WRAPPING METHOD AND PACKER MACHINE TO MANUFACTURE A PACK WITH A SLIDING OPENING

Abstract

 Wrapping method and packer machine (21) to manufacture a pack (1) with a sliding opening having a tray (3), which contains at least one product (4), and a case (2), which houses, on the inside, the tray (3) in a sliding manner. It is provided to: fold a first blank (10) designed to manufacture the case (2) so as to give the first blank (10) a "U"-shaped conformation having an open upper end; fold a second blank (17) so as to manufacture the tray (3); insert the at least partially formed tray (3) into the first "U"-shaped blank (10); and complete the folding of the first blank (10) around the tray (3) previously inserted into the first "U"-shaped blank (10) so as to manufacture the case (2) already containing the tray (3).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority from Italian patent application no. 102022000006320 filed on March 31, 2022, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

[0002] The present invention relates to a wrapping method and to a packer machine to manufacture a pack with a sliding opening.

PRIOR ART

[0003] A pack with a sliding opening comprises a tray which is open at the top (namely, is devoid of upper wall) and contains a group of products and a case which is open on at least one side and houses, on the inside, the tray so that the tray can slide relative to the case between a closed position in which the tray is fully inserted into the case and an open position in which the tray is at least partially extracted from the case.

[0004] Some examples of a pack with a sliding opening are provided in patent applications JP2014136590A, JP2014136591A and JP2004231292A.

[0005] A further example of a pack with a sliding opening is provided by patent application US2021276758A1.

[0006] Generally, two separate packer machines arranged in series are used to manufacture a pack with a sliding opening: a first packer machine manufactures the trays containing the respective groups of products while a second packer machine manufactures (wraps) the cases around the trays received from the first packer machine. Consequently, the production of a pack with a sliding opening has very high fixed costs (namely, equipment expenses) as it requires the use of two different packer machines.

DESCRIPTION OF THE INVENTION

[0007] The object of the present invention is to provide a wrapping method and a packer machine to manufacture a pack with a sliding opening without the drawbacks described above and therefore allowing to reduce fixed costs (namely, equipment expenses).

[0008] According to the present invention, a wrapping method and a packer machine are provided to manufacture a pack with a sliding opening, according to what is claimed in the appended claims.

[0009] The claims describe preferred embodiments of the present invention forming an integral part of the present description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention will now be described with reference to the attached drawings, which illustrate some non-limiting embodiments thereof, wherein:

• Figure 1 is a perspective view of a pack with a sliding opening;
• Figure 2 is a partially exploded perspective view of a case of the pack with a sliding opening of Figure 1;
• Figure 3 is a plan view of a blank used to manufacture the case of Figure 2;
• Figure 4 is a perspective view of a tray of the pack with a sliding opening of Figure 1;
• Figure 5 is a plan view of a blank used to manufacture the tray of Figure 4;
• Figure 6 is a schematic view of a packer machine which manufactures the pack with a sliding opening of Figure 1;
• Figures 7-12 are a series of perspective views of corresponding manufacturing steps of the pack with a sliding opening of Figure 1;
• Figure 13 is a partially exploded perspective view of an alternative of the pack with a sliding opening of Figure 1;
• Figure 14 is a perspective view of a manufacturing step of the pack with a sliding opening of Figure 13;
• Figure 15 is a plan view of a blank used to manufacture the tray of the pack with a sliding opening of Figure 13;
• Figure 16 is a perspective view of the blank of Figure 15 partially folded on itself;
• Figure 17 is a partially exploded perspective view of a further alternative of the pack with a sliding opening of Figure 1; and
• Figure 18 is a plan view of a blank used to manufacture the tray of the pack with a sliding opening of Figure 17.

PREFERRED EMBODIMENTS OF THE INVENTION

[0011] In Figure 1, number 1 denotes, as a whole, a pack with a sliding opening comprising a case 2 which is open on at least one side and houses, on the inside, a tray 3 which is open at the top (namely, is devoid of upper wall) and contains a group of products 4 (schematically illustrated in Figure 6). By way of example, the products 4 can be food products such as capsules containing a powder for the production of beverages (typically coffee capsules) or the products 4 can be tobacco industry articles such as single doses of molasses.

