Method and system for preparing a packaging bag for receipt of a product therein

Abstract

Method of preparing a packaging bag for receipt of a product therein, comprising: tearing a perforation of a first layer of a web of packaging material by forcing a medial portion of the first layer away from a second layer of the web in an opening direction substantially normal to a plane in which the web extends at a position just distal from the perforation while retaining together the first layer and the second layer at a position just proximal from the perforation; and holding the forced away medial portion of the first layer apart from the second layer to hold the packaging bag open at its top end for receipt of a product, wherein at least an initial part of the forcing away is performed using suction applied to the medial portion of the first layer in the opening direction.

Description

[0001] P138000PC00

[0002] Title: Method and system for preparing a packaging bag for receipt of a product therein

[0003] FIELD

[0004] The invention relates to a method of preparing a packaging bag for receipt of a product therein, as well as to a system therefor.

[0005] BACKGROUND

[0006] Methods and systems for preparing a packaging bag for receipt of a product therein are known as such. The packaging bag is typically formed from an elongate continuous web of dual-layer packaging material that is separable into subsequent bag forming sections at transversely applied perforations. To open the packaging bag for receipt of a product, the two layers of the packaging bag are moved apart at one end of the packaging bag. After receipt of the product, the packaging bag may be closed.

[0007] Subsequent products may be thus packaged in respective bags obtained from a same web of packaging material.

[0008] Various types of packaging materials are known, wherein the selection of a packaging material may depend on various factors, e.g. associated with the product, its logistics and its intended use. It has been found that known methods and systems for preparing a packaging bag for receipt of a product therein can pose difficulties in combination with some types of packaging material, in particular inextensible materials and materials prone to electrostatic charging. For example, the packaging bag may become warped or damaged or may fail to open reliably. In view thereof, improvements are desired. Meanwhile, it is desired to promote speed and efficiency. SUMMARY

[0009] An object of the invention is to at least partly alleviate one or more of the above-mentioned difficulties associated with known methods and systems for preparing a packaging bag for receipt of a product therein, in particular while maintaining or improving one or more advantages thereof. An object is to at least provide an alternative method and system for preparing a packaging bag for receipt of a product therein.

[0010] Thereto, an aspect of the invention provides a method of preparing a packaging bag for receipt of a product therein.

[0011] The method comprises extending an elongate continuous web of packaging material from a web origin longitudinally along a web path. The web has a first layer and a second layer that are mutually joined along lateral sides of the web while being mutually separable between said lateral sides.

[0012] At a first longitudinal position along the web, a bottom end of the packaging bag is, or has been, preformed by mutually joining the first layer and the second layer along a transverse path across the web.

[0013] At a second longitudinal position along the web more proximal to the web origin, a top end of the packaging bag is, or has been, preformed by applying a perforation in the first layer and the second layer along a transverse path across the web. The perforation allows the packaging bag as a distal section of the web to be separated from a more proximal remainder of the web by tearing of the perforation.

[0014] The method comprises tearing the perforation of the first layer while leaving the distal section of the web attached to the remainder of the web at the second layer. Thereto, a medial portion of the first layer is torn away from the second layer at a bag engagement position just distal from the perforation in an opening direction substantially normal to a plane in which the web extends. Meanwhile, medial portions of the first layer and the second layer are retained together at a retention position just proximal from the perforation. The tearing of the perforation of the first layer provides the packaging bag in a state with its top end open.

[0015] The method comprises, at the bag engagement position, holding the forced away medial portion of the first layer apart from the second layer to hold the packaging bag open at its top end for receipt of a product in the packaging bag via the open top end.

[0016] At least an initial part of the forcing away of the medial portion of the first layer from the second layer at the bag engagement position is performed using suction applied to the medial portion of the first layer at the bag engagement position in the opening direction.

[0017] Advantageously, using the suction, the forcing away can be initiated without requiring a prior tearing of the perforation of the first layer. Thereby, the forcing away can itself be used to cause the tearing of the perforation of the first layer, wherein the forcing away can subsequently be continued without interruption to eventually allow the packaging bag to be held open for receipt of the product. In this way, a relatively efficient and effective method is provided that can be applied using a wide variety of packaging materials, including inextensible materials and materials prone to electrostatic charging.

