Method for making pouches

Abstract

The present invention relates to a method for making pouches providing a continuous web; folding the web to provide confronting side surfaces joined along a bottom edge; forming a vertical seal between the confronting side surfaces, thereby providing a series of adjacent pockets having opposite side walls with each pocket having an unsealed opening along a top edge; filling the pockets through the unsealed opening with material; sealing the unsealed opening. In the inventive method, which facilitates handling of the continuous web forming the pouches, the web is perforated by a perforation between a leading length piece of the web adapted to form a leading pocket and a trailing length piece of the web adapted to form a trailing pocket, and the distance between a trailing edge of the leading length piece and a leading edge of a trailing length piece is increased for tearing the leading and the trailing lengths pieces apart at the perforation.

Claims

1. A method for making pouches comprising: providing a continuous web; folding the web to provide confronting side surfaces joined along a bottom edge; forming a vertical seal between the confronting side surfaces, thereby providing a series of adjacent pockets having opposite side walls with each pocket having an unsealed opening along a top edge; filling the pockets through the unsealed opening with material; and sealing the unsealed opening, wherein the web is perforated by a perforation between a leading length piece of the web adapted to form a leading pocket and a trailing length piece of the web adapted to form a trailing pocket, wherein the continuous web is abutted against an outer circumference of a rotating filler wheel to follow a circular path and wherein a distance between a trailing edge of the leading length piece and a leading edge of a trailing length piece is increased for tearing the leading and the trailing lengths pieces apart at the perforation while the length pieces are moved on the circular path; wherein the trailing edge of a leading pocket is pierced by a trailing arm of a gripping unit of the filler wheel and the leading edge of a trailing pocket is pierced by a leading arm of the gripping unit and the leading and the trailing pockets are torn apart for forming open pouches by pivoting at least one of the leading and the trailing arms of the gripping unit toward the other of the trailing and the leading arms of said gripping unit.

2. The method according to claim 1, wherein the continuous web is perforated after the pockets have been formed.

3. The method as defined in claim 1, wherein the continuous web is pressed against the leading and the trailing arm by a rotating pressure roll.

4. The method according to claim 3, wherein after filling, the pouches are closed by pivoting at least one of the leading and the trailing arms away from the other of the trailing and the leading arms.

5. The method according to claim 1, wherein a longitudinal opening guide means is introduced between the confronting side surfaces and through the unsealed opening as the continuous web is abutted against the outer circumference of the rotating filler and that the confronting side surfaces are separated from each other by the longitudinal opening guide means until a spout of a spout wheel has been introduced into the pocket.

6. The method according to claim 5, wherein the leading and the trailing length pieces are torn apart after the longitudinal opening guide means are received between the confronting side surfaces.

7. The method according to claim 1, wherein the pouches are transferred from the circular path to a linear sealing path for sealing the opening.

8. A method for making pouches comprising: providing a continuous web; folding the web to provide confronting side surfaces joined along a bottom edge; forming a vertical seal between the confronting side surfaces, thereby providing a series of adjacent pockets having opposite side walls with each pocket having an unsealed opening along a top edge; filling the pockets through the unsealed opening with material; and sealing the unsealed opening, wherein a longitudinal opening guide means is introduced between the confronting side surfaces and through the unsealed opening as the continuous web is abutted against the outer circumference of a rotating filler and that the confronting side surfaces are separated from each other by the longitudinal opening guide means until a spout of a spout wheel has been introduced into the pocket; wherein the web is perforated by a perforation between a leading length piece of the web adapted to form a leading pocket and a trailing length piece of the web adapted to form a trailing pocket, wherein the continuous web is abutted against an outer circumference of a rotating filler wheel to follow a circular path, wherein a distance between a trailing edge of the leading length piece and a leading edge of a trailing length piece is increased for tearing the leading and the trailing lengths pieces apart at the perforation while the length pieces are moved on the circular path, wherein the continuous web is perforated after the pockets have been formed, and wherein the trailing edge of a leading pocket is pierced by a trailing arm of a gripping unit of the filler wheel and the leading edge of a trailing pocket is pierced by a leading arm of the gripping unit and the leading and the trailing pockets are torn apart for forming open pouches by pivoting at least one of the leading and the trailing arms of the gripping unit toward the other of the trailing and the leading arms of said gripping unit.

9. The method according to claim 8, wherein the leading and the trailing length pieces are torn apart after the longitudinal opening guide means are received between the confronting side surfaces.

