WO2010023661A2

WO2010023661A2 - Continuous web or tape having a pressure sensitive adhesive layer

Info

Publication number: WO2010023661A2
Application number: PCT/IL2009/000821
Authority: WO
Inventors: Tsion Habshush; Uri Dat; Guy Wind
Original assignee: Davik Cooperative Agricultural Society Ltd.
Priority date: 2008-08-26
Filing date: 2009-08-25
Publication date: 2010-03-04
Also published as: WO2010023661A3

Abstract

A continuous web or tape having a pressure sensitive adhesive layer having a plurality of cross-strips that are spaced along the length of the web or tape and that are easily identifiable so as to mark discrete segments in the web or tape.

Description

Continuous web or tape having a pressure sensitive adhesive layer

FIELD OF THE INVENTION

The present invention relates to continuous segmented pressure sensitive adhesive web or tape.

BACKGROUND OF THE INVENTION Self-adhesive products are offered in different forms such as continuous wide web or narrow tapes supplied in rolls, sheets or strips supplied in stacks or individually packed, in one or more layers, coated on one or both surfaces. Individually packed medical products such as bandages, patches, sutures etc. are cumbersome to use. One needs to tear the packing material, remove the protecting liner from the adhesive and only then is the product ready to be applied on the skin. During these acts there is a risk of contamination of the adhesive that may occur on contact with the user's fingers. After a product has served its purpose and it is time to remove it from the surface to which it was stuck, it is sometimes difficult to lift the edge of the product. It is particularly problematic with medical bandages or patches stuck to the skin, where in extreme cases, the user or medical staff must use a solvent, such as benzene, to loosen the edge of the bandage from the skin.

When discrete segments from a continuous web or tape in a roll are needed, it is possible to use a dispenser equipped with a cutting blade. In the case of segments of predetermined length, it is possible to avoid the need for a dispenser by making perforations, which allow the user to manually tear segments apart. A problem when using a roll of single-layer adhesive tape or perforated pressure sensitive web or tape is that after cutting or tearing a segment from the roll, the leading edge of the next segment will in most cases stick to the exposed surface of the roll. This will occur regardless of whether or not the adhesive roll is divided in advance into discrete segments or whether the segments are defined by the act of cutting the tape. When another segment is needed, it is then hard to locate the leading edge of the segment and time is frequently wasted searching for the edge around the circumference of the roll. Once located, the leading edge needs to be scratched with a finger-nail or the like in order to release it from the roll.

Care is required to release the whole width of the web or tape prior to pulling since failure to do so may cause the web or tape to split in the longitudinal direction, rendering at least the end of the material unusable and causing waste. A series of perforated holes or cuts can sometimes be effective but some materials do not tear reliably along the perforations causing tear propagation in unexpected directions. Particularly problematic in this respect are web or tape based on mono-oriented film or fabric with strong filaments. The latter tend to split easily in the longitudinal direction and cause a waste of material.

BRIEF SUMMARY OF THE INVENTION

In accordance with an aspect of the invention there is provided a continuous web or tape having a pressure-sensitive adhesive layer, said continuous web or tape having a plurality of cross-strips that are spaced along the length of the web or tape and that are easily identifiable so as to mark discrete segments in the web or tape.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figs. 1 is a pictorial representation showing a section of a roll of adhesive tape having cross strips and areas of reduced strength in accordance with an embodiment of the invention; Figs. 2a and 2b are pictorial representations showing respective layout of blades used for forming areas of reduced strength in a roll of adhesive tape according to an embodiment of the invention; and

Figs. 3a and 3b are pictorial representations showing applications of the invention according to different embodiments. DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 is a pictorial representation showing a section of a roll of adhesive tape 11 in accordance with an embodiment of the invention having a plurality of cross-strips 12. Each cross-strip 12 has an area of reduced strength 13 so as to allow the tape to be torn easily therethrough. The spaces between the strips can be regular or in another desired pattern. The cross- strips are easily identifiable so as to mark discrete segments in the web or tape.

In one embodiment, the strips are not sticky thus forming tabs at the end of each segment. The tabs enable the user to manually grip and pull the segment without the need for a dispenser and without touching the adhesive with the fingers. In some cases after applying the web or tape to a surface, the tabs allow the user to peel the segment off the surface.

Lack of stickiness may be achieved by not coating the strip with adhesive. Alternatively, the strips may be formed by removing or neutralizing adhesive previously coated on or otherwise applied to the web or tape. Such an approach is also suitable when the web or tape is formed by extrusion so that the adhesive layer is formed together with the web or tape during manufacture, the strips then being formed by neutralizing the adhesive or rendering it inactive. The adhesive may be neutralized by lamination of another material, powder coating, printing, etc. Alternatively, the strips may be formed of a material applied to the adhesive web or tape prior to coating adhesive thereon and which does retain the adhesive that is subsequently applied to the adhesive web or tape. For example, the material may be a release agent that effectively dispels the adhesive or renders it inactive.

The strips 12 may be rendered visibly distinguishable by having a different shade than the web or tape. This difference in shade may be achieved by printing the film prior to coating with adhesive or after coating by laminating with another web, coating with powder, printing with ink etc, all having different shade than the web or tape.

The strips 12 have an area 13 of reduced strength which may be achieved in various ways. In the case of oriented polymeric web or tape the lower strength area can be made by irradiation or heating in order to disturb the orientation of the polymer at that area and thereby substantially reduce its strength. The irradiation may be within a wavelength range where the polymer absorbs most of the energy thereby raising the temperature most effectively. Heating the web or tape can be done by direct contact with a suitable heating element such as a heated bar. Other heating elements suitable for obtaining low strength in polymeric web or tape are a heated blade having variable temperature zones, or an electrically conducting foil through which electric current run, having one straight edge and second edge having a wavy shape and thereby having alternate temperatures zones along said straight edge. The lower strength area can be also achieved by scoring the web or tape using a wavy sharp cold blade particularly in non-heat sensitive materials.