[0018] By contrast, in some known methods, a tearing of the first layer is caused by driving the first layer with respect to the second layer along the web path, i.e. in a mutually sliding manner. It has been found that this approach tends to cause warping or damaging in case inextensible packaging materials. Meanwhile, in case of packaging materials prone to electrostatic charging, the two layers tend to electrostatically cling together, making it difficult to slide the layers with respect to each other and to subsequently keep the layers mutually separated.

[0019] A further aspect provides a system for preparing a packaging bag for receipt of a product therein according to the method as described herein. The system comprises a web guide assembly configured to guide the elongate continuous web of packaging material so as to extend from the web origin along the web path.

[0020] The system comprises a handling assembly configured to perform: the tearing of the perforation of the first layer while leaving the distal section of the web attached to the remainder of the web at the second layer, and the holding apart of the forced away medial portion of the first layer from the second layer.

[0021] The handling assembly comprises a suction device configured to apply the suction to the medial portion of the first layer in the opening direction.

[0022] Advantages of such a system correspond to those described above for the method.

[0023] Optional advantageous elaborations of the above aspects are disclosed and explained in the below detailed description, wherein it shall be appreciated that options disclosed for the method can correspondingly be applied to the system and vice versa.

[0024] DETAILED DESCRIPTION

[0025] In the following, the invention will be explained using examples of embodiments and drawings. The drawings are schematic and merely show examples. Descriptions of embodiments herein can also be understood without reference to the drawings, and are thus not inextricably linked to the examples in the drawings. In the drawings, corresponding elements are provided with corresponding reference signs. For clarity of the drawings, some reference signs may be omitted in some figures where visibility of the corresponding elements is otherwise apparent, e.g. from the same or similar elements in the same or corresponding figures. Also for clarity of the drawings, some elements may be omitted in some figures where the possible presence of such elements is otherwise apparent, e.g. from other figures. In the drawings:

[0026] Figs. 1A, IB and 1C show a partly cross-sectional front view, a side view and a partly cross-sectional top view, respectively, of a web prior to the tearing of the perforation of the first layer, along with elements of an associated system;

[0027] Figs. 2A, 2B and 2C show a partly cross-sectional front view, a side view and a partly cross-sectional top view, respectively, of the web and system elements after the tearing of the perforation of the first layer, wherein the packaging bag is held open at its top end for receipt of a product;

[0028] Figs. 3A, 3B and 4A show side views corresponding to Fig. 2B, wherein optional additional system elements are shown; and

[0029] Fig. 4B shows a side view corresponding to Fig. 4A, wherein the packaging bag is closed at its top end after receipt of the product.

[0030] The figures illustrate a method of preparing a packaging bag 1 for receipt of a product 100 therein. The method comprises extending an elongate continuous web 2 of packaging material from a web origin 3 longitudinally along a web path W. The web 2 has a first layer 4 and a second layer 5 that are mutually joined along lateral sides 6 of the web 2 while being mutually separable between said lateral sides 6.

[0031] At a first longitudinal position Pl along the web 2, a bottom end 7 of the packaging bag 1 is, or has been, preformed by mutually joining, e.g. sealing, the first layer 4 and the second layer 5 along a transverse path 27 across the web 2.

[0032] At a second longitudinal position P2 along the web 2 more proximal to the web origin 3, a top end 8 of the packaging bag 1 is, or has been, preformed by applying a perforation 9 in the first layer 4 and the second layer 5 along a transverse path across the web 2. The perforation 9 allows the packaging bag 1 as a distal section 10 of the web 2 to be separated from a more proximal remainder 11 of the web 2 by tearing of the perforation 9.

[0033] The method comprises tearing the perforation 9-4 of the first layer 4 while leaving the distal section 10 of the web 2 attached to the remainder 11 of the web 2 at the second layer 5 by forcing a medial portion 12 of the first layer 4 away from the second layer 5 at a bag engagement position E just distal from the perforation 9 in an opening direction D substantially normal to a plane in which the web 2 extends while retaining together medial portions 13,14 of the first layer 4 and the second layer 5 at a retention position R just proximal from the perforation 9. The tearing of the perforation 9-4 of the first layer 4 provides the packaging bag 1 in a state with its top end 8 open.

