WO2002094961A1 - Adhesive tape with predetermined incisions for tearing - Google Patents

Abstract

This adhesive tape has the feature of comprising a continuity of holes disposed in a central position and spaced apart by predetermined lengths, said holes forming a reference for the location of a pressure to be exerted by the tip of the operator's thumb in order to increase the tape tension in said regions compared with the handling tension distributed over the entire width of the tape, until compete transverse rupture is triggered for tearing the tape.

Description

"ADHESIVE TAPE WITH PREDETERMINED INCISIONS FOR TEARING"

DESCRIPTION

TECHNICAL FIELD This invention relates to an adhesive tape with predetermined incisions for cutting by manual tearing. BACKGROUND ART

The applications for which adhesive tape can be used are increasingly more numerous. It is usually formed of plastic materials (generally polypropylene) which vary considerably in their ease of tearing. As the adhesive tape has to be cut or otherwise detached from the winding reel, suitable implements for its cutting or for making incisions which facilitate its tearing have to be used, including scissors, knives, or dispensers provided with an appropriate blade comprising transverse cutting teeth. All these implements perform their function to a reasonable degree of satisfaction, depending on the tearing ability of the tape, but this has two negative aspects; the first aspect is that such implements are not always available or are not associated with the particular tape used; the second aspect is that their operation is sometimes insufficient for certain types of adhesive tape.

An object of the present invention is to define an adhesive tape which can be torn into pieces of the required length without the aid of conventional implements. Another object is to define a tape which is of cost substantially equal to that of normal tape. DISCLOSURE OF THE INVENTION

These and further objects will be seen to have been attained on reading the ensuing detailed description of an adhesive tape having the feature of comprising a continuity of holes disposed in a central position and spaced apart by predetermined lengths, said holes forming a reference for the location of a pressure to be exerted by the tip of the operator's thumb in order to increase the tape tension in said regions compared with the handling tension distributed over the entire width of the tape, until compete transverse rupture is triggered for tearing the tape. BRIEF DESCRIPTION OF DRAWINGS

The invention is illustrated by way of non-limiting example in the accompanying drawing, showing a typical packaging tape 1 unwinding from a transverse line 7 while tensioned by a hand 2 gripping a reel 8. BEST MODE FOR CARRYING OUT THE INVENTION This positioning enables the tip 3 of the thumb of the hand to press on an underlying hole 4C (which is covered by the thumb). This hole 4C forms part of a continuous row of holes 4A, 4B, 4C, 4D, 4E, 4F, 4G. This pressing increases the mechanical tension in the film especially in the hole region, to create in this manner a force concentration able to trigger a double notch for tearing the tape along its entire width. This triggering takes place simultaneously both in a right region 5 and in a region 6 positioned to the left of the hole 4C present in the tape 1. In the figure, the holes 4 are very close together, at about 3 cm apart. They can however be spaced further apart, for example at about 30 cm. The distance between the holes 4 depends on the method used to make them. In this respect, these holes could be formed directly on a reel with the tape already wound on it; alternatively they could be formed in the film while extended in a plane before being wound on the reel. In the first case the maximum possible distance between the holes is that achievable by radially perforating the reel with a single hole; consequently said distance depends on the tape winding diameter. A tape wound on a circumference of 10 cm diameter and perforated radially with a single hole has a continuity of holes, when presented in its extended or unwound configuration, with a pitch equal to the winding circumference, i.e. 3.14 (i.e. π) x 10 = 31.4 cm. In the second case, however, the distance between the holes could be of any length. The said holes 4 can be of flat rectangular form as shown in the figure, with a length of about seven millimetres, or could be of circular shape with a diameter of just a few millimetres. Said holes can be made using mechanical means, such as rotating drill bits, or shearing punches with reciprocating linear movement. They could however also be made by thermal means such as perforating blades of rectangular cross-section suitably maintained at a sufficiently high temperature to melt the plastic below the blades.

Claims

1. An adhesive tape, characterised by a having a continuity of holes (4) disposed in a central position and spaced apart by predetermined lengths, said holes forming a reference for the location of a pressure to be exerted by the tip (3) of the operator's thumb (3) increase the tension of the tape (1) in said regions compared with the handling tension distributed over the entire width of the tape, until compete transverse rupture is triggered for tearing the tape.

2. A tape as claimed in the preceding claim, characterised in that the holes (4) are of flat rectangular shape.

3. A tape as claimed in the preceding claims, characterised in that the ^•holes (4) are of round shape.