GB2269366A - Blister packaging - Google Patents

Abstract

A blister pack for packaging goods includes a package sealing technique which avoids the use of glue seals, and in particular avoids cardboard to plastics seals. Apertures (72) in a backing card (62) are used in which to create bonding points between two plastics layers (74), (75) around the card. Alternatively, portions of the layers (74), (75) may cooperate mechanically through the apertures (72). <IMAGE>

Description

BLISTER PACKAGING The present invention relates to blister packaging of the type commonly used, for example, for the display and sale of multifarious goods.

Such packages normally provide a display area, upon which product details, instructions and advertising features may be printed. Such a display area may be provided as a cardboard layer, or other suitable medium.

This cardboard layer is attached to or incorporated within a plastics layer which is commonly moulded to accommodate the shape of the product or products to be contained therein. Typically, the plastics layer is formed from a transparent plastic material, such that the product contained therein and any portions of the display area behind the plastics layer may be visible therethrough.

Commonly, the plastics layer also has mechanical rigidity such that a product containment volume can be moulded from the plastics. (Alternatively, the plastics layer may take the shape of the product being enclosed in the form of a "skin pack", where the product is held against the cardboard layer by a skin or film of plastics.) It is common practice to use at least a portion of the display area or cardboard layer to assist in containment of the product, or to form part of the walls of the package, thus reducing the quantity of plastics used.

Such packages are usually required to meet specific individual product requirements (eg. shape), and are required at minimum cost to avoid undue loading of the product costs with those of the packaging. Minimal use of both cardboard as a display or backing material, and plastics as a moulded layer is desirable.

In order to meet certain desirable requirements relating to recycling of packaging materials, it is also necessary to avoid the use of plastics to cardboard glue bonding, or the like.

Individual packaging requirements may also prescribe the use of package sealing techniques which are "tamper evident" in order to clearly indicate whether a product has at some time been removed from the package, or at least to indicate that an attempt has been made to do so.

Alternatively, other package requirements may prescribe the use of package closure techniques which allow the removal and reinsertion of the product without causing damage to the fabric of the package.

It is also advantageous to provide a package which may be filled easily by machine, rather than requiring final assembly by human operator.

It is an object of the present invention to provide a packaging system which confers at least some of the above advantages.

According to one embodiment, the present invention provides a package including: a backing layer having a front surface and a back surface and incorporating at least one bonding aperture therethrough; a moulded layer including a product containment portion and at least one engagement portion adapted to retain said backing layer, said engagement portion including a first portion proximal to said front surface, a second portion proximal said back surface, and a third portion occupying at least part of said bonding aperture.

According to a further embodiment, the present invention provides a method of producing a package including the following steps: providing a backing layer having a front surface and a back surface and at least one aperture therethrough; providing a moulded layer including a product containment portion and at least one engagement portion; forming said engagement portion around at least a portion of said backing layer; bonding or mechanically contacting said engagement portion to itself through at least part of said bonding aperture.

Various prior art packaging techniques with disadvantages related thereto, and embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which: Figure 1 shows a perspective view of a prior art blister pack; Figure 2 shows a perspective view of a prior art clam shell pack; Figure 3 shows a perspective view of a prior art slide blister pack; Figure 4 shows a front view of a package in accordance with one embodiment of the present invention; Figure 5 shows a cross-section through line A-A of the embodiment of the present invention shown in figure 4; Figure 6 shows a perspective view of the embodiment of the present invention shown in figures 4 and 5; Figures 7, 8 and 9 show in cross-section a variety of bonding or mechanical contacting techniques which may be used in accordance with the present invention.

With reference to figure 1, there is shown a prior art blister pack 10, comprising a cardboard backing layer 12, providing a display area 14 upon which product information may be printed, a slot 16 facilitating the hanging of the package on a suitable apparatus, a pre-formed blister 18 manufactured from a transparent plastics material and defining a product containment portion 20 in conjunction with card 12. The preformed blister 18 includes a bonding portion 22 which is glued to the card 12. A problem with this type of package is that upon separating the blister 18 from the card 12 to extract the product contained therein, the blister retains cardboard and glue residues on the bonding portion 22. This presently causes difficulties with subsequent recycling techniques. Preferably, the cardboard and plastics layers should be entirely separable, and the use of glues avoided entirely.

With reference to figure 2, there is shown a prior art "clam-shell" pack 30, comprising a first plastics moulded blister 32 including a product containment portion 34, and a second plastics moulded blister 36 having a corresponding product containment portion (not shown) beneath the first blister 32. The two plastics moulded blisters are coupled together around the peripheral edges thereof to form seal 38. The seal 38 is a plastics-plastics seal, and may be achieved by heat sealing, hinge and snap-fit arrangement or other suitable type. A display card 39 may be inserted within the pack. Clearly, this package overcomes the problem relating to recyclability identified above, but is an expensive type of package to manufacture requiring plastics of high mechanical strength and of sufficient quantity to entirely envelop the product. Such packages are normally used with high value product.

