FR2704204A1 - Flan, blank cutting method, and tray made of corrugated sheet. - Google Patents

Abstract

The invention relates to a blank (1) made from a corrugated cardboard sheet for producing a tray (16) with cut corners, a method for cutting such a blank and a tray made from such a blank. The sidewall comprising a series of nine flaps connected to each other by first fold lines (2 'to 9'), namely four main flaps (3, 5, 7, 9) identical two by two, three intermediate flaps ( 4, 6, 8) separating said main flaps two by two, and two end flaps (2, 10), one of which (10) forming a fixing tab. The first fold lines (2 'to 9') converge, the main flaps (3, 5, 7, 9) forming isosceles trapezoids.

Description

FLAN, METHOD OF CUTTING FLAN, AND TRAY IN

CORRUGATED CARTON SHEET

  The present invention relates to a blank and a method for cutting a blank of corrugated cardboard sheet or the like for the production of a tray with cut corners, of the type comprising a series of nine shutters connected to each other by

first folding lines.

  It also relates to a tray obtained

with such a flan.

  It finds a particularly important but not exclusive application in the field of vegetable packaging or fragile fruits such as

  mushrooms or red fruits.

  There are currently known flat cardboard trays, for example strawberry trays, manufactured in the form of a basket. These trays are not feasible easily, are fragile and

  poorly protect their contents from external shocks.

  There are also plastic trays, stronger, but are significantly more expensive and are not otherwise biodegradable. Also known (FR-A-2665137) boxes with cut corners of corrugated sheet material made from a blank of the type defined above. These boxes, primarily designed to have a lid, are parallelepipedic shape. They are therefore not

  stackable in each other.

  The present invention aims to provide a blank, a cutting process and a tray for red fruits, mushrooms and other fragile fruits or vegetables better than those previously known to the requirements of the practice, in particular in that it allows the easy manufacture of robust, low-cost trays, which can be stacked one inside the other, for example to

be stored before filling.

  For this purpose, the invention essentially proposes a corrugated sheet blank for the production of a cut-corner container, comprising a series of nine components connected to each other by first folding lines, namely four identical main components. two to two, three intermediate flaps separating said two main flaps two, and two end flaps, one forming a fastening tab, each main flap having a flap connected to an edge of said main flap, said lower edge, by a second folding line, to form the bottom of the box, the intermediate flaps and the end flaps being devoid of flaps, said intermediate flaps and at least one end flap being adapted to form the cut corners of said box to be produced, characterized in that the first fold lines are convergent, the main shutters

forming isosceles trapezoids.

  Such an arrangement thus allows and in particular the stacking of trays obtained with

  such blanks in one another.

  In advantageous embodiments, one and / or the other of the following provisions is also used: the respective lateral edges and opposite two adjacent flaps are in contact with each other; other for part of their length when the blank is in a developed position; - The flaps of two of said main flaps are identical and each have and respectively two side edges comprising a first portion biased outwardly from the second fold lines and a second part

  perpendicular to said fold lines.

  These features include the non-obvious advantages of optimizing the use of cardboard for the constitution of a reinforced bottom; - the intermediate and end flaps

  have a hollow bottom edge.

  Such an arrangement, which may in particular seem to weaken the tray to be made in its lower part, allows a folding much easier; the identical flaps are of transverse dimension equal to half the transverse dimension of the bottom of the tray; - The second fold lines are arranged to allow the formation of the bottom by folding said identical flaps above the flaps of the other two main flaps; the first portions, at an angle, of said lateral edges form an angle of 45 with respect to the corresponding fold line, and extend over a length equal to the length of the base

  horyzontale lower intermediate flaps.

  Such an arrangement has the advantage of allowing the formation of the bottom of the tray without vacuum to the right of the cut corners; - The second fold lines are arranged in the direction substantially parallel to the corrugated corrugations; - The upper edges of two identical main flaps have a portion projecting from the upper edge of the intermediate flaps or adjacent end; the angle formed by the first two fold lines of each shutter is between about 2 and about 15, and is preferably

the order of 5.

