WO2002055623A1

WO2002055623A1 - Adhesive tape coiled into a roll-

Info

Publication number: WO2002055623A1
Application number: PCT/IB2002/000100
Authority: WO
Inventors: Leon Ribi; Valentino Ribi
Original assignee: World Wide Sealing Corporation (Pa)
Priority date: 2001-01-16
Filing date: 2002-01-16
Publication date: 2002-07-18

Abstract

The invention relates to a continuous adhesive tape coiled into a roll, characterized in that it consists of an alternate succession of portions (2) which are attached by their lower intrados adhesive-coated side, with a certain adhesion strenght but in a detachable manner, to the outer extrados side of the underlying turn of the coiled tape, and of detached or easily detachable portions (3), whereat the adhesion strenght of the lower intrados side of the tape against the upper extrados side of the underlying turn of the coiled tape is null or considerably reduced. The detached or easily detachable portions (3) may be obtained by annulling or reducing the adhesive action of the adhesive, e.g. by omitting the application or by reducing the amount and/or the application area thereof, or by completely or partly removing, covering or inactivating e.g. through drying and crystallization steps, the adhesive already applied on the lower intrados side of the tape and/or by making the upper extrados side of the tape wholly or partly abherent.

Description

-Adhesive tape coiled Into a roll-

INTRODUCTION The invention relates to continuous adhesive tapes coiled into rolls, whose lower intrados adhesive-coated side adheres with a certain adhesion strength but in a detachable manner against the upper extrados side of the underlying turn of the coiled tape. The difficulty is known of finding and peeling the leading end of such an adhesive tape when, after peeling, unwinding and separating a portion of the tape from the roll, said end sticks onto the roll again. In order to obviate this difficulty, each time, the free leading end of the adhesive tape has to be folded on itself, or a lift-tab of nonadhesive material, e.g. paper, has to be attached to said end, requiring an inconvenient and troublesome operation, which is not always possible. Various types of dispensers for adhesive tapes coiled into rolls are also known, which are provided with a tape cutting edge and in which, after each cut, the free leading end of the tape remains attached in a detachable manner to a specially designed surface in a position wherein it can be easily grasped. These dispensers are rather costly and their cutting means, when they are effective, may easily wound the user.

The present invention has the object to obviate these and other drawbacks in an effective though simple and cost-effective manner. The object is achieved by the invention thanks to a continuous adhesive tape coiled into a roll, and substantially characterized in that it consists of an alternate succession of portions which are attached by their lower intrados adhesive-coated side with a certain adhesion strength but in a detachable manner, against the outer extrados side of the underlying turn of the coiled tape, and of detached or easily detachable portions, whereat the adhesion strength of the lower intrados side of the tape against the upper extrados side of the undelying turn of the coiled tape is null or considerably reduced. Therefore, according to the invention, after unwinding an adhesive tape strip, consisting of one or more attached portions, from the roll , and after separating said strip from the remaining adhesive tape of the roll at the leading end of the next detached or easily detachable portion or at an intermediate position thereof, the leading end of the adhesive tape which is still coiled onto the roll is always automatically formed by a portion which is detached or easily detachable from the upper extrados side of the underlying coiled tape and allows to easily lift and grasp the leading end of the remaining adhesive tape to unwind it from the coil . In accordance with an additional characteristic of the invention, in order to easily find the leading end of the adhesive tape on the roll, said attached portions and/or detached or easily detachable portions are provided with identification marks, which allow to distinguish them from each other and may also consist of a particular color of at least one of the two types of portions .

As a rule, the detached or easily detachable portions of the coiled adhesive tape of the invention are considerably shorter than the attached portions . Nevertheless, the invention does not exclude the possibility to provide, for special purposes, adhesive tapes wherein the attached portions are shorter than the detached or easily detachable portions or wherein the attached portions and the detached or easily detachable portions are substantially of the same length .

In order to easily peel an adhesive tape strip comprising one or more attached portions, joined together by detached or easily detachable portions , from the roll, according to an additional characteristic of the invention, between the rear end (as viewed facing in the tape unwinding direction) of each attached portion and the next detached or easily detachable portion and/or in at least one intermediate position of each detached or easily detachable portion and/or possibly between the rear end (still as viewed facing in the tape unwinding direction) of each detached or easily detachable portion and the next attached portion, cross-web lines with predetermined and facilitated break strength are provided which may have any profile, for instance a straight, wavy, V- shaped or other profile and may be obtained in any manner, e.g. by die cutting, half-cutting, embossing, punching, notching, or the like. The lines with predetermined and facilitated break strength appropriately have such a resistance as to allow that a strip comprising one or more attached portions joined together may be unwound and separated from the roll , while allowing the user to easily separate the individual attached portions from each other and/or from the detached or easily detachable portions .

