DESCRIPTION

[0001] The present invention relates to the field of flexible bags with a spout, usually called "spouted pouches", and in particular to the field of methods of filling said flexible bags with liquid or semi-dense products, for example fruit juices, yoghurt, fruit puree and the like.

[0002] Flexible bags with spout have recently become widespread, due to the practicality of use thereof, which makes them an article particularly appreciated for children, the versatility of use for the containment of products with very different physical-chemical features and the very low cost.

[0003] To date, it is estimated that the worldwide production of flexible bags with spout is a few hundred million pieces per year.

[0004] Therefore, the filling lines of the packaging must be particularly efficient to ensure high production volumes, and reliable, to avoid production stops.

[0005] One of the most felt needs in the field of flexible bags with spout is to have a spout that can prevent the accidental leakage of the product, especially since they are widely consumed among children. [0006] For this reason, spouts have been designed provided with valve systems capable of preventing or limiting the accidental leakage of the product (no-spill systems) . An example of embodiment is described in document WO 2015/145277 by the Applicant. A further example of embodiment is described in document WO 00/30969.

[0007] Obviously, the filling of a flexible bag with spout, the spout whereof has a no-spill system inside, poses some problems. For example, the no-spill system could negatively affect filling times and therefore production volumes .

[0008] The object of the present invention is to provide a method for filling a flexible bag with a spout provided with a no-spill system which is particularly effective and reliable.

[0009] Such an object is achieved by a filling method according to claim 1. The dependent claims describe further advantageous embodiments of the invention.

[0010] The features and the advantages of the filling method according to the present invention will appear more clearly from the following description, made by way of an indicative and non-limiting example with reference to the accompanying figures, in which:

figure 1 shows a thin-body flexible bag provided with a spout; - figures 2a and 2b show the spout of the bag in figure

1;

- figure 3 shows a partially sectional view of the spout shown in figures 2a and 2b;

- figure 4 shows a plan sectional view of the spout of the preceding figures;

- figure 5 shows an enlargement of region V in figure 4; figure 6 shows the spout of the preceding figures, partially sectional, in a configuration of closing a valve;

- figure 7 shows an enlargement of region VII in figure

6;

figure 8 shows the spout in figure 6, in a configuration of opening the valve;

- figure 9 shows an enlargement of region IX in figure 8; and

- figures 10 and 11 schematically show a filling nozzle and a flexible bag to be filled according to an embodiment of the present invention.

[0011] With reference to the accompanying drawings, reference numeral 1 indicates a flexible pouch, comprising a bag 2 formed by two or more walls 4 made of flexible film, facing and joined, for example welded, along the edges, possibly with gusset side walls (gusset pouch) or with a back wall. [0012] The pouch 1 comprises a spout 6 (spouted pouch) of rigid material, sealingly applied to the bag 2. In particular, the spout 6 is typically inserted in a portion of the edge of the bag 2, usually between the side walls 4.

[0013] Preferably, the spout 6 is made as a single piece, internally hollow, of plastic material, for example of polyethylene or polypropylene, by injection molding.

[0014] The spout 6 develops substantially along a longitudinal axis Z and provides externally, in succession, a welding portion 8, an intermediate portion 10 and an end portion 12.

[0015] The welding portion 8 comprises an annular base wall 14, usually internally cylindrical and externally circular, having an inner opening 15, and a plurality of ribs 16 protruding from the outer surface of the base wall 14, arranged parallel to each other, in axial succession .

[0016] Moreover, the welding portion 8 comprises a pair of flat side tabs 18a, 18b, projecting radially outwardly from the base wall 14, arranged diametrically opposite and coplanar on an imaginary plane which contains the longitudinal axis Z.

[0017] The ribs 16 are arranged on one side and on the other of said imaginary plane, extending over the base wall 14 and up to the end of said side tabs 18a, 18b, forming a typical "boat" structure, so much so that said welding portion is often referred to as a "welding boat".

[0018] The intermediate portion 10 preferably comprises a plurality of transverse plates 20a, 20b, 20c, for example in a number of three, lying on imaginary planes orthogonal to the longitudinal axis Z, axially spaced apart from each other.

[0019] The plate 20c closest to the end portion 12 preferably carries a plurality of engagement elements 22 for engaging with a guarantee seal of a spout cap.

[0020] The end portion 12 typically has a thread 26 and a free outer surface 24.

[0021] Internally, the spout 6 is provided with at least two compartments: an inner chamber 30, accessible through the inner opening 15, and a main duct 32, accessible through the mouth portion 28 and adjacent to the inner chamber 30.

[0022] Preferably, the inner chamber 30 extends axially starting from the inner opening 15 for the whole welding portion 8 and for a part of the intermediate portion 10; the main duct 32 extends axially starting from the mouth portion 28 for the whole end portion 12 and for the remaining part of the intermediate portion 10.

[0023] In particular, the main duct 32 leads into the inner chamber 30 through a tubular tang wall 34.

[0024] Preferably, said tang wall 34 has a cylindrical circular inner side surface and a diameter smaller than the diameter of the main duct 32.

[0025] The connection between the inner side surface of the tang wall 34 and the surface of the main duct 32 is obtained from a frustoconical connecting surface 36.

[0026] On the side of the inner chamber 30, the tang wall 34 is surrounded by an annular recess 38.

