GB1584147A - Containers made of cardboard or like material - Google Patents

Description

(54) CONTAINERS MADE OF CARDBOARD OR LIKE MATERIAL (71) We, METAL BOX LIMITED, a British Company, of Queens House, Forbury Road, Reading RG1 3JH, England, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be per formed, to be particularly described in and by the following statement: This invention relates to containers made of cardboard or like material and in particular to a container comprising a bottom and four sides upfolded therefrom.

It is known to make containers of the kind just set forth from blanks which have a heatsealable coating on one side and a surface receptive to the said coating on the other side, the containers being conventionally retained in their erected condition for filling by bellows folded corner portions formed of mutually articulated, substantially triangular panels and each heat-sealed to an adjacent side wall of the container. With this kind of container each bellows-folded corner portion is typically heat-sealed to the adjacent side wall at a small area adjacent the free top edge of that panel of the comer portion which is remote from the side wall, the panel of the corner portion adjacent the side wall being notched to permit the securing to take place.

This method of securing the corner portions not only keeps each corner portion closed but it also holds it against the adjacent side wall. The corner is thus prevented from all movement. However, this method involves both sides of the blank and so is not suitable, for example, if the blank is coated on its two sides with mutually incompatible coatings, or alternatively if one side of the blank is uncoated but non-receptive to a heat sealable coating on the other side.

The present invention derives from Applicants' discovery that, by suitable arrangement, only one side of the blank need be involved in the securing of the corner portions. Accordingly, the invention provides a rectangular container made of cardboard or like material which is provided with a heat-sealable coating on only one of its surfaces, the container comprising a bottom and four side walls upfolded therefrom, wherein the corners between the side walls comprise bellows-folded comer portions each of which is formed from two mutually articulated and overlying substantially triangular panels folded together respectively one from each of two mutually adjacent side walls, each said corner portion having its two substantially triangular panels secured to one another by heat-sealing the coating on the face of one panel to the coating on the adjacent face of the other panel.

The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawing, in which: Fig. 1 is a plan of a blank from which a container according to the invention can be made; Fig. 2 illustrates a container according to the invention set up from the blank of Fig.

1; and Fig. 3 illustrates an alternative setting-up of the blank.

Referring to the drawing, a container is made from a blank of cardboard or like material with a heat-sealable coating on only one of its surfaces and comprises a bottom 1 and four side walls 2, 3, 4, 5 unfolded, Figs.

2 and 3, therefrom. The container is rectangular in plan view, the side walls 2, 3 being longer than the side walls 4, 5. The side walls are retained substantially in the upright upfolded condition thereof by bellows-folded corner portions each formed of two overlying and substantially triangular panels 6, 7 infolded respectively one from each of two adjacent side walls and mutually articulated along an inclined fold line 6a.

In both the embodiments shown in the drawing a lid 8 is hingedly connected at 9 to the top of one side wall (the wall 2 as shown) and is provided with flaps 10, 11, 12 adapted to be secured, as by adhesive, one to each of the outer faces of the other three side walls 3, 4, 5. If desired one of the flaps, the flap 11 as shown in Fig. 1, may be provided in conventional manner with a tear strip 13 to facilitate opening of the container.

In the embodiment illustrated, only the surface of the blank generally providing the outer surface of the container has the coating of heat-sealable material, for example a coating of polyethylene. The infolded panels 6, 7 of each corner portion are heat-sealed one to the other, the corner portions themselves then being unattached to the side walls 2 to 5 except by the fold lines between them.

It will be understood that with the arrangement described above there is the possibility of some movement at each corner of the container. Because the panels 6, 7 are only secured one to the other, each corner portion is able to move through a 90" arc between the adjacent side walls as indicated by the arrow A, Fig. 2; with certain types of filling no problems are caused if the corner portions protrude into the box after the box has been set up.

Figs. 2 and 3 show containers ready for filling with product and having their corner portions disposed to lie against, respectively, the shorter (Fig. 2) and longer (Fig. 3) side walls of the erected tray.

It will be appreciated that it is not essential that the corner portions are infolded into the interior of the box when the box is set up.

