WO1997001495A1

WO1997001495A1 - A self-adhesive label with tear strip

Info

Publication number: WO1997001495A1
Application number: PCT/DK1996/000095
Authority: WO
Inventors: Per-Christian LERSTRØM; Kim Hansen
Original assignee: KLIMAX ETIKETTERING AS
Current assignee: KLIMAX ETIKETTERING AS
Priority date: 1995-06-29
Filing date: 1996-03-07
Publication date: 1997-01-16
Anticipated expiration: 1997-12-29
Also published as: DK9500245U3; AU4938996A

Abstract

The invention relates to a self-adhesive label (2'), being originally part of a front material (2) adheringly affixed, by an adhesive layer (6), to a carrier material (1), said label being intended for transferral from the carrier material to a two piece packing article, so as to cover the joint between those two pieces, and a part of the label in the front material (2) carrying a perforation (4) to be torn up in connection with the opening of the packing, and the carrier material (1) comprising a punch-out (3) being situated underneath the perforation in the front material and being extended in an important part of the longitudinal extension of the perforation, said punch-out in the carrier material extending into the tear-up starting area of the perforation in the front material. The characteristic feature is, that the whole punched-out piece (3') of the carrier material, as such, remains on a back side (7) of the label (2'), when said label is transferred from the carrier to the packing article. Thereby is obtained, that the punched-out piece (3') of carrier material, like a tear thread member, goes along with the perforation strip (4) during the tearing-up thereof in connection with the opening of the packing article. In a preferred embodiment, a tear flap (5) is provided at the one end of the perforation in the front material.

Description

A self-adhesive label with tear strip

Technical field

The invention relates to a self-adhesive label according to the preamble of claim 1 , the combi_¬ nation consisting of such label stuck up on a carrier, the manufacture thereof, the use of the label for sealing two-piece packing containers, and to the sealed articles as such.

Background art

Labels with tear strip are known, inter alia for sealing cylindrical cardboard packing containers with a body part and a lid part, for instance comprising cheese in portions. Such labels are mounted on the filled-up packing container so as to cover the joint between the body part and the lid part. When the packing container is to be opened by the consumer, the sealing label has to be broken. In a known label type, the opening is accomplished using a thread on the back side, underneath the front, said thread being gripable, and the label being tearable using this thread, following which the lid part of the packing is removable or at least releasable from the body part.

Labels with a tear strip like member in the form of a perforation, the adhesive underneath the perforation being neutralised and thus allowing the tearing off of the strip, are also known.

These known sealing labels, however, are disadvantageous. The manufacturing of the type of labels having a thread or tear strip inteφosed between the label and the carrier is difficult, because at first you have to separate the label and the carrier, next the thread has to be put in, and then the label and the carrier must be reassembled. An exact adjustment, difficult to con¬ trol in practice, of these operations is required. What often happens is, that the two layers of the reassembled label are mutually wrongly or aslant positioned, or the thread is put in wrongly or aslant.

Concerning the labels of the latter type, a tear strip being formed of the label material as such, the same considerations apply as above, because also in this case you have to first separate the two webs, neutralise the adhesive in a central stripe and then reassemble the two webs; a very high accuracy is required. Still further, labels of this type have shown up not to have the required strength; when trying to tear up the strip, it simply breaks, thus irritating and being disadvantageous to the consumer.

Two embodiments of a sealing label are described in EP-B1-0 373 013, viz. a first and a sec¬ ond embodiment (figs. 1-5 and 6-9, respectively). In both labels, the label as well as the carrier is made of a plastic material. In the first embodiment, a tear strip with a tear tab is described as being "part of the carrier. From fig. 3, however, it is apparent that one has to inteφret this statement as follows: A portion of the carrier is punched out, and an enlarged or thicker portion of the label material projects down into this cut-out. Accordingly, the punched out portion of the carrier as such does not go along with the label. In the second embodiment, the canier has a punch out, however in a limited area in the vicinity of the tear flap only, and accordingly only a rather limited part of the punched out carrier material goes along with the label to the packing, viz. the part in the tear flap area, cf. fig. 8.

Primarily, the thicker tear tab (fig. 6-9) or the thicker tear tab plus tear strip (fig. 1-5) serve(s) the puφose of having the label correctly seated on the containers during the high speed trans- ferral of the labels to the containers. That is to say, these thicker parts, being at least partially "part of the carrier, are preferably positioned in a special groove between the container body and lid. In a container without such groove, the need to incoφorate the carrier in the label structure as such is abolished (fig. 9).