  The invention also proposes a method for cutting identical blanks in a sheet or strip of corrugated cardboard, characterized in that the flap and flap suites corresponding to each blank are cut by punching along parallel broken lines substantially forming a blank. arc of circle with a large radius of curvature, the upper edges of the flaps of a blank remaining in contact with the lower edges of the flaps of the preceding blank, - between two parallel adjacent blanks, a first portion of cardboard in the form of a symmetrical slot is hollowed out; relative to a line, to constitute on one side the upper edges of a main flap symmetrical with respect to said line, and the upper edges of the two adjacent intermediate flaps, and on the other side the lower edge of the flap corresponding to said flap main symmetrical with respect to said right of the next blank and a portion of the lower edges of the flaps adjacent to said corr flap In the lower part of each of the intermediate and end flaps, a second portion of cardboard is hollowed out to form the lower edges of the said intermediate and end flaps and the lateral edges, at an angle towards the outside, of the flaps of two. main flaps, the blank edges of the flaps of a blank facing each other are cut for each blank, said flap lateral edges remaining in contact, and the blanks are formed for each blank;

  second fold lines between flaps and flaps.

  Such features allow the cutting of the blanks according to the invention, which are then, surprisingly, particularly easy to bend and despite the problems related to

  direction of the corrugated corrugations.

  By large radius of curvature must include a radius of between 30 cm

and of the order of 150 cm.

  Advantageously, the method is further characterized in that two rows of blanks arranged next to each other, turned 180 relative to one another, the outer lateral edges of the shutters end of the blanks of a row being in contact after cutting with the outer side edges of the opposite end flaps of the blanks of the other row arranged head to tail, and - one recesses on either side of the upper and lower side edges said adjacent end flaps of each pair of blanks respectively belonging to the rows arranged head to tail, two identical cardboard portions arranged symmetrically to form the lower and upper edges of said end flaps and the outer lateral edges of the flaps of the main flaps

  adjacent to said end flaps.

  Thanks to such provisions an optimization not obvious a priori of the use of sheets

corrugated cardboard is possible.

  The invention also proposes a container obtained with a blank as described above, in the form of a truncated pyramid, having four main lateral faces, two by two identical and interconnected by four secondary faces forming cut corners, one of said faces. secondary members comprising at least in part a double thickness of cardboard for adhesive bonding, and a bottom consisting of four flaps respectively connected to said main lateral faces by fold lines, called second fold lines, characterized in that the lateral faces

  The main ones form isosceles trapezoids.

  In an advantageous embodiment, one and / or the other of the following provisions is also used: the second fold lines are arranged in the direction substantially parallel to the corrugated corrugations; the respective outer edges of two opposite flaps belonging to two main lateral faces facing each other, are parallel to the second fold lines of said lateral faces and are in contact with each other; - The secondary side faces have a lower edge devoid of flap shaped or substantially shaped semicircle or half-circle portion whose radius of curvature is directed outwardly from said secondary side faces; the respective upper edges of two identical main lateral faces each have a portion projecting from the upper edge of the adjacent secondary faces; the angle of the isosceles trapezoids of the lateral faces, between the lower base and a lateral side, is between 92 and 105, and preferably from

the order of 950.

  The invention will be better understood on reading the following embodiments given as a

non-limiting examples.

  The description refers to the drawings which

  accompany it in which: - Figure 1 is a plan view of a blank according to the embodiment of the invention more

particularly described here.

  FIG. 2 is a perspective view of a

  container made from the blank of FIG.

  FIG. 3 is a diagrammatic plan view of a sheet of corrugated cardboard cut according to a method of

  performing the cutting process of the invention.

  FIGS. 4 and 5 are views on a larger scale of FIG. 3 showing the cardboard parts hollowed out between two blanks and between two

rows of blanks.

  - Figure 6 is a view on a larger scale of a cutting variant according to the invention showing the cardboard parts recessed between two rows of blanks. FIG. 1 shows a blank 1 made of corrugated cardboard, for example 2 mm thick, according to a method of

embodiment of the invention.

