GB2575014A

GB2575014A - Laminated sheet material

Info

Publication number: GB2575014A
Application number: GB201808358A
Authority: GB
Inventors: stokes Matthew
Original assignee: Suretech Adhesive Tapes Ltd
Current assignee: Suretech Adhesive Tapes Ltd
Priority date: 2018-05-22
Filing date: 2018-05-22
Publication date: 2020-01-01
Also published as: GB201808358D0

Abstract

The laminated sheet comprises a flexible backing 11 and a flexible cover 12. Adhesive regions 13a, 13b, 13c extend across only part of the interface between the backing and the cover. The adhesive remains on the backing when the cover is removed. Preferably, the cover 12 includes frangible lines 15 defining closed shapes 14 and the backing includes corresponding depressions or witness lines W. The packaging is preferably a blister pack. The preferred adhesive is a pressure sensitive adhesive or double-sided tape. The backing 11 is preferably opaque, e.g. coated paper. The cover 12 is preferably transparent plastic. The methods of producing the sheet, computer program controlling the method and system for supplying materials are also claimed.

Description

LAMINATED SHEET MATERIAL

This invention relates generally to laminated sheet material. More specifically, although not exclusively, this invention relates to laminated sheet material including a releasable cover sheet for use in a blister pack or other medication vessel.

Medicaments are often supplied in a foil or paper wrapped blister pack with a plurality of individual unit doses. Such blister packs generally contain a plurality of identical doses of the same medicament. However, it is also known to provide blister packs containing a plurality of different medications and/or different dosages prescribed as part of a complex treatment regimen. These blister packs can be organised according to their respective times of administration.

In some known blister pack designs, each dose can also include information relating to the particular dose. Such information can be printed on the blister pack, for example on a cover sheet at a location corresponding to the dose contained in the blister pack.

US2009084702 describes a blister pack having a first sheet formed with a plurality of indentations for receiving a respective dose of a medicament and a second, cover sheet secured to the first sheet. The cover sheet includes printed matter aligned with each indentation relating to the dose contained therein. The cover sheet is also scored, cut and/or perforated to enable an individual unit dose (a “blister”) to be removed from the blister pack.

The applicant has observed that manipulating perforated sheets through cutting and/or printing stations can be problematic. The applicant has also observed that, where such sheets are clear, printing can also be problematic

It is therefore a first non-exclusive object of the invention to provide a sheet material that at least mitigates the aforementioned and other issues with known designs.

Accordingly, a first aspect of the invention provides a laminated sheet material, e.g. for use in sealing an opening of a blister pack or other medication vessel, the sheet material comprising a backing sheet, which may be flexible, and a cover sheet, which may be flexible, releasably secured to the backing sheet by one or more adhesive regions, preferably wherein the or each adhesive region is configured to remain on the backing sheet when the cover sheet is removed, in use, from the backing sheet.

The use of adhesive regions that remain on the backing sheet enables, inter alia, greater control of the adherence between the sheet material and the backing sheet.

The cover sheet may comprise one or more, e.g. a plurality or array of, closed shapes, which may be described, defined or delineated by one or more frangible lines. The adhesive regions may therefore be configured, for example positioned, to inhibit separation of the closed shapes from the cover sheet.

The closed shapes may be substantially rectangular or square (e.g. with rounded corners), obround, elliptical, circular or any other suitable shape. The array of closed shapes may comprise one or more, e.g. a plurality of, columns of closed shapes. Additionally or alternatively, the array of closed shapes may comprise one or more, e.g. a plurality of, rows of closed shapes. The laminated sheet may comprise a first, e.g. longitudinal, dimension and/or a second, e.g. lateral, dimension. The lateral dimension may be orthogonal to the longitudinal dimension. The columns of closed shapes may extend along the first dimension and/or the rows of closed shapes may extend along the second dimension.

The cover sheet may be scored, cut or perforated, for example to describe, define or delineate the or each or at least one of the closed shapes. The or each or at least one frangible line may comprise a weakened line, such as a score line, a cut line, e.g. an interrupted cut line, or a perforated line. The cover sheet may comprise one or more interrupted cuts, which may describe, define or delineate the or each closed shape.