The label according to the first embodiment of EP-B1-0 373 013 is considered the closest piece of prior art, as it is appreciated in the preamble of claim 1.

Disclosure of the invention

The problems mentioned above conceming the known self-adhesive labels with tear strip, as related to their manufacture, and the problem due to the lacking consumer friendliness, are solved in a suφrisingly simple way by the features indicated in the characterising part of claim 1. This is because the cut-out piece of carrier material remains on the back side of the label when transferred from the carrier to the packing container, and thereby is obtained that the said piece of carrier functions as a tear thread like member, reinforcing the tear strip as perforated in the label at the front, so as to keep this perforation intact during its tearing off.

In claim 11 , the invention is worded differently, focusing on this aspect of use.

The punching of the carrier as well as the perforation of the front material is successively per- formable, in a continuous process using one and the same apparatus, the need to separating and reassembling the webs being thus eliminated.

This simple and inexpensive solution has shown up to work satisfactorily in practice.

The label is transferred from the carrier to the two piece packing using for instance a dispenser. When later on breaking the sealed packing, the co-transferred piece of carrier is going along with the tear strip as defined by the perforation in the front. In the present text, "perforation" defines a punctiform or partial release, whereas "punching" defines a higher degree of release, in particular complete release. In the following, however, the potential existence of so-called "lice" is discussed.

The cut-out in the carrier should correspond to the perforation in the front, that is to say the cut¬ out must be positioned underneath the perforation in the front and following a considerable part of the length of the perforation; in particular, it is essential for the cut-out to overlap with the perforation in the front material in the area of starting the tearing up. The above expression "a considerable part of the length of the perforation" means preferably minimum 50%, especially minimum 75%, more especially minimum 90%. However, the cut-out and the perforation might also be of identical length, i.e. corresponding to 100%. The perforation need not extend in the whole length of the label; this depends on the specific intended use of the label.

The width of the cut-out may be equal to, somewhat larger or somewhat smaller than the width of the perforation.

In the labels field, the direct incoφoration of a large piece of carrier material as such in a label is a rather unusual approach, in particular for the purpose of reinforcing a tear strip perforated in the front material. In the conventional type labels, the front material only is punched. In fact, a technical prejudice is prevailing as to the possibility of punching the carrier, said prejudice telling that the strength of the carrier material would thereby be prohibitively reduced, of ne¬ cessity resulting in manufacturing problems or in problems in connection with the use of the labels. With the label of the invention, this technical prejudice is now overcome.

The starting label material and the label shape is highly variable, depending on the actual use of the label. For instance, the label may be of an overall lengthy shape, viz. generally rectangu¬ lar, if desired having rounded edge areas and curved sides, the length being several times the width, e.g. 20 times. Labels of this type are used for instance in connection with packing con¬ tainers for cheese in portions mentioned above. These oblong, slim labels are to be placed externally around the cylindrical cardboard packing so as to cover the joint between body and lid thereof, the perforation and the punch-out accordingly being extended approximately in the longitudinal direction of the label, preferably at the middle thereof and preferably in parallel with the longitudinal sides thereof. However, the label could as well be relatively short and wide, for instance if intended for capped bottles.

The labels of the invention are transferred to the packing containers in a dispensing step. In this connection the label roll is mounted on a roller, and the disengaged carrier web is spooled onto another roller. The spooling occurs at high speed (perhaps 10-50 m/min), and accordingly a rather high tension is applied, in particular to the carrier paper web. Besides, during the manu¬ facturing process, a high tensile impact is applied to the combined label web, viz. in the strip¬ ping process step of removing excess front material, leaving the ready-for-use labels back on the carrier and removing any waste material.

Following the punching step, the strength of the carrier web, as well as that of the web consist¬ ing of labels on the punched carrier, is drastically reduced. In this connection, it is probably the tensile strength, which is of relevance. Accordingly, if a roller spools or draws slightly unequally, or if a web roll happens to be not very precisely positioned on the roller, breaks in the carrier web or in the combined web are readily foreseeable, leading to production hold up and the like troubles.

