamber are sealed by a longitudinal edge seal and the head ends of each chamber are sealed by a transverse heat seal, and in that a further transverse heat seal is provided at the head end as a connection for tacking, preferably with an inner one , from the interior between the chambers pull-out thread loop is provided, at one or both ends a label is attached.

The double-chamber infusion bag preferably has longitudinal edge seals folded inwards. Furthermore, in a preferred embodiment, the two strands of the thread loop can advantageously be guided through the closure connection at a distance from one another, the heat sealing at the head ends of the chambers being carried out in such a way that at least one, preferably two, channel-like spaced areas remain free for thread passage. The thread loop is expediently completely accommodated in the interior between the chambers and can be pulled out by pulling on the label, a closed suspension eyelet for the bag being formed in the preferred embodiment. The free thread ends can be connected to a roof-like folded label strip, the thread ends running from the sides against one another are preferably inserted into the fold of the label and fastened there, in particular heat-sealed, so that the roof surfaces of the label extending underneath remain free and in the manner of a Rider can be placed on the head end of the bag with the inner thread loop. In order to make the pulling out trouble-free, it is expedient to place the thread loop in a meandering shape in the interior between the two chambers.

Fig. 1

einen Doppelkammer-Aufgußbeutel im Abpackzustand, perspektivisch, wobei die vordere Kammer teilweise weggebrochen dargestellt ist,

Fig. 2

einen Doppelkammer-Aufgußbeutel gem. Fig. 1 mit Verdeutlichung innenliegende Teile in Form von gestrichelten Linien,

Fig. 3

eine Ausführungsform einer Faden/Etikett-Anbringung,

Fig. 4

eine weitere Ausführungsform einer Faden/Etikett-Anbringung,

Fig. 5

einen Teil eines 4-bahnigen Herstellungsverfahrens, schematisch in perspektivischer Darstellung,

Fig. 6

einen weiteren Verfahrensteil des 4-bahnigen Herstellungsverfahrens in einer Draufsicht, schematisch, und

Fig. 7

einen Ausschnitt einer vielbahnigen Herstellung von erfindungsgemäßen Doppelkammer-Aufgußbeuteln, ausschnittsweise in Draufsicht.

Further details, features and advantages of the subject matter of the invention result from the following description of the accompanying drawing, in which the method according to the invention is shown schematically in connection with the double chamber infusion bag thus produced is shown. The drawing shows:

Fig. 1

a double-chamber infusion bag in the packed state, in perspective, the front chamber being shown partially broken away,

Fig. 2

a double chamber infusion bag acc. 1 with clarification internal parts in the form of dashed lines,

Fig. 3

one embodiment of a thread / label application,

Fig. 4

another embodiment of a thread / label application,

Fig. 5

a part of a 4-lane manufacturing process, schematically in perspective,

Fig. 6

a further process part of the 4-lane manufacturing process in a plan view, schematic, and

Fig. 7

a section of a multi-lane production of double-chamber infusion bags according to the invention, a partial top view.

The double-chamber infusion bag 1 shown in FIG. 1 of the drawing has two side-by-side chambers 2 and 3 which are connected to one another at the bottom 4 via a W-shaped transverse fold 5 and each have a predetermined quantity of substance to be leached out by an infusion liquid, especially tea. The two chambers 2 and 3 are closed at their head end 6 by a transverse heat seal 7 and 8 respectively, reference being made to the illustration in FIGS. 3 and 4 in which the front chamber of the infusion bag has been partially omitted.

Between the side-by-side chambers 2 and 3 there is an interior 9, in which a thread 10 is inserted in a meandering shape, on the free ends 12, 13 of which a label 11 is attached on the outside. The meandering in the interior 9 between the two chambers 2 and 3 arranged Accordingly, thread 10 forms at least one, in the exemplary embodiment of FIGS. 1 and 2, a plurality of loops 14, which make it possible to "hide" it in its entire length in the packaged state between the two chambers.

In order to complete the double-chamber infusion bag 1 described so far, it is necessary to connect the two chambers 2 and 3 at their head ends. This closure connection of the chambers 2 and 3 is made by a transverse heat seal 15, which is shown hatched in Fig. 1 of the drawing and is created in an additional process step after the head ends 6 of the chambers, which have already been provided with the transverse heat seals 7 and 8, are placed mechanically against one another have been. In order to enable the thread ends 12 and 13 to be brought out of the interior 9 to the outside, the transverse heat seal 15 is carried out in such a way that two channel-like, spaced-apart regions 16, 17 remain free for the thread passage.

