WO2007057745A2

WO2007057745A2 - Holding tray of paper material and its manufacturing process

Info

Publication number: WO2007057745A2
Application number: PCT/IB2006/003211
Authority: WO
Inventors: Gianmario Anghileri
Original assignee: Novacart S.P.A.
Priority date: 2005-11-15
Filing date: 2006-11-14
Publication date: 2007-05-24
Also published as: WO2007057745A3; ITMI20052178A1

Abstract

It is disclosed a holding tray of paper material, in particular for foodstuffs, comprising a bottom wall (2) and side walls (3, 4) delimiting a holding space (5) . The side walls (3, 4) comprise a first pair (3) of mutually opposite side walls provided with end flaps (6) overlapping a second pair (4) of side walls and joined thereto. The tray further comprises angular reinforcing elements (12) externally applied to angular junction regions (7) of the tray (1) .

Description

HOLDING TRAY OF PAPER MATERIAL AND ITS MANUFACTURING PROCESS

The present invention relates to a holding tray of paper material and to its manufacturing process.

It is known that holding trays for foodstuffs made of laminar paper material, usually thin paperboard coated on a face thereof with a film of plastic material for food, polyethylene for example, are generally obtained starting from a single portion of said paper material conveniently shaped by a cutting-out operation carried out at a suitable contour line, and subsequently submitted to folding along appropriate lines adapted to define the different parts of which the trays are made.

More specifically, the folding lines delimit a bottom wall usually of substantially rectangular shape, four side walls and four angular junction regions interposed between said side walls and each made up of two portions disposed side by side that are then to be superposed and folded against the outer surface of an adjacent side wall.

Said side wall belongs to a pair of opposite side walls provided, at their upper part, with respective end tabs adapted to be turned up too against the outer surface of the same walls. Said end tabs are to be disposed upon border bands of the above mentioned angular regions to lock the latter against said pair of opposite side walls.

Practically, in the known art a certain amount of adhesive material is used to obtain steady engagement of the end tabs with the outer surface of the corresponding side walls and consequently keep the angular regions too fastened against said outer surface thus giving the tray the required structural solidity.

The known art briefly described above has some limits and drawbacks.

First of all, it is to be pointed out that the trays of known type can sometimes have problems in terms of structural yielding at the weakest regions, i.e. at the angular junction regions. In fact, at said regions the material is pre-deformed to a greater degree and submitted to important mechanical stresses when the tray is manipulated.

In addition, the trays of the described type are filled with liquid or semi-liquid products designed to be submitted to cooking or, once the finished product has been obtained, to be possibly submitted to a conservation step through freezing.

In both the above described situations, the material of which the tray is made can get wet and therefore it generally sags exactly at the structurally weakest regions.

Under this situation, the technical task underlying the present invention is to conceive a holding tray of paper material for foodstuffs and a process for manufacturing said tray which are capable of substantially obviating the mentioned drawbacks.

Within the scope of this technical task it is an important aim of the invention to conceive a holding tray that • has a high structural solidity remaining unchanged over time.

The technical task mentioned and the aims specified are substantially achieved by a holding tray of paper material and a process for manufacturing said tray that are characterised in that they comprise one or more of the technical solutions hereinafter claimed.

Description of a preferred but not exclusive embodiment of a holding tray made of paper material in accordance with the invention is now given hereinafter by way of non-limiting example, and illustrated in the accompanying drawings, in which:

- Fig. 1 is a perspective view of a tray in accordance with the invention;

- Fig. 2 shows a detail of the tray seen in Fig. 1 with some parts removed so that others may be rendered more prominent; and

- Fig. 3 is a top view of the blank from which the tray seen in Fig. 1 is obtained.

With reference to the drawings, a holding tray of paper material in accordance with the invention is generally identified with reference numeral 1.

Tray 1 (Fig. 1) comprises a bottom wall 2, preferably but not exclusively of rectangular shape. Connected to the bottom wall 2 are four side walls 3, 4 confining a holding space 5 designed to receive a liquid or semi- liquid material.

The side walls 3, 4 are inclined to the bottom wall 2 according to an inclination greater than 90° so as to give the tray a flaring shape. In particular, for convenience, a first pair 3 of opposite side walls is defined to be connected to the major sides of the bottom wall 2 and a second pair 4 of opposite side walls is defined to be connected to the minor sides of said bottom wall 2.

In more detail, end flaps 6 are present at the extremities of the first pair 3 of side walls. Said flaps are designed to be folded over against the outer surface 4a of the second pair 4 of side walls and possibly joined to the latter by means of adhesive. In this way angular junction regions 7 are defined between adjacent walls. The end flaps 6 are of substantially triangular shape and are folded over relative to the first pair 3 of walls in such a manner as to ensure correct inclination of the side walls 3, 4 relative to the bottom wall 2.

In addition, stiffening flaps 8 are connected along the upper edges 3a of the first pair 3 of side walls. The latter protrude from the first pair 3 of side walls away therefrom and are formed by a flattened double folding of upper flaps 9 projecting from the first pair

3 of walls. A respective strip (not shown) of stiff paper material can be interposed between an upper side

8a and a lower side 8b of the stiffening flaps 8 to increase stiffness of said flaps 8.