[0034] The method comprises, at the bag engagement position E, holding the forced away medial portion 12 of the first layer 4 apart from the second layer 5 to hold the packaging bag 1 open at its top end 8 for receipt of a product 100 in the packaging bag 1 via the open top end 8.

[0035] At least an initial part of the forcing away of the medial portion 12 of the first layer 4 from the second layer 5 at the bag engagement position E is performed using suction applied to the medial portion 12 of the first layer 4 at the bag engagement position E in the opening direction D.

[0036] The figures also illustrate a system for preparing a packaging bag 1 for receipt of a product 100 therein according to the method as described herein. The system comprises a web guide assembly 17 configured to guide the elongate continuous web 2 of packaging material so as to extend from the web origin 3 along the web path W. The system comprises a handling assembly 18 configured to perform: the tearing of the perforation 9-4 of the first layer 4 while leaving the distal section 10 of the web 2 attached to the remainder 11 of the web 2 at the second layer 5, and the holding apart of the forced away medial portion 12 of the first layer 4 from the second layer 5 at the bag engagement position E. The handling assembly 18 comprises a suction device 19 configured to apply the suction to the medial portion 12 of the first layer 4 at the bag engagement position E in the opening direction D.

[0037] Advantages of such a method and system have been described in the above summary section. With reference to the figures as illustrative example, it may be particularly well understood how, using suction, here applied by a suction device 19 comprising suction cups 20, the packaging bag 1 can be brought from a state as illustrated in Figs. 1A-C, in which the perforation 9 at the top end 10 of the bag 1 is not yet torn, to a state as illustrated in Figs. 2A-C, in which the perforation 9 of the first layer 4 is torn and the top end 10 is held open for receipt of the product 100.

[0038] It shall be appreciated that the web guide assembly 17, indicated in Fig. 1A-B by a pair of rollers as illustrative example, may comprise various web guide elements such as active rollers, passive rollers, static web guide elements, etc., at various positions along the web path W, e.g. essentially as in known packaging systems. Similarly, the web path W may be arranged in various ways. Preferably, a section of the web path W where the bag 1 is held open extends downwardly, in particular so as to facilitate insertion of the product 100 into the bag 1 using gravity.

[0039] In embodiments, including in the shown examples, the system further comprises a web drive device 25, e.g. comprising a motor 28 coupled to one or more elements of the web guide assembly 17, configured to drive the web 2 through the web guide assembly 17 along the web path W.

[0040] In embodiments, the system is further configured to perform the preforming of the bottom end 7 of the packaging bag, in particular before the tearing of the perforation 9-4 of the first layer 4. Alternatively, the preforming of the bottom end 7 may be performed outside the system, e.g. prior to the web 2 being arranged in the web guide assembly 17. Methods and systems for such preforming of a bottom end 7 are known as such and can correspondingly be applied in the present context. In embodiments, the system is further configured to perform the preforming of the top end 8 of the packaging bag 1 by the applying of the perforation 9 in the first layer 4 and the second layer 5. Alternatively, the preforming of the top end 8 may be performed outside the system, e.g. prior to the web 2 being arranged in the web guide assembly 17. Methods and systems for such preforming of a top end 8 are known as such and can correspondingly be applied in the present context.

[0041] In embodiments, including in the shown examples, the suction device 19 comprises one or more suction cups 20 arranged to face the medial portion 12 of the first layer 4 at the bag engagement position E, wherein the handling assembly 18 is configured to move the one or more suction cups 20 with respect to the web guide assembly 17 along the opening direction D. In embodiments, including in the shown examples, the suction device 19 comprises a suction pump 21 operatively connected to the one or more suction cups 20, in particular so as to create a sub-atmospheric pressure in the one or more suction cups 20. In this way, the medial portion 12 of the first layer 4 can be engaged for suction particularly effectively. Although the figures show two suction cups 20, it shall be appreciated that different numbers of suction cups 20 are possible and may be advantageous, e.g. depending on the width and / or material of the bag 1. The suctions cups 20 are preferably distributed evenly along the transverse direction, e.g. across a transverse range corresponding to a transverse range of the medial portions 13,14.