In order to enable a simple connection to the label 11, this is made from a roof-like folded label strip, the shape of which can best be seen from FIG. 3 of the drawing. The thread ends 12 and 13 are inserted into the fold of the label 11 from the sides and fastened there by heat sealing. The roof surfaces of the label 11 which extend under the heat seal remain free and can be placed in the manner of a rider on the head end 6 of the bag with the thread loop 14 lying on the inside, as shown in FIGS. 1 and 2 of the drawing. The user can then simply pull the tab, ie the label 11, from the bag 1 and pull the thread out of the interior 9 through the channel-like areas 16 and 17 until the loop 14 comes to rest on the central area of the transverse heat seal. In this way, a suspension eyelet 18 is formed, which can be hung by the user of the bag 1, for example over the spout of the teapot, so that the bag 1 suspended in the teapot is perfectly accessible to leaching through the water from all sides.

Fig. 4 of the drawing shows an embodiment modified with regard to the fastening of the thread, in which the heat seal leaves only a single channel-like area for the passage of the thread, the inner end of which is connected to the transverse heat seal 15 for fastening. The label 11 is then attached to the free, outwardly guided thread end by heat sealing.

It is characteristic of the graphically illustrated double-chamber infusion bags that they are provided on the left and right sides with a longitudinal edge seal 19 which results from the manufacturing process described below. The double-chamber infusion bag therefore has two chambers 2 and 3, which are connected to one another at the bottom 4 via the W-shaped transverse fold, the two longitudinal edges of which are each closed by a longitudinal edge seal 19 and the top sides of which are each sealed by a transverse seal. The longitudinal edge seals 19, 20, as illustrated by the broken line in FIG. 2, are folded inwards into the interior 9 between the two chambers 2 and 3 in order to reduce the outer dimensions of the bags and to bring about a seam reinforcement.

The manufacture of the double-chamber infusion bag 1 results from the procedure described in more detail below using the example of a 4-lane production according to FIGS. 5 and 6 of the drawing, with a free expansion of the number of production lanes resulting from FIG. 7 of the drawing.

5, 6 and 7 of the drawing, the starting point for the method for producing, filling and closing double-chamber infusion bags 1 according to the embodiment shown in FIGS. 1 to 3 of the drawing is a heat-sealable filter paper web 21 which is used to form four individual tubes 22, 23, 24, 25 is widened to about 4 times the width of the bag plus the width of the longitudinal seals. The filter paper web 21 is pulled off a roll of material, not shown, by a pulling device and fed as a web to a metering device for tea. Positioned substance quanta 26, that is to say heaps of tea, are deposited on the filter paper web 21 at regular intervals in four rows from this.

From a roll of material, not shown, a second, upper heat-sealable filter paper web 27 of identical dimensions and transport speed is fed in the direction of the arrow to the lower filter paper web 21 and arranged in parallel above it by means of a roller 28, so that in the direction of arrow 29 there is a uniform forward movement of the filter paper web 21 and the filter paper web 27 arranged one on top of the other and resulting in an overlapping relationship. In a device consisting of heat-sealing rollers 30, 31, the lower filter paper web 21 and upper filter paper web 27 are brought close together and are still connected by means of longitudinal heat seals 33 at the web edges and in the center according to the reference numerals 34, 35 and 36 between the rows of substance quanta 26 Individual tubes 37, 38, 39, 40 are formed, which are subjected to heat seals 41, 42 in the transverse direction at regular intervals, each of which detects two substance quanta 26 of the rows, corresponding to the length dimensions of the double-chamber infusion bags to be produced.

In a subsequent processing station, not shown in the drawing, the individual tubes 37, 38, 39 and 40, which were connected up to that point, are separated by cutting along the center line of the lengthways 34, 35 and 36, as can be seen from FIG. 6 of the drawing. Each individual tube has tube parts 43 separated from one another in the feed direction according to the arrow by the transverse sealing seams 41 and 42, each of which contains two substance quanta. In a subsequent process step, the longitudinal sealing seams of the individual tubes 37, 38, 49, 40 are folded inwards or upwards by a folder.