The tray further comprises laminar reinforcing elements 10 at least located on the outer surface 3b of the first pair 3 of side walls. In the embodiment shown, the laminar reinforcing elements 10 are positioned close to the upper edge of the first pair 3 of side walls. In detail, the laminar reinforcing elements 10 positioned along the first pair 3 of side walls are obtained by suitable continuations of the extensions constituting the stiffening flaps 8.

Laminar reinforcing elements 10 are therefore superposed on the first pair 3 of side walls and are maintained in contact with the latter by use of adhesive material for example.

The laminar reinforcing elements 10 (Fig. 2) are further located along the upper edges 4b of the second pair of said walls 4 and are obtained from the upper projecting flaps 11 of the latter. These elements 10 are folded over to overlap the second pair 4 of side walls and partially the end flaps 6. In fact, formation of the laminar reinforcing elements 10 of the second pair 4 of side walls takes place after overlapping and gluing of the end flaps 6 onto the outer surface 4a of said second pair 4 of side walls.

Finally, angular reinforcing elements 12 (Fig. 2) are present on said angular junction regions 7 close to the respective upper ends 7a. These angular reinforcing elements 12 preferably consist of extensions of the laminar reinforcing elements 10 of the first 3 or second 4 pair of side walls and are superposed on and glued to the end flaps 6. In the described embodiment, the angular reinforcing elements 12 are e-xtensions of the laminar elements 10 of the first pair 3 of side walls. When the tray 1 is fully made, the laminar reinforcing elements 10 of the second pair 4 partially overlap the angular reinforcing elements 12.

The tray 1 is manufactured starting from a single blank

13 (Fig. 3) of laminar material, that can be submitted at least partly to plastic deformation, such as thin paperboard, - coated on one side thereof with an impermeable plastic material for food, such as polyethylene. The blank is delimited by a contour line 14 and comprises a central panel 15. Said central panel defines the bottom wall 2 of tray 1.

The central panel 1 preferably but not exclusively has a rectangular shape and is connected along its major sides to major side panels 16 by respective weakening lines 17. The major side panels 16 are substantially of trapezoidal shape in which the lower bases are coincident with the respective weakening lines 17. The major side panels 16 constitute the first pair 3 of side walls of tray 1. Minor side panels 18 are connected along the minor sides of the central panel 15 by a further respective weakening line 19. The minor side panels 18 are of substantially trapezoidal shape the lower bases of which are coincident with the respective weakening lines 19. The minor side panels 18 constitute the second pair 4 of side walls of tray 1.

Wings 20 of substantially triangular shape and defined by suitable folding lines 21 are present at the ends of the major side panels 16. Said wings 20 are separated from the minor side panels 18 by respective cuts 22, and they constitute the end flaps 6 of tray 1, being designed to be superposed on and glued to the minor side panels 18.

A first 24 and a second 25 strip defined by a folding line 23 and separated from each other by a suitable weakening line 26 are present along each major side panel 16. In tray 1 the first strip 24 is superposed on and glued to the second strip 25, forming the upper side 8a and lower side 8b respectively of said _ -j

stiffening flaps 8.

Formed along each second strip 25 is a band 27 defined by a respective folding line 28. These bands 27 correspond to said laminar reinforcing elements 10 of the first pair 3 of side walls.

Defined at the ends of each band 27 by respective folding lines 30 are tailpieces 29. Said tailpieces 29 are designed to be superposed on and glued to said wings 20 during formation of tray 1 and they correspond to said angular reinforcing elements 12.

Defined along each minor side panel 18 is a respective strip 31 delimited by a respective weakening line 32. Each strip 31 is designed to be folded over and glued onto the respective minor side panel 18 to define the laminar reinforcing elements 10 of the second pair 4 of side walls in tray 1.

The invention puts into practice a new process which also is an integral part of the present patent.

The process comprises the step of obtaining said blank 13 by a cutting-out operation carried out along the contour line 14 of a portion of paper material that can be at least partly submitted to plastic deformation.

Then the blank 13 is such folded as to obtain the tray 1 comprising said bottom wall 2, side walls 3, 4 and angular junction regions 7.

In particular, with reference to blank 13, each major side panel 16 is folded along the respective weakening line 17 for formation of the first pair 3 of side walls, while for formation of the second pair 4, folding of each minor side panel 18 along the respective weakening line 19 is carried out.

Then the end flaps 6 are folded over against the outer surface 4a of the second pair 4 of side walls and gluing of said flaps thereto is carried out. In detail, each wing 20 is folded relative to the respective folding line 21 to be superposed on and glued to each adjacent minor side panel 18.

To make the laminar reinforcing elements 10, the upper flaps 9, 11 projecting from walls 3, 4 are turned up against the outer surfaces 3b, 4a of said walls and are then fastened thereto by means of an adhesive material. This operation also involves the step of forming a flattened double folding so as to form the stiffening flaps 8.