In the label of the invention, any conventional type self-adhesive material can be used as a starting material. In particular, ready-for-use label material comprising a front material adhered to a carrier material, usually provided in the form of rolls, the width and the length of which being as desired. In this self-adhesive material, the front material already carries adhesive on its back side, and the carrier material, if desired, has been treated with a release agent with a view to easily disengaging the label. Lots of labels of varying front and carrier material are commercially available (e.g. paper or plastic or combinations thereof, of varying glazing, calli- per (thickness) etc.). In-between these web layers, various adhesives can be used (various types of adhesive, permanent/releasable etc.). The release treatment, if any, e.g. a silicone treatment, may result in any desired release value. The skilled man certainly knows how to choose the correct starting material, paying regard to i.a. the intended use.

In fact, it has proved possible to make the label of the invention on the basis of front and carrier materials containing paper, in particular on the basis of materials, the important part of which is paper, i.e. materials on a paper basis, even though the strength, in particular the tensile strength, is smaller than for instance of plastic materials. Even paper as such is a suitable starting material. This is rather suφrising, because the strength of a punched-out carrier mate- rial, as well as that of the combined web comprising such punched-out carrier web, is drastically reduced because of the punch-out. In conclusion, one would expect, in particular for materials on a paper basis, that this would lead to invincible technical problems, i.a. breaks of the paper web because of rollers, which are drawing a bit unequally, a not perfectly positioned web etc.

To arrive at the label of the invention, on the basis of the starting material described above, the label as such has to be punched out in an overall shape according to the intended use (as desired). Usually, the label carries a message printed upon it, for instance an advertising or informational text. Finally, of course, the punching of the carrier and the perforation of the front material is made. All of the said steps can be carried out using a label printing apparatus.

The label of the invention is widely applicable, for instance in the dairy sector; cheese having already been mentioned; but also in the confectionery sector, lid-carrying boxes for sweets and cookies being obvious articles. The use in connection with sanitary articles and for goods such as washing powder is straight forward. The same goes for any bottle packing. In principle, the cross-sectional shape of the label carrying area of the actual packing can be curved as well as angular or edged.

The dependent claims relate to particular embodiments of the invention.

According to claim 2, the label may be provided with a tear flap, with a view to making the tearing up easier. This tear flap, too, has to be reinforced by correspondingly extending the punch-out in the carrier material.

Preferably, however, according to claim 3, the carrier material is not extended to exactly corre¬ spond with the length of the tear flap. Thereby is obtained a slight sticking of the tear flap to the packing article, viz. because of the adhesive on the back side at those surfaces, which do not carry along punched-out carrier material. Accordingly, during storage etc., the tear flap does not protrude, what could otherwise result in unintentional breaking of the sealing. Only when it is desired to open the packing by tearing the seal, and when one accordingly slightly pulls or draws at the tear flap, it is released from the packing and is willingly torn along.

With the embodiment of claim 4, an improved adherence of the tear flap is obtained.

With the embodiment of claim 5, the tearing-up process ends, when the end of the cut-out of the earner material is reached. Accordingly, the lid is not immediately removable, anyhow it is tiltably openable. Thereby, the strength of the carrier material is improved (a higher degree of intact carrier, cf. below).

Following several production trials, the width of the carrier cut-out indicated in claim 6 has shown up to be optimum,. Preferably, the width of the cut-out is about 10% of the label width, e.g. for a label width of the order of 20 mm.

A too narrow cut-out, i.e. of too small width, is very easily flying off, for instance in the manu¬ facturing process, during the final spooling step, or perhaps during the dispensing of the labels to the packing articles. And the cut-out should remain on the back side of the label when placed on the packing article.

If on the other hand the width of the cut-out is too large, the strength of the carrier is too much reduced. As explained above, this may lead to breaking webs, for instance during the dispens¬ ing, and accordingly production hold up.

With a view to further reducing the risk of web breaking, the incoφoration of so-called "lice" is foreseen, viz. punctiform areas of non-complete punching-out of the carrier.

For reasons related to the manufacturing, the perforation of the front material is preferably of a different width as compared to the punch-out of the carrier, in particular, the former perforation is somewhat larger than the latter punch-out. This is because the two cutting operations take place in one process on one and the same apparatus. And the cutting of a perforation in the front exactly on top of a cutting line already existing in the carrier material is not immediately that easy, since the front cutting tool would then lack a stable support for its cutting operation.

Brief description of the drawings Special embodiments Reference is now had to the drawings which describe special embodiments of the label of the invention. -

Fig. 1 shows, from the carrier material side, a label adhered to a carrier material; fig. 2 the same as in fig. 1 , but from the front side, excess front material having been stripped off; fig. 3 a label, from the front side and having been stripped off the carrier, and fig. 4 a preferred embodiment of a stripped-off label comprising a tear tap, and fig. 5 a sectional view of the label of fig. 4, along the line ll-ll, however still being positioned on the carrier.