[0012] The case 2 houses, on the inside, the tray 3 so that the tray can slide (lengthwise) relative to the case 2 between a closed position (illustrated in Figure 1) in which the tray 3 is completely inserted into the case 2 and an open position (not illustrated) in which the tray 3 is at least partially extracted from the case 2 to allow the products 4 contained in the tray 3 to be removed.

[0013] As illustrated in Figure 2, the case 2 has a rectangular parallelepiped shape and has a lower wall 5 and an upper wall 6 parallel and opposite to one another, two larger side walls 7 and 8 parallel and opposite to one another, and a single smaller side wall 9; on the opposite side of the smaller side wall 9, the case 2 has a through opening through which the tray 3 can be extracted. The upper wall 6 has a recess, which by way of example can have the shape of a semicircle, which is arranged in the area of the through opening and facilitates the gripping of the tray 3 contained inside the case 2.

[0014] Figure 3 illustrates a blank 10 used to manufacture the case 2; namely, the case 2 is formed by folding and gluing the blank 10.

[0015] The blank 10 sequentially comprises a panel 8' which forms the outer portion of the larger side wall 8, the upper wall 6, which is connected to the upper panel 8' along a pre-weakened longitudinal folding line, the larger side wall 7, which is connected to the upper wall 6 along a pre-weakened longitudinal folding line, the lower wall 5, which is connected to the larger side wall 7 along a pre-weakened longitudinal folding line, and a panel 8", which forms the inner part of the larger side wall 8, overlaps and is glued to the panel 8', and is connected to the lower wall 5 along a pre-weakened longitudinal folding line.

[0016] The blank 10 comprises a panel 9' which forms the outer part of the smaller side wall 7 and is connected to the upper wall 6 along a pre-weakened transverse folding line; the blank 10 comprises, furthermore, a panel 9" which forms the inner part of the smaller side wall 7, overlaps and is glued to the panel 9', and is connected to the lower wall 5 along a pre-weakened transverse folding line.

[0017] The blank 10 comprises two tabs 11 which are connected along respective pre-weakened transverse folding lines to the larger side wall 7 and to the panel 8", are folded by 90° relative to the larger side wall 7 and to the panel 8", and rest, from the inside, against the panel 9".

[0018] As illustrated in Figure 4, the tray 3 has a rectangular parallelepiped shape and has a lower wall 12, two larger side walls 13 and 14 parallel and opposite to one another, and two smaller side walls 15 and 16; on the opposite side of the lower wall 12, the tray 3 is open (that is, devoid of upper wall) and therefore has a through opening through which the products 4 contained in the tray 3 can be removed.

[0019] The smaller side wall 16 is arranged in the area of the through opening of the case 2, is box-shaped (namely, is formed by an internally hollow structure), and is elastically deformable to be gripped and pulled more easily when it is necessary to extract the tray 3 out of the case 2.

[0020] Figure 5 illustrates a blank 17 used to manufacture the tray 3; namely, tray 3 is formed by folding and gluing the blank 17.

[0021] The blank 17 sequentially comprises the larger sidewall 14, the bottom wall 12 that is connected to the larger sidewall 14 along a pre-weakened longitudinal folding line, and the larger sidewall 13 that is connected to the bottom wall 12 along a pre-weakened longitudinal folding line.

[0022] The blank 17 comprises a panel 15' which forms the outer portion of the smaller side wall 15 and is connected to the bottom wall 12 along a pre-weakened transverse folding line; the blank 10 further comprises a panel 15" which forms the inner part of the smaller side wall 15, overlaps (by means of a 180° fold) the panel 15', and is connected to the panel 15' along a pre-weakened transverse folding line. According to a preferred embodiment, the panel 15" has an appendage 18 which enters (fits) into a through slot 19 formed through the lower wall 12 (in the area of the transverse folding line provided between the panel 15' and the lower wall 12); the function of the appendage 18 is to mechanically lock the panel 15" to the lower wall 12 so as to keep the panel 15" folded against the panel 15'.

[0023] The blank 10 comprises two tabs 20 which are connected along respective pre-weakened transverse folding lines to the larger side walls 13 and 14, are folded by 90° relative to the larger side walls 13 and 14, and are arranged between the two panels 15' and 15" (namely, they are enclosed between the two panels 15' and 15").