10. The method according to claim 8, wherein after filling, the pouches are closed by pivoting at least one of the leading or the trailing arms away from the other of the trailing or the leading arms.

11. The method according to claim 8, wherein the pouches are transferred from the circular path to a linear sealing path for sealing the opening.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further details, advantages and features of the present invention will become apparent from the following description of a specific embodiment thereof in connection with the drawing. In the drawing:

(2) FIG. 1 is a perspective side view of a first embodiment;

(3) FIG. 2 is a top view of the first embodiment;

(4) FIG. 3 is a perspective side view of the first embodiment with the spout wheel;

(5) FIG. 4 is a perspective side view of a piercing section of the first embodiment;

(6) FIG. 5 is an enlarged perspective side view of an opening and separation section of the first embodiment;

(7) FIG. 6 is an enlarged perspective side view of a discharging section of the first embodiment;

(8) FIG. 7 is a perspective view of the second embodiment of the present invention;

(9) FIG. 8 is a top view of the second embodiment;

(10) FIG. 9 is an enlarged perspective side view essentially in accordance with FIG. 7 elucidating the sealing section of the second embodiment; and

(11) FIG. 10 is a perspective side view of the discharging section of the second embodiment.

DETAILED DESCRIPTION

(12) FIGS. 1 and 2 are provided to illustrate a filler wheel 2 of the inventive packaging apparatus. This filler wheel 2 comprises a plurality of leading arms 4 projecting in radial direction and being stationary held on the filler wheel 2 and a plurality of trailing arms 6 which are pivotably held about a joint 8 providing a pivot axis extending essentially parallel to a rotational axis 10 of the filler wheel 2. One leading and one trailing arm define a gripping unit 11.

(13) From a radial end face 12 of each arm 4, 6 plural needles 14 project in radial direction of the filler wheel 2. As derivable in particular from FIGS. 1 and 4, each arm 4, 6 defines an upper segment 4a, 6a and a lower segment 4b 6b, respectively. The needles 14 are each provided on the upper segments 4a, 6a and the lower segments 4b, 6b. Between those upper segments 4a, 6a and the lower segments 4b, 6b, a recess 16 is formed projecting radially inwardly. The filler wheel 2 receives a continuous web 18 which is pulled by opposing pulling rollers 20. The continuous web 18 is received by the pulling rollers 20 as a folded web 18 in which confronting side surfaces 22 are joined along a bottom edge 24 formed by folding. This folded continuous web 18 is furthermore provided with vertical seals 26 defining therebetween pockets 28 which are vertically closed by the vertical seals 26 and, at their bottom, closed by the bottom edge 24, but have an unsealed opening 30 at and below their top edge 31. Respective folded continuous web 18 is e.g. prepared by a sealer previously described e.g. in WO 2007/089838 A2, the disclosure thereof being incorporated herein by reference.

(14) At a piercing section PI, a pressure roll 32 is provided which is adapted to press the continuous web 18 against the radial end face 12 of the arms 4, 6, respectively. As in particular derivable from FIGS. 3 and 6, the pressure roll 32 is provided with circumferential groove 34 adapted to receive the needles 14. Between this pressure roll 32 and the pulling rollers 20, the web is conveyed on a linear path. Within said linear path, a rotating perforation knife 36 is provided which cooperates with a stationary knife counter-element 38. The perforation knife 36 and the knife counter-element 38 are adapted to provide a perforation 46 within the vertical seal 26 to divide the same into a leading sealing section 40 of a trailing length piece 48 and a trailing sealing section 42 of a leading length piece 48. In the embodiment shown in FIG. 4, the vertical seal 26 does not extend over the entire width, i.e. the vertical extension, of the continuous web 18. In fact, the vertical end section arranged above the upper segment 4a, 6a of each arm 4, 6 is not provided with a seal, thereby defining an unsealed vertical end section 44. This unsealed vertical end section 44 has an extension corresponding essentially to 10% of the overall width of the folded continuous web 18 starting from the top edge 31.

(15) In FIG. 4, the perforation 46 resulting from the treatment of the folded continuous web 18 by the perforation knife 36 and the knife counter-element 38 is depicted between the leading sealing section 44 and the trailing sealing section 42 of two neighboring length pieces 48 of the continuous folded web 18.

