FILM BAG

Abstract

A bag has front and back face panels formed of a body film and each having two generally parallel and normally vertical side edges bridging ends of respective upper and lower edges, respective longitudinal side welds fixing the side edges of the front panel to the side edges of the back panel, a separate piece of label film different from the body film, covering a mid portion of one of the face panels between the respective longitudinal edges, and spaced downward from the upper edge of the one face panel and upward from the lower edge of the one face panel, and structure at the longitudinal edges holding the piece of label film on the one face panel without surface bonding of the piece of label film to the one face panel between the respective longitudinal edges.

Claims

1. A bag comprising: front and back face panels formed of a body film and each having two generally parallel and normally vertical side edges bridging ends of respective upper and lower edges; respective longitudinal side welds fixing the side edges of the front panel to the side edges of the back panel; a separate piece of label film different from the body film, covering a mid portion of one of the face panels between the respective longitudinal edges, and spaced downward from the upper edge of the one face panel and upward from the lower edge of the one face panel; and structure at the longitudinal edges holding the piece of label film on the one face panel without surface bonding of the piece of label film to the one face panel between the respective longitudinal edges.

2. The bag defined in claim 1, wherein the label film has a thickness between 20 m and 170 m, and the label film and body films have respective densities that differ by at least 0.02 g/cm.sup.3.

3. The bag defined in claim 1, wherein the label film has a thickness between 20 m and 100 m, and a ratio between a thickness of the body film and a thickness of the label film is larger than 3:2.

4. The bag defined in claim 3, wherein a ratio between a thickness of the body film and a thickness of the label film is larger than 2:1.

4. The bag defined in claim 1, wherein the piece of label film extends a full width of the one face panel between the longitudinal edges thereof.

5. The bag defined in claim 4, wherein the piece of label film is free of and not connected to the one face panel between the longitudinal edges thereof.

6. The bag defined in claim 1, wherein another such piece of label film different from the body film covers a mid portion of the other of the face panels between the respective longitudinal edges thereof, and is spaced downward from the upper edge of the other face panel and upward from the lower edge of the other face panel, the structure also holding the other piece on the other face panel without surface bonding and between the longitudinal edges thereof.

7. The bag defined in claim 1, wherein the piece of label film is fixed to the longitudinal welds.

8. The bag defined in claim 7, wherein the piece of label film is unitarily welded into the longitudinal welds.

9. The bag defined in claim 7, wherein the piece of label film is formed with a weakening line immediately adjacent and generally parallel to each of the longitudinal welds of the one face panel.

10. The bag defined in claim 1, wherein the face panels are joined so as to form a hermetically sealed interior.

11. The bag defined in claim 10, further comprising: a resealable closure fixed to at least one of the face panels and opening into the interior.

12. The bag defined in claim 1, wherein the body film is a polyolefin and is devoid of printing.

13. The bag defined in claim 1, wherein the body film has a thickness between 125 m and 250 m.

14. The bag defined in claim 1, wherein the body film has a density between 0.89 g/cm.sup.3 and 0.95 g/cm.sup.3.

15. The bag defined in claim 1, wherein the label film has a density greater than 1 g/cm.sup.3.

16. The bag defined in claim 1, wherein the piece of label film is a laminate having an inner layer turned toward the one face film and an outer layer turned away from the face film, the printing being between the layers.

17. The bag defined in claim 16, wherein the inner layer is of polyolefin and weldable and the outer layer is of polyethyleneterephthalate.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0044] The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

[0045] FIG. 1 is a front view of a film bag having a body made from a body film and a separate piece of label film;

[0046] FIG. 2 is a side view of the film bag according to FIG. 1;

[0047] FIGS. 3 and 4 are front views of alternative designs for the film bag of the is invention;

[0048] FIG. 5 is a horizontal section through the bag of this invention;

[0049] FIG. 6 is a large-scale view of a detail of FIG. 5; and

[0050] FIG. 7 is a large-scale view of a detail of the invention.