Instead, the corner portions may be bellows folded to remain outside the box, the triangular panels then being glued to the outside face of one of the adjacent sides. Such an arrangement is used where only the inner surface of the blank is coated with the heatsealable material.

After filling, and subsequent closing by the lid 8, the desired upright disposition of the side walls (if this is not already achieved by the corner portions) is maintained by the lid itself. If desired, the lid may be omitted and the filled tray may be overwrapped or fitted with a separate lid (such as thermoformed from plastics material); the same effect is thereby achieved.

WHAT WE CLAIM IS:- 1. A rectangular container made of card board or like material which is provided with a heat-sealable coating on only one of its sur faces, the container comprising a bottom and four side walls upfolded therefrom, wherein the corners between the side walls comprise bellows-folded corner portions each of which is formed from two mutually articulated and overlying substantially triangular panels folded together respectively one from each of two mutually adjacent side walls, each said corner portion having its two substantially triangular panels secured to one another by heat-sealing the coating on the face of one panel to the coating on the adjacent face of the other panel.

2. A container according to Claim 1, where in the corner portions are infolded from their respective mutually adjacent side walls and are disposed within the walls of the container.

3. A container according to Claim 1, wherein the corner portions are folded outwardly from their respective mutually adjacent side walls and are disposed outside the walls of the container.

4. A container according to Claim 3, wherein each corner portion has one of the substantially triangular panels secured to the outside of the adjacent side wall with an adhesive.

5. A container according to any one of the preceding Claims wherein a lid is hingedly connected to the upper edge of one of said side walls.

6. A rectangular container made of cardboard or like material, substantially as herein described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. In the embodiment illustrated, only the surface of the blank generally providing the outer surface of the container has the coating of heat-sealable material, for example a coating of polyethylene. The infolded panels 6, 7 of each corner portion are heat-sealed one to the other, the corner portions themselves then being unattached to the side walls 2 to 5 except by the fold lines between them. It will be understood that with the arrangement described above there is the possibility of some movement at each corner of the container. Because the panels 6, 7 are only secured one to the other, each corner portion is able to move through a 90" arc between the adjacent side walls as indicated by the arrow A, Fig. 2; with certain types of filling no problems are caused if the corner portions protrude into the box after the box has been set up. Figs. 2 and 3 show containers ready for filling with product and having their corner portions disposed to lie against, respectively, the shorter (Fig. 2) and longer (Fig. 3) side walls of the erected tray. It will be appreciated that it is not essential that the corner portions are infolded into the interior of the box when the box is set up. Instead, the corner portions may be bellows folded to remain outside the box, the triangular panels then being glued to the outside face of one of the adjacent sides. Such an arrangement is used where only the inner surface of the blank is coated with the heatsealable material. After filling, and subsequent closing by the lid 8, the desired upright disposition of the side walls (if this is not already achieved by the corner portions) is maintained by the lid itself. If desired, the lid may be omitted and the filled tray may be overwrapped or fitted with a separate lid (such as thermoformed from plastics material); the same effect is thereby achieved. WHAT WE CLAIM IS:-

1. A rectangular container made of card board or like material which is provided with a heat-sealable coating on only one of its sur faces, the container comprising a bottom and four side walls upfolded therefrom, wherein the corners between the side walls comprise bellows-folded corner portions each of which is formed from two mutually articulated and overlying substantially triangular panels folded together respectively one from each of two mutually adjacent side walls, each said corner portion having its two substantially triangular panels secured to one another by heat-sealing the coating on the face of one panel to the coating on the adjacent face of the other panel.

2. A container according to Claim 1, where in the corner portions are infolded from their respective mutually adjacent side walls and are disposed within the walls of the container.

3. A container according to Claim 1, wherein the corner portions are folded outwardly from their respective mutually adjacent side walls and are disposed outside the walls of the container.

4. A container according to Claim 3, wherein each corner portion has one of the substantially triangular panels secured to the outside of the adjacent side wall with an adhesive.

5. A container according to any one of the preceding Claims wherein a lid is hingedly connected to the upper edge of one of said side walls.

6. A rectangular container made of cardboard or like material, substantially as herein described with reference to the accompanying drawing.