The adhesion of the lower intrados portion of the adhesive tape against the upper extrados side of the underlying turn of the coiled tape at the detached or easily detachable portions may be inhibited or reduced in any manner and by any means for annulling or weakening the adhesive action of the adhesive coating the lower intrados side. To this end, the invention provides, for instance, the following possibilities which may be used individually or together in any combination:

- omitting to apply adhesive at the detached or easily detachable portions of the tape or applying, at said portions, a smaller amount of adhesive and/or applying adhesive at these portions only over a zone of the corresponding tape surface, e.g. over one or more limited zones, of any shape or pattern, - after applying adhesive evenly over the whole surface, covering the adhesive wholly or partly at said portions with nonadhesive covering materials, e.g. by printing processes, or wholly or partly removing the adhesive at the detached or easily detachable portions, or applying strips or labels of nonadhesive covering material, e.g. paper or plastic.

- after evenly coating the whole surface of the tape with adhesive, applying a powdered material at the detached or easily detachable portions, e.g. directly or indirectly by an electrostatic process, by jet application or else, and/or catalyzing, crystallizing or drying wholly or partly at said portions by any process or means fit for the purpose,

- making the upper extrados side of the tape, at the detached or easily detachable portions wholly or partly adhesive repellent at least with respect to the adhesive of the lower intrados side by application of an adhesive-repellent substance thereon, e.g. wax, silicone or the like and/or by a corresponding physical and/or chemical and/or mechanical treatment of said upper extrados side, e.g. a laser or electromagnetic beam treatment, a corona discharge, heat treatments, or else. When this arrangement is implemented alone, it has the advantage that the tape has an uninterrupted adhesiveness, as the lower intrados side may be evenly coated with adhesive all over its length, while achieving all the advantages determined, according to the invention, by the alternation of tape portions attached to the underlying turn of the coiled tape and tape portions detached or easily detachable from said turn.

Further characteristics of the invention are included in the other dependent claims . DESCRIPTION An embodiment of an adhesive tape according to the invention is shown in the schematic and perspective view of Figure 1 of the annexed drawing and will be described hereafter without limitation.

The illustrated adhesive tape is coiled into a roll 1 and has an alternate succession of portions 2, whereat its lower intrados adhesive-coated side, is attached with a certain adhesion strength, though in a removable manner, against the upper extrados side of the underlying turn of the coiled tape, and of portions 3, as shown in dashed lines, whereat the lower intrados side of the tape is detached or easily detachable from the upper extrados side of the underlying turn of the coiled tape. To this end, in the illustrated embodiment, at said portions 3, the adhesive wherewith the lower intrados side of the tape is coated, is omitted, removed, covered or rendered inactive. Hence, the tape is composed of adhesive portions 2 alternated to nonadhesive portions 3.

The nonadhesive portions 3 preferably have a different color from the adhesive portions 2 or are otherwise arranged to be recognizable by any mark. At least one cross-web line 4 with predetermined and facilitated break strength of the tape is provided between the rear end of each adhesive portion 2 (as viewed facing in the tape unwinding direction from the roll 1) and the next nonadhesive portion 3. The leading end 5 of the coiled tape consists of a nonadhesive portion 3 which may also be separated from the next first adhesive portion 2 by means of at least one line with predetermined and facilitated break strength. The user unwinds from the roll 1 a tape strip comprising one or more adhesive portions 2 joined together by nonadhesive portions 3 and peels this strip from the remaining tape of the roll 1 at the line 4 with predetermined and facilitated break strength. The leading end of the tape which remains on the coil 1 is still a nonadhesive portion 3, detached from the underlying turn of the coiled tape and forming a tab which helps to find, grasp and lift the end of the tape to unwind it from the roll 1. The tape strip peeled off the roll 1 also has a tab at one of its ends, which is formed by a corresponding nonadhesive portion 3 and is very useful to handle the separated adhesive tape strip and to peel and remove it, after its use, from the object whereon it is applied. Hence, for example, in the case of adhesive tapes used to attach drawings on drawing tables, said nonadhesive end 3, which is integral with an end of the adhesive tape strip separated from the roll 1, is highly useful to detach the strip from the drawing to remove, displace or stretch the drawing.

The nonadhesive portions 3 and the adhesive portions 2 may be of any length. So, for instance, the adhesive portions 2 may have each a length of about 5 cm, whereas the nonadhesive portions 3 may have each a length of about 0.5 cm. When the user needs an adhesive tape portion longer than 5 cm, he will simply unwind and separate from the roll a strip comprising two or more adhesive portions 2, joined together by interposed nonadhesive portions 3. The short nonadhesive portions 3 included in this strip between the adhesive portions 2 do not affect considerably the action of said strip, and even have an advantageous effect thereon, as they provide adhesiveness discontinuity, which has the effect of limiting any adhesion unevenness and compensating for the stresses of the material.