[0024] The blank 17 comprises a panel 16' which forms the outer part of the smaller side wall 16 and is connected to the bottom wall 12 along a pre-weakened transverse folding line. The blank 10 comprises a panel 16" which forms an upper portion of the smaller side wall 16, is folded by 90° relative to the panel 16', and is connected to the panel 16' along a pre-weakened transverse folding line. The blank 17 further comprises a panel 16'", which forms the outer part of the smaller side wall 16, is folded by 90° relative to the panel 16", and is connected to the panel 16" along a pre-weakened transverse folding line. Finally, the blank 10 comprises a panel 16"", which rests against and is glued to the lower wall 12, is folded by 90° relative to the panel 16'", and is connected to the panel 16'" along a pre-weakened transverse folding line. In the tray 3, the panels 16', 16" e 16'" have a "U"-shaped conformation (namely, a portal-like shape) and are elastically deformable. In particular, the four panels 16', 16", 16'" and 16"" form an articulated quadrilateral (namely, a kinematic chain made up of four rigid members connected in pairs by means of articulation hinges) which is deformable: the panel 16" forms the connecting rod, the panel 16"" (glued to the lower wall 12) forms the frame, and the panels 16' and 16'" form the two handles.

[0025] According to an alternative embodiment of the blank 17 of Figure 5, the blank 17 is devoid of the appendage 18 (and of the slot 19) and provides for the gluing of the panel 15" to the two tabs 20 folded (and possibly glued) against panel 15' .

[0026] According to a further alternative embodiment of the blank 17 of Figure 5, the blank 17 is devoid of the appendage 18, the slot 19 and the panel 15"; it also provides for the gluing of the tabs 20 to the panel 15'.

[0027] Number 21 in Figure 6 illustrates, as a whole, a packer machine which produces the pack 1 with a sliding opening.

[0028] The packer machine 21 comprises a conveyor 22 which moves with a law of intermittent motion (namely, in a step-like manner by cyclically alternating motion steps and stop steps) a plurality of pockets 23 along a linear wrapping path; typically, the conveyor 22 is of the belt (chain) type and therefore comprises (at least) a belt (chain) closed in a loop and to which the pockets 23 are fixed.

[0029] Each pocket 23 is stopped at a feeding station S1 in which a feeding device 24 inserts a corresponding blank 10 into the pocket 23, and is subsequently stopped at a feeding station S2 in which a feeding device 25 inserts into the pocket 23 (or rather in the case 2 partially formed and contained inside the pocket 23) a corresponding blank 17 which has been glued and partially pre-folded beforehand, a feeding station S3 in which a feeding device 26 inserts into the pocket 23 (or rather into the tray 3 inserted into the case 2 contained in the pocket 23) the group 4 of products, and a folding station S4 in which the folding of the blank 10 is completed (namely, the forming of the case 2 is completed) around the tray 3 containing the products 4.

[0030] According to a different embodiment not illustrated, the feeding station S2 could be incorporated with the feeding station S1, namely, the feeding device 24 could alternatively feed the blanks 10 and the blanks 17. According to a further embodiment not illustrated, the feeding station S2 could be incorporated with the feeding station S3, namely, the feeding device 26 could alternatively feed the blanks 17 and the groups of products 4. According to another embodiment not illustrated, the feeding stations S2 and S3 could be incorporated with the feeding station S1, namely, the feeding device 24 could alternatively feed the blanks 10, the blanks 17, and the groups of products 4.

[0031] The methods to manufacture a single pack 1 with a sliding opening are described in the following with reference to Figures 7-12.

[0032] Initially and as illustrated in Figure 7, in station S1 the blank 10 is folded into a "U"-shaped conformation by being inserted from above (namely, by being inserted with a movement from top to bottom and along a vertical downward path) into a corresponding pocket 23 by the feeding device 24. In other words, the feeding device 24 picks up the blank 10 with a suction head, transports the same above the pocket 23 and then inserts the blank 10 into the pocket 23 from above, thus causing the side walls 7 and 8 to fold by 90° relative to the lower wall 5 and also causing the 90° folding of the smaller side wall 9 relative to the lower wall 5. Preferably, during the transport of the blank 10 over the pocket 23, glue is applied to the panel 9" (at the areas of the panel 9'' which will overlap the tabs 11).