In fact, the stiffening flaps 8 are obtained by folding each second strip 25 around the weakening line 26 separating each second strip 25 from each first strip 24. In this way, each second strip 25 overlaps each first strip 24 and each band 27 overlaps each major side panel 16, also forming the laminar reinforcing elements 10 of the first pair 3 of side walls. This configuration is fixed by application of adhesive material between the folded portions.

Formation of the angular reinforcing elements 12 takes place by folding the tailpieces 29 of the laminar reinforcing elements 10 of the first sidewall pair 3 against the angular regions 7. A step of gluing the tailpieces 29 to the angular regions 7, in particular onto the wings 20 of blank 13 is provided. The invention achieves important advantages.

In fact, tray 1 is provided with greatly improved features of structural solidity, above all at the points of more marked weakness, i.e. the angular junction regions 7. Application of the angular reinforcing elements 12 allows the sturdiness of the angular junction regions 7 to be increased. Therefore tray 1 is for example adapted to withstand introduction of liquid or semi-liquid material involving increased mechanical stresses, without sagging of the angular regions 7.

In addition, introduction of the angular reinforcing elements 12 does not make the manufacturing process for said tray 1 heavier. In fact, no specific operating step is required but it is sufficient to modify the blank shape by providing said tailpieces 29 and to carry out fastening of the latter to the respective wings 20.

Claims

C L A I M S

1. A holding tray of paper material, in particular for foodstuffs, comprising a bottom wall (2) and side walls (3, 4) that together with said bottom wall (2), delimit a holding space (5); the side walls (3, 4) comprising a first pair (3) of mutually opposite side walls having end flaps (6) superposed on and joined to a second pair (4) of mutually opposite side walls; characterised in that it further comprises angular reinforcing elements (12) externally applied to angular junction regions (7) of said tray (1) defined by said side walls (3, 4) .

2. A tray as claimed in claim 1, characterised in that the angular reinforcing elements (12) are applied close to upper ends (7a) of the angular junction regions (7).

3. A tray as claimed in claim 1 or 2, characterised in that it further comprises laminar reinforcing elements

(10) also applied along at least the first (3) or the second (4) pair of side walls.

4. A tray as claimed in claim 1 or 2, characterised in that it further comprises laminar reinforcing elements

(10) also applied along the first (3) and the second (4) pairs of side walls.

5. A tray as claimed in anyone of claims 1 to 4, characterised in that it further comprises stiffening flaps (8) extending away from upper edges (3a) of the first pair of side walls (3) .

6. A tray as claimed in claim 3 or 4, characterised in that the angular reinforcing elements (12) externally applied to the angular junction regions (7) are an extension of the laminar reinforcing elements (10) applied to the first pair of side walls (3) .

7. A tray as claimed in claim 5, characterised in that the stiffening flaps (8) are defined by a flattened double folding of upper projecting flaps of the first pair (3) of side walls.

8. A tray as claimed in claim 5, characterised in that each of the laminar reinforcing elements (10) disposed along the first pair (3) of side walls extends without interruption from the respective stiffening flap (8).

9. A tray as claimed in claim 6, characterised in that the angular reinforcing elements (12) externally applied to the angular junction regions (7) partly lie under the laminar reinforcing elements (10) of the second pair (4) of side walls.

10. A process for manufacturing a holding tray of paper material, comprising the steps of:

- cutting out a single blank (13) of laminar material along a contour line (14), which blank can be at least partially subjected to plastic deformation;

- folding said blank (13) of laminar material along folding or weakening lines (17, 19, 21, 23, 26, 28, 30, 31) adapted to form a tray (1) having a bottom wall (2), at least four side walls (3, 4) and at least four angular junction regions (7) interposed between said side walls (3, 4) ;

- folding over end flaps (6) of a first pair (3) of side walls against an outer surface (4a) of a second pair (4) of adjacent side walls and join said end flaps (6) to the respective outer surface (4a); and - turning up upper projecting flaps (9, 11) of the side walls (3, 4) against outer surfaces of said side walls (3b, 4a) and join them to said outer surfaces to form laminar reinforcing elements (10); characterised in that it further comprises the step of folding tailpieces (29) of the laminar reinforcing elements (10) against the angular junction regions (7) and join said tailpieces (29) to the angular junction regions (7) to form angular reinforcing elements (12) of said angular regions (7) .

11. A process as claimed in claim 10, characterised in that the step of folding tailpieces (29) of the laminar reinforcing elements (10) is carried out by folding the tailpieces (29) of the laminar reinforcing elements (10) of the first pair (3) of side walls.

12. A process as claimed in claim 11, characterised in that the upper projecting flaps (11) of the second pair (4) of side walls are partly superposed on the angular reinforcing elements (12) of the angular regions (7) .

13. A process as claimed in claim 10, characterised in that the step of turning up the upper projecting flaps (9, 11) of the side walls (3, 4) against the outer surfaces (3b, 4a) of said side walls further comprises the step of forming a flattened double folding of the upper projecting flaps of the first pair (3) of said walls and obtaining stiffening flaps (8) extending away from the upper edges (3a, 4b) of the side walls (3, 4) of the tray (1) .