PUNCHED SHEET FOR A TRAY-LIKE PACKAGING

Abstract: The invention relates to a punched blank for a tray-like package. It comprises a bottom part (1), two long sides (2) and two short sides (3) in one piece with the bottom part (1) and marked with respect to this by fold lines. The invention is characterized in that the fold lines (7) between the bottom part (1) and at least the long sides (2) are directed outwardly at the ends and form an angle with the middle part (6) of the fold lines of 2-20 DEG .

Description: PUNCHED SHEET FOR A TRAY-LIKE PACKAGING TECHNICAL FIELD: The present invention relates to a punched blank which is intended to form a tray comprising a bottom part, two long sides and two short sides, which sides are folded up from the bottom part and united at their ends for completing the tray. The planar blank is primarily intended to consist of cardboard or corrugated fibreboard. PRIOR ART: Trays of fibreboard or other materials are well known. They are typically produced by punching a blank of corrugated fibreboard which is provided with folding lines for the short and long sides, whereupon these sides are folded up and united with each other at the ends to thereby form vertical corners compared to the bottom part. The blank is usually punched out and provided with narrow recesses between the intended long sides and the intended short sides at the corners of the bottom part, in such a way that the long sides are given their final length and the short sides are thereby provided with flaps which are folded in inside the long sides after folding up. These flaps are provided with glue and glued to the long sides after folding. The folding, and accordingly the completion, of the tray normally occurs automatically and the glue is cured after a few seconds, whereby the tray gets its strength. If materials other than corrugated fibreboard are used, it is possible to proceed in the same way as above, although completely different production methods can also be used. The trays which are produced according to said methods and which preferably consist of fibreboard are used for differ¬ ent purposes. They may for example be used to carry beer cans or completely different objects, such as vegetables. TECHNICAL PROBLEM: Depending on the field of application different demands are put on the different trays. For example, if the tray is to be used for beer cans it is important that the tray, if it is carried at the short sides, does not crack at the middle part due to the weight of the beer cans. A normal tray usually has an outwardly curved long side as a result of the fact that the moveability of the cans in the tray influences the long sides with outwardly-directed forces during normal manual handling. This is of course a great disadvantage as the tray can thereby easily collapse due to folding of the long sides. THE SOLUTION: The problems with the known trays have therefore been solved according to the present invention by creating a punched blank for a tray comprising a bottom part, two long sides and two short sides in one piece with the bottom part and marked with respect to this by pre-formed fold lines and intended to be folded up and united with each other at the ends, which blank is characterized in that the folding lines between the bottom part and at least the long sides are directed outwardly at the ends and form an angle with the middle part of the fold lines of 2-20°. According to the invention it is suitable if the fold lines between the bottom part and both the short and long sides are directed outwardly at the ends. According to the invention it is further suitable that the blank consists of corrugated fibreboard, plastics or the like. The punched blank according to the invention has short sides which are longer than the width of the bottom part. According to the invention the punched blank is provided with straight fold markings, at a 90° angle with respect to the fold lines between the bottom part and the long sides in the long sides at the border between the middle part of the fold lines and the outwardly-directed end part of these. According to the invention it is further suitable that straight fold markings are made, at a 90° angle with respect to the fold lines between the bottom part and both the short and long sides at the border between the middle part of the fold lines and the outwardly-directed end part of these on both the short and long sides. DESCRIPTION OF THE FIGURE: The invention will now be described in more detail in connection with the attached drawing which shows an embodiment of the invention in the shape of a punched blank of corrugated fibreboard. DETAILED DESCRIPTION: The plane blank in the figure, which consists of corrugated fibreboard, comprises a bottom part 1 of substantially rectangular shape and two long sides 2 and two short sides 3. Between the short and the long sides 3 and 2 slots 4 have been punched in such a way that the long sides 2 have been given their final length and the short sides 3 have been formed with flaps 5. To mark the short and long sides, pre-formed fold lines have been pressed into the cardboard. These fold lines consist of a straight middle part 6, but have been directed outwardly at the ends and form a separate part 7 of the fold line. This outwardly-directed part 7 of the fold lines may form an angle of 2-20° with respect to the middle part 6 of the fold lines. These outwardly-directed parts 7 of the fold lines may be made only in the long sides whereas the short sides 3 may have a fold line 6 which extends all the way to the corners. The middle parts 6 of the fold lines have been drawn straight in the figure, but they may also consist of a part of a circle having a large radius which practically gives a straight line for the circular arc. When the punched blank is to be formed into a tray, both the short and the long sides 3 and 2 are folded up from the bottom part 1 at their fold lines and the flaps 5 are glued to the inside of the long sides 2. By forming the fold lines in that way, according to the invention, with the outwardly directed ends 7, an inwardly-directed force will arise in the long sides 2. These folds will be greater, the greater the angle the outwardly-directed parts 7 has compared to the middle parts 6 of the fold lines. By creating an inwardly directed force in the long sides they will not tend to be cracked outwardly. They will instead rest against, and press against, the contents, for example beer cans in the tray. The same will of course occur even at the short sides if these have been provided with outwardly-directed end parts 7 of the fold lines. Apart from the effect that the long sides 2 will press inwardly against the contents, the effect is also obtained that the bottom part at the short sides will be given a smoother transition to the short sides 3. This is an advantage for the strength of the tray. With normal trays without the outwardly-directed parts 7, high stresses will usually arise at the short sides 3. It has surprisingly been shown that these stresses are strongly decreased with the construction according to the present invention and it is possible to load the tray with a load which is about 20% greater than with conventional trays. The figure shows further fold indications 8 on both the long and the short sides at the border between the middle parts 6 and the outwardly-directed parts 7 of the fold lines. These fold markings 8 are made to make the tray more easily able to adopt its final shape, but they are not necessary for the function of the invention. The invention is not limited to the embodiment shown and it can be varied in different ways within the scope of the claims.