[0033] Beforehand, namely, before inserting the blank 10 into the pocket 23, the tabs 11 are folded (by a special folding device 27 schematically illustrated in Figure 6) by (almost) 90° relative to the larger side walls 7 and 8, so that by folding the larger side walls 7 and 8 by 90° relative to the lower wall 5, the tabs 11 rest against the panel 9" of the smaller side wall 9.

[0034] As illustrated in Figure 8, once the blank 10 has been inserted into the pocket 23, the case 2 is almost completely formed (made) lacking only the folding of the upper wall 6; therefore, the insertion of the blank 10 into the pocket 23 in the feeding station S1 causes a folding of the blank 10 (designed to form the case 2) so as to give the blank 10 a "U"-shaped conformation having an open upper end.

[0035] Once the "U"-shaped blank 10 has been inserted into the pocket 23 in the feeding station S1, the pocket 23 moves from the feeding station S1 to the feeding station S2 where the feeding device 25 feeds the blank 17.

[0036] As illustrated in Figures 9, 10 and 11, in the feeding station S2 the blank 17 (designed to form the tray 3) is folded so as to manufacture the tray 3 which is inserted at least partially formed inside the "U"-shaped blank 10. In particular, in the feeding station S2 the feeding device 25 feeds the blank 17 from top to bottom and along a vertical downward path into the "U"-shaped blank 10 (still contained in the pocket 23); along this vertical downward path the blank 17 is folded to form (at least partially) the tray 3 before the blank 17 (namely, the at least partially formed tray 3) enters the "U"-shaped blank 10.

[0037] According to a preferred embodiment, the blank 17 is made to pass through a folding profile 28 (illustrated schematically in Figure 6 and movable from and towards the feeding station S2) arranged along the vertical downward path so as to cause at least one "U"-fold of the blank 17. In particular, the folding profile 28 has the shape of a rectangular frame and is crossed from side to side by the blank 17 to determine both the 90° folding of the two larger side walls 13 and 14 of the tray 3 relative to the lower wall 12 of the tray 3, and the 90° folding of the two smaller side walls 15 and 16 of the tray 3 relative to the lower wall 12 of the tray 3 (as illustrated in Figure 10).

[0038] As previously stated, the smaller side wall 16 of the tray 3 is box-shaped, is elastically deformable, and is arranged in the area of an open end of the tray 2; preferably, the smaller box-shaped side wall 16 is made in advance by folding and gluing the blank 17 before inserting the at least partially formed tray 3 into the "U"-shaped blank 10 and then the smaller box-shaped side wall 16 is flattened before inserting the tray 3 at least partially formed inside the "U"-shaped blank 10 so as to give the blank 17 a flat shape (illustrated in Figure 9).

[0039] As previously stated, the smaller side wall 15 of the tray 3 is formed by two panels 15' and 15" overlapping one another; preferably, the overlap of the two panels 15' and 15" which form the smaller side wall 15 of the tray 3 is obtained after having inserted the only partially formed tray 3 (lacking, in fact, the completion of the smaller side wall 15) inside the "U"-shaped blank 10. Namely, only after having inserted the only partially formed tray 3 (lacking, in fact, the completion of the smaller side wall 15) inside the "U"-shaped blank 10, the panel 15" is folded by 180° relative to the panel 15', being, the same, overlapping the panel 15'. At the end of the folding of the panel 15", the appendage 18 of the panel 15" is inserted (fixed) into the slot 19 obtained through the lower wall 12 of the tray 3. In the event that the blank 17 does not comprise the appendage 18 and the slot 19, then after the blank 17 has been removed, glue is applied to the panel 15'.

[0040] In other words, the tray 3 is inserted inside the "U"-shaped blank 10 only partially formed (lacking the completion of the smaller side wall 15) and the folding of the blank 17 is completed (by folding the panel 15" by 180° relative to the panel 15') only after having inserted the only partially formed tray 3 inside the "U"-shaped blank 10.

[0041] According to a different embodiment not illustrated, the tray 3 is completely formed (namely, the folding of the blank 17 is completed) before inserting the tray 3 inside the "U"-shaped blank 10 so as not to have to perform further folding operations after tray 3 has been inserted into the "U"-shaped blank 10.