  The blank comprises a series of nine shutters 2, 3, 4, 5, 6, 7, 8, 9 and 10 interconnected by first folding lines 2 'to 9' converging, that is to say non-parallel between them. They form two by two, that is to say two fold lines by two fold lines belonging to the same flap, an acute angle between them, for example

of 3.

  More specifically, the suite comprises four main sections 3, 5, 7 and 9, three intermediate flaps 4, 6 and 8, and two end flaps

2 and 10.

  The main flaps 3 and 7 on one side (large flaps in the embodiment more particularly described here), 5 and 9 on the other (small flaps) are identical in pairs and form isosceles trapezes whose large bases 3a, 5a, 7a and 9a constitute the upper edges of the main faces of the tray to be made from the blank 1, and the small bases 3b, 5b, 7b and 9b correspond to the lower edges of said faces and are respectively connected by the lines of folding 3 ", 5", 7 "and 9" (merged with the lower edges in the figure) with four flaps 11, 12, 13 and 14 to form the bottom of the box and

which will be detailed later.

  In the embodiment more particularly described here, the intermediate and end flaps are such that the flaps 2 and 6 on the one hand, 4, 8 and 10 on the other hand,

are the same.

  Each intermediate or end flap has an upper edge comprising a slight recess, for example 3 mm, relative to the

  top edge of an adjacent main pane.

  Thus, the upper edges 2a and 4a of the flaps 2 and 4, they have a recess 2'a and 3'a in the extension of the fold lines 2 'and 3', with respect to the upper edge 3a of the main flap 3 which , as a consequence, presents a part

  projecting from said edges 2a and 4a.

  The edges 4a, 5a and 6a are in the extension of each other and form a broken line. The edges 6a and 8a also have a recess 6'a and 7'a with respect to the edge 7a in a manner identical to the recesses of the edges 2a and 4a.

with respect to the edge 3a.

  Finally, the edges 8a and 9a are in the extension of one another, the edge 10a of the end flap 10 having against a recess 9'a relative to the edge 9a of the main flap 9 adjacent. Such provisions on the upper edges of the flaps of the blank have the effect of overhanging the upper edges 3a and 7a of the main flaps 3 and 7, which therefore have a portion projecting from the upper edges of the adjacent flaps 2,

4, 6 and 8.

  The intermediate flaps 4, 6, 8 and the end flaps 2 and 10 have for their part, and more precisely a substantially identical shape, of

contour isosceles trapezium.

  They are devoid of flaps and have recessed lower edges, respectively 4b, 6b, 8b and 2b, lob shaped portion of a circle whose ends are located at the junction of the first and second fold lines of the adjacent main flaps and whose radius of curvature is directed to the outside of the middle flap or

end concerned.

  The flaps 11, 12, 13 and 14 respectively comprise outer edges 11a, 12a, 13a and 14a and side edges 11b, 11c; 12b, 12c; 13b, 13c and 14b, 14c, the respective lateral edges and opposite two adjacent flaps being in contact with each other, for example two thirds of their length from the outer edges, when

the blank is flat.

  More specifically, in the embodiment more particularly described here, two flaps 11 and 13 corresponding to the main flaps 3 and 7 are identical, their side edges having portions 45 at an angle towards the outside, from the second fold lines over a length 1 equal to the distance between the ends of the second fold lines located opposite, on the one hand the main flap 11 or 13 and other

part of the adjacent flap 12 or 14.

  The remaining side edge portions of the non-angled flaps 11 and 13 are perpendicular to the corresponding second fold lines 3 "and 7", the outer edges 11a and 13a being respectively parallel to said second lines

Folding 3 "and 7".

  The flaps 12 and 14 have specific forms that will be detailed with reference to the cutting process. These forms are determined on the one hand by the shapes of the two other flaps and on the other hand by the cutting

simultaneous adjacent blanks.

  Finally, there are provided openings 15 in the main flaps, for example circular and arranged symmetrically with respect to the median perpendicular line of the trapezoidal flaps, to facilitate the examination of the contents of the tray,

and allow aeration.