The frangible lines, scores, cuts or perforations in, through or along the cover sheet may comprise kiss cuts. The cover sheet may comprise one or more ties, which may comprise or correspond, e.g. respectively, to one or more interruptions in the interrupted cut(s). The or each closed shape may correspond to a blister or dose described in a blister pack or other medication vessel to which the cover sheet is to be mounted, secured or incorporated.

The one or more adhesive regions may extend across only part of the interface between the sheets. Additionally or alternatively, the one or more adhesive regions may describe, e.g. therebetween, one or more adhesive free regions. The one or more adhesive regions may comprise one or more, e.g. a plurality of, adhesive strips or tracks. The or each or at least one adhesive strip or track may extend along the first or second dimension of the cover sheet. As such, the position(s) of the adhesive free region(s) may be selected to match partly or substantially the frangible lines and/or closed shapes, e.g. thereby inhibiting or reducing the tendency of the closed shapes being separated from the cover sheet when it is removed or delaminated, in use, from the backing sheet. This has an additional benefit in that the quantity of adhesive required is reduced.

The proportion of the adhesive region(s) that overlap the closed shapes is preferably less than 50%, more preferably less than 30% and most preferably less than 20%, for example less than 15% or 10% or even 5%. Alternatively, there may be no overlap between the adhesive region(s) and the closed shapes. The or each or at least one adhesive region may, but need not, be located at least partially, substantially or completely between at least two adjacent closed shapes. The or each or at least one closed shape may be or be located or lie substantially within the adhesive free regions. The or each or at least one adhesive strip or track may extend at least partially, substantially or completely between adjacent columns or rows of closed shapes. The closed shapes of the cover sheet may be at least partially, substantially or completely free of adhesive regions.

Preferably, the or each or at least one adhesive strip or track extends along the longitudinal dimension and/or at least partially, substantially or completely between adjacent columns of closed shapes. The adhesive strips or tracks may extend entirely between adjacent columns or rows of closed shapes. The closed shapes are substantially free of adhesive strip(s), track(s) or region(s) or substantially free of any contact with the adhesive strip(s), track(s) or region(s).

The or each or at least one adhesive region may comprise at least one adhesive. The at least one adhesive may comprise a pressure-sensitive adhesive. The adhesive region may exhibit a greater adhesion or tack with the backing sheet than with the cover sheet. The or each or at least one adhesive region may comprise a double sided or double face tape.

The or each or at least one adhesive region may comprise a first adhesive facing the backing sheet and a second adhesive facing the cover sheet. Alternatively, the adhesive region may comprise an adhesive, e.g. a single or mixed composite adhesive, which exhibits a greater adhesion or tack with the backing sheet than with the cover sheet.

The cover sheet may be at least partially, substantially or completely clear, transparent or translucent. The cover sheet may be described, defined or delineated by a frangible line, e.g. in, through or along a cover sheet layer. The cover sheet may comprise a weldable, for example heat or ultrasonically weldable, material. The cover sheet may comprise a plastics or polymeric material. The cover sheet may comprise a laminated construction, for example incorporating two or more layers of different material. The cover sheet may comprise a nonpermeable material. The cover sheet may comprise a film.

The cover sheet may comprise a surface receptive to ink, e.g. a surface receptive to the depositing of an ink material thereon and/or to which an ink readily adheres. The cover sheet may comprise a major surface, for example first and/or exposed major surface. The surface receptive to ink may comprise the major surface or first and/or exposed major surface of the cover sheet. The cover sheet may comprise a major surface, e.g. a second major surface, which faces and/or which is in contact with the adhesive region(s) and/or the backing sheet. The first major surface may be on the opposite side of the cover sheet to the second major surface.

The cover sheet may comprise indicia or information printed thereon, e.g. on the surface receptive to ink. The or at least one or each closed shape may comprise indicia or information printed thereon. Each or at least two closed shapes may comprise indicia or information printed thereon, which may be different and/or may relate or correspond to a blister or dose described in a blister pack or other medication vessel to which the cover sheet is to be mounted, secured or incorporated.