Claims: CLAIMS: 1. Punched blank for a tray-like package comprising a bottom part (1), two long sides (2) and two short sides (3) in one piece with the bottom part (1) and marked with respect to this by fold lines (6) and being intended to be folded up and united with each other at the ends, c h a r ¬ a c t e r i z e d i n that the fold lines (7) between the bottom part and at least the long sides are directed outwardly at the ends and form an angle with the middle part (6) of the fold lines of 2-20°. 2. Punched blank according to claim 1, c h a r a c ¬ t e r i z e d i n that the fold lines (7) between the bottom part (1) and both the short and the long sides (3, 2) are directed outwardly at the ends. 3. Punched blank according to claim 1 or 2, c h a r ¬ a c t e r i z e d i n that the blank consists of corru¬ gated fibreboard, plastics or the like. 4. Punched blank according to any one of claims 1-3, c h a r a c t e r i z e d i n that the short sides (3) are longer than the width of the bottom part (1). 5. Punched blank according to any one of claims 1-4, c h a r a c t e r i z e d i n that straight fold markings (8) are made at a 90° angle with respect to the fold lines (6) between the bottom part (1) and the long sides (2), on the long sides (2) at the border between the middle part (6) of the fold lines and the outwardly-directed end part (7) of these. 6. Punched blank according to any one of claims 1-5, c h a r a c t e r i z e d i n that straight fold markings (8) are made at a 90° angle with respect to the fold lines (6) between the bottom part (1) and both the short and long sides (3, 2), at the border between the middle part (6) of the fold lines and the outwardly-directed end part (7) of these on both the short and long sides (3, 2).

Inventors: BRUS LARS, RENMAN MAGNUS, SAMUELSSON ROLF, BRUS, LARS, RENMAN, MAGNUS, SAMUELSSON, ROLF
Applicants: BRUS LARS, RENMAN MAGNUS, SAMUELSSON ROLF, SCA PACKAGING HOLDING BV, BRUS, LARS, RENMAN, MAGNUS, SAMUELSSON, ROLF, SCA PACKAGING HOLDING B.V.
Application year: 1996
Main classification: B65D5
IPC codes: B65D5