[0027] Moreover, at a predefined axial distance from the free end of the tang wall 34, the inner chamber 30 has a circumferential projection 40, continuous or in segments, and preferably a connecting surface 44 of the inner chamber 30, between said circumferential projection 40 and said recess 38, is frustoconical , converging towards the recess.

[0028] According to the invention, a valve assembly 50 is provided inside the spout 6, in the inner chamber 30, at said tang wall 34.

[0029] Said valve assembly 50 comprises a valve 52, made as a single piece, preferably made of silicone, and a retaining ring 54, made as a single piece, made of plastic material, for supporting and applying the valve 52.

[0030] The valve 52 comprises an annular outer wall 60, an annular inner wall 62, radially arranged inside the outer wall 60, an intermediate wall 64, substantially lying on a plane orthogonal to the longitudinal axis Z, and a flexible membrane 66 which closes the inner wall 62.

[0031] The membrane 66 has at least one cut 68, preferably a plurality of through cuts 68 which form membrane flaps

69, normally closed (figure 7) .

[0032] The valve 52 is placed abutting against the tang wall 34; in particular, said outer wall 60 is at the tang wall 34.

[0033] Overall, the valve 52 has a concave profile on the side of the main duct 32.

[0034] In particular, the membrane 66 is flat or concave on the side facing the main duct, while preferably it has a convex profile towards the inner chamber 30.

[0035] The retaining ring 54 comprises a support portion

70, which supports the valve 52, and a tail portion 72.

[0036] The support portion 70 has internally an annular seat 74, in which the outer wall 60 of the valve 52 is inserted, and externally a radial projection 76 for the snap engagement with the circumferential projection 40 of the inner chamber 30.

[0037] In front of the radial projection 76, the support portion 70 has a concave support surface 78 to facilitate the snap engagement with the circumferential projection 40.

[0038] The axial dimensions of the valve assembly are such that said valve assembly 50 is arranged in the inner chamber 30, but outside the portion of said inner chamber 30 corresponding to the welding portion 8.

[0039] Advantageously, this allows preventing structural deformations of the valve or of the retaining ring or of both, due to the heat and to the mechanical actions that develop during the welding process of the spout to the bag.

[0040] For the assembly of the spout 6 and the valve assembly 50, the latter is inserted into the spout 6 on the side of the inner opening 15 and the valve 52 is brought in abutment with the tang wall 34.

[0041] By axially forcing the retaining ring 54, a snap engagement with the spout is implemented, and in particular between the radial projection 76 of the retaining ring 54 and the circumferential projection 40 of the inner chamber.

[0042] The valve 52, and in particular the outer wall 60, remains pinched between the tang wall 34 and the support portion 70 of the retaining ring.

[0043] Once the spout 6 is applied to the bag 2, the bag is filled through the mouth portion 28 of the main duct 32

( figures 6 to 9 ) . [0044] In particular, the filling is carried out by means of a filling nozzle, from which the product to be filled comes out, which for the entire filling step of the bag remains outside the spout.

[0045] In the prior art filling procedures, a cannula is provided which is inserted into the main duct, passes through the valve membrane, thus spreading the flaps and feeds the product directly into the bag or into the inner chamber of the spout.

[0046] Contrary to what happens in the prior art processes, the present invention provides for positioning the filling nozzle outside the spout and letting the product out of it.

[0047] The product flows into the main duct and comes into contact with the membrane 66 of the valve 52, operating an action from the outside on the latter, such as to deform the flaps 69 inwardly, so as to enter the inner chamber 30.

[0048] In other words, the membrane 66 of the valve 52 provides flaps 69 having sufficient flexibility to be deformed inwardly by the action of the product fed into the main duct.

[0049] According to a preferred embodiment, a filling machine for filling the bags with a spout described above comprises a plurality of nozzle groups 100 (figures 10 and 11), comprising a gripping body 102, which engages with the spout 6, and a nozzle 104 for dispensing the product, provided with a dispensing end 106 located inside the gripping body 102.

[0050] In particular, the gripping body 102 is provided with a straight gripping conduit 108, in which the end portion 12 of the spout 6 is partially inserted, and in particular the portion thereof corresponding to the free outer surface 24.

[0051] The gripping body 102 then internally has a collection compartment 110, which feeds the gripping conduit 108 and which houses the dispensing end 106 of the nozzle 104.

[0052] Said dispensing end 106 has a delivery port 112, normally closed, for example by a shutter 114, preferably in the form of a stem.

[0053] From the delivery port 112, arranged upstream of the mouth portion 28, the product for filling comes out.

[0054] The shutter 114 can be controlled so as to open and close the delivery port 112.

[0055] When the shutter 114 opens the delivery port 112, the product flows into the collection compartment 110, then into the gripping conduit 108 and, through the mouth portion 28, into the main conduit 32 of the spout 6 and, when the valve 52 is opened, inside of the bag 2. [0056] Innovatively, the filling method according to the present invention meets the needs of the industry, since it is particularly reliable, does not provide complex injection cannulas and therefore does not put the integrity of the valve at risk, which could be damaged by insertion of the cannula according to the prior art.

[0057] It is clear that a man skilled in the art can make changes to the filling method described above.

[0058] For example, according to a variant embodiment, the nozzle partially penetrates into the main duct of the spout, so that the delivery port 112 is located in the main duct 32, upstream of the valve 52, without passing therethrough .

[0059] Also such variants are included within the scope as defined by the following claims.