[0042] In embodiments, including in the shown examples, the one or more suction cups 20 are of a bellows type and / or are made from a resilient material. In this way, the suction cups 20 may advantageously accommodate flexibility of the bag 1 in a robust yet non-damaging manner. Moreover, the suction cups 20 may thus automatically retract from the bag 1 when the suction is switched off, e.g. after engagement of hooks 16 as explained elsewhere herein and illustrated in Figs. 3A-B. In embodiments, including in the shown examples, the handling assembly 18 comprises one or more retention elements 22 for the retaining together of the medial portions 13,14 of the first layer 4 and the second layer 5 at the retention position R, wherein the one or more retention elements 22 together define a transverse retention range T, in particular corresponding to a transverse range of the medial portions 13,14. In this way, the medial portions 13,14 of the first layer 4 and the second layer 5 can be retained together particularly effectively. The retention elements 22 may for example be or comprise fingers extending along the web 2 towards the second position P2. The retention elements 22 may be static or be provided with an actuator. In some variants, the retention elements 22 may be formed by actuated fingers or hooks of a bag spreading assembly (not shown) that is configured to spread, e.g. stretch, the bag 1 sideways after opening thereof, wherein the fingers or hooks then e.g. are actively extended into the bag 1 through the open top end 8.

[0043] In embodiments, the handling assembly 18 is adjustable for varying the transverse retention range T. In this way, versatility of the system can be increased, in particular to accommodate bags of various widths.

[0044] In embodiments, including in the shown examples, lateral portions 15 of the web 2 adjacent the lateral sides 6 are left free by the forcing away of the medial portion 12 of the first layer 4 from the second layer 5 at the bag engagement position E. In embodiments, including in the shown examples, lateral portions 15 of the web 2 adjacent the lateral sides 6 are left free by the retaining together of the medial portions 13,14 of the first layer 4 and the second layer 5 at the retention position R. In this way, the first layer 4 and the second layer 5 can be mutually spaced apart particularly well, in particular also without relying on stretching of the web and thus on stretchable web materials. In embodiments, including in the shown examples, during a continuous period in which the medial portion 12 of the first layer 4 is both forced away and held apart from the second layer 5 at the bag engagement position E, the web 2 is held stably with respect to the web path W, in particular without being driven along the web path W. In embodiments, including in the shown examples, the tearing of the perforation 9-4 of the first layer 4 is performed without the first layer 4 and the second layer 5 being driven with respect to each other along the web path W. Thus, during these activities, the bag 1 may be engaged substantially only transverse to the web path W. In this way, bags of various materials including elastic materials can be opened particularly effectively.

[0045] In embodiments, a non-initial part of the forcing away of the medial portion 12 the first layer 4 at the bag engagement position E may be performed without suction applied to the first layer 4 at the bag engagement position E. During such a non-initial part of the forcing away, for example, hooks 16 as described elsewhere herein may be used to continue the forcing away. By limiting the suction to an initial part of the forcing away, energy expenditure and noise from the suction can be reduced. In alternative embodiments, all of the forcing away of the medial portion 12 of the first layer 4 at the bag engagement position E may be performed using suction applied to the medial portion 12 of the first layer 4 at the bag engagement position E in the opening direction D.

