EP3023357B1

EP3023357B1 - Sealed package opening witness based on a label comprising incisions

Info

Publication number: EP3023357B1
Application number: EP15195471.6A
Authority: EP
Inventors: Valerio Binda
Original assignee: Masterpack SpA
Current assignee: Masterpack SpA
Priority date: 2014-11-19
Filing date: 2015-11-19
Publication date: 2017-11-15
Anticipated expiration: 2035-11-19
Also published as: EP3023357A1; ITMI20140361U1

Description

TECHNICAL FIELD

The invention relates in general to techniques for packaging products in sealed enclosures of flexible plastic film, preferably heat-sealable, in general, but not exclusively, for dry food products for long shelf life, in sizes suited to a partial withdrawal of their contents.

BACKGROUND

The packaging of food products for human or livestock consumption in flexible packages of heat-sealable film is a widespread practice in the industry and in the commercial distribution.
Packages that can be reclosed to neatly preserve the product not consumed when the package is opened by breaking the airtight sealing of the heat-sealed package are desirable for many products. Some food products in current use, typically of small size and easily dispersible from packages which have been badly closed or which have not been provided with rubber bands, clips or clothes pegs, are in some cases packed in heat-sealed wrappers made of a flexible film and provided with a zip closure or a self-adhesive label for opening and reclosing a perimetric window which is suitably pre-defined in the flexible film of the package and is arranged under the self-adhesive label to allow a first tear-off pre-defined opening of the film and repeatable accesses to withdraw the required quantities of the product.
Such labels maintain over time self-adhesive properties along a perimetric strip projecting from the portion of the underlying film of the package that is commonly torn along a predefined breakage line while remaining adherent to the self-adhesive label when the package is opened for the first time.
A reclosable opening device of this type is described in the Italian patent application MI2014A001984 of the same applicant. Obvious reasons for preserving the sealing of the packaged product, often in a modified atmosphere for a longer shelf life, for hygienic safety as well as for allowing an easy control of a possible opening/misappropriation of part of the content, require the presence of seals or physical "witnesses" of the opened package.
It is a common practice to make, along the adhesive perimetric strip projecting from the portion of the packaging film adhering to the central portion of the reclosable label, incisions (cuts), generally partial cuts of corners or protuberances along the sides of the perimeter of the liftable part, often having shaped curve, which cause detachment of small perimetric portions (fragments) of the label delimited by partial incisions, so as to affect the possibility to restore the perimeter (with a perfect mating with such fragments) when re-adhering the adhesive label on the underlying film of the package once the incisions have undergone the inevitable deformation at the time of opening the packaging for the first time. The common practice to make these witnesses along the perimetric edge so as to avoid interferences by residues of witnesses with the lifted portion of the adhesive label when the latter is re-adhered to reclose the package, typically requires a greater overall size of the label to be applied on the packing film. These witnesses must on the one hand guarantee the effectiveness and reliability in confirming, to a careful inspection, the actual opening of the sealed package, and on the other hand must not, once deformed, be an obstacle when the lifted portion of the adhesive label is re-adhered on the packing film. US 2002/182359 A1 and EP 1 975 081 A1 disclose solutions in accordance with the preamble of claim 1.

GENERAL DESCRIPTION OF THE INVENTION

The applicant has devised an effective form of opening witness of a sealed package of flexible film with an opening device reclosable by a self-adhesive label sealing a window to access the contents, having a pre-defined area, through the underlying packing film, comprising incisions in the self-adhesive label in areas resting on perimetric areas of a liftable portion of the label in the opening phase, projecting with respect to the perimeter of said pre-defined opening area through the underlying packing film.
According to the invention of the applicant, said incisions in the label are entirely made on areas of the perimetric strip of the label portion to be lifted and bent backwards, inwards from the edge thereof. Each witness incision includes some U-shaped cuts arranged side by side, wherein the two rectilinear and parallel branches extending from the base of each U have a ratio preferably between 6 and 20 between the extension and separation distance between adjacent branches and the rectilinear extreme branches of a first U-shaped cut and the last U-shaped cut, respectively, of several cuts side by side, and are connected together by an arched cut, for example a semi-circumference.
Generally the witness incisions define from 2 to 10 U-shaped cuts, arranged side by side, although even with only 2 cuts the device demonstrates an acceptable reliability. Preferably the number of side by side cuts is between 2 and 6.
The incised areas of label have the bases of all the U-shaped cuts positioned side by side facing against the feed direction of the progressive lifting of the liftable portion of the label in the opening phase.
The orientation of the incisions may also be more or less inclined with respect to the axis of said direction within limits between -45° and + 45°, without the witnessing function being affected.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows the profile of a self-adhesive label overlapping a line of predetermined fracture of the underlying packing film with two incised areas according to an exemplifying embodiment of opening witnesses of the package.
Figures 2 and 3 respectively show alternative shapes of the incisions and their different orientations with respect to the axis of the feed direction of the progressive lifting of the liftable portion of the label in the opening phase.

