METHOD FOR CLOSING A MESH BAG AND BAG OBTAINABLE BY MEANS OF SAID METHOD

Abstract

A method for closing a mesh bag including applying an ancillary closing element around a transversely collected portion of the bag, tightly girdling the same, thereby determining on a first side of the closing element a storage portion of the bag and on a second side of the closing element, adjacent thereto, a mesh bundle. The method further including the operation of bonding yarns of the mesh bundle together to form at least one bulge that acts as a retainer as it prevents, by abutment with the ancillary closing element, the mesh bundle from passing from the second side to the first side of the ancillary closing element.

Claims

1-15. (canceled)

16. A method for closing a mesh bag comprising applying an ancillary closing element around a transversely collected portion of the bag, tightly girdling the same, thereby determining on a first side of the closing element a storage portion of the bag and on a second side of the closing element, adjacent thereto, a mesh bundle, the method further comprising the operation of bonding packed yarns of said mesh bundle together to form at least one bulge that acts as a retainer because it prevents, by abutment with the ancillary closing element, the mesh bundle from passing from the second side to the first side of said ancillary closing element.

17. The method according to claim 16, wherein the bonding together of the packed yarns of the mesh bundle is produced by melting the material of which the yarns are made.

18. The method according to claim 16, wherein said melting is achieved by applying pressure and temperature in a controlled manner to the mesh bundle.

19. The method according to claim 16, wherein the pressure and temperature are applied in a controlled manner to one side of the mesh bundle, producing a sort of lateral notch in said mesh bundle.

20. The method according to claim 16, wherein the operation of bonding packed yarns of the mesh bundle together is carried out such that not all of the packed yarns of the mesh bundle are bonded together.

21. The method according to claim 16, wherein the application of the ancillary closing element on the collected longitudinal portion of the bag is carried out with interposition between the mesh and the ancillary closing element of an external element that is a portion of a label or the like.

22. The method according to claim 16, wherein the external element does not completely surround the mesh bundle; in that the bonding together of the packed yarns of the mesh bundle occurs by melting the material of which the yarns are made; and in that said melting is achieved by applying pressure and temperature in a controlled manner to a lateral area of the mesh bundle that is not surrounded by the external element.

23. The method according to claim 16, wherein the tooling used for bonding yarns of the mesh bundle together is configured to form a bulge whose shape develops in a main direction which is transverse to the mesh bundle.

24. The method according to claim 16, wherein the bulge extends across the full width, from one side to the other, of the mesh bundle.

25. The method according to claim 16, wherein the bulge extends in a direction at an angle with respect to a flattened collected portion of the mesh bundle.

26. A method according to claim 16, wherein the ancillary closing element and the mesh are made of the same material or at least belong to the same type of selective collection.

27. The method according to claim 16, wherein the material is a plastic or a bioplastic.

28. The method according to claim 16, wherein in that the ancillary closing element is made of a single piece of plastic or bioplastic material and configured in the shape of a clamp with two arms which, when brought together, cooperate to close by flattening the longitudinal collected portion of the bag located between the arms, the arms being bonded by a proximal end to a connecting bridge and the arms having at their distal end complementary retention elements for retention by mutual latching when the arms come together.

29. A closed mesh bag obtained by following the method of claim 16.

30. The mesh bag according to claim 29, wherein the mesh bundle is a tail of the bag with at least a portion of the packed yarns of which are bonded together forming the at least one bulge which acts as a retainer, which prevents by abutment with the ancillary closing element that the latter can slide along the entire tail of the bag formed by the mesh bundle, unintentionally opening said bag.

31. The mesh bag according to claim 30, wherein the ancillary closing element and the mesh are made of the same material or at least belong to the same type of selective collection.