In accordance with an embodiment which is not shown but may be easily imagined, the adhesive portions 2 and the nonadhesive portions 3 of the tape of the invention substantially have the same length, preferably relatively small, whereby an adhesive tape is obtained which exerts a sew-like action.

According to another embodiment of the invention, the portions 2 form self-adhesive labels, whereas the nonadhesive portions 3 form non self-adhesive labels. The nonadhesive portions 3 may be arranged to be only slightly or partly adhesive or easily detachable, for instance figure 2 shows one of the methods disclosed in the introduction, description and claims hereof, and may thereby form substantially nonadhesive labels, for instance by the application of a strip of adhesive on one edge, to be attached in a non permanent and easily detachable way.

Obviously, the adhesive tape of the invention may have any length and be made of any material, e.g. plastic, transparent or not, or paper, textile material and others .

In accordance with a further characteristic, the easily detachable portions of the tape are obtained by means of the so-called hal -cuts, i.e. indentations through partial portions of the tape thickness along a predetermined break or tear-off line for separating individual easily detachable portions .

Regarding the provision of lines for separating easily detachable portions from the roll and the zones in which the tape extrados is partly or fully adhesive- repellent, it was observed that the position staggering between said zones due to the progressive increase of the winding radius remains within tolerances of one to a few millimeters for standard tape lengths (about 10 meters), i.e. definitely below the extension of the adhesive-repellent zones. However, in the process of coiling the tape with the back having adhesive- repellent (waxed) sections, the desired pitch is to be considered as a function of the start diameter of the roll : if the roll has a diameter D and the pitch of the segment, defined by the cut-off line is P, in order that the non-inhibited part overlaps the cutoff line, the staggered length shall be equal to the decimal part of the D/P ratio and, when the tape is very thick and/or long, the diameter of the dinking die may be appropriately increased to compensate for the staggering due to the thickness of the tape.

A further characteristic of the invention provides that a film having transverse fibers, with respect to the longitudinal extension of the tape, is used as a tape. This allows to tear the tape portions off the remaining coiled tape part along precise transverse lines, which do not tend to deviate in an uncontrolled manner in the tape longitudinal direction. The process for manufacturing the adhesive tape of the invention may be obtained, for instance, by using the most inexpensive of the state of the art methods, which includes, as is known, the steps of coating the whole tape web and of rereeling and cutting it to a smaller size by a special machine; this machine may be complemented with modules which, in this step, may perform all the operations provided herein, such as cutoff lines, tape printing, adhesive inhibition, physical/chemical processes as set out in the descriptions and claims hereof.

The invention is not limited to the embodiments illustrated and described herein, but may be greatly varied and modified, especially in the range of equivalents, without departure from the guiding principle disclosed above and claimed below.

ADVANTAGES The invention provides a number of advantages . Thanks to the tape of the invention, there is no need to fold the free leading end of the adhesive tape on itself, or to attach a lift-tab of nonadhesive material, e.g. paper, to said end, whereby an inconvenient and troublesome operation, which is not always possible, is avoided. The economic and operational problems of well- known dispensers, as well as the dangerousness thereof, are also obviated.

The invention, besides allowing a highly convenient and economic implementation, which does not require substantial changes of current adhesive tape manufacturing processes, provides a considerable convenience of use for the user. After unwinding an adhesive tape strip, consisting of one or more attached portions , from the roll , and a ter separating said strip from the remaining adhesive tape of the roll at the leading end of the next detached or easily detachable portion or at an intermediate position thereof, the leading end of the adhesive tape which is still coiled onto the roll is always automatically formed by a portion which is detached or easily detachable from the upper extrados side of the underlying coiled tape and allows to easily lift and grasp the leading end of the remaining adhesive tape to unwind it from the coil . The lines with predetermined and facilitated break strength appropriately have such a resistance as to allow that a strip comprising one or more attached portions joined together may be unwound and separated rom the roll , while allowing the user to easily separate the individual attached portions from each other and/or from the detached or easily detachable portions .

Thanks to the physical/chemical treatment of the adhesive coating, for the provision of adhesive- repellent zones, the advantage is obtained that the tape has an uninterrupted adhesiveness, since the tape lower intrados side may be evenly coated with adhesive all over its length, while achieving all the advantages determined, according to the invention, by the alternation of tape portions attached to the underlying turn of the coiled tape and tape portions detached or easily detachable from said turn.