DETAILED DESCRIPTION OF THE EXAMPLE SHOWN IN THE DRAWINGS

Figure 1 shows the image of a self-adhesive label 1, typically pre-applied "in register" on the outer surface of the film which the sealed package of the product is made with, in an overlapping position on a pre-defined fracture line of the underlying packing film.
The fracture line of the underlying film may consist of small cuts 2 aligned with each other, pre-incised in the film, separated by bridges of intact film and may describe a more or less elongated U that defines the rectangular area A of the reclosable opening of the package.
The self-adhesive label has one end defining a tear tab 3 free of adhesive, so as to be easily grasped between the fingertips of a hand and pulled back by progressively lifting the label and with it the portion of the underlying packing film, defined by incisions 2, which adheres to the label, as it separates from the remainder of the film along the pre-defined U-shaped fracture line when the separating bridges between cuts 2 are broken.
The profile of this liftable and foldable portion of the label is defined, in its last portion to be lifted, by a pair of identical cuts 4a and 4b at the two sides of the label, which define inwardly folded lips of the liftable profile, with swirl terminations 5a and 5b which stop the lifting and identify two points of a straight transverse line representing the extreme fold line of the liftable portion of the self-adhesive label. Once this line is reached, the two branches of the pre-defined tear line of the underlying film also end, if, as an alternative, that line is not transversally closed like a closed loop (in which case it causes a complete separation of the film portion of the opening when the sealed package is opened for the first time).
In the illustrated example, two internal areas of the peripheral strip of the liftable portion of the label have incisions T that carry out an effective witnesses evidence of opening according to the embodiment of the invention, while not requiring a purposely enlarged layout of self-adhesive label.
In the example, both incised areas indicated by arrows T define three U-shaped cuts t1, t2, t3 arranged side by side, with a ratio of about 10 between the length of extension (approximately 11 mm) from the base of the U and the separation distance (about 1,1 mm). The extreme straight branches of a first U-shaped cut t1 and of the last U-shaped cut t3, respectively, of the three cuts side by side, are connected together by an arched cut Tb which in the example is a semi-circumference even though it may have a different curved shape having a similar convexity.
The shape of the witness-incisions T allows them to be made inside the rim of the liftable portion of the label, thus ensuring a high reliability of their witnessing function and an insignificant tendency to create entanglements of stretched and fractured portions of adhesive film which may affect or disturb the re-sealing of the package after part of the product is withdrawn.

Claims

Opening witness of a sealed package of flexible film with an opening device reclosable by a self-adhesive label (1) which seals a window for accessing the content, having a pre-defined area (A), through the underlying film of the package, the witness comprising incisions (T) in the self-adhesive label (1) in areas resting on perimetric areas of a liftable portion of the label, projecting with respect to the perimeter of said pre-defined opening area (A) through the film of the package, characterized in that said incisions (T) in the label comprise some U-shaped cuts (t1, t2, t3) arranged side by side, two rectilinear and parallel branches extending from the base of each U, in which the straight extreme branches of the first U-shaped cut (t1) and the last U-shaped cut, respectively, of the cuts (t1, t2, t3) arranged side by side, are connected together by an arched cut (Tb).
Opening witness according to claim 1, wherein said cuts (t1, t2, t3) define from 2 to 10 U-shaped cuts, arranged side by side.
Opening witness according to claim 1, wherein said parallel branches of the U-shaped cuts (t1, t2, t3) have a ratio between 6 and 20 between the extension and the separation distance between adjacent branches.
Opening witness according to any one of the preceding claims, characterized in that the bases of the two parallel rectilinear branches of all U-shaped cuts (t1, t2, t3) adjacent to each other are facing against the feed direction of the progressive lifting of the liftable portion of the label (1) in the opening phase.
Opening witness according to claim 4, in which the orientation of the incisions (T) has an angle of inclination relative to the axis of said direction between -45 ° and + 45°.
Opening witness according to claim 1, wherein said connecting arched cut is a semi-circumference.
Opening witness according to any one of the preceding claims, characterized in that the length of extension of the branches of the U-shaped cuts (t1, t2, t3) is approximately 11 mm and the separation distance between these branches is about 1,1 mm.