SPECIFIC DESCRIPTION OF THE INVENTION

[0051] FIG. 1 shows a hermetically sealed film bag with a self-supporting body 1 having identical front and back face panels 2 opposite one another and each formed of a body film. An unillustrated folded floor panel also of the body film closes the bottom of the body 1 and allows the bag to stand as illustrated. The face panels 2 each have an upper bag edge, a lower bag edge and two normally vertically and longitudinally extending side edges extending between outer ends of the respective upper and lower edges. The face panels 2 are welded together circumferentially to one another, and in particular has longitudinal welds 3 running along the side edges. According to this embodiment, the two face panels 1 are welded together at one upper corner and there form a stamped-out handle 4, and at the other upper corner they are provided with a reclosable spout 5.

[0052] According to the invention, the film bag has a piece 6 of label film carrying printing that is only attached to the body film forming the face panels 2 at the longitudinal welds 3. In other words, the piece 5 engages the face panel 2 between the edge welds 3, but is not bonded, adhered, or otherwise affixed to it except at the welds 3. One such piece 6 of label film is provided on each of the face panels 2 according to FIG. 2 and forms a type of sleeve.

[0053] The body 1 itself is not printed and can be either transparent, translucent or colored in a single color. All printing 7 formed by markings and information is applied to the piece 6 of label film. While the printing 7 can be printed on the separate piece 6 of label film in particularly high quality, no ink is applied to the body 1, which is beneficial with regard to both manufacturing and recycling.

[0054] During mechanical shredding, the face panels 2 on the one hand and the piece 6 of label film on the other hand form separate particles since the piece 6 of label film is not attached to the underlying front panel 2 between the longitudinal welds 3. Only at the longitudinal welds 3 can the body film forming the face panels 2 not be separated from the piece 6 of label film. Thus only a tiny fraction of the label film will be inseparable from the body film when the bag is comminuted.

[0055] According to the invention, there is an upper gap between the piece 6 of label film and the upper bag edge and a lower gap between the piece 6 of label film and the lower bag edge that are each generally at least 1 cm, preferably at least 5 cm wide, measured longitudinally parallel to the side-edge welds 3. In addition, the piece of label film only has a thickness of between 20 m and 170 m, preferably between 30 mm and 60 m, so that relative little material is required for the piece 6 of label film.

[0056] Multilayered laminated films in which the print is located in the interior and that are preferably also made from different materials are particularly suitable for the provision of a high quality print 7. Owing to the different materials and owing to the ink of the print 7, reprocessing through recycling is not possible or is only possible to a limited extent, which is why such materials are often only burnt as fuel. In the context of the invention, due to the comparatively thin piece 6 of label film that only stretches over part of the body 3 the proportion of such material that is not recyclable or is difficult to recycle is reduced.

[0057] Furthermore according to the invention the body film and the label film have different densities with a difference of at least 0.02 g/cm.sup.3. The materials can therefore be separated from one another using a suitable fluid technique. In the simplest case, separation can occur in a liquid bath thanks to the different densities. If, for example, the body film has a density greater than 1 g/cm.sup.3, which is the density of water, and the piece of label film has a density greater than 1 g/cm.sup.3 according to a preferred design of the invention, separation can occur in a simple water bath using a float-sink process.

[0058] Alternatively, separation can also be done by air classification with an air stream so that the separation threshold with regard to the density can easily be varied to a certain extent.

[0059] Depending on the procedure, air classification is also possible regardless of the different densities if the body film and the piece 6 of label film have thicknesses that differ significantly from one another.

[0060] Against this background, it is also envisaged in the context of the embodiment that the piece 6 of label film is on at least one of the face panels spaced from the upper edge and from the lower edge, and the piece 6 of label film, with a thickness of between 20 m and 100 m, is significantly thinner than the body film. The ratio of the thickness of the body film to the thickness of the piece 6 of label film is thereby appropriately greater than 3:2, in particular greater than 2:1, with the label film being the thinner film.