[0042] According to a preferred embodiment, along the vertical downward path (and before crossing the folding profile 28), the tabs 20 are folded (by a suitable folding device 29 illustrated schematically in Figure 6) by (almost) 90° relative to to the larger side walls 13 and 14, so that by folding the larger side walls 13 and 14 by 90° relative to the lower wall 12, the tabs 20 rest against the panel 15' of the smaller side wall 15 (before being enclosed between the two panels 15' and 15" of the smaller side wall 15).

[0043] Once in the feeding station S2 the tray 3 (formed by folding the blank 17) has been inserted inside the "U"-shaped blank 10 and contained in the pocket 23, the pocket 23 moves from the feeding station S2 to the feeding station S3, in which the feeding device 26 feeds the group of products 4. In the feeding station S3, the group of products 4 is inserted into the tray 3 which is inside the "U"-shaped blank 10 and contained in the pocket 23. Namely, the product 4 is inserted into tray 3 after having inserted tray 3 inside the "U"-shaped blank 10 contained in pocket 23 and before completing the folding of blank 10.

[0044] According to a different embodiment not illustrated, the group of products 4 is inserted into the tray 3 before inserting the tray 3 (at this point already containing the group of products 4 and therefore no longer empty) inside the "U"-shaped blank 10 contained in the pocket 23.

[0045] Once in the feeding station S3 the group of products 4 has been inserted into the tray 3 that is inside the "U"-shaped blank 10 contained in the pocket 23, the pocket 23 moves from the feeding station S3 to the folding station S4. In the folding station S4, a folding device 30 (illustrated schematically in Figure 6) completes the folding of the blank 10 around the tray 3 previously inserted into the "U"-shaped blank 10 to form the case 2 already containing the tray 3 (which obviously in turn contains the group of products 4).

[0046] As illustrated in Figure 12, in the folding station S4 (to complete the folding of the blank 10 around the tray 3 previously inserted into the "U"-shaped blank 10), the folding device 30 folds the upper wall 6 of the case 2 over the tray 3 and then fold the panel 8' by 90° against the underlying panel 8" and fold the panel 9' by 90° against the underlying panel 9"; the panels 8' and 9' (or the panels 8" and 9") are previously glued to stabilize the shape of the case 2 by gluing. Preferably, the folding device 30 has fixed folding profiles which fold the upper wall 6 of the case 2 by exploiting the forward movement of the conveyor 22 (preferably at the same time glue is applied to the panel 8'' and/or to the panel 8') and has other fixed folding profiles which fold the panels 8' and 9' by exploiting a vertical extraction movement of the pack 1 with a sliding opening from the pocket 23. For example, glue can also be applied to the panels 8" and/or 9"; said application can, for example, take place during the vertical extraction movement before the panels 8' and 9' have come into contact with the panels 8'' and 9".

[0047] In the embodiment illustrated in Figures 1-12, the tray 3 is internally "bare" (empty) as it is devoid of supports for the products 4; according to a different embodiment illustrated in Figures 13-18, the tray 3 is a supporting structure 31 for the products 4 which is preferably connected to at least one larger side wall 13 or 14 of the tray 3.

[0048] According to a preferred embodiment, the support structure 31 is formed by folding and gluing the blank 17 before inserting the at least partially formed tray 3 inside the "U"-shaped blank 10 and the support structure 31 is flattened before inserting the at least partially formed tray 3 into the "U"-shaped blank 10 so as to give the blank 17 a flat shape (as illustrated in Figure 16).

[0049] Figures 13-16 show a possible embodiment of the support structure 31, whereas Figures 17 and 18 show a different embodiment of the support structure 31.

[0050] The support structure 31 illustrated in Figures 13-16 comprises three housings 32, each configured to house a single product 4 and is obtained through an upper wall 33 (parallel to the lower wall 12 of the tray 3) divided into two distinct and side by side halves. Each half of the upper wall 33 of the support structure 31 is connected along a pre-weakened longitudinal folding line to a corresponding larger side wall 13 or 14 of the tray 3 by means of a connecting strip 34 which is folded by 90° relative to the middle of the upper wall 33 and rests against (and is preferably glued to) the corresponding larger side wall 13 or 14 of the tray 3. A connecting strip 34 is connected to the larger side wall 14 of the tray 3 along a pre-weakened longitudinal folding line. Furthermore, the support structure 31 comprises a lower wall 35 which rests against (and is preferably glued to) the lower wall 12 of the tray 3 and is connected to the two halves of the upper wall 33 by means of two connecting strips 36 folded at 90° both relative to lower wall 35, and relative to the upper wall 33.