32. The mesh bag according to claim 16, wherein the material is a plastic or a bioplastic.

33. The mesh bag according to claim 30 wherein the ancillary closing element is made of a single piece of plastic or bioplastic material and configured in the shape of a clamp with two arms which, when brought together, cooperate to close by flattening the longitudinal collected portion of the bag located between the arms, the arms being bonded by a proximal end to a connecting bridge and the arms having at their distal end complementary retention elements for retention by mutual latching when the arms come together.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIGS. 1 and 2 show graphically and realistically, respectively, the result of implementing the method according to the invention, using as an ancillary closing element a particular clip, which is clamp-shaped;

[0043] FIG. 3 schematically illustrates the direction that a bulge formed by the union of packed yarns of the mesh bundle on a second side of the ancillary closing element can follow with respect to a general direction adopted by the transversely collected portion of the mesh bag captured by the ancillary closing element, the particular clip in the example; and

[0044] FIGS. 4 and 5 realistically show the result of implementing the method according to the invention, using an adhesive tape and a metal strap as ancillary closing elements, respectively.

DETAILED DESCRIPTION OF THE INVENTION

[0045] The invention is exemplified in FIGS. 1 and 2 with an ancillary closing element 1 in the form of the particular clip 1.1 described in Utility Model ES1305762, the content of which is included by reference, therefore only briefly described herein.

[0046] The clip 1.1 is made of plastic material, is flexible and is made in a single piece.

[0047] The clip 1.1 comprises two arms 2, 3 each connected to a connecting bridge 4 by means of a respective lightened portion of material 4.1, each determining a respective joint.

[0048] This particular configuration, based on two joints, one for each arm 2, 3, helps to better control the bending deformation of the material from which the clip 1.1 is made when the arms 2, 3 of the clip are suddenly pushed closer together, specifically to move the same from an open position that they adopt by default to the closed position shown in FIG. 1.

[0049] The arms 2, 3 of the clip 1.1, in a conventional manner, have respective compression means which, when the arms 2, 3 are brought together, will cooperate to close by flattening a longitudinal collected portion from the mesh bag arranged between said arms; the arms 2, 3 being also provided, at their distal end, with respective complementary retention elements suitable for their mutual latching when the arms 2, 3 are brought together and the clip 1.1 is arranged in the closed position, avoiding its accidental or unwanted opening.

[0050] The bag 100 is a mesh bag made of the same or similar plastic as the clip 1.1. Therefore, the set formed by the bag and the clip can be disposed of in the same selective collection container. In other words, it is not necessary to remove the clip from the bag to dispose of each one in a corresponding container, according to the material of which the bag and the clip are made, respectively.

[0051] FIGS. 1 and 2 show graphically and realistically, respectively, the result of closing the mesh bag 100 by applying the clip 1.1 around a transversely collected portion 9 of the bag located at one end thereof, tightly girdling the same, thereby determining on a first side of the clip 1.1 a storage portion 100a of the bag, which is only partially shown, and on a second side of the clip 1.1, adjacent thereto, a tail of the bag formed by a mesh bundle 100b, all following the method according to the invention comprising the operation of bonding packed yarns of said mesh bundle 100b together to form at least one bulge 20 that acts as a retainer, which prevents by abutment with the clip 1.1 the entire tail of the bag from passing from the second side to the first side of said clip 1.1.

[0052] The contribution of the operation of bonding the packed yarns of the mesh bundle 100b together for improving the retention of the ancillary closing element 1, in this example constituted by the clip 1.1, and preventing the unwanted opening of the mesh bag, is verified by carrying out tests on market mesh bags, specifically on tubular bags, following a test protocol using self-manufactured equipment, which simulates the handling of a bag by the consumer.

[0053] Essentially, said test protocol consists of holding the tested bags closed with the clip 1.1 by their bottom and in an inverted position, holding them with a clamp that is hung or connected to a vertical cylinder with variable pressure regulation that exerts a succession of pulls at different pressures. The cylinder contracts and expands every two seconds, increasing the pressure by half a bar every five pulls, with the succession of pulls beginning at a pressure of 1.5 bar. When the contents of the bag fall out due to the opening of the bag, the number of pulls made so far is noted down.