Fig. 2a shows a blade 20 having a sharp wavy edge 21 formed of a plurality of crests 22 and troughs 23, so that when the blade is applied to the web, it cuts the web non-uniformly. In use, the blade 20 is applied transversely to the web so as to only partially score the web without severing it completely whereby the lower strength area thus formed may be easily torn.

Fig. 2b shows a heating element 25 that may be in uniform in shape but is configured to exhibit a plurality of maximum temperature zones 26 separated by corresponding minimum temperature zones 27. In use, the heating element 25 is placed transversely on the web so as to apply heat non- uniformly to the web, so as to weaken the web without severing it completely whereby the lower strength area thus formed may be easily torn.

The depth of penetration of the above-mentioned heating elements and blades into the web or tape may be varied from partial scoring to complete penetration. Disturbing the orientation of the polymer and partial penetration through a cross-section of the web or tape creates straight lines, which prevents propagation of the split in unexpected directions.

In one embodiment, the web or tape comprises a carrier material coated on one surface with a pressure-sensitive adhesive and coated on an opposite surface with a release agent. In another embodiment both surfaces are coated with a pressure-sensitive adhesive. Example 1

Medical bandage - Fig. 3a shows a section of a roll of medical tape 31 , one side of which is coated with a pressure sensitive adhesive. Segments of the tape include an intermediate area 34 that serves as a substrate in the form of a pad medicated during the manufacturing process and having tabs 32 at opposite ends thereof. Low strength lines 33 are stamped between bandages.

The tabs have a different shade to the tape, making it easy to locate and to pull a bandage for use. The low strength lines enable the user to manually snap a bandage with ease. The core of a roll is made with side discs in accordance with the width of the tape so as to keep the product sterile. By gripping the end tab of a bandage and unwinding it from the roll, it is possible to apply the bandage immediately on the skin without finger-contact and risk of contamination of the adhesive and the user's skin. Disengaging the bandage from the roll is easily done by pulling the entire roll from the bandage. When the time arrives to remove the bandage, the tabs at each end enable the user to grip and peel the bandage off the skin, thus eliminating the use of a solvent upon difficulty in removing the bandage. An economic benefit of the product lies in the elimination of costly release liner and individual wrap of each bandage. The product is user-friendly by avoiding the need to tear the wrap and remove the release liner. In addition the product is cheaper to produce.

The principles of the invention are equally applicable to other medical products such as transdermal patches for controlled release drug delivery, wound dressings, diagnosis etc. They are applicable to non-medical products as will now be described.

Example 2

Carry handles - Fig. 3b shows a section of a roll of tape 35, one side of which is coated with a pressure sensitive adhesive. Segments of the tape include an intermediate area 36, where the adhesive is covered with a plain or printed layer and non-sticky tabs 37 at the ends. Low strength lines 38 are stamped between segments. The tabs 37 have a different shade to rest of the tape 35, making it easy to locate and to pull a handle for use. The low strength lines enable the user to manually detach a handle for use with ease.

While the invention has been described in connection with a number of embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A continuous web or tape having a pressure-sensitive adhesive layer, said continuous web or tape having a plurality of cross-strips that are spaced along the length of the web or tape and that are easily identifiable so as to mark discrete segments in the web or tape.

2. The adhesive web or tape according to claim 1 , wherein the strips are non-sticky.

3. The adhesive web or tape according to claim 2, wherein the strips are not coated with adhesive.

4. The adhesive web or tape according to claim 2, wherein during manufacture the strips are formed of a neutralized coating of adhesive.

5. The adhesive web or tape according to claim 2, wherein the strips are formed of a material applied to the adhesive web or tape prior to coating adhesive thereon and which does retain the adhesive.

6. The adhesive web or tape according to claim 1 comprising a backing material coated on one surface with pressure sensitive adhesive and coated on an opposite surface with a release agent.

7. The adhesive web or tape according to claim 1 comprising a backing material coated on opposite surfaces thereof with a pressure sensitive adhesive.

8. The adhesive web or tape according to claim 1, wherein the strips contain areas of lower strength.

9. A medical bandage including an adhesive web or tape according to any one of claims 1 to 8.

10. A carry handle including an adhesive web or tape according to any one of claims 1 to 8.

11. A method for producing areas of lower strength in the adhesive polymeric web or tape according to claim 8, the method comprising: irradiating or heating said areas of the web or tape.

12. A method for producing areas of lower strength in the adhesive polymeric web or tape according to claim 8, the method comprising: scoring a surface of said areas of the web or tape with a heated blade having variable temperature zones which penetrates to a variable depth into polymeric web or tape.

13. The method according to claim 12, including using a heated electrically conductive blade having one straight edge and a second opposite edge of non-uniform straightness so that the blade is of variable width along its length causing electrical current and thereby temperature to vary along the straight edge.

14. The method according to claim 13, wherein variations in said width along the length of the blade are periodic.

15. The method according to claim 14, wherein variations in said width along the length of the blade are sinusoidal.

16. A method for producing areas of lower strength in the adhesive polymeric web or tape according to claim 8, the method comprising: using a blade with wavy sharp edge to penetrate to variable depth into the web or tape.

17. A method for manufacturing the adhesive web or tape according to claim 2, said method comprising: coating the adhesive web or tape with adhesive, and subsequently neutralizing the adhesiveness of areas of the adhesive web or tape so as to form said strips.

18. The method according to claim 17, wherein neutralizing the adhesiveness of said areas is achieved by lamination, powder coating, or ink printing.