  In the embodiment shown, the large shutters 3 and 7 have three in triangle and the small shutters 5 and 9, two on the median itself. We will now describe the tray 16

  carried out with the blank 1 with reference to FIG.

  The tray 16 has a slightly truncated conical shape with cut corners, and has four main lateral faces 17, 18, 19, 20, two by two identical constituted by the main flaps 3, 7 and 9, interconnected by four secondary faces. 21, 22, 23, 24 constituted by the intermediate flaps 4, 6, 8 and by the end flap 2, one of said faces 24 comprising at least partly a double thickness 25 of cardboard constituted by the other end flap 10 fixed on

  said end flap 2 for example by gluing.

  The tray 16 comprises a bottom 26 constituted by the four flaps 11, 12, 13 and 14 connected to the lateral faces by the second fold lines,

  as seen previously for the blank 1.

  In the embodiment more particularly described here the bottom 26 comprises two identical flaps 11 and 13 of transverse dimension d equal to half of the transverse dimension of the bottom, so that the outer edges 11a and 13a of the flaps are in contact with each other. with the other, the lateral edges of said flaps being, for their part, on the one hand in contact with the lower edges 5b and 9b of the main flaps 5 and 9 along the second fold lines 5 "and 9", and on the other hand in the extension of the oblique surface of the corresponding secondary faces, adjacent to the

main face carrying the flap.

  The other two flaps 12 and 14 are themselves folded below the two identical flaps it

  and 13, on the outer face of which they are glued.

  The above features on the flaps and their arrangement relative to each other allow to obtain a solid bottom whose inner surface is smooth, without blunt part, and occupies the whole section of the tray in

lower part of the latter.

  Figure 3 shows a sheet 27 of corrugated cardboard whose grooves are arranged parallel to the transverse direction (arrow 28) of the sheet. Two rows 30 and 50 arranged head to tail,

  blanks 31, 31 ', 31 ", etc ... and 51, 51', 51", etc.

  according to the invention are formed and cut according to the embodiment of the cutting method of

  the invention more particularly described here.

  To do this, we use a type of existing machine known in itself, flat cutting, whose constituent elements are within the reach of the skilled person to implement the method according to the invention, the blades and against parts cutting and upsetting being simply and for example adapted to new blank shapes according to the invention; Referring now also to Figures 4 and 5. To obtain the blanks of the invention is punched by cutting the flap suites 32, 32 ', etc .; 52, 52 ', etc. connected to the flaps 33, 33', etc ....; 53, 53 ', etc ... along parallel broken lines 34, 34', etc ...; 54, 54 ', etc ... substantially forming an arc of a circle whose radius of curvature 35, (35', etc ....); (55, etc ...), 55n 'is between 1m and 5m, the upper edges 36', (36 ", etc ...); 56 ', (56", etc ...) (see FIG. 4) flaps remaining in contact with the lower edges 37, (37 ', etc.) and 57, (57', etc.)

flaps of the previous flan.

  The upper edges 36, (36 ', etc.) and 56, (56', etc.) of the two adjacent rows (see FIG. 5) are tangent at the beginning and then in the extension of one another. , so as to form a

  S shape in the transverse direction 28.

  Moreover, it is also possible, for example simultaneously with the cutting operation between two adjacent parallel blanks, at a second main flap from the end, a first portion of cardboard 38, (38 ', etc ... ); 58, (58 ', etc ...) in the form of a slot symmetrical with respect to a straight line 39; 59, to constitute on one side (see Figure 4) the upper edges 40'a of the main flap 40 'symmetrical with respect to the straight line 39, and the upper edges 41'a and 42'a of two intermediate flaps 41' and 42 'adjacent to the flap 40', and on the other side the lower edge 43a of the flap 43 corresponding to the flap 40, and a portion 44a and 45a of the lateral edges of the two flaps

adjacent 44 and 45.

  At the same time, the lower part 46 is also hollowed out (46 '...); 66 (66 '...) intermediate flaps a portion of cardboard to form the lower edges 47, (47', etc ...); 67, (67 ', etc ...) of said flaps and the lateral edges of

adjacent flaps.