[0054] The following is a non-limiting example of the number of pulls/cycles that the tested mesh bags withstood, with content distributed in the form of discrete balls, simulating fruit or vegetables, closed with a clip 1.1 similar to that in FIG. 1 and sized according to z=4 mm; y=16 mm; and x=9.2 mm, without breaking/opening, the clip being mainly made of REPSOL ALCUDIA 5703L HDPE material.

[0055] In all cases, the operation of bonding packed yarns of the mesh bundle together has been carried out using a tool with a single active head, specifically a hot head with a rectangular attack surface having 12 mm2.5 mm size, applied under pressure on one side of the tail of the bag formed by the mesh bundle to be molten and bonding packed yarns of the mesh bundle together, the results where n is the number of trials being shown; MAX is the maximum number of pulls that can be withstood before the ancillary closing element detaches; MIN is the minimum number of pulls that can be withstood before the ancillary closing element detaches; PROM is the average number of pulls withstood; and Welding time indicates, if there is a value associated with this field, the duration of the operation of bonding together packed yarns of the mesh bundle.

TABLE-US-00001 TABLE 1 Number of pulls/cycles that mesh bags withstood when tested without interposition of any external element between the ancillary closing element and the mesh; with a product content of 0.8 kg; with a head temperature of 250 C.; exerting a pressure of 0.8 kg/mm.sup.2. Welding 80-57-R4 1925 (4.5 g/ml) time 0.8 Kg (s) n MAX MIN PROM 5 9 5 7 0.3 5 60 5 32 0.4 5 64 8 31

[0056] It follows from the results in Table 1, where [0057] 80-57-R4-1925:80-yarn polyethylene (PE) mesh, 1.9 mm62.5 micron yarn, 4.5 grams per linear meter weight, 57 cm mesh tube diameter, [0058] that in all cases the operation of bonding the packed yarns of the mesh bundle together contributes by a factor of 4 to the increase in the number of pulls that the bag can withstand without opening, even when the time invested in the operation is only 0.3 s.

[0059] Similar tests were repeated with other mesh configurations, this time even with the interposition of an external elementin the form of a label tail made of PE being 12 mm wide and 600 gauge (150 microns) thick-interposed between the ancillary closing element and the mesh, wherein: [0060] 80-57-R4-2220: 80-yarn PE mesh, 2.2 mm50 micron yarn, 3.7 grams per linear meter weight, 57 cm mesh tube diameter. [0061] 92-57-R4-1925: 92-yarn PE mesh, 1.9 mm62.5 micron yarn, 5.2 grams per linear meter weight, 57 cm mesh tube diameter. [0062] 104-57-R4-1920: 104-yarn PE mesh, 1.9 mm50 micron yarn, 4.8 grams per linear meter weight, 57 cm mesh tube diameter. [0063] 72-57-R4-1925: 72-yarn PE mesh, 1.9 mm62.5 micron yarn, 4.2 grams per linear meter weight, 57 cm mesh tube diameter.

TABLE-US-00002 TABLE 2 Number of pulls/cycles that mesh bags withstood when tested according to the mesh type and with interposition of a label tail between the ancillary closing element and the mesh; with a product content of 0.8 kg; with a head temperature of 250 C.; exerting a pressure of 0.8 kg/mm.sup.2. 80-57-R4 1925 (4.5 g/ml) 80-57-R4-2220 (3.7 g/ml) Welding 0.8 Kg 0.8 Kg time (s) n MAX MIN PROM n MAX MIN PROM 4 8 4 6 3 5 3 4 0.2 4 11 8 10 4 8 5 6 0.3 4 20 14 17 4 15 12 14 0.4 4 18 9 13 4 18 11 15 92-57-R4-1925 (5.2 g/ml) 104-57-R4-1920 (4.8 g/ml) Welding 0.8 Kg 0.8 Kg time (s) n MAX MIN PROM n MAX MIN PROM 4 7 5 7 3 7 5 6 0.2 4 12 8 10 4 12 8 10 0.3 4 12 9 11 4 18 9 12 0.4 4 24 12 18 5 59 12 33 72-57-R4-1925 (4.2 g/ml) Welding 0.8 Kg time (s) n MAX MIN PROM 4 4 4 4 0.2 4 9 5 7 0.3 4 10 8 9 0.4 4 10 6 9

[0064] It is clear from the results in Table 2 that in all cases the operation of bonding packed yarns of the mesh bundle together contributes to an increase in the number of pulls that the bag can withstand without opening, even when the time spent on the operation is only 0.2 s.