With reference to figure 3 there are shown two variants of a prior art "slide blister' pack 40,42, each comprising a backing card 44, a preformed blister 46 having a product containment portion 48. The blister 46 is attached to the card 44 by recurved or folded portions 50 which lap around the edges of the card 44. The product is dropped into an upturned blister, and the card slid into place over the product. The card and blister may be mutually affixed by, for example stapling through both with staples 52 on pack 40, or, on pack 42, extending the card 44 to include a pair of shoulders 54 at one end of the slide blister, such that the blister may only be slid off in one direction. The slide blister overcomes the problems associated with recycling identified herein, but does not provide a package that is readily "tamper proof or "tamper evident". Further, the pack 42, while being "resealable", tends to open during handling and transit. The use of the shoulders 54 also necessitates waste in the manufacture of the card backing since cards cannot be stamped out of a large sheet exactly adjacent one another without waste.

The shoulders 54 also have a tendency to become dog-eared with time, or to become torn off completely. A small increase in width of shelf space to hang adjacent packages is also required as a result of the shoulders 54.

With reference to figure 4, 5 and 6 there is shown a pack 60 in accordance with one embodiment of the present invention. The pack comprises a backing card 62 including a display area 64 (not essential) upon which product information may be printed, a slot aperture 66 (also not essential) in the backing card 62 facilitating the hanging of the package on a suitable apparatus, a pre-formed blister 68 manufactured from a transparent plastic material and defining a product containment portion 70 in conjunction with backing card 62. The backing card 62 also includes a series of apertures 72 punched therethrough, which, in the embodiment shown include a series of small circular holes along the edges of the backing card.

The blister 68 includes two portions 74 (best seen on figure 5) which fold around the edges of the backing card 62. The card is thus restrained from moving in relation to the blister except by sliding in the same plane as the folded portions 74. The folded portions 74 are dimensioned to ensure overlap with the apertures 72 beneath the card.

The card is then prevented from slidable detachment from the blister by bonding the folded portion 74 of the blister 68 to a corresponding portion 75 on the front face of the card 62 through the apertures 72. Such bonding is preferably achieved by high frequency welding or heat stamp techniques, or any other method suitable to the materials being used.

The backing card is typically manufactured from a cardboard or paper based material, and the blister typically formed from a transparent plastic material.

However, any suitable material exhibiting the requisite mechanical properties may be used, and the blister need not be transparent. The bonding apertures may be of any suitable shape and number: for example, a long slot or other pattern may be used.

With reference to figures 7, 8 and 9, a number of bonding or mechanical contacting techniques appropriate to the present invention are now described. Figure 7 shows in detail the arrangement described with reference to figures 4, 5 and 6, wherein folded portion 74 is welded to a corresponding portion 75 of the front face of the blister, forming weld 76. The strength of the weld would be predetermined to allow opening of the package by exerting sufficient sliding force on the card 62 to break through the welds 76. Alternatively, the method of lifting of the folded portion 74 away from the card 62 to break the individual seals may be employed. In this case, the opening of the package and subsequent closure thereof will be evidenced by the broken welds.

Where tamper evidencing is not required, however, the structures shown in figures 8 and 9 may be used. In figure 8, the blister portion 75 is formed with indented regions 78 which are spaced to collocate with the holes 72 punched in the card. The resilience of the folded portion 74 of the blister maintains it in mechanical contact with the indented regions 78 through the apertures 72. Indented regions could alternatively be formed in the folded portion 74, or in both folded portion 74 and front portion 75 of the blister 68. In each variant, the formation of a mechanical contact between the folded portion 74 and the front blister portion 75 is achieved.

A further technique, shown in figure 9 uses a "pressstud" type arrangement with male and female portions 80,82 formed in the blister portions 75,74, again forming a mechanical contact therebetween. This technique results in complete resealability of the pack, with a high degree of mechanical robustness.

As described hereinbefore, when filling the packs with the articles to be packaged, commonly the blister is placed in an upturned position allowing the dropping of the product therein. Sliding of the backing card into the folded portions of the blister is an operation difficult to achieve automatically. An alternative is to form the blister without folded portions 74, but with outsized edges preparatory to forming said portions, and to place the card on the blister after the product has been inserted.

Appropriate heat forming equipment, in conjunction with the welding equipment to form bonds 76, indents 78 or studs 80,82 may complete the forming of the folded portion and seal the pack in a single pass operation.

Claims (9)

1 A package including: a backing layer having a front surface and a back surface and incorporating at least one bonding aperture therethrough; a moulded layer including a product containment portion and at least one engagement portion adapted to retain said backing layer, said engagement portion including a first portion proximal to said front surface, a second portion proximal said back surface, and a third portion occupying at least part of said bonding aperture.

2 A package according to claim 1 wherein said third portion comprises a bond between said first portion and said second portion.

3 A package according to claim 2 wherein said bond is achieved by high frequency welding or heat stamp.

4 A package according to claim 1 wherein said third portion comprises an indented portion in at least one of said first and second portions.

5 A package according to claim 4 wherein said third portion includes mechanically cooperating portions of said first and second portions.

6 A method of producing a package including the following steps: providing a backing layer having a front surface and a back surface and at least one aperture therethrough; providing a moulded layer including a product containment portion and at least one engagement portion; forming said engagement portion around at least a portion of said backing layer; bonding or mechanically contacting said engagement portion to itself through at least part of said bonding aperture.

7 A method according to claim 6 wherein said bonding step includes the step of heat stamping or high frequency welding the moulded layer.

8 A method according to claim 6 wherein said bonding or mechanically contacting step includes the steps of preparing an indented portion in the moulded layer.

9 A method according to claim 6 wherein said engagement portion is folded around said backing at immediately prior to said bonding step taking place.