Claims

1. A continuous adhesive tape coiled into a roll, characterized in that it consists of an alternate succession of portions (2) which are attached by their lower intrados adhesive-coated side, with a certain adhesion strength but in a detachable manner, to the outer extrados side of the underlying turn of the coiled tape, and of detached or easily detachable portions (3) , whereat the adhesion strength at the lower intrados side of the tape against the upper extrados side of the underlying turn of the coiled tape is null or considerably reduced.

2. An adhesive tape as claimed in claim 1 , characterized in that the adhesion of the lower intrados side of the adhesive tape against the upper extrados side of the underlying turn of the coiled tape at the detached or easily detachable portions is inhibited or reduced by annulling or weakening in any manner and by any means the adhesive action of the adhesive coating the lower intrados side.

3. An adhesive tape as claimed in claim 4 , characterized in that the adhesion at the detached or easily detachable portions is inhibited or reduced by wholly or partly covering the adhesive applied onto the lower side of the tape with a nonadhesive material or substance, applied with any process whatever.

4. An adhesive tape as claimed in claim 5 , characterized in that the nonadhesive covering material is ink or a mixture and is applied, for instance by printing processes .

5. An adhesive tape as claimed in claim 5 , characterized in that the nonadhesive covering substance is in powder form and is applied for instance directly or indirectly by an electrostatic process .

6. An adhesive tape as claimed in claim , characterized in that the adhesive action of the adhesive at the detached or easily detachable portions is annulled or reduced by wholly or partially drying or crystallizing, with any processes, the adhesive applied on the inner side of the tape.

7. An adhesive tape as claimed in claim 1 or one or more of claims 2 to 10, characterized in that the adhesion of the lower intrados side against the upper extrados side of the underlying turn of the coiled tape at the detached or easily detachable portions is inhibited or reduced wholly or partly by rendering said upper extrados side of the tape at least wholly or partly adhesive-repellent, by any processes and means and at least with respect to the adhesive applied on the lower intrados side of the tape.

8. An adhesive layer as claimed in claim 11, characterized in that the outer extrados side of the tape is rendered wholly or partly adhesive-repellent at the detached or easily detachable portions , by wholly or partly coating said side with an adhesive-repellent material or substance, applied with any process.

9. An adhesive tape as claimed in claim 8, characterized in that the adhesive-repellent material is a wax and is applied, for instance by means of printing processes.

10. An adhesive tape as claimed in claim 11, characterized in that, at the detached or easily detachable portions, the outer extrados side of the tape is rendered wholly or partly adhesive-repellent by means of chemical and/or physical and/or mechanical treatments, e.g. by laser beams, electromagnetic beams, corona discharge, heat treatments, catalysts, or others .

11. An adhesive tape as claimed in one or more of the preceding claims, characterized in that at least one line with predetermined and facilitated break strength is provided in the detached or easily detachable portion, preferably at the beginning of the portion in the roll unwinding direction, but without excluding other intermediate and/or opposite end positions .

12. An adhesive tape as claimed in one or more of the preceding claims, characterized in that the lines with predetermined and facilitated break strength in the tape keep such a resistance as to allow winding and unwinding from the roll of a continuous strip comprising two or more attached portions, joined together by detached or easily detachable portions, but in such a manner as to subsequently allow an easy separation between the individual portions of the peeled off strip.

13. An adhesive tape as claimed in one or more of the preceding claims, characterized in that the lines with predetermined and facilitated break strength may have any profile, particularly a straight, wavy, v- shaped, arrow-shaped profile directed towards the tape unwinding direction, and the like.

14. An adhesive tape as claimed in one or more of the preceding claims, characterized in that the lines with predetermined and facilitated break strength are obtained by any process and means, e.g. by die cutting, hal -cutting, embossing, punching, notching, and the like or generally with methods which allow the break to start on the edge of the tape.

15. An adhesive tape as claimed in one or more of the preceding claims, characterized in that the ratio of the detached or easily detachable portions to the attached portions mat be included in a range from a value in which it is maximized through intermediate values to an opposite value in which it is minimized.

16. An adhesive tape as claimed in one or more of the preceding claims, characterized in that the attached portions and/or the detached or easily detachable portions are provided with identification marks, which allow to distinguish them from each other and may even simply consist of a particular color.

17. An adhesive tape as claimed in one or more of the preceding claims, characterized in that the attached portions form normally self-adhesive labels, whereas the detached or easily detachable portions may form non self-adhesive labels or slightly or temporarily self-adhesive labels.

18. An adhesive tape as claimed in one or more of the preceding claims, characterized in that the non self-adhesive portions form labels having a self- adhesive or slightly or temporarily self-adhesive zone, for instance with the adhesive portion limited to an edge.

19. An adhesive tape as claimed in one or more of the preceding claims, characterized in that the tape is printed inside its portions, thereby forming labels.