TABLE-US-00003 TABLE 3 Number of pulls/cycles that mesh bags withstood when tested according to the mesh type and with interposition of a label tail between the ancillary closing element and the mesh; with a product content of 0.8 kg; with a head temperature of 250 C.; exerting a pressure of 0.2 kg/mm.sup.2. 80-57-R4 1925 (4.5 g/ml) 80-57-R4-2220 (3.7 g/ml) Welding 0.8 Kg 0.8 Kg time (s) n MAX MIN PROM n MAX MIN PROM 0.2 4 10 8 9 4 10 7 9 0.3 4 13 8 11 4 11 6 8 0.4 4 13 9 12 4 11 9 11 92-57-R4-1925 (5.2 g/ml) 104-57-R4-1920 (4.8 g/ml) Welding 0.8 Kg 0.8 Kg time (s) n MAX MIN PROM n MAX MIN PROM 0.2 4 11 8 10 4 11 8 9 0.3 4 13 10 12 4 13 8 11 0.4 4 14 10 12 4 10 8 9

[0065] It can be seen from the results in Table 3 that in all cases the operation of bonding packed yarns of the mesh bundle together continues to contribute to an increase in the number of pulls that the bag can withstand without opening, even when the pressure exerted on the mesh bundle is reduced to 0.2 Kg/mm, which in practice means bonding together only a portion of the packed yarns of the aforementioned mesh bundle.

[0066] The bulge 20 formed by the bonding of packed yarns of the mesh bundle becomes a more or less compact mass or body that aggregates or gathers material from several yarns, which is not necessarily an elevation on the surface of the bundle and which can, therefore, be an internal bulge.

[0067] When the method according to the invention is carried out by selecting a conventional metal strap or adhesive tape for the ancillary closing element, the formation of a bulge or bulges by bonding packed yarns of the mesh bundle also improves the retention capacity.

[0068] FIGS. 4 and 5 realistically show the result of implementing the method according to the invention, using as ancillary closing element 1 an adhesive tape 1.2 and a metal strap 1.3, respectively. In both cases, the same tools and conditions were used to ensure that the bonding of packed yarns of the tail of the bag formed by the mesh bundle together as described above in relation to the tests in Tables 1 to 3.

[0069] It can be observed in FIGS. 2, 4 and 5 the characteristic notch produced in the mesh bundle using a single active head as a tool, in the case of the examples a hot head that bonds yarns of the mesh bundle, specifically by melting the material of which said yarns are made, applied to one side of said bundle, the head having a width dimension that exceeds the width dimension of the mesh bundle.

[0070] It can also be observed in FIGS. 2, 4 and 5 that, the transversely collected mesh portion being partially surrounded by an external element, specifically a label tail, the head has been applied to the side of the mesh bundle coinciding with the lateral area of the bundle that is not surrounded by the label tail. In this way, the temperature of the head is transmitted directly to the yarns of the mesh bundle, without physical interposition of the label tail that partially surrounds said mesh bundle.

[0071] It is also observed, especially in FIGS. 2 and 4, the result of using an active head configured and/or positioned with respect to the mesh bundle such that the bulge 20 formed is transverse to the mesh bundle and in an angle direction a with respect to the general direction adopted by the collected portion of mesh imprisoned by the ancillary closing element 1, all as intended to be schematically illustrated in FIG. 3. In the exemplary embodiments illustrated, this angle is approximately 90.