[0046] In embodiments, at least an initial part of the holding apart of the forced away medial portion 12 of the first layer 4 from the second layer 5 at the bag engagement position E is performed using suction applied to the medial portion 12 of the first layer 4 at the bag engagement position E in the opening direction D. In this way, after the forcing away of the medial portion 12 of the first layer 4, the suction can continue to be used to hold the bag 1 open at its top end 8. In embodiments, with particular reference to Figs. 3A-B as illustrations, at least a non-initial part of the holding apart of the forced away medial portion 12 of the first layer 4 from the second layer 5 at the bag engagement position E is performed without suction applied to the first layer 4 at the bag engagement position E. In embodiments, with particular reference to Figs. 3A-B as illustrations, the holding apart of the forced away medial portion 12 of the first layer 4 from the second layer 5 at the bag engagement position E is performed using one or more hooks 16 extending through the open top end 8 of the packaging bag 1. In embodiments, with particular reference to Figs. 3A-B as illustrations, the handling assembly 18 comprises one or more hooks 16 and is configured to extend the one or more hooks 16 through the open top end 8 of the packaging bag 1 for the holding apart of the forced away medial portion 12 of the first layer 4 from the second layer 5 at the bag engagement position E. In embodiments, with particular reference to Figs. 3A-B as illustrations, the handling assembly 18 is configured to rotate the one or more hooks 16 with respect to the web guide assembly 17 about a rotation axis X substantially transverse to the web path W. In embodiments, the handling assembly 18 is configured to move the one or more hooks 16 with respect to the web guide assembly 17 along the opening direction D, in particular for use of the one or more hooks 16 in a non-initial part of the forcing away of the medial portion 12 of the first layer 4 from the second layer 5 at the bag engagement position E. In embodiments, with particular reference to Figs. 3A-B as illustrations, the handling assembly 18 is configured to move the one or more hooks 16 and the one or more suction cups 20 together with respect to the web guide assembly 17 along the opening direction D, in particular wherein the handling assembly 18 comprises a common actuator 23 for said movement, preferably a linear actuator 23 having an actuation direction along the opening direction D. In embodiments, the system is configured to control the suction device 19 to pause the suction when the one or more hooks 16 extend through the open top end 8 of the packaging bag 1, in particular after the initial part of the forcing away. In this way, advantageously, the suction can be limited to an initial phase so as to limit energy expenditure and noise, wherein in a subsequent phase the hooks 16 can be used to continue the engagement of the first layer 4 at the top end 8 so as to force and / or hold the bag 1 open. Meanwhile, the initial suction enables to hooks 16 to engage the first layer 4. Preferably the hooks 16 are extended into the bag 1 before the suction is released so as to promote a reliable handover from the suction to the hooks. Transverse positions of the hooks 16 may correspond to those of the suction cups 20, for example, although different positions are possible as well, wherein the number of hooks 16 may be the same or different compared to the number of suction cups 20.

[0047] The figures also illustrate a method of packaging a product 100 in a packaging bag 1, comprising: preparing the packaging bag 1 for receipt of the product 100 as described herein; causing the product 100 to be received in the prepared packaging bag 1 via the open top end 8 of the held open packaging bag 1; closing the top end 8 of the packaging bag 1 with the product 100 received therein; and separating the packaging bag 1 from the remainder 11 of the web 2 using tearing of the perforation 9-5 of the second layer 5, in particular after the closing of the top end 8 of the packaging bag 1 with the product 100 received therein.

[0048] In embodiments, with particular reference to Fig. 3B as an illustration, the system comprises a product handling assembly 26, e.g. comprising a conveyor, for causing the product 100 to be received in the prepared packaging bag 1 via the open top end 8 of the held open packaging bag 1. Alternatively, a product 100 may be positioned, e.g. dropped, into the bag 1 manually, for example.

[0049] In embodiments, with particular reference to Figs. 4A-B as illustrations, the system is further configured to close the top end 8 of the packaging bag 1 after the holding open of the packaging bag 1. In embodiments, with particular reference to Figs. 4A-B as illustrations, the handling assembly 18 comprises a joining device 24 configured to mutually join the first layer 4 and the second layer 5 along a transverse path across the web 2 at the top end 8 of the packaging bag 1. For example, the layers may be joined by heat sealing or ultrasonic welding using a joining device 24 of a corresponding type, e.g. a joining device known as such. In embodiments, the joining device 24 is coupled to the common actuator 23, or at least an actuator for the suction cups 20, to allow the joining device 24 to move so as to close the bag 1 at its top end 8 in a direction opposite to the opening direction D before performing the joining, while also allowing the joining device 24 to remain at a distance from the bag 1 before its closure.

[0050] In embodiments, the system is further configured to separate the distal section 10 comprising the packaging bag 1 from the remainder 11 of the web 2 by tearing of the perforation 9-5 of the second layer 5 after the holding open of the packaging bag 1, preferably after the closing of the top end 8 of the packaging bag 1. In embodiments, the system is configured to pull the distal section 10 and the remainder 11 of the web 2 away from each other, in particular by holding the packaging bag 1 at its top end 8 fixed with respect to the web guide assembly 17 while causing a retraction of the remainder 11 of the web 2, preferably along the web path W, away from the top end 8. For example, with reference to Fig. 4B as illustration, the bag 1 may be held fixed at its top end 8 using the joining device 24, whereupon the remainder 11 of the web 2 may be retracted to separate the bag from the remainder 11 of the web 2.