(16) As in particular derivable from FIG. 3, the continuous folded web 18, when moved along the circular path, will cooperate with a longitudinal opening guide means 50. This longitudinal opening guide means 50 is bent to conform to the outer circumferential contour of the filler wheel 2 and is inclined relative to the plane in which the filler wheel 2 extends and which runs perpendicular to the rotational axis 10 the filler wheel 2. Accordingly, when moved along the circular path, the longitudinal opening guide means 50 is introduced through the unsealed opening 30 and arranged between the confronting side surfaces 22. A forward end of the longitudinal guide means 50 is formed by a single central guide rail 52 (see FIG. 5). This central guide rail 52 merges into a chamfered widening section 54 of the longitudinal opening guide 50, from which two parallel guide rails 56 project towards the rearward end of the longitudinal opening guide means 50 which parallel guide rails 56 extend parallel to each other and along the circular path for forming a longitudinal slot 58 therebetween.

(17) As derivable in particular from FIGS. 3 and 5, the embodiment furthermore has a spout wheel 60 from which a plurality of spouts 62 extend which have a chamfered forward free end defining a tip 64. As the confronting side surfaces 22 are forced away from each other by the parallel guide rails 56, this forward tip 64 of the assigned spout 62 will enter into the longitudinal slot 58 and thereby between confronting side surfaces 22 defining the unsealed vertical end section 44. After the spout 52 has been introduced into the pocket 28 with its forward tip 64, the pocket 28 will run free from the longitudinal opening guide means 50 in the course of the rotational movement of the continuous web 18.

(18) As derivable from FIGS. 3 and 4 in combination with FIG. 2, and as the longitudinal opening guide means 50 remain introduced into the pockets 28, the trailing arm 6 is pivoted so as to assume a position in which the radial end face 12 of the assigned trailing arm 6 is arranged closer to the respective radial end face 12 of the assigned leading arm 4 of the same gripping unit 11. By this pivotable movement, the neighboring length pieces 48 secured to respective arms 4, 6 by means of the needles 14 are torn apart and, thus, individual unsealed pouches P are formed. Each pouch P has a leading edge 26a formed by the leading vertical seals 26 and a trailing edge formed by the trailing vertical seals 26.

(19) By the pivotable movement the distance between the leading edge 26a and the trailing edge 26b of a single length piece 48 is increased, leading to separation of individual pouches P. Further, by reducing the distance between the radial free end faces 12 of the assigned arms 4, 6, the confronting side surfaces 22 of a single pouch P are bent outwardly to open the pouches (see FIG. 5). Pivoting of the trailing arm 4 for tearing neighboring length pieces 48 apart essentially starts at a circumferential position of the filler wheel 2 corresponding to the position of the chamfered widening section 54 of the longitudinal opening guide means 50. This circumferential segment around the rotating filler wheel 2 is identified as a separation and opening section S in FIG. 2. This separation and opening section S is followed by a filling section F in rotational direction of the filler wheel 2. In the other direction and ahead of the separation and opening section S, there is provided an opening section in which the longitudinal opening guide means 50 are merged into the pockets 28. The segment comprising the pressure roll 32 is identified as a piercing section PI in which the continuous web 18 is pierced by the needles 14. The piercing section PI, the opening section O, the separation and opening section S as well as the filling section F are arranged around the circumference of the filler wheel 2 and, thus, on the circular path on which the continuous web 18 is conveyed when the filler wheel 2 is rotated.

(20) In the filling section F, the spout wheel 60, having a rotational axis 65 slightly inclined relative to the rotational axis 10 of the filler wheel 2 while essentially being co-axially positioned in relation thereto, is brought closer to the filler wheel 2. Thus, the individual spouts 62 are introduced into the pouches P. Material is filled through the spouts 62 into the pouches P. Simultaneously, in the course of the rotation of the filler wheel 2 and of the spout wheel 60, the spouts 62 are withdrawn from the pouches P, while material is still being filled into the pouches P. At the end of the filler section F, the spout 62 is completely retracted from the assigned pouch P.

(21) Along the rotational movement of the filler wheel 2 and, thus, along the circular path of the continuous web 18, the latter will be transferred from the filler section F to a closing section C. In this closing section C, the trailing arm 6 is pivoted back to its initial position in which it is arranged in the piercing section PI. In the course of this pivotable movement, the unsealed vertical end section 44 of the pouch P is straightened. The confronting side surfaces 22 are brought closer to each other, thereby closing the pouch P.