Fig. 1 illustrates a tom-off part of a label roll comprising labels adhered to a carrier 1. Fig. 1 is seen from the carrier side. The dotted lines indicate one complete punch-out 3 in the carrier 1. The beginning of a next punch-out 13 corresponding to another label is also indicated.

Fig. 2 illustrates the same tom-off part of a label roll as in fig. 1, however this time one is look¬ ing down on a front 2 thereof. The label as such, the one to be transferred, is a part of this front material 2. One complete label 2' is shown having a central, longitudinal perforation 4 (shown in dotted lines), however not extending over the whole length of the label, and a tear flap 5. In the embodiment shown, the tear flap 5 is not enlarged as compared to the rest of the perforation 4. A rear part of a previous label and a foremost part of a label 12' to follow is also indicated, said label 12' having a perforation 14 and a tear flap 15. Waste front material 2 not to be made use of is stripped off, so as to reveal the carrier 1 surrounding the label 2'. As such, i.e. in this shape, the label of the invention is delivered to the user. In the embodiment shown, the punch- out in the carrier and the perforation in the front are of equal length and width, however not extended in the whole length of the label.

A stripped-off label corresponding to the one shown in fig. 1 and 2 is illustrated in fig. 3. During the dispensing or stripping-off step, usually, the label is, in the same process, applied to the actual packing article. Therefore, fig. 3, shows a purely hypothetical situation, the label having just been released from the carrier, but not stickingly adhered to a packing article.

A preferred embodiment of a stripped-off label 2' according to the invention is shown in fig. 4, said label having a tear flap 5 protruding at the one end. The perforation in the front 2 is indi¬ cated by dotted lines, and the underlying punch-out 3 in the carrier 1 is shown in hatching. In this embodiment, the punch-out 3 is shorter and slimmer than the perforation 4. The tear flap 5 constitutes an elongation of the perforation 4. The punch-out 3 in the carrier 1 lies centrally underneath the perforation 4 in the front 2 and extends to the tear flap 5 area, however not to the free end thereof. The length of the label without tear flap is 354 mm. The perforation in the front extends over the whole length of the label. The outermost 10 mm of the canier at the end opposite to the tear flap are not punched. The width of the label as such is about 19 mm and of the perforation in the front 4 mm. The width of the carrier material 1 is about 20 mm. The width of the punch-out in the carrier is 2 mm. The tear flap projects 5 mm from the label and has an outermost width of 5 mm, narrowing down or tapering towards the rear end over a length of 5 mm to the same width as the rest of the perforation.

Fig. 5 illustrates a sectional view of a label 2', section along the line ll-ll of fig. 4, anyhow, the label 2' is still on its carrier 1 , stuck via a Iayer of adhesive 6. The dimensions shown do not necessarily reflect the actual ones. The perforation 4 in the front is defined by dotted lines, whereas the punch-out 3 in the carrier is shown in unbroken lines. When transferred to a pack¬ ing article, the punched-out piece 3' as such of carrier material remains on a back side 7 of the label 2' (an adhesive Iayer in-between). When the perforation strip 4 is later on torn up, the punched-out piece 3' of carrier material goes along with it.

In the example below, a preferred embodiment of the invention is described in detail, said em¬ bodiment corresponding to the one shown in figs. 4 and 5. Example

The preferred embodiment

The starting material is self-adhesive label material in rolls of a web width of 220 mm and of the type MC 90 - S-451 of the company FASSON. Front paper (face stock): White, one side adhesive coated, supercalendered woodfree printing paper with semi gloss appearance. Basic weight (ISO 536): 90 g/m² . Calliper (thickness) (ISO 534): 0,084 mm. Adhesive: A general puφose permanent rubber based adhesive. Peel adhesion 90°: 440 N/m. (FINAT test method no. 9, stainless steel). Quick stick: 700 N/m (FINAT test method no. 9, glass). Min. application temperature: -5"C. Service temperature: -40/+80°C. Liner: BG40 brown/white, a super calen- dered glassine paper. Basic weight (ISO 536): 65 g/m² . Calliper (ISO 534): 0,057 mm. Trans¬ parency (DIN 53147): 45%

For punching and printing a Nilpeter label printing machine is used, type B200 for UV letter¬ press printing. The desired message is printed, and the punching is made as follows:

Punch for the label, front side: Format (width x length): 18,8 x 359F mm, R (edge radius) = 2 mm, Z (number of teeth, teeth on 1/8 inch) = 114; Circumference = 361,95 mm; 10 labels across a 220 mm web width.

