Rigid, hinged-lid packets of cigarettes are currently the most widely marketed, by being easy to produce, practical and easy to use, and by effectively protecting the cigarettes inside.
A rigid, hinged-lid packet of cigarettes comprises an inner package defined by a group of cigarettes wrapped in a sheet of inner foil packing material; and a rigid outer package housing the inner package. The outer package comprises a cup-shaped container housing the group of cigarettes and having an open top end; and a cup-shaped lid hinged to the container along a hinge to rotate, with respect to the container, between an open and a closed position opening and closing the open end respectively. A U-folded collar is normally fitted inside the container, and projects partly outwards of the open end to engage a corresponding inner surface of the lid when the lid is in the closed position.
Tobacco is highly sensitive to environment. That is, in contact with the atmosphere, its organic characteristics tend to vary alongside variations in humidity (by losing or absorbing too much moisture) or due to evaporation of the volatile substances with which the tobacco is impregnated (especially in the case of aromatic cigarettes treated with spices such as cloves). To preserve the tobacco, packets of cigarettes are therefore cellophane-wrapped, i.e. wrapped in a heat-sealed overwrapping of airtight plastic material. This, however, may not always be sufficient to fully preserve the tobacco in the packet, especially if the packet is consumed some time after manufacture. Moreover, when the packet is unsealed, the overwrapping is removed, thus exposing the tobacco to the atmosphere, and, if the cigarettes are not consumed soon after the packet is unsealed, the organic characteristics of the remaining cigarettes may deteriorate visibly.
In an attempt to eliminate this drawback, rigid packets of cigarettes have been proposed, in which the inner package is heat sealed airtight, and comprises a sheet of airtight inner packing material having a cigarette extraction opening closed by a reusable cover flap. In other words, the cover flap has fastening means (e.g. a strip of non-dry re-stick adhesive) by which to repeatedly secure the cover flap in a closed position closing the cigarette extraction opening.
One problem of rigid packets of cigarettes, in which the inner package comprises a sheet of airtight packing material with a cigarette extraction opening, is that, once some of the cigarettes are removed, the inner package tends to collapse, thus making it difficult to withdraw the remaining cigarettes, and, in particular, to open and close the cover flap. Moreover, when heat sealing the superimposed portions of the sheet of airtight inner packing material, the cigarettes are subjected to mechanical stress that may result in local deformation and/or tobacco fallout, and to thermal stress possibly resulting in local deterioration of the tobacco.
By way of a solution to the problem, it has been proposed to insert a rigid collar, in the form of a cardboard strengthener, inside the inner package and about the group of cigarettes to maintain the shape of the inner package and protect the cigarettes when folding and heat sealing the sheet of airtight inner packing material. However, placing and folding the rigid collar about the group of cigarettes before folding the sheet of inner packing material about the group is extremely complicated on a standard packing machine; which means this type of packet calls for a special packing machine that is much more expensive than an equivalent standard type.
Moreover, the sheets of airtight inner packing material currently used to produce airtight inner packages are made of multilayer packing material comprising at least one foil inner layer and an outer layer of heat-seal plastic. As a result, they are thick and stiff and therefore difficult to fold, and fail to faithfully reproduce the outer contour of the group of cigarettes (i.e. fail to form square edges), thus resulting in “convex” airtight inner packages that are normally unpopular with users.
GB311957A and U.S. Pat. No. 1,790,370 A1 disclose a package of cigarettes comprising an outer pouch-like case open at one end and an inner drawer slidable therein and containing the cigarettes which are wrapped in air and moisture proof material.