  It is furthermore evidenced (see FIG. 5) on either side of the upper lateral edges 48a, etc .;

  68a, etc ... and lower 48b, etc ...; 68b, etc.

  end flaps 48, 68 adjacent the two rows, two symmetrical portions 70 forming said lower and upper edges of said end flaps and the outer side edges 49c, 69c flaps 49, 69 of the adjacent main flap

to said end flaps.

  In Figure 5 the recess is entirely located above the upper edge of a main shutter. FIG. 6 shows a variant of the cutout between two rows, showing a recess 71 partially overlapping two upper flap edges, namely a main upper flap 72 and

  an intermediate upper flap 73.

  For each blank, the side edges of the flaps of the same blank situated opposite, for example in FIG. 4, the edges 44c and

  43b, 43c and 45b, etc ..., which remain in contact.

  Finally, the first and second fold lines are formed between flaps and flaps in a manner known per se, for example by compression

between a blade and a blade.

  In FIG. 4, the arrangement that allows the folding of the opposite opposite flaps 44, 45 above is also more precisely illustrated.

  of the two others of which only one is represented in 43.

  To do this, the folding lines 43 'and 44' of the flaps 43 and 44 will be intersecting at a point 73, offset by a determined distance from the point of intersection 74 between the fold line 43 'and the extension 44c of the flap 44, which makes it possible to make up the differences in levels between the fold lines of the two identical main flaps and the fold lines of the two flaps

  remaining, which must be a little lower.

  It goes without saying, and as it follows from the foregoing, the present invention is not limited to the embodiments more particularly described here. On the contrary, it embraces all the variants and especially those or: - The tray has four identical main components. - The thickness of the corrugated board is greater than 1 mm,

for example 3 mm.

  - The shape of the lower edges of the shutters

intermediaries is different.

Claims (16)