[0051] The figures also illustrate a method of packaging products 100 in respective packaging bags 1, comprising, subsequently: packaging a first product 100 in a first packaging bag 1 as described herein; driving the remainder 11 of the web 2 along the web path W, in particular to position a subsequent perforation 9 between the engagement position E and the retention position R; and packaging a further product 100 in a further packaging bag 1 according to claim 11, wherein the remainder 11 of the web 2 from the packaging of the first product 100 is used as the web 2 for the packaging of the further product 100. In this way, subsequent products 100 can be packaged in subsequent bags 1 in a particularly effective manner. Thus, the system described herein may additionally be suitable, in particular configured, for packaging products 100 in respective packaging bags 1 as described herein.

[0052] In view of the above, aspects and embodiments of the present invention advantageously enable relatively efficient and effective preparation of a packaging bag for receipt of a product, in particular for a wide variety of packaging materials including inextensible materials and materials prone to electrostatic charging. More generally, various improvements in the packaging of products in packaging bags are thereby enabled.

[0053] Although the invention has been described herein using examples of embodiments and drawings, these do not limit the scope of the invention as defined by the claims. Within said scope, many variations are possible. Examples thereof have been provided in the description.

[0054] LIST OF REFERENCE SIGNS

[0055] 1. Packaging bag

[0056] 2. Web

[0057] 3. Web origin

[0058] 4. First layer

[0059] 5. Second layer

[0060] 6. Lateral side

[0061] 7. Bottom end

[0062] 8. Top end

[0063] 9. Perforation of first layer and second layer

[0064] 9-4. Perforation of first layer 9-5. Perforation of second layer

[0065] 10. Distal section

[0066] 11. Remainder

[0067] 12. Medial portion of first layer at bag engagement position 13. Medial portion of first layer at retention position 14. Medial portion of second layer at retention position 15. Lateral portion

[0068] 16. Hook

[0069] 17. Web guide assembly

[0070] 18. Handling assembly

[0071] 19. Suction device

[0072] 20. Suction cup

[0073] 21. Suction pump

[0074] 22. Retention element

[0075] 23. Common actuator

[0076] 24. Joining device

[0077] 25. Web drive device

[0078] 26. Product handling assembly

[0079] 27. Mutual joining of first and second layer

[0080] 28. Motor of web drive device

[0081] 100. Product

[0082] D. Opening direction

[0083] E. Bag engagement position

[0084] Pl. First longitudinal position

[0085] P2. Second longitudinal position

[0086] R. Retention position

[0087] T. Transverse retention range

[0088] W. Web path

[0089] X. Rotation axis of hook

Claims

Claims1. Method of preparing a packaging bag (1) for receipt of a product (100) therein, comprising:extending an elongate continuous web (2) of packaging material from a web origin (3) longitudinally along a web path (W), the web (2) having a first layer (4) and a second layer (5) that are mutually joined along lateral sides (6) of the web (2) while being mutually separable between said lateral sides (6),wherein, at a first longitudinal position (Pl) along the web (2), a bottom end (7) of the packaging bag (1) is, or has been, preformed by mutually joining the first layer (4) and the second layer (5) along a transverse path across the web (2),wherein, at a second longitudinal position (P2) along the web (2) more proximal to the web origin (3), a top end (8) of the packaging bag (1) is, or has been, preformed by applying a perforation (9) in the first layer (4) and the second layer (5) along a transverse path across the web (2), the perforation (9) allowing the packaging bag (1) as a distal section (10) of the web (2) to be separated from a more proximal remainder (11) of the web (2) by tearing of the perforation (9);tearing the perforation (9-4) of the first layer (4) while leaving the distal section (10) of the web (2) attached to the remainder (11) of the web (2) at the second layer (5) by forcing a medial portion (12) of the first layer (4) away from the second layer (5) at a bag engagement position (E) just distal from the perforation (9) in an opening direction (D) substantially normal to a plane in which the web (2) extends while retaining together medial portions (13,14) of the first layer (4) and the second layer (5) at a retention position (R) just proximal from the perforation (9), the tearing ofthe perforation (9-4) of the first layer (4) providing the packaging bag (1) in a state with its top end (8) open; andat the bag engagement position (E), holding the forced away medial portion (12) of the first layer (4) apart from the second layer (5) to hold the packaging bag (1) open at its top end (8) for receipt of a product (100) in the packaging bag (1) via the open top end (8),wherein at least an initial part of the forcing away of the medial portion (12) of the first layer (4) from the second layer (5) at the bag engagement position (E) is performed using suction applied to the medial portion (12) of the first layer (4) at the bag engagement position (E) in the opening direction (D).

