GB2232657A - Containers for food products - Google Patents

Abstract

A container e.g. bag, carton, wrapping, containing a granular, transformation food product, for example popcorn, has apertures 5 in a wall or walls 1, the apertures being sealed by sheet material 6 that can be removed to uncover the apertures 5 after the food product has been treated, e.g. by microwave heating, to effect the desired transformation (e.g. popping). The container facilitates the removal of untransformed food product, which may pass through the apertures 5 by shaking. The sheet material may be an outer ply of the container wall. After removal of the untransformed product, a meltable coating may be introduced and the container placed in a microwave oven. <IMAGE>

Description

"Improvements in and relating to containers for food products" The invention relates to containers, especially bags, for granular food products, particularly transformation products.

Some granular food products are sold in a form in which they are not fit for consumption, but which can be caused to undergo a transformation, for example, by the application of heat, which renders them fit for consumption and which is accompanied by a change in the size and/or configuration of the grains. Typically, the untransformed granules are hard and liable to cause dental damage if they are eaten, for example as a result of their being unnoticed among transformed granules and possible flavouring additions. Further, it is commonly the case that the treatment, for example, the application of heat, that brings about the transformation leaves a proportion of the grains in their untransformed state.

Perhaps, the best known transformation food product is maize, the grains of which are sold as popping corn. Heating the grains in the presence of moisture, which derives at least in part from the grains themselves, causes them to soften and then "pop", that is to say, to undergo a sudden expansion which ruptures the outer skin and gives rise to a product ("popcorn"), in which the grains are relatively soft and which are considerably larger in size than the grains of popping corn. Almost always, however, not all the grains of popping corn undergo the desired transformation, and any untransformed grains that remain present a serious dental hazard to anybody attempting to eat them.

It is known to pack popping corn in sealed bags, and to apply the required heat by placing a bag or bags in a microwave oven.

The invention provides a container that contains granules of a transformation food product, the container having apertures in a wall or walls, the apertures being sealed by sheet material that can be removed to uncover the apertures after the food product has been treated to effect the desired transformation, and the size and shape of the apertures being such that, with the sheet of sealing material removed, any untransformed granules can leave the container through the apertures, but transformed granules cannot pass through the apertures.

In use, the food product is treated to effect the desired transformation and the sheet material is removed to expose the apertures. The size of the apertures having been chosen appropriately for the particular food product, shaking the container then causes any untransformed granules to leave the container through the apertures while retaining the transformed granules within the container. The container is then opened to give access to the transformed granules.

Preferably, one of the walls of the container constitutes a base. The apertures are preferably located in a wall other than the base. The apertures are advantageously located in a side wall of the container, in a position remote from the base of the container. The container is advantageously a bag.

Preferably, such a bag is arranged to be opened at the top, that is to say, at the end remote from the base.

In that case, the apertures are advantageously provided adjacent to the openable top of the bag.

Another preferred form of bag is a bag of generally tetrahedral form. In a bag of that form, two mutually perpendicular edges are preferably shorter than the separation between them, the two perpendicular edges then constituting the ends of the bag. Then, the apertures are formed in a side of the bag, preferably in a region adjacent to one of the ends.

Instead of a bag, the container may take the form of a carton which can be folded so that it lies relatively flat when it is empty or contains only an untransformed food product, but which can unfold to give an increased internal volume when the food product undergoes the transformation.

A container in accordance with the invention and containing granules of a transformation food product, may be formed using flexible sheet wrapping material formed with the said apertures, the apertures being sealed by sheet material which can be removed, the wrapping material being wrapped round the granules and then sealed to form a sealed container containing the granules.

Grains of popping corn are commonly about 5 mm in diameter, whereas the transformed grains (the grains of popcorn) typically have a diameter of about 25 mm.

Thus, circular apertures of from 10 to 15 mm, especially from 10 mm to 12 mm in diameter will allow the popping corn to pass through readily while retaining the popcorn. For a typical bag of popping corn, about 15 to 25 such apertures will be found to be satisfactory. The apertures may be, for example, 25 mm apart.

When, as is preferred, the container is a bag, the walls may be of paper, which may be lined with a layer of polyester. The walls may be, for example, of two plies of paper which may be adhered by any suitable means, for example by a lacquer. As the material for sealing the apertures, there can be used any material which is such that it will remain adhered to the bag under the transformation conditions, but can be removed easily thereafter. The material used to seal the apertures is advantageously a coated polyester material for example a polyester material having an acrylic coating which is adhesively united with a wall or walls of the bag by heat-sealing. A suitable heat-sealable polyester is MYLAR OL (Registered Trade Mark). A pressure-sensitive polyester may also be used.

The bag is preferably so sealed that it remains sealed under conditions normally used for transforming granules in the bag, but that when the temperature exceeds a certain temperature which is greater than that normally reached in transforming the granules, the container will open at the seal without exploding.

If desired, when the bag has at least one wall of two-ply material, the apertures may be formed in the inside ply of material, the outer ply of material having a region which seals the apertures, the said region being delined by lines of weakness, for example, lines of perforations in the outer ply of material which permit the said region to be removed by tearing, so uncovering the apertures.

Three forms of container constructed in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of one form of bag which is unsealed and standing on its base; Fig. 2 is a plan view from below of the base of the bag shown in Fig. 1; Fig. 3 is a perspective view of a second form of bag; and Fig. 4 is a perspective view of a third form of bag.

Referring to the accompanying drawings, the first form of bag has a flat base 1 and side walls 2 and 3 which are joined by gussets 4. The bag is designed to be sealed by securing together, for example, by heatsealing, upper edge portions of the side walls 2 and 3.

