The invention relates to a roll of self-adhesive tape made from plastic or equivalent film for packing and other purposes, according to the preamble of claim 1. Such a roll is produced and traded under the name "Scotch Brand 3M TM Mailing tape".
The forms in which these plastic films are currently presented for use in the home or office, or for use in workshops and factories for taping up cardboard packaging boxes by hand, have the self-adhesive film wound on cores, usually of board, with tape widths generally of from 35 to 80 mm and tape lengths of around 35 to 130 m and with the tubular core having a diameter of around 3 inches, that is approximately 75 mm, while the external diameter of the finished article, that is with the plastic film wound on the core, is around 12 cm. Figs 1 and 2 show on a scale of 1:1, i.e. actual size, two known rolls of this type for shorter lengths and longer lengths of tape respectively.
This known kind of roll has considerable disadvantages. In particular there is a considerable space requirement in view of the diameter of the core, relative to the lengths of tape wound thereon, and consequently a considerable space requirement and cost both for the material of the core (that is the ring on which the tape is wound) and for the completed roll and the packaging of these products in either single or multiple packs; consequently space requirements (and costs) of shipping and storage are also considerable and there are difficulties in respect of display space for sales purposes. So large a size in relation to the amount of plastic or equivalent film also creates an ecological problem when it comes to disposal, because of the great volumes and weights to be disposed of, both of the wrapping itself - consisting of the protective packing and of the packs in which a multiple number of single components are wrapped - and also of the very material of the core, which is relatively large owing to the great thickness and even more to the large diameter of this core; the large diameter also means that the tubular core has to be very thick in order to give it strength.
All these problems are solved by a roll according to claim 1.
The result is much reduced space requirements, by as much as a third, in comparison with those of a conventional roll, and moreover the waste to be disposed of is in consequence much less than that generated by conventional types of roll. Furthermore, for the same external diameter (of around 120 mm) a roll of tape can be prepared with a length of up to approximately three times that of a conventional roll.
In the drawing:
As can be seen in Figs 3, 4 and 5, the core is much smaller than those of the conventional rolls shown in Figs 1 and 2. The smaller diameter of the tubular core also means that the thickness of the tubular wall can be reduced without strength being reduced below that of the tubular cores of the conventional rolls shown in Figs 1 and 2. The smaller amount of material and the smaller dimension of the core illustrated in Figs 3, 4 and 5 provide a reduction in costs and a great reduction in space requirements for the same amount of tape wound on the core, or less total space requirements and a smaller amount of materials for the various single and multiple packs of the products produced in this way.
The smaller amount of materials of both the tubular core and the completed roll provides a solution that creates few difficulties for disposal and from the ecological point of view, and also creates a lesser problem from the point of view of space requirements during storage and shipping, with consequent yet further reductions in costs, as well as a lesser problem with regard to the space taken up in premises and areas of display.
The use of individual rolls is also more convenient owing to the smaller size of the roll made according to Figs 3, 4 and 5 when compared with conventional rolls.
If Figs 2 and 5 are compared it will be seen that a very large amount of self-adhesive plastic film can be contained in the same amount of overall space in a roll as shown in Fig. 5 compared with that shown in Fig. 2. In practice around 1.5 to 3 times the length of packed film can be achieved within an equivalent final volume.
If Figs 1 and 3 are compared, it will be observed that for an equivalent length of plastic film the roll shown in Fig. 3 according to the invention is much smaller than that shown in Fig. 1, while holding the same amount of plastic film.
A comparison furthermore of Figs 2 and 4 leads to the same condusion, namely that a smaller volume can be achieved for the same amount of wound plastic film.
The use of tubular rods of small diameters to produce the tubular cores on the principles of the present invention, i.e.according to Figs 3, 4 and 5, as opposed to the use of rods for making cores like the conventional ones shown in Figs 1 and 2, affords great convenience and a great cost saving as far as disposal of the cores and their production is concerned, and hence a greater utility of the solution according to the invention. A further advantage is that for the same deformation resistance the necessary thickness of a small-diameter core is less than for a large-diameter core.