In a subsequent process step, the tube parts 43 are separated by a cutting device, not shown, by cutting the transverse heat seals 41, 42 in the center. There are then individual tube parts 43 arranged one behind the other on four webs, from which double-chamber bags are produced parallel to one another in the 4-web processing in the further course of the method. The hose pieces 43 used to form the double-chamber infusion bags are dimensioned and pre-shaped such that after a side-by-side placement of the hose parts forming the chambers, their head ends are in register with one another brought to be able to perform a closure connection of the chambers with each other on the head side. Before this, however, the design of the thread 10 is still necessary for the label attachment and the production of a W-shaped bottom fold.

In the running direction behind the described device for cutting off the tube pieces 43 with the cross cutter, not shown, a device for forming the W-shaped bottom fold 5 is combined with the device for laying out and cutting the thread 10 in the longitudinal direction. For the four individual hoses 37, 38, 39, 40 or the hose parts 43 cut therefrom, the latter each has a folding sword which, by moving downwards, presses the hose pieces 43 into a die arranged underneath and thereby the hose parts containing the substance quanta 26 on the side Lays side and forms the W-shaped bottom fold 5 as a transverse fold. This is illustrated in the drawing by the curved arrows in FIG. 6. At this stage of manufacture, the two chambers of each piece of hose are already side by side and the head ends of the chambers are adjacent to one another. The head ends 6 of the chambers are clamped together, including the thread located in the interior 9, and held for the further process steps by means of mold jaws which can move against one another.

The cross-sealing of the head ends 6 of the two chambers is then carried out with a plier-like tool, this heat sealing being carried out in such a way that the two channel-like, spaced-apart regions 16 and 17 remain free for thread passage. The thread 10 is therefore free to move and not sealed in and can be pulled outwards.

In a device for attaching the label 11 to the thread 10 in the running direction, first a roof-shaped folding of the label strip and then an insertion of the two thread ends from the sides into the folding of the label takes place, so that their attachment there by heat sealing is carried out in this way can be that the underlying roof surfaces of the label remain free and can be placed on the bag head like a rider. At this point In the four-lane processing, four double-chamber infusion bags are finished at the same time, which can be fed into a carton filling next to each other.

Fig. 7 of the drawing illustrates a more than four-lane processing, which expresses that double-chamber infusion bags of the type described can be produced side by side with any number of lanes by the inventive method.

Reference list

1

Double chamber tea bags

2nd

chamber

3rd

chamber

4th

ground

5

W-shaped cross fold

6

Headboard

7

Heat seal

8th

Heat seal

9

inner space

10th

thread

11

label

12th

The End

13

The End

14

loop

15

Heat seal

16

channel-like area

17th

channel-like area

18th

Suspension eyelet

19th

Longitudinal edge sealing

20th

Longitudinal edge sealing

21

Filter paper web

22

Single hose

23

Single hose

24th

Single hose

25th

Single hose

26

Substance quantum

27

Filter paper web

28

role

29

arrow

30th

Heat sealing rollers

31

Heat seal roller

33

Longitudinal sealing on the edge

34

Longitudinal sealing between the sheets

35

Longitudinal sealing between the sheets

36

Longitudinal sealing between the sheets

37

Single hose

38

Single hose

39

Single hose

40

Single hose

41

Cross seal seam

42

Cross seal seam

43

Hose part

Claims (11)