Punching cylinder for the carrier material designed for this special puφose: Format 2 X 348F mm; R = 2 mm; Z = 114; Circumference = 361,95 mm; 10 labels across a 220 mm web width.

Punch cylinder of the magnet type for perforating the front material: Format approximately 3 x 359 mm, besides as above under punch for the label, the front side, however with perfora¬ tion, viz. 3 mm punch, 2 mm non-punch alternating in the longitudinal direction. Besides a flap is perforated at the one end, said flap protruding 5 mm from the label, width 5 mm, however changing over a 5 mm length to the same width as the rest of the perforation (4 mm).

In case of carrier material flying off or release problems, the punch cylinder for the carrier may be covered with a foam rubber pad having openings corresponding to the cutting edges.

Following the printing and the punching steps, the labels are cut up into 10 rolls and waste front material is stripped off.

Final (dispensed or stripped-off) label size and shape: Rectangular with rounded edges, 359 x 18,8 mm (length x width), a 4 mm wide perforation in the front material and a 2 mm wide punch-out in the carrier material. Tear flap as mentioned above. Thickness: 150 μ, viz. front paper: approximately 60 μ and carrier paper approximately 80 μ.

Application: Cylindrical cheese packing, diameter about 110 mm, height about 20 mm. Mounted using a Collamat dispenser, whatever type.

Claims

1. A self-adhesive label (2'), forming originally part of a front material (2) adheringly af¬ fixed, by an adhesive Iayer (6), to a carrier material (1), said label being intended for transferral from the carrier material to a two piece packing article, so as to cover the joint between those two pieces, and a part of the label in the front material (2) carrying a perforation (4) to be torn up in connection with the opening of the packing, and the carrier material (1) comprising a punch-out (3) being situated underneath the perforation in the front material and being ex¬ tended in an important part of the longitudinal extension of the perforation, said punch-out in the carrier material extending into the tear-up starting area of the perforation in the front mate¬ rial, characterized in that the whole punched-out piece (3') of the carrier material, as such, remains on a back side (7) ofthe label (2'), when said label is transferred from the carrier to the packing article.

2. A label according to claim 1, characterized in that the front material (2) at the one end thereof has a tear flap (5), directiy in continuation of the perforation (4), and that the punch-out (3) in the carrier material at the same end is also longitudinally extended.

3. A label according to claim 2, characterized in that the tear flap (5) in the front material is longer than the corresponding longitudinal extension of the punch-out (3) in the carrier material.

4. A label according to any one of claims 2-3, characterized in that the tear flap (5) in the front material, at the free end thereof, is wider than the rest of the front material perforation (4).

5. A label according to any one of claims 1-4, characterized in that the carrier punch-out (3) is shorter than the front perforation (4).

6. A label according to any one of ciaims 1-5, characterized in that the width of the punched-out piece (3') of carrier material constitutes maximum 25%, particularly maximum 20%, especially maximum 15%, more especially maximum 10% ofthe label width.

7. The combined product consisting of a label (2') according to claim 1 adheringly affixed to a carrier (1).

8. Use of a self-adhesive label (2') according to claim 1 for sealing two piece packing articles.

9. A packed good sealed with a self-adhesive label (2') according to claim 1.

10. A process of preparing a label (2') according to claim 1 , adheringly affixed to a carrier, comprising the steps of punching in the front and carrier material to produce a perforation (4) in the front and a punch-out (3) in the carrier, the punch-out being situated underneath the perfo¬ ration in the front material and being extended for an important part of the length of this perfo¬ ration, said punch-out in the carrier material being extended into the tear up starting part of the perforation in the front material, and so as to make the punched-out piece (3') of carrier mate- rial remain on a back side (7) of the label (2') in connection with the transferral thereof from the carrier material to the packing article.

11. The use, in a self-adhesive label (2') of the type as described in the preamble of claim 1 , of a punched-out piece (3') of carrier material for reinforcing a tear strip in the shape of a perforation (4) in the label, said punched-out carrier piece (3') remaining on a back side (7) of the self-adhesive label in connection with its transferral from the carrier to a packing article.