The cover sheet may comprise, or one or more frangible lines may describe, one or more ties configured to act as a hinge, e.g. such that the closed shape provides a hinged flap. For example, the hinge tie may be configured to resist or inhibit removal of the closed shape from the cover sheet, e.g. instead providing a hinge about which the closed shape may pivot or bend. The hinge tie may extend across some, most or all of one side of the closed shape.

The cover sheet may comprise one or more location features, for example locators. The location features may be for locating, e.g. by a packaging system, the cover sheet relative to a blister pack or other medication vessel. The location features may be on, at or adjacent a periphery of the cover sheet.

The backing sheet may be opaque or substantially opaque. The backing sheet may comprise one or more depressions or witness lines, which may correspond to and/or be aligned with the frangible lines, scores, cuts, perforations or kiss cuts in, through or along the cover sheet. The backing sheet may comprise paper or a paper based material or any suitable material. Optionally, the backing sheet may comprise a coated paper material. The coated paper material may comprise a first major surface, which may (but need not)_be coated, for example with a silicone material. The coated paper material may comprise a second major surface, which may be uncoated or coated with a different material to the coating on the first major surface. The second major surface of the backing sheet may face the cover sheet.

Another aspect of the invention provides a method of making a laminated sheet material, for example as described above. The method may comprise releasably securing a backing sheet, which may be flexible, to a cover sheet, which may be flexible, by one or more adhesive regions. The or each adhesive region may be configured to remain on the backing sheet when the cover sheet is removed, in use, from the backing sheet.

The method may comprise forming in, along or thorough the cover sheet one or more, e.g. a plurality or array of, closed shapes. The method may comprise forming one or more frangible lines, e.g. to describe, define or delineate the closed shapes. The frangible lines may be formed to describe, define or delineate rectangles or squares (e.g. with rounded corners), obrounds, ellipses, circles or any other suitable shapes.

The frangible lines may be formed to describe, define or delineate one or more, e.g. a plurality of, columns and/or rows of closed shapes. The columns of closed shapes may be formed along a first, longitudinal dimension of the laminated sheet and/or the rows of closed shapes may be formed along a second, lateral dimension of the laminated sheet or vice versa.

The frangible lines may be formed by scoring, cutting or perforating the cover sheet. The method may comprise kiss cutting the frangible lines, e.g. in, through or along the cover sheet. The method may comprise forming depressions or witness lines in or on or across the backing sheet, which may correspond to and/or be aligned with the frangible lines, scores, cuts, perforations or kiss cuts in, through or along the cover sheet. The frangible lines may be formed by forming or making one or more interrupted cuts, which may describe, define or delineate the or each closed shape. The frangible lines may be formed to describe, define or delineate one or more ties, which may comprise or correspond, e.g. respectively, to one or more interruptions in the interrupted cut(s).

The frangible lines may be formed to correspond to one or more blister(s) or dose(s) described in a blister pack or other medication vessel to which the cover sheet is to be mounted, secured or incorporated. The method may comprise forming one or more location features, for example locators, in, on or through the cover sheet, e.g. at or adjacent a periphery thereof.

The method may comprise providing or applying one or more adhesive regions across only part of the interface between the sheets. Additionally or alternatively, the method may comprise providing or applying one or more adhesive regions to the backing sheet and/or cover sheet so as to describe, e.g. therebetween, one or more adhesive free regions. The method may comprise providing or applying one or more, e.g. a plurality of, adhesive strips or tracks, e.g. corresponding to the adhesive regions.

The method comprises providing or applying at least one adhesive strip or track along the first or second dimension of the cover sheet. The method comprises providing or applying at least one adhesive strip or track at least partially, substantially or completely between at least two adjacent closed shapes. The method comprises providing or applying at least one adhesive strip or track at least partially, substantially or completely between adjacent columns or rows of closed shapes.

Preferably, the method comprises providing or applying at least one adhesive strip or track, which may comprise a double sided or double face tape. The adhesive strip or track may comprise a pressure-sensitive adhesive and/or may exhibit a greater adhesion or tack with the backing sheet than with the cover sheet. The method may comprise providing or applying the at least one adhesive strip or track along the longitudinal dimension and/or at least partially, substantially or completely between adjacent columns of closed shapes.