[0051] The support structure 31 illustrated in Figures 17 and 18 is different from the support structure 31 illustrated in Figures 13-16, since in the support structure 31 illustrated in Figures 17 and 18 the upper wall 33 is formed by a single undivided piece (instead of two side by side halves) and the lower wall 35 of the tray 3 is connected to the upper wall 33 by means of a corresponding connecting strip 34 resting against (and preferably glued to) the larger side wall 13 of the tray 3.

[0052] According to a particular embodiment not illustrated, the pack 1 can comprise one (or more) sealing labels which fix the tray 3 to the case 2 before the first opening. In particular, said sealing label can be fixed (glued in a removable manner, for example with re-stick glue) to the smaller side wall 16 of the tray 3 and to the upper 6 or lower 5 wall of the case 2. In said case, upon first opening the user will have to remove the label in order to then be able to slide the tray 3 out of the case 2.

[0053] According to a further alternative embodiment not illustrated, the smaller side wall 16 of the tray 3 could be made in a similar way to the smaller side wall 15 of the tray. In said case, the wall 16 would also be a fixed and non-elastically deformable wall. In said case, the sliding of the tray 3 relative to the case would be facilitated exclusively by the recess provided on the upper wall 6 of the case 2.

[0054] The embodiments described herein can be combined with one another without departing from the scope of the present invention.

[0055] The wrapping method described above has numerous advantages.

[0056] In the first place, the wrapping method described above allows to reduce fixed costs (namely, equipment costs), since to manufacture the pack 1 with a sliding opening a single packer machine 21 is sufficient, which allows, in a small space, to fold together both a blank 10 to form a case 2, and a blank 17 to form a tray 3.

[0057] Furthermore, the wrapping method described above allows to operate at a relatively high operating speed (measured as number of packs 1 with a sliding opening per unit of time) while guaranteeing at the same time a high quality (precision) in folding the blanks 10 and 17.

[0058] Finally, by implementing the wrapping method described above, it is possible to produce a particularly compact packer machine 21.

LIST OF FIGURE REFERENCE NUMBERS

[0059] 

1

pack

2

case

3

tray

4

products

5

lower wall

6

upper wall

7

larger side wall

8

larger side wall

9

smaller side wall

10

blank

11

tab

12

lower wall

13

larger side wall

14

larger side wall

15

smaller side wall

16

smaller side wall

17

blank

18

appendage

19

slot

20

tab

21

packer machine

22

conveyor

23

pockets

24

feeding device

25

feeding device

26

feeding device

27

folding device

28

folding profile

29

folding device

30

folding device

31

support structure

32

housings

33

upper wall

34

connecting strip

35

lower wall

36

connecting strip

S1

feeding station

S2

feeding station

S3

feeding station

S4

folding station

Claims

1. A wrapping method to manufacture a pack (1) with a sliding opening comprising a tray (3), which contains at least one product (4), and a case (2), which houses, on the inside, the tray (3) in a sliding manner; the wrapping method comprises the steps of:

folding a first blank (10) designed to manufacture the case (2) so as to give the first blank (10) a "U"-shaped conformation having an open upper end; and

folding a second blank (17) designed to manufacture the tray (3) so as to manufacture the tray (3);

the wrapping method is characterized in that it comprises the further steps of:

inserting the at least partially formed tray (3) into the first "U"-shaped blank (10); and

completing the folding of the first blank (10) around the tray (3) previously inserted into the first "U"-shaped blank (10) so as to manufacture the case (2) already containing the tray (3).

2. The wrapping method according to claim 1 and comprising the further step of inserting the product (4) into the tray (3) after having inserted the tray (3) into the first "U"-shaped blank (10) and before completing the folding of the first blank (10).