(22) The closing section C is followed by a discharging section D in which the pouches P are transferred from the circular path and, thus, from the rotational movement of the filler wheel 2, to a linear sealing path formed between an inner conveyor belt 66 and an outer conveyor belt 68 which are depicted in further detail in FIG. 6. The discharging section D comprises a discharging guide 70 which projects into the filler wheel 2 and is arranged in the recess 16, i.e. between the upper segment 4a, 6a and the lower segment 4b, 6b of the respective arm 4, 6. This discharging guide 70 has a guide surface which forces each pouch P in radial direction away from the filler wheel 2, thereby forcing the material of the web 18 to be extracted from the needles 14. The movement of the pouches P affected by the discharging guide 70 is tangential to the filler wheel 2. The inner conveyor belt 66 has a single belt element cooperating with a lower section of the pouches P. The outer conveyor belt 68 has a lower belt element 68a assigned to the inner conveyor belt 66 and an upper conveyor belt 68b cooperating with the unsealed vertical end section 44. On the inner side, there is provided a head sealing means 72 for the purpose of fusing and thereby sealing the unsealed vertical end section 44 in order to seal the whole pouch P.

(23) FIGS. 7 to 10 visualize a second embodiment which is essentially identical with the first embodiment described above. Thus, identical parts are identified with respective reference signs as used for the first embodiment. However, the filing section F has a slightly reduced extension in circumferential direction. Between the closing section C and the discharging section D, there is provided a sealing section SI in which the unsealed opening 30 and the unsealed vertical end section 44 is sealed as the pouches P are moved on the circular path with the rotational movement on the filler wheel 2. Details of the sealing means SI are depicted in FIG. 9.

(24) In FIG. 9 of the second embodiment, the head sealing means 72 is arranged above the filler wheel 2 to thereby provide a sealing section SI on the outer circumference of the filler wheel 2. The head sealing means 72 is provided with a heated bar 74 which is curved essentially corresponding to the outer radius of the filler wheel 2. This heated bar 74 is arranged slightly above the upper segment of each leading and trailing arm 4, 6, respectively, so as to cooperate with the unsealed vertical end section 44 of the pockets 28, which are pressed against the head sealing means 72 by an outer sealing belt 76.

(25) Specifically, the head sealing means 72 have a guiding in section which is level with the radial end face 12 of each arm 4, 6 and a guiding out section which radially projects the forward tip provided by all needles 14. Accordingly, by means of the head sealing means 72 the open pockets 28 are forced away from at least the needles 14 provided by the upper segments 4a, 6a of the leading and trailing arm 4, 6, respectively, while at the same time pressing the unsealed vertical end section 44 against the outer sealing belt 76 and as the open pouches P are rotated with the filler wheel 2. After sealing the unsealed vertical end section 44 and thereby providing sealed pouches P, the same are discharged in the discharging section D.

(26) The discharging section D comprises inner and outer conveyor belts 66, 68. Both of those conveyor belts 66, 68 have lower and upper conveyor belts a, b. The lower conveyor belt 66b of the inner conveyor belt 66 is arranged within the recess 16, while the upper conveyor belt 66a is arranged above the upper segment 4a, 6a of the arms 4, 6.

(27) The conveyor belts 66, 68 are each guided by a curved guiding surface (not shown) to discharge the sealed pouches from the filler wheel 2.

REFERENCE SIGNS

(28) 2 filler wheel 4 leading arm 4a upper segment of leading arm 4b lower segment of leading arm 6 trailing arm 6a upper segment of trailing arm 6b lower segment of trailing arm 8 joint 10 rotational axis 11 gripping unit 12 radial end face 14 needle 16 recess 18 continuous web (folded) 20 pulling rollers 22 confronting side surfaces 24 bottom edge 26 vertical seal 26a leading edge 26b trailing edge 28 pocket 30 unsealed opening 31 top edge 32 pressure roll 34 circumferential groove 36 perforation knife 38 knife counter-element 40 leading sealing section 42 trailing sealing section 44 unsealed vertical end section 46 perforation 48 length piece 50 longitudinal opening guide means 52 central guide rail 54 chamfered widening section 56 parallel guide rail 58 longitudinal slot 60 spout wheel 62 spout 64 forward tip 65 rotational axis of the spout wheel 66 inner conveyor belt 66a lower inner conveyor belt 66a outer conveyor belt 68a lower outer conveyor belt 68b upper outer conveyor belt 70 discharging guide 72 head sealing means 74 heated bar 76 sealing belt PI piercing section P pouch S separation and opening section F filling section O opening section C closing section D discharging section SI sealing section