The method may comprise providing or applying at least one the adhesive strips or tracks entirely between adjacent columns or rows of closed shapes. The method may comprise providing or applying the adhesive strip(s), track(s) or region(s) such that the closed shapes are substantially free thereof or substantially free of any contact therewith.

The method may comprise applying ink to and/or printing on the cover sheet, for example to form indicia or information thereon. The method may comprise applying ink to and/or printing on at least one or each closed shape. The method may comprise printing indicia or information on at least one or each closed shape. The method may comprise printing different indicia or information on each of at least two of the closed shapes. The indicia or information may relate or correspond to a blister or dose described in a blister pack or other medication vessel to which the cover sheet is to be mounted, secured or incorporated.

Another aspect of the invention provides a system for making a laminated sheet material, for example as described above. The system may be operable or configured to make the laminated sheet material according to the method described above.

The system may comprise a cover sheet supply means or mechanism, a backing sheet supply means or mechanism and/or an adhesive supply means or mechanism. The system may be operable or configured to apply, e.g. using the adhesive supply means or mechanism, an adhesive to a backing sheet material supplied by the backing sheet supply means or mechanism.

Additionally or alternatively, system may be operable or configured to apply, e.g. using the adhesive supply means or mechanism, an adhesive to a cover sheet material supplied by the cover sheet supply means or mechanism. The system may be operable or configured to bring the backing sheet material and the cover sheet material together with the adhesive therebetween. The system may comprise a cutting, scoring or perforating station, which may be operable or configured to cut, score or perforate the cover sheet.

For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention. For example, the laminated sheet material may comprise any one or more features of the system or method relevant thereto. Similarly, the method may comprise any one or more features or steps relevant to one or more features of the system or the laminated sheet material or vice versa.

A further aspect of the invention provides a computer program element comprising computer readable program code means for causing a processor to execute a procedure to implement one or more steps of the aforementioned method. A yet further aspect of the invention provides the computer program element embodied on a computer readable medium. A yet further aspect of the invention provides a computer readable medium having a program stored thereon, where the program is arranged to make a computer execute a procedure to implement one or more steps of the aforementioned method.

A yet further aspect of the invention provides a control means or control system or controller comprising the aforementioned computer program element or computer readable medium. Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. For the avoidance of doubt, the terms “may”, “and/or”, “e.g.”, “for example” and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a laminated sheet material according to an embodiment of the invention;

Figure 2 is a perspective view of a laminated sheet material according to another embodiment of the invention;

Figure 3 is a plan view of a backing sheet having three adhesive tracks;

Figure 4 is a plan view of a laminated sheet material according to another embodiment of the invention incorporating the backing sheet of Figure 3;

Figure 5 is a plan view of a backing sheet having five adhesive tracks;

Figure 6 is a plan view of a laminated sheet material according to yet another embodiment of the invention incorporating the backing sheet of Figure 5;

Figure 7 is a perspective exploded view of a laminated sheet material according to another embodiment of the invention; and

Figure 8 is a perspective exploded view of a laminated sheet material according to yet another embodiment of the invention.

Referring now to Figure 1, there is shown a laminated sheet material 10 for use in sealing an opening of a blister pack or other medication vessel (not shown). The sheet material 10 includes a flexible backing sheet 11 and a flexible cover sheet 12 releasably secured to the backing sheet 11 by three adhesive strips or tracks 13a, 13b, 13c. The sheet material 10 is rectangular in this example and has a longitudinal dimension Li and a lateral dimension l_2, perpendicular to the longitudinal dimension Li.

The backing sheet 11 is formed of an opaque paper with a silicone coating on its reverse major surface 11a, in order to facilitate handling. However, it will be appreciated that the coating is purely optional and may be omitted or replaced with a different coating. The cover sheet 12 is formed of a substantially transparent weldable plastics material having an exposed major surface 12a that is receptive to ink, in order to facilitate printing of information thereon. The adhesive tracks 13a, 13b, 13c are located between the facing major surfaces of the backing sheet 11 and cover sheet 12 and along the longitudinal dimension Li. The adhesive tracks 13a, 13b, 13c include a central track 13a and two lateral tracks 13b, 13c each extending along one of the longitudinal edges of the laminated sheet material 10 to describe adhesive free regions AF.