3. The wrapping method according to claim 1 or 2 and comprising the further steps of:

inserting the only partially formed tray (3) into the first "U"-shaped blank (10); and

completing the folding of the second blank (17) after having inserted the only partially formed tray (3) into the first "U"-shaped blank (10).

4. The wrapping method according to claim 3, wherein:

the tray (3) has at least one smaller side wall (15) made up of two overlapping panels (15', 15"); and

the overlap of the two panels (15', 15") making up the smaller side wall (15) is obtained after having inserted the partially formed tray (3) into the first "U"-shaped blank (10) .

5. The wrapping method according to one of the claims from 1 to 4 and comprising the further step of feeding the second blank (17) into the first "U"-shaped blank (10) from the bottom to the top and along a vertical downward path.

6. The wrapping method according to claim 5 and comprising the further step of having the second blank (17) go through a folding profile (28) arranged along the downward path so as to determine at least one "U"-shaped fold of the second blank (17).

7. The wrapping method according to claim 6, wherein the folding profile (28) has the shape of a rectangular frame and the second blank (17) goes through the same from side to side in order to determine both the 90° folding of two larger side walls (13, 14) of the tray (3) relative to a lower wall (12) of the tray (3) and the 90° folding of two smaller side walls (15, 16) of the tray (3) relative to the lower wall (12) of the tray (3).

8. The wrapping method according to one of the claims from 1 to 7, wherein a smaller side wall (16) of the tray (3) is box-shaped, is elastically deformable and is arranged in the area of an open end of the tray (2).

9. The wrapping method according to claim 8 and comprising the further steps of:

manufacturing the smaller box-shaped side wall (16) by folding and gluing the second blank (17) before inserting the at least partially formed tray (3) into the first "U"-shaped blank (10);

flattening the smaller box-shaped side wall (16) before inserting the at least partially formed tray (3) into the first "U"-shaped blank (10) so as to give the second blank (17) a flat shape; and

folding the smaller box-shaped side wall (16) by 90° relative to a lower wall (12) during the insertion of the second blank (17) making up the tray (3) into the first "U"-shaped blank (10) .

10. The wrapping method according to one of the claims from 1 to 9, wherein the tray (3) comprises two larger side walls (13, 14) and a support structure (31) for the product (4) connected to at least one larger side wall (13, 14).

11. The wrapping method according to claim 10 and comprising the further steps of:

manufacturing the support structure (31) by folding and gluing the second blank (17) before inserting the at least partially formed tray (3) into the first "U"-shaped blank (10) ;

flattening the support structure (31) before inserting the at least partially formed tray (3) into the first "U"-shaped blank (10) so as to give the second blank (17) a flat shape; and

folding the support structure (31) during the insertion of the second blank (17) making up the tray (3) into the first "U"-shaped blank (10).

12. The wrapping method according to one of the claims from 1 to 11 and comprising the further step of folding the first blank (10) giving the first blank (10) a "U"-shaped conformation by folding two larger side walls (7, 8) of the case (2) by 90° relative to a lower wall (5) of the case (2) .

13. The wrapping method according to one of the claims from 1 to 12 and comprising the further step of folding the first blank (10) giving the first blank (10) a "U"-shaped conformation by inserting the first blank (10) into a pocket (23) moved by a conveyor (22).

14. The wrapping method according to one of the claims from 1 to 13 and comprising the further step of folding an upper wall (6) of the case (2) onto the tray (3) so as to complete the folding of the first blank (10) around the tray (3) previously inserted into the first "U"-shaped blank (10).

15. A packer machine (21) to manufacture a pack (1) with a sliding opening comprising a tray (3), which contains at least one product (4), and a case (2), which houses, on the inside, the tray (3) in a sliding manner; the packer machine (21) comprises:

a first folding device configured to fold a first blank (10) designed to manufacture the case (2) so as to give the first blank (10) a "U"-shaped conformation having an open upper end; and

a second folding device configured to fold a second blank (17) designed to manufacture the tray (3) so as to manufacture the tray (3);

the packer machine (21) is characterized in that it comprises:

a feeding device (25), which is configured to insert the at least partially formed tray (3) into the first "U"-shaped blank (10); and

a third folding device (30) configured to complete the folding of the first blank (10) around the tray (3) previously inserted into the first "U"-shaped blank (10) so as to manufacture the case (2) already containing the tray (3) .

Drawing