Process for the continuous production, filling and sealing of double-chamber infusion bags (1) for a substance to be leached out by an infusion liquid, in particular tea, with two chambers (2, 3), side by side, each containing a quantity of substance (26) Bottom (4) are connected to one another via a transverse fold (5) and the head ends (6) of which are attached to one another by a connection, a uniformly advanced flat web (21) on heat-sealable material, in particular filter paper material, with a number of identical substance quanta (26) in evenly spaced,
characterized by
that several rows of substance quanta (26) are deposited symmetrically to one another on the correspondingly widened web (21), over which a second upper web (27) made of heat-sealable material, in particular filter paper material, of the same width is guided, that the lower and upper web ( 21 and 27) are brought together and are formed by means of heat seals (33, 34, 35, 36) running in the longitudinal direction at the web edges and in the middle between the rows of substance quanta (26) to form still connected single tubes (37, 38, 39, 40) which are subjected to heat seals (41, 42) in the transverse direction at regular intervals, each of which detects two substance quanta (26) of the rows - corresponding to the length dimensions of the double-chamber infusion bags to be produced, so that the longitudinal sealing seams (34, 35, 36) and transverse sealing seams ( 41, 42) are each cut at the center lines and such tube parts (43) are formed, d They each have two chambers (2, 3) containing a quantity of substance (26), that in a further process step, preferably simultaneously and parallel to one another, the adjacent tube parts (26) are folded over to form a bottom fold (5) and the two chambers (2, 3) each piece of hose (26) are placed side by side in such a way that the head ends (6) of the chambers (2, 3) are adjacent to one another, and that a head seal (15) is carried out synchronously together or branched differentially on all webs becomes. Method according to Claim 1, characterized in that the lower web (21) is widened to a width which corresponds to the sum of the widths of the bags to be produced parallel to one another plus the widths of the longitudinal edge seals (33, 34, 35, 36) to be produced, and that the upper track (27) is formed with congruent dimensions and is fed synchronously to the lower track (21) at the same speed. Method according to claim 1 or 2, characterized in that in the step of heat sealing, the longitudinal seals for producing the longitudinal seal seams (33, 34, 35, 36) and the transverse seals for producing the transverse seal seams (41, 42) simultaneously with a combined tool, in particular Heat sealing rollers (30, 31) are carried out. Method according to one of Claims 1 to 3, characterized in that the longitudinal sealing seams (34, 35, 36) and the transverse sealing seams (41, 42) are each cut on the center lines in two separate process steps. Method according to one of claims 1 to 4, characterized in that first the longitudinal sealing seams (34, 35, 36) are cut at their center lines, then the longitudinal edge seals (19, 20.) On all individual tubes (37, 38, 39, 40) produced in this way ) are folded inwards and then the cutting of the transverse sealing seams (41, 42) is carried out, whereupon the transverse folding to form the bottom fold (5) is carried out in such a way that the folded longitudinal edge seals (19, 20) in the interior (9) between the two chambers (2, 3) of the double-chamber infusion bag (1) can be arranged. Method according to one of claims 1 to 5, characterized in that before the transverse folding step to form the bottom fold (5), a thread (10) is arranged in the longitudinal direction above each tube part (43) such that the thread after the bag chambers have been formed (2, 3) and arrangement of this side by side in the form of a Loop (14) is arranged in the interior (9) between the chambers (2, 3), with at least one strand, preferably both strands of the thread loop (14) with their free ends (12, 13) protruding outside and by means of the final head sealing of a roof-shaped folded label (11) are connected to one another. Double-chamber infusion bag, in particular manufactured according to one of Claims 1 to 6, with two chambers (2, 3) lying side by side, each containing a quantity of substance (26), which are connected to one another at the bottom (4) via a transverse fold (5) and the head ends (6) of which are connected to one another by a connection, characterized in that the longitudinal edges of each chamber (2, 3) are sealed by a longitudinal edge (19, 20) and the head ends (6) of each chamber (2, 3) by a transverse Heat seal (7, 8) are closed, and in that a further transverse heat seal (15) is provided at the head end (6) as a connection for attaching to one another, preferably with an inner one from the interior (9) between the chambers (2, 3) pull-out thread loop (14) is provided, at one or both ends (12, 13) of which a label (11) is attached. Double-chamber infusion bag according to claim 7, characterized in that the longitudinal edge seals (19, 20) are folded inwards. Double-chamber infusion bag according to claim 7 or 8, characterized in that the two strands of the thread loop (14) are guided at a distance from one another through the closure connection (15), the heat sealing of the closure connection being carried out in such a way that at least one, preferably two, channel-like to one another spaced areas (16, 17) remain free for thread passage. Double-chamber infusion bag according to one of Claims 7 to 9, characterized in that the thread (10) in the form of a thread loop (14) is completely accommodated in the interior (9) between the chambers (2, 3) and by pulling on the label (11 ) can be pulled out, a closed suspension eye (18) for the bag preferably being formed. Double-chamber infusion bag according to one of claims 7 to 10, characterized in that the free thread ends (12, 13) are connected with a roof-like folded label strip, the thread ends being inserted from the sides into the fold of the label (11) and there are fastened, in particular heat-sealed, in such a way that the roof surfaces of the label extending underneath remain free and can be placed in the manner of a rider on the head end (6) of the bag with the thread loop (14) on the inside.

Images