The cover sheet 12 includes an array often closed shapes 14, rectangles in this example, which are described by a plurality of frangible lines 15. The array of rectangles 14 include two columns C and five rows R. The columns C extend along the longitudinal dimension Li and the rows R extend along the lateral dimension l_2. The frangible lines 15 are interrupted cut lines, formed by a kiss cut operation so as to define a plurality of ties T that inhibit separation of the rectangles 14 from the cover sheet 12. The backing sheet 11 also includes witness lines W formed by the kiss cut operation, but without penetrating the backing sheet 11, thereby maintaining its structural integrity and facilitating the manipulation of the laminated sheet material 10.

Each of the rectangles 14 corresponds to a blister or dose (not shown) described in a blister pack or other medication vessel (not shown) to which the cover sheet 12 is to be mounted, secured or incorporated. More specifically, the cover sheet 12 is to be removed from the backing sheet 11 and subsequently welded or otherwise secured to the blister pack or other medication vessel (not shown) such that each rectangle 14 covers and seals one of the blisters or doses (not shown) of the blister pack or other medication vessel (not shown). In some applications, each rectangle 14 will be secured or welded along its periphery to the medication vessel (not shown). In other applications, only the margins between the rectangles will be secured or welded to the medication vessel (not shown) and the frangible lines 15 facilitate removal of the rectangle 14 to expose the relevant dose.

In order to facilitate the separation, or delamination, of the cover sheet 12 and backing sheet 11, the adhesive tracks 13a, 13b, 13c are configured to remain on the backing sheet when the cover sheet 12 is removed, in use, from the backing sheet 11. This can be achieved in a number of different ways. For example, the adhesive tracks 13a, 13b, 13c may include an adhesive that exhibits a greater adhesion or tack with the backing sheet 11 than with the cover sheet 12. Alternatively, the adhesive tracks 13a, 13b, 13c could include more than one adhesive, one of which may be a permanent adhesive facing the backing sheet 11 and another of which may be a pressure-sensitive adhesive facing the cover sheet such that the adhesive tracks 13a, 13b, 13c are retained on the backing sheet 11. Conveniently, each adhesive track 13a, 13b, 13c may be applied as a double sided or double face tape, preferably through an automated process.

Moreover, the adhesive tracks 13a, 13b, 13c extend along the margins between the rectangles 14, with the central adhesive track 13a extending between the columns C of rectangles 14 and the lateral tracks 13b, 13c extending along the outer edge of the columns C. As such, the rectangles 14 overlie the adhesive free regions AF. Whilst the rectangles may overlie the adhesive tracks 13a, 13b, 13c to some extent, it is preferred that rectangles 14 are at least substantially free, if not entirely free, of any overlap or contact with the adhesive tracks 13a, 13b, 13c. This reduces the likelihood of inadvertent separation of the rectangles 14 from the cover sheet 12 during separation or delamination thereof from the backing sheet 11.

In use, the laminated sheet material 10 is passed through a printer (not shown), which prints bespoke information (not shown) specific to each rectangle 14. The information relates to a specific blister or dose of a blister pack or other medication vessel (not shown) to which the cover sheet 12 is to be secured. After the printing operation, the cover sheet 12 is peeled from the backing sheet 11, with the adhesive tracks 13a, 13b, 13c remaining on the backing sheet 11. The cover sheet 12 is then applied to the medication vessel (not shown) such that each rectangle 14 is aligned with a respective dose and to which the information relates.

Referring now to Figure 2, there is shown another example of a laminated sheet material 20 for use in sealing an opening of a medication vessel (not shown). The sheet material 20 according to this example is similar to the sheet material 10 according to the first example, wherein like features are labelled with like references with the prefix ‘2’. The sheet material 20 according to this example differs from the sheet material 10 according to the first example in that the array of ten rectangles 14 is replaced with an array of twenty squares 24 arranged in four columns C and five rows R. The sheet material 20 also includes two additional, intermediate adhesive tracks 23c, 23d in addition to the central and lateral adhesive tracks 23a, 23b, 23c.