2. Method according to claim 1, wherein, during a continuous period in which the medial portion (12) of the first layer (4) is both forced away and held apart from the second layer (5) at the bag engagement position (E), the web (2) is held stably with respect to the web path (W), in particular without being driven along the web path (W).

3. Method according to any claim 1 or 2, wherein the tearing of the perforation (9-4) of the first layer (4) is performed without the first layer (4) and the second layer (5) being driven with respect to each other along the web path (W).

4. Method according to any of the preceding claims, wherein lateral portions (15) of the web (2) adjacent the lateral sides (6) are left free by the forcing away of the medial portion (12) of the first layer (4) from the second layer (5) at the bag engagement position (E).

5. Method according to any of the preceding claims, wherein lateral portions (15) of the web (2) adjacent the lateral sides (6) are left free by theretaining together of the medial portions (13,14) of the first layer (4) and the second layer (5) at the retention position (R).

6. Method according to any of the preceding claims, wherein a noninitial part of the forcing away of the medial portion (12) the first layer (4) at the bag engagement position (E) is performed without suction applied to the first layer (4) at the bag engagement position (E).

7. Method according to any of claims 1 - 5, wherein all of the forcing away of the medial portion (12) of the first layer (4) at the bag engagement position (E) is performed using suction applied to the medial portion (12) of the first layer (4) at the bag engagement position (E) in the opening direction (D).

8. Method according to any of the preceding claims, wherein at least an initial part of the holding apart of the forced away medial portion (12) of the first layer (4) from the second layer (5) at the bag engagement position (E) is performed using suction applied to the medial portion (12) of the first layer (4) at the bag engagement position (E) in the opening direction (D).

9. Method according to any of the preceding claims, wherein at least a non-initial part of the holding apart of the forced away medial portion (12) of the first layer (4) from the second layer (5) at the bag engagement position (E) is performed without suction applied to the first layer (4) at the bag engagement position (E).

10. Method according to any of the preceding claims, wherein the holding apart of the forced away medial portion (12) of the first layer (4) from the second layer (5) at the bag engagement position (E) is performedusing one or more hooks (16) extending through the open top end (8) of the packaging bag (1).

11. Method of packaging a product (100) in a packaging bag (1), comprising:preparing the packaging bag (1) for receipt of the product (100) according to any of the preceding claims;causing the product (100) to be received in the prepared packaging bag (1) via the open top end (8) of the held open packaging bag (1);closing the top end (8) of the packaging bag (1) with the product (100) received therein; andseparating the packaging bag (1) from the remainder (11) of the web (2) using tearing of the perforation (9-5) of the second layer (5), in particular after the closing of the top end (8) of the packaging bag (1) with the product (100) received therein.

12. Method of packaging products (100) in respective packaging bags (1), comprising, subsequently:packaging a first product (100) in a first packaging bag (1) according to claim 11;driving the remainder (11) of the web (2) along the web path (W), in particular to position a subsequent perforation (9) between the engagement position (E) and the retention position (R); andpackaging a further product (100) in a further packaging bag (1) according to claim 11, wherein the remainder (11) of the web (2) from the packaging of the first product (100) is used as the web (2) for the packaging of the further product (100).

13. System for preparing a packaging bag (1) for receipt of a product (100) therein according to the method of any of claims 1 - 10, comprising:a web guide assembly (17) configured to guide the elongate continuous web (2) of packaging material so as to extend from the web origin (3) along the web path (W); anda handling assembly (18) configured to perform: the tearing of the perforation (9-4) of the first layer (4) while leaving the distal section (10) of the web (2) attached to the remainder (11) of the web (2) at the second layer (5), and the holding apart of the forced away medial portion (12) of the first layer (4) from the second layer (5) at the bag engagement position (E),wherein the handling assembly (18) comprises a suction device (19) configured to apply the suction to the medial portion (12) of the first layer (4) at the bag engagement position (E) in the opening direction (D).

