GB2240766A

GB2240766A - Corrugated-cardboard packaging box and manufacturing method thereof

Info

Publication number: GB2240766A
Application number: GB9003184A
Authority: GB
Inventors: Claudio Cavalieri
Original assignee: PBW Srl
Current assignee: PBW Srl
Priority date: 1989-01-13
Filing date: 1990-02-13
Publication date: 1991-08-14
Also published as: IT8903313A0; GB9003184D0; DE9000056U1; FR2643874A3

Abstract

A packaging box is constituted by a panel of corrugated cardboard conveniently pre-punched and creased so that it can be folded in a tube and closed along a coupling line. The two sheets 2, 3, which cover an intermediate corrugated layer 4 and constitute the inner and outer surface of the box, protrude with two respective flaps 2a, 3a from the two edges which are joined together and form the coupling line. In the manufacturing method, by placing the opposite edges of the panel together head-on, the protruding flaps 2a, 3a overlap the outer and respectively inner marginal portions of the panel and are glued thereon. <IMAGE>

Description

CORRUGATED-CARDBOARD PACKAGING BOX AND MANUFACTURING METHOD THEREOF The present invention relates to a corrugated-cardboard packaging box and to a manufacturing method thereof.

Packaging boxes obtained from a panel of corrugated cardboard, constituted by two sheets which cover a corrugated intermediate layer on opposite sides, are known.

Said panel is provided with cutting lines and grooves which allow tube-like folding, with the two edges which define the coupling line glued to one another.

Said glueing is usually performed at an edge, and this first of all creates an unwanted doubling in thickness in this region. Secondly, a structural weakening is produced due to the fact that the sheet of cardboard which forms the inner wall of the box is usually lower in quality than the sheet which forms the outer wall, so that there is lower resistance in the glueing region.

The technical aim of the present invention is to provide a packaging box which does not have the above described disadvantages.

Within the scope of the above described aim, an object of the present invention is to provide a packaging box in which the coupling line can be located in any position, therefore allowing the best utilization of the cardboard sheet according to glueing and strength requirements.

This aim and this object are achieved by a packaging box, as defined in claim 1, and by a panel as defined in claim 2.

The invention further relates to a method for manufacturing said box, as defined in claim 3.

The characteristics and advantages of the invention will become apparent from the following detailed description on the basis of the accompanying drawings, wherein: figure 1 is a perspective view of the present packaging box; figure 2 is a cross-sectional view of a cardboard panel for the box of figure 1; figure 3 is an enlarged-scale cross-sectional view of the box coupling region; and figure 4 is a view of a method step for preparing the edges of the panel which are to be glued.

With reference to the above figures, the reference numeral 1 indicates the corrugated-cardboard panel for the manufacture of the packaging box according to the invention.

Said cardboard is of the kind which comprises two sheets 2,3 between which a layer 4 of corrugated sheet is arranged and is rigidly associated with said sheets 2 and 3 by glueing.

Said panel is folded and assembled by means of cutting and crease lines so as to assume the appearance of a tube, indicated at 5 in figure 1.

Said tube has a prism-like shape with rectangular cross-section, defining two larger walls 6, 7 and two smaller walls 8, 9 which end, on opposite sides, with respective closure wings 6a, 7a and 8a, 9a adapted to define the opposite bases of the box.

In order to provide the coupling line 10, the two sheets 2, 3 of the panel have respective flaps 2a and 3a which protrude from opposite edges of the layer 4. More precisely, the flap 2a protrudes from one edge and the flap 3a protrudes from the opposite edge of layer 4.

In this manner, by folding the panel 1 in the shape of a tube along the folding lines which define the four longitudinal edges of the box and by placing the opposite edges of the panel head-on, the protruding flaps 2a and 3a of the sheets 2 and 3 respectively overlap the outer and inner marginal portions of said sheets 2 and 3. A particularly strong coupling line is obtained by interposing appropriate adhesive material between the flaps 2a and 3a and the respective marginal portions; the thickness of said coupling line is increased, with respect to the thickness of the cardboard being used, to a negligible extent by the thickness of the sheets 2 and 3.

It should be noted that glueing occurs between identical sheets, so that there is no risk of incompatibility between sheets with different mechanical and quality characteristics.

The coupling line is particularly strong, so that it is possible to arrange it even on the lateral faces, as illustrated in figure 1.

As to the manufacturing method, the protruding flaps 2a and 3a are conveniently formed by removing an edge portion 11 of the intermediate corrugated layer and a portion of the opposite sheet. For this purpose, two mutually orthogonal rotating blades 12, 13 can be used, whereof one blade 12 cuts the cardboard on the plane between the flap of sheet to be obtained and the corrugated layer, the other blade 13 removes the separated portion by means of a cut which is perpendicular to the panel.

By means of the same inventive concept it is possible to produce boxes of any shape, whether prismatic or cylindrical. The corrugated cardboard used can furthermore be single- or multi-layer.

Claims

1. A packaging box comprising a panel of corrugated cardboard having two opposite edges and including two sheets and at least one intermediate corrugated layer, said panel being folded into a tube with said opposite edges being joined along a coupling line, wherein said two sheets have each a respective protruding flap, protruding from a respective one of said two opposite edges of the panel, said opposite edges being arranged head-on adjacent to each other and said protruding flaps being glued to an outer and respectively an inner marginal portions of said panel.

2. A panel of corrugated cardboard for a packaging box, the panel having two opposite edges and including two sheets and an intermediate corrugated layer, said panel being pre-punched and creased to be folded into a tube with said opposite edges being joined along a coupling line, wherein said two sheets have each a respective protruding flap protruding from a respective one of said opposite edges of the panel to be glued onto the respective one of said two sheets when said opposite edges are placed head-on adjacent to each other.

3. A method for manufacturing a packaging box from a panel of corrugated cardboard including two sheets and at least one intermediate corrugated layer, comprising forming two opposite protruding flaps, each said protruding flap being obtained by removing corresponding portions of the intermediate corrugated layer and of one sheet by cutting a portion of the panel along a plane between another one of the two sheets and the intermediate corrugated layer, and removing said portion of the panel by cutting said portion of panel along a direction which is perpendicular to said panel.