Another example of a laminated sheet material 30 for sealing an opening of a medication vessel (not shown) is illustrated in Figures 3 and 4. The sheet material 30 according to this example is similar to those according to earlier examples, wherein like features are labelled with like references with the prefix ‘3’. The backing sheet 31 of the sheet material 30, shown in Figure 3, is substantially the same as the backing sheet 11 of the first example in that it includes a central adhesive track 33a and a pair of lateral adhesive tracks 33b, 33c extending along the longitudinal side edges of the backing sheet, with adhesive free regions AF therebetween.

As shown more clearly in Figure 4, the sheet material 30 according to this example differs from the sheet material 10, 20 described above in that the rectangles 14 and squares 24 are replaced with an array of twenty-eight closed shapes 34 arranged in four columns C and seven rows R. The central adhesive track 33a extends along the margin between the two innermost columns C, while the margin between each of the central and outer columns C is free of adhesive. The lateral adhesive tracks 33b, 33c extend along the outer margins of the sheet material 30, as in the previous examples.

The closed shapes 34 in this example are substantially square with rounded corners 34a, 34b. A first pair of adjacent corners 34a (uppermost in Figure 4) have a smaller radius of curvature than the opposite pair of adjacent corners 34b (lowermost in Figure 4). In this example, the cover sheet 32 extends across only part of the upper layer of the sheet material 30 and is described by cut lines 36a, 36b. The cover sheet 32 also includes a pair of opposed semi-circular location cutouts 37 on each longitudinal edge adjacent its lower edge, which serve to provide a locating function in subsequent assembly operations when the cover sheet 32 is incorporated into a medication vessel (not shown).

Another example of a laminated sheet material 40 for sealing an opening of a medication vessel (not shown) is illustrated in Figures 5 and 6. The sheet material 40 according to this example is similar to those according to earlier examples, wherein like features are labelled with like references with the prefix ‘4’. The backing sheet 41 of the sheet material 40, shown in Figure 5, is substantially the same as the backing sheet 21 of the second example in that it includes central, lateral and intermediate adhesive tracks 43a, 43b, 43c, 43d, 43e with adhesive free regions AF therebetween.

As shown more clearly in Figure 6, the cover sheet 42 of the sheet material 40 according to this example is similar to that of the third example. Specifically, the closed shapes 44 are substantially square with rounded corners 44a, 44b and are arranged in four columns C and seven rows R. However, in this embodiment, the intermediate adhesive tracks 43d, 43e extend along the margin between each of the central and outer columns C. As such, adhesive tracks 43a, 43b, 43c, 43d, 43e are present at the margins between all columns C and along the longitudinal edges of the sheet material 40. In addition, each closed shape 44 includes bespoke information 48 specific thereto and relating to a specific dose of a medication vessel (not shown) to which the cover sheet 42 is to be secured.

Another example of a laminated sheet material 50 is illustrated in Figure 7. The sheet material 50 according to this example is similar to those according to earlier examples, wherein like features are labelled with like references with the prefix ‘5’. The sheet material 50 according to this example differs from the sheet material 10 according to the first example in that the array of rectangles 14 is omitted.

Yet another example of a laminated sheet material 60 is illustrated in Figure 7. The sheet material 60 according to this example is similar to those according to earlier examples, wherein like features are labelled with like references with the prefix ‘6’. The sheet material 60 according to this example differs from the sheet material 20 according to the second example in that the array of squares 24 is omitted.

It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, the array of closed shapes 14, 24, 34, 44 may comprise any shape or arrangement, which need not be cartesian or arranged in rows R and columns C. The adhesive tracks 13a, 13b, 13c, 23a, 23b, 23c, 23d, 23e, 33a, 33b, 33c, 43a, 43b, 43c, 43d, 43e, 53a, 53b, 53c, 63a, 63b, 63c, 63d, 63e may be replaced with one or more adhesive region(s) of any shape. The backing sheet 11, 21, 31, 41, 51, 61 need not be opaque or formed of a paper material or have a coating thereon. Similarly, the cover sheet 12, 22, 32, 42, 52, 62 need not be clear or flexible or formed of a plastics material. The frangible lines 15, 25, 35, 45 need not be interrupted cut lines formed by a kiss cut operation; they may comprise any form of weakened line formed by any suitable operation.