  1. Flan (1) of corrugated sheet for producing a tray (16) with cut corners, comprising a series of nine flaps connected to each other by first fold lines (2 'to 9'), that is to say four main flaps (3, 5, 7, 9) identical two by two, three intermediate flaps (4, 6, 8) separating said principal flaps two by two, and two end flaps (2, 10), of which a fastener tongue (10), each main flap having a flap (11, 12, 13, 14) connected to an edge (3b, 5b, 7b, 9b) of said main flap, said lower edge, by a second line of folding (3 ", 5", 7 ", 9"), to form the bottom (26) of the body, the intermediate flaps and the end flaps being devoid of flaps, said intermediate flaps and at least one flap of end being adapted to form the cut corners of said box to be produced, characterized in that the first fold lines (2 'to 9') are convergent, the shutters s (3, 5, 7, 9) forming isosceles trapezoids. 2. blank according to claim 1, characterized in that the respective side edges (11c, 12b, 12c, 13b, 13c, 14b) and opposite two adjacent flaps are in contact with each other when   the blank is in the developed position. 3. Flan according to any one of   preceding claims, characterized in that   the flaps (11, 13) of two of said main flaps (3, 7) are identical and each have and respectively two lateral edges (11b, 11c, 13b, 13c) comprising a first portion biased outwards from the seconds fold lines (3 ", 7"), and a second part   perpendicular to said second fold lines. 4. Flan according to any one of   preceding claims, characterized in that   the intermediate and end flaps present   a lower edge (2b, 4b, 6b, 8b, 10b) recessed.   5. blank according to claim 4, characterized in that said identical flaps (11, 13) are of transverse dimension equal to half the transverse dimension of the bottom (26) of the tray, and in that the second fold lines (3 ", 5", 7 ", 9") are arranged to allow the formation of the bottom by folding of said identical flaps above   flaps of the other two main components. 6. Flan according to any one of   preceding claims, characterized in that   the second folding lines (3 ", 5", 7 ", 9") are arranged in the direction substantially parallel to the grooves of corrugated cardboard. 7. Blank according to any one of   preceding claims, characterized in that   the upper edges (3a, 7a) of the two identical main flaps (3, 7) have a portion protruding from the upper edges (2a, 4a, 6a, 8a) of the intermediate flaps or adjacent end. 8. Blank according to any one of   preceding claims, characterized in that   the angle formed by the first two fold lines of one and the same flap is between the order of 2 and of the order of 10, and preferably of the order of 5.   9. Process for cutting blanks (31, 31 ', etc.)   51, 51 ', etc.) are identical according to any one of   of the preceding claims, in a sheet or   a strip of corrugated cardboard, characterized in that - the flap and flap suites (32, 32 ', etc ...; 52, 52', etc.) are cut out (33, 33 ', etc.). 53, 53 ', etc ...) corresponding to each blank by punching, along broken lines (34, 34', etc ...; 54, 54 ', etc ...) parallel substantially forming a circular arc large radius of curvature, the upper edges of the flaps of a blank remaining in contact with the lower edges of the flaps of the previous blank, - is hollowed between two adjacent blanks a first portion (38, 38 ', ...; 58 , 58 ', ...) of cardboard in the form of a slot symmetrical with respect to a line (39, 59), to constitute on one side the upper edges of a main flap symmetrical with respect to said straight line, and the edges upper side of the two adjacent intermediate flaps, and on the other side the lower edge of the flap corresponding to said main flap symmetrical with respect to said straight of the next blank and a portion of the inferior edges. the flaps adjacent to said corresponding flap are hollowed out at the bottom of each of the intermediate and end flaps a second portion of cardboard (70, 71) to form the lower edges of said intermediate and end flaps and the lateral edges thereof. bias towards the outside of the flaps of main flaps, - is cut for each blank side edges flaps of the same flan located opposite, said flap lateral bors remaining in contact, and - one forms for each blank the first and   second fold lines between flaps and flaps.   10. Cutting process according to claim 9, characterized in that two rows (30, 50) of blanks arranged next to one another, turned from one to the other, are cut simultaneously. outer side edges of the end flaps of the blanks of a row being in contact after cutting with the outer side edges of the opposite end flaps of the blanks of the other row arranged head to tail, and is evidenced on both sides upper and lower side edges of said adjacent end flaps of each pair of blanks respectively belonging to the rows arranged head to tail, two identical cardboard portions (70, 71) to form the lower and upper edges of said end flaps and the edges outer side of main flap flaps adjacent to said end flaps.   11. Tray (16) corrugated cardboard, having four main lateral faces (17, 18, 19, 20), two by two identical and interconnected by four side faces (21, 22, 23, 24) forming cut corners, one of said secondary faces comprising at least in part a double thickness of cardboard (25) for adhesive bonding, and a bottom (26) constituted by four flaps (11, 12, 13, 14) respectively connected to said main lateral faces by lines folding device (3 ",", 7 ", 9"), called second folding lines, characterized in that the main lateral faces (17, 18, 19, 20) form isosceles trapezoids. 12. Tray (16) according to claim 11, characterized in that the respective outer edges (11a, 13a) of two flaps belonging to two main lateral faces (11, 13) opposite are parallel to the second fold lines of said side faces and are in contact one with the other.   Tray according to claim 11, characterized in that the second fold lines (3 ", 5", 7 ", 9") are arranged in the direction substantially parallel to the corrugated corrugations. 14. Tray according to any one of   claims 11 to 13, characterized in that the   secondary lateral faces (21, 22, 23, 24) have a lower edge devoid of a flap in shape or substantially in the shape of a semi-circle or of a half-circle portion whose radius of curvature is directed towards the outside of said lateral faces secondary. 15. Tray according to any one of   Claims 11 to 14, characterized in that the   respective upper edges (3a, 7a) of two identical main lateral faces (17, 19) each have a portion slightly protruding from each other;   at the upper edge of the adjacent secondary faces.   16. Tray according to any one of   Claims 11 to 13, characterized in that   the angle of the isosceles trapezoids of the lateral faces is between 92 and 98, and preferably of the order of 95.