14. System according to claim 13, wherein the suction device (19) comprises one or more suction cups (20) arranged to face the medial portion (12) of the first layer (4) at the bag engagement position (E), wherein the handling assembly (18) is configured to move the one or more suction cups (20) with respect to the web guide assembly (17) along the opening direction (D).

15. System according to claim 14, wherein the one or more suction cups (20) are of a bellows type and / or are made from a resilient material.

16. System according to claim 14 or 15, wherein the suction device (19) comprises a suction pump (21) operatively connected to the one or more suction cups (20), in particular so as to create a sub-atmospheric pressure in the one or more suction cups (20).

17. System according to any of claims 13 - 16, wherein the handling assembly (18) comprises one or more retention elements (22) for the retaining together of the medial portions (13,14) of the first layer (4) and thesecond layer (5) at the retention position (R), wherein the one or more retention elements (22) together define a transverse retention range (T), in particular corresponding to a transverse range of the medial portions (13,14).

18. System according to claim 17, wherein the handling assembly (18) is adjustable for varying the transverse retention range (T).

19. System according to any of claims 13 - 18, wherein the handling assembly (18) comprises one or more hooks (16) and is configured to extend the one or more hooks (16) through the open top end (8) of the packaging bag (1) for the holding apart of the forced away medial portion (12) of the first layer (4) from the second layer (5) at the bag engagement position (E).

20. System according to claim 19, wherein the handling assembly (18) is configured to rotate the one or more hooks (16) with respect to the web guide assembly (17) about a rotation axis (X) substantially transverse to the web path (W).

21. System according to claim 19 or 20, wherein the handling assembly (18) is configured to move the one or more hooks (16) with respect to the web guide assembly (17) along the opening direction (D), in particular for use of the one or more hooks (16) in a non-initial part of the forcing away of the medial portion (12) of the first layer (4) from the second layer (5) at the bag engagement position (E).

22. System according to claims 21 and 15, wherein the handling assembly (18) is configured to move the one or more hooks (16) and the one or more suction cups (20) together with respect to the web guide assembly(17) along the opening direction (D), in particular wherein the handling assembly (18) comprises a common actuator (23) for said movement.

23. System according to any of claims 19 - 22, configured to control the suction device (19) to pause the suction when the one or more hooks (16) extend through the open top end (8) of the packaging bag (1), in particular after the initial part of the forcing away.

24. System according to any of claims 13 - 23, further configured to close the top end (8) of the packaging bag (1) after the holding open of the packaging bag (1).

25. System according to claim 24, wherein the handling assembly (18) comprises a joining device (24) configured to mutually join the first layer (4) and the second layer (5) along a transverse path across the web (2) at the top end (8) of the packaging bag (1).

26. System according to any of claims 13 - 25, further configured to separate the distal section (10) comprising the packaging bag (1) from the remainder (11) of the web (2) by tearing of the perforation (9-5) of the second layer (5) after the holding open of the packaging bag (1), preferably after the closing of the top end (8) of the packaging bag (1).

27. System according to claim 26, configured to pull the distal section (10) and the remainder (11) of the web (2) away from each other, in particular by holding the packaging bag (1) at its top end (8) fixed with respect to the web guide assembly (17) while causing a retraction of the remainder (11) of the web (2), preferably along the web path (W), away from the top end (8).

28. System according to any of claims 13 - 27, further comprising a web drive device (25) configured to drive the web (2) through the web guide assembly (17) along the web path (W).

29. System according to any of claims 13 - 28, further configured to perform the preforming of the bottom end (7) of the packaging bag, in particular before the tearing of the perforation (9-4) of the first layer (4).

30. System according to any of claims 13 - 29, further configured to perform the preforming of the top end (8) of the packaging bag (1) by the applying of the perforation (9) in the first layer (4) and the second layer (5).

31. System for packaging products (100) in respective packaging bags (1) according to the method of claim 12, comprising the system according to any of claims 13 - 30.

32. System according to claim 31, comprising a product handling assembly (26) for causing the product (100) to be received in the prepared packaging bag (1) via the open top end (8) of the held open packaging bag (1).

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