It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.

Claims

1. A laminated sheet material for use in sealing an opening of a medication vessel, the sheet material comprising a flexible backing sheet and a flexible cover sheet releasably secured to the backing sheet by one or more adhesive regions extending across only part of the interface between the sheets, wherein the or each adhesive region is configured to remain on the backing sheet when the cover sheet is removed, in use, from the backing sheet.

2. Sheet material according to claim 1, wherein the cover sheet comprises an array of closed shapes described by frangible lines and the backing sheet comprises depressions or witness lines corresponding to the frangible lines.

3. Sheet material according to claim 2, wherein the or each adhesive region is substantially between adjacent closed shapes, such that the closed shapes of the cover sheet are substantially free of adhesive regions.

4. Sheet material according to claim 3, wherein the array of closed shapes comprises a plurality of columns extending along a first, longitudinal dimension of the sheet material and a plurality of rows extending along a second, lateral dimension of the sheet material, the adhesive region(s) comprising an adhesive strip or track extending along the longitudinal dimension substantially between two adjacent columns and/or an adhesive strip or track extending along the lateral dimension substantially between two adjacent rows.

5. Sheet material according to any one of claims 2 to 4, wherein each closed shape corresponds to a blister or dose described in a blister pack or other medication vessel to which the cover sheet is to be secured, the cover sheet being receptive to ink for printing indicia or information relating to the blister or dose.

6. Sheet material according to claim 5 comprising indicia or information printed on one or more of the closed shapes relating to a corresponding blister or dose of a blister pack or other medication vessel to which the cover sheet is to be secured.

7. Sheet according to any preceding claim, wherein the or each adhesive region comprises a pressure-sensitive adhesive exhibiting a greater adhesion or tack with the backing sheet than with the cover sheet.

8. Sheet according to any preceding claim, wherein the or each adhesive region comprises a double sided or double face tape.

9. Sheet according to any preceding claim, wherein the cover sheet is transparent or translucent and the backing sheet is substantially opaque.

10. Sheet according to any preceding claim, wherein the cover sheet comprises a weldable plastics or polymeric material.

11. A method of making a laminated sheet material, the method comprising releasably securing a flexible backing sheet to a flexible cover sheet by one or more adhesive regions extending across only part of the interface between the sheets, wherein the or each adhesive region is configured to remain on the backing sheet if the cover sheet is removed from the backing sheet.

12. Method according to claim 11 comprising applying one or more adhesives to the backing sheet or to the cover sheet to form the adhesive region(s) before securing the cover sheet to the backing sheet.

13. Method according to claim 11 or claim 12 comprising kiss cutting the cover sheet after it is secured to the backing sheet to form an array of closed shapes described by frangible lines in the cover sheet and to form depressions or witness lines in the backing sheet which correspond to the frangible lines.

14. Method according to claim 13 comprising forming a plurality of columns extending along a first, longitudinal dimension of the sheet material and a plurality of rows extending along a second, lateral dimension of the sheet material, the adhesive region(s) comprising an adhesive strip or track extending along the longitudinal dimension substantially between two adjacent columns and/or an adhesive strip or track extending along the lateral dimension substantially between two adjacent rows.

15. Method according to claim 13 or claim 14 comprising printing different indicia or information on each of at least two of the closed shapes, the indicia or information on each closed shape corresponding to a blister or dose described in a blister pack or other medication vessel to which the cover sheet is to be mounted, secured or incorporated.

16. A computer program element comprising computer readable program code means for causing a processor to execute a procedure to implement the method of any one of claims 11 to 15.

17. A computer program element according to claim 16 embodied on a computer readable medium.

18. A computer readable medium having a program stored thereon, where the program is arranged to make a computer execute a procedure to implement the method of any one of claims 11 to 15.

19. A system for carrying out the method of any one of claims 11 to 15, the system comprising a cover sheet supply means, a backing sheet supply means and an adhesive supply means, wherein the system is operable or configured to apply, using the adhesive supply means, an adhesive to a backing sheet material supplied by the backing sheet supply means and to secure a cover sheet material supplied by the cover sheet supply means to the backing sheet carrying the adhesive.