When the bag is of a material which is not itself heatsealable to seal the bag, a strip of a suitable heatsealable material may be provided at the upper edge of a side wall 2, 3.

It will be appreciated that the side walls 2 and 3, and the gussets 4, can readily be folded near the base 1 of the bag so that the side walls 2 and 3 extend parallel to, and only a short distance above, the base 1 of the bag.

Formed in the base 1 of the bag are three rows of circular apertures 5, which are sealed by a rectangular piece of sheet material 6 which is heat-sealed to the outer surface of the base of the bag, and which can be peeled off to expose the apertures. If desired, a tab (not shown) can be provided at one end of the piece of sheet material 6 to facilitate its removal.

In use of the bag popping corn is introduced into the bag through the open, upper end of the bag. The bag is then sealed at that end.

If it is intended that the popping corn should be heated to effect the transformation to popcorn by placing the bag in a microwave oven, then the bag (which will be provided with a susceptor panel in any suitable manner, for example, being positioned between the plies of a part of one of the side walls 2 and 3 when the walls are of a two-ply material) is placed in the oven on its side (with the side provided with the susceptor panel lowermost).

When popping has taken place, the bag is removed from the microwave or other oven, the sheet 6 of sealing material is removed. The bag is held vertically by its top and is shaken vigorously so that any grains of popping corn that may remain untransformed fall through the holes so that the bag then contains only the transformed product, that is to say, popcorn.

The second form of bag (see Fig. 3) is shown sealed and contains a quantity of popping corn, which is not shown. The bag is of generally tetrahedral form having two mutuall orthogonal end edges 7 and 8 and being bounded by four generally triangular side walls of which two are indicated by the reference numerals 9 and 10, respectively. It will be appreciated that the configuration of the bag enables it to lie relatively flat while it contains the popping corn and then to expand sufficiently to accommodate the popcorn that results from transformation of the popping corn.

As in the case of the first form of bag, the second form of bag may incorporate a susceptor pad (not shown) to facilitate heating in a microwave oven.

In one side wall 10 of the bag, three rows of circular apertures 11 are formed close to one end edge 8 of the bag, the apertures being sealed by a sheet of material 12 which is heat-sealed or adhered to the outer surface of the side wall 10 and which can be peeled off after popping has occurred. If desired the sheet 12 may be provided with a tab 13 which may be gripped by the user to facilitate removal of the sheet.

The removal from the bag of any untransformed popping corn that may remain is achieved by shaking the bag vigorously with the wall 10 facing downwards.

Fig. 4 shows a further, especially advantageous, form of bag. The bag of Fig. 4, which is shown sealed, is of similar construction to the bag of Fig. 1 and corresponding parts are indicated by the same reference numerals. The apertures 5, however, are provided in an upper portion of the side wall 2, instead of in the flat base 1. The apertures are adjacent to the upper edge portion 2a of the side wall 2 that is sealed to the upper edge portion of the side wall 3.

In use of the bag of Fig. 4, when transformation has taken place, the bag is removed from the microwave or other oven and the sheet 6 of sealing material is removed. The bag is then inverted and shaken vigorously so that any grains of the transformation product, for example, popping corn, that remain untransformed fall through the apertures 5, so that the bag then contains only the transformed product.

The bag of Fig. 4 provides particular advantages if the transformed product is to be coated with a liquid or meltable substance.

If, for example, a meltable coating is to be applied to popcorn, the untransformed corn may be removed before addition of the coating substance by vigorously shaking the inverted bag as described above.The bag can then be unsealed and the meltable coating substance introduced into the bag through the open top. The bag can then be placed in the upright position in a microwave or other oven so that the coating metls and percolates through the mass of transformed corn. Because the apertures are in an upper region of the bag, there is no risk of leakage of the melted coating through the apertures, provided that the bag remains upright. As a result, soiling of the oven is avnided,

Claims (12)

What we claim is:

1. A container that contains granules of a transformation food product, the container having apertures in a wall or walls, the apertures being sealed by sheet material that can be removed to uncover the apertures after the food product has been treated to effect the desired transformation, and the size and shape of the apertures being such that, with the sheet of sealing material removed, any untransformed granules can leave the container through the apertures, but transformed granules cannot pass through the apertures.

2. A container as claimed in claim 1, wherein one wall of the container constitutes a flat base.

3. A container as claimed in claim 2, wherein the apertures are located in a wall other than the base.

4. A container as claimed in any one of claims 1 to 3, which is a bag.

5. A container as claimed in claim 4, wherein the bag is of generally tetrahedral form.

6. A container as claimed in any one of claims 1 to 5, which has been formed by wrapping a flexible wrapping material round the granules and then sealing it, the flexible wrapping material having formed in it apertures sealed by a removable layer of sheet material.

7. A container as claimed in any one of claims 1 to 6, wherein the granular material comprises cereal grains.

8. A container as claimed in claim 7, wherein the transformation food product is popping corn, and the apertures are substantially circular and have a diameter of from 10 mm to 15 mm.

9. A container as claimed in claim 8, wherein the number of apertures is 15 to 25.

10. A container substantially as hereinbefore described with reference to, and as shown in, Figs. 1 and 2, Fig. 3 or Fig. 4 of the accompanying drawings.

11. A method of treating a granular transformation food product, which comprises heating the product in a container as claimed in any one of claims 1 to 10, removing the material that seals the apertures and shaking the container to cause untransformed granules to fall through the apertures.

12. A method as claimed in claim 11, wherein the heating is effected by placing the container in a microwave oven.