[0061] While the body film forming the body 1 is preferably a monocomponent film, the label film is preferably a multilayer laminate.

[0062] FIG. 7 shows an example of a preferred layer structure where the label film has an outer layer 8 made from PET toward the exterior of the bag and a weldable inner layer 9 made from polyethylene on the opposite side. According to FIG. 7, the print 7 is located on the inside on the outer layer 8, and the outer layer 8 and the weldable layer 9 are attached to one another using a laminating adhesive 10, for example a 2-part PUR adhesive.

[0063] For the embodiment in FIG. 1, the piece 6 of label film that runs across the two face panels 2 is incorporated into the longitudinal welds 3 and is firmly welded to the body 1 there. The thermoplastic inner layer 9 of the label film being easily welded to the thermoplastic and normally monocomponent body film.

[0064] Immediately adjacent the longitudinal welds 3, the piece 6 of label film has tear lines 11 that are generated with a laser or can be realized as rows of perforations. At least a majority of the piece 6 of label film can thus be torn off manually from the body 1 along the tear lines 11 by the user so that the user can then dispose of the piece separately from the outset, or simply remove it to unencumber the package from advertising. This results in improved separation if the film bag is not subsequently shredded for recycling. In addition, a user can also recognize the ecological benefits of the film bag according to the invention immediately.

[0065] Since the print is limited to the separate piece 6 of label film in the context of the invention, easy adaptation for a variety of contents, marketing areas or similar is also possible.

[0066] According to FIG. 1, some attached areas in which the piece 6 of label film and the body 1 are still attached remain after shredding. Taking this into account, complete separating can be made possible if the piece 6 of label film is welded at the longitudinal welds 3 in a separable manner.

[0067] Alternatively, FIG. 3 shows a design in which the body 1 itself has a necking area of reduced cross section in the middle level with the separate piece 6 of label film so that the piece 6 of label film is then held permanently as a circumferential sleeve as a result of just the bag shape. In the context of such a design, the piece 6 of label film can then be easily pulled off the body 1 by a user in the form of a sleeve once the body 1 has been emptied. Complete separation also occurs during mechanical processing.

[0068] Based on this, FIG. 4 shows another variant in which the longitudinal welds 3 are furnished with slits 13 through which the piece 6 of label film extends in the manner of a sleeve. The necking area provided according to FIG. 3 is not necessary in this embodiment.

[0069] Further variants for attaching the piece 6 of label film to the body 1 are explained by FIGS. 5 and 6 where the basic shape of the piece 6 of label film and the body 1, as well as their proportions should thereby remain unchanged based on the previously described embodiments.

[0070] According to FIG. 5, the face panels 2 have openings 14 in central regions of the longitudinal weld 3. The piece 6 of label film is formed by a front and back piece that are attached to one another through the openings 14 so as to form a circumferential sleeve. The unattached side edges of the film pieces extend beyond the openings 14 and align roughly with the side edges of the body film 1.

[0071] According to a variant of this, the piece of label film is formed as a circumferential sleeve that encircles the body made from a single piece of label film, and the piece of label film is circumferentially sealed with a fin seal on one of the face panels that forms a back side. Alternatively, the piece of label film can also be circumferentially sealed using adhesive, for example. The actual attachment to the body is done here in that the face panels have openings in the longitudinal weld area, and the piece of label film designed according to FIG. 7 is welded to itself through these openings on its weldable layer. This also results in the benefit that the piece of label film does not need to be threaded through slits arranged in the longitudinal welds.

[0072] In a variant of this, FIG. 6 shows that a piece 6 of label film that predominantly only covers one of the two face panels 2 and can thus be provided in a simple manner. The edges of the piece 6 of label film then encircle the side edges and are fixed through the openings 14.

[0073] In a variant of this, the part of the piece of label film that encircles the side edge can also be replaced with another narrower film strip that does not cover the full width of the back panel, but rather only covers the opening 14 area. Sufficient attachment of a piece of label film applied to one side can likewise be ensured in this manner.