Foil sheet for blister packs

The invention relates to a blister film for a press through package according to the preamble of claim 1, wherein the foil sheet seals the packaged product, but by the pressing of the packaging material is torn open or broken.

Such blister foils are usually made of metal and are connected to an existing plastic thermoforming sheet to refer, for example medicines in tablet form individually, can be exposed without other tablets of the atmosphere. Even small parts are offered in such packages or in blister packs. If such an existing packaging made of different materials are reprocessed, there are considerable difficulties.

Although it has been suggested occasionally to provide a blister pack with a cover made of paper, but then goes often the protection for the packaged drug is not, and moreover also give problems in recycling, especially paper must then often coated and adhesive to connect with the deep-drawing packaging may be required.

From DE-GM 91 03 973 a press-through foil for a blister package of the type mentioned is known to exist in which the front and rear part of the same plastic. In order for this package can be opened, the blister film is provided with a rupturable perforation, ie, the interior of this packaging is not sealed.

Although already existing plastic cover films have been mentioned for example for packaging of medicines, but this one by pressing especially more sensitive drug is usually not or not without damaging the sometimes provided in the form of capsules available tablets possible. Plastic films as cover films for dense packaging have therefore not enforced in practice.

The invention has for its object to provide a foil sheet of the type mentioned for blister packaging, the finished despite its breakaway or openability its contents tightly and protectively surrounds by its barrier properties against spoilage.

The solution to this apparently contradictory task is that of forming the foil sheet material is a mixture of plastics that forms in the melt and the film formed therefrom at least two phases.

There are so together per se incompatible plastics are mixed and processed into the foil sheet, so that it indeed gives a closed and therefore suitable for cover film, but has only a low tensile or Schlagzugfestigkeit. Thus arises despite the use of a plastic film which is easily recycled along with the rest of the plastic packaging, the ability to press through this rupture foil the packaged part easily and without risk of damage and without unnecessary effort and without using tools. This is achieved, that are mixed here per se incompatible plastics.

Although is known from DE 37 10 670 A1 already an adhesive tape having a backing sheet of plastic known that turns easily with your fingers or can be demolished. However, this is based on a granularity of particulate aggregates.

From DE 28 46 002 A1 discloses a process to make polyolefin films by means of coating compositions better thermally weldable, wherein the coating agent may contain PMMA. A push-through film of the generic type with the means for solving the above problem is not obvious.

The blister sheet may consist of a mixture of polyolefins and other polymers. It can thus be used and mixed plastics which form a multiphase system, yet also used together again or can be reprocessed.

The mixture of the film-forming resin may be from 10% to 90%, in particular 40% to 70%, from polyolefins (non-polar polymers), and 90% to 10%, in particular 60% to 30%, of other polymers (polar polymers) be composed. Depending on the choice of the mixing ratios of different features can be more or less set and highlighted.

The forming the sheet plastics mixture may consist of polypropylene (PP) and / or polyethylene (PE) and / or ethylene vinyl acetate (EVA) on the one hand, and polymethylmethacrylate (PMMA) and / or polyacrylonitrile (PAN) and / or acrylonitrile-butadiene-styrene block copolymer ( ABS) and / or styrene-acrylonitrile block copolymer (SAN) and / or polyvinyl chloride (PVC) on the other hand consist. With these different plastics can be films with multiple phases are formed, which thus have a correspondingly slight crushing or tearability when you press a packaged object.

It is expedient if the rupture foil can be welded or sealable with other films or the like. They can then be connected to a thermoformed blister or without adhesive or a sealing layer is required, which in turn promotes the remanufacturing or recycling. Of course, also be coated with a suitable adhesive, the push-through film but, for example, to provide a desired adhesion to other films.

A controller or favoring certain properties can be effected by that forming the rupture foil mixture an increased proportion of PMMA, PVC, ABS, PAN and / or SAN for bonding agents weldability with films or the like made of PVC, ABS, PAN or PS (polystyrene) contains.

Another possibility is that the forming the rupture foil mixture contains an increased polyolefin for bonding agents weldability to PP foils or the like.

The blister foil may be to improve the barrier properties against gas, water vapor and the like, for example, with PVDC (polyvinylidene chloride) or SiO (silicon oxide) or aluminum coated or vapor-deposited. This medication can for example be packaged that are sensitive to moisture or require a defined atmosphere within the package.

The thickness of the foil sheet may be about 20 to 500 .mu.m, in particular amount to about 60 to 300 microns. Thus Durchdrückbarkeit can moreover be influenced by the thickness of the film.

Overall, especially in combination of one or more of the features and measures a rupture foil can be packed tightly sealed with the pills or other drugs or small parts and allows a material or thermal recycling of this rupture foil having packing in much simpler form, as is the case in the use of aluminum or other masking materials to plastic packaging. Thus, it is practically created a mono packaging, the material may be in accordance with well again used, but nevertheless the required good Durchdrückbarkeit is achieved by the multi-phase system of the push-through film.

Below two embodiments of the invention using the drawings are described in detail. It shows in perspective view:<dl id="dl0001"><dt>Fig.1</dt><dd>a blister pack with a push-through film as a rear closure, which is already depressed, and</dd><dt>Fig.2</dt><dd>a Tablettenblisterpackung with foil sheet, from which a tablet is taken.</dd></dl>

A designated as a whole with 1 blister packaging can be designed either as a blister pack or as tablet blister pack with individual thermoformed departments for the individual tablets. In both cases, the deep-drawn area for receiving a product or several tablets or the like sealed by a foil sheet 2 that protects the packaged product and moisture-proof or even air-tight, but easy removal of the packaged product is characterized allowed that this simply pushed through the blister foil 2 becomes. In Fig.1 and 2, a product to be packaged has already been pushed through the push-through film 2, so that this is torn open or broken open.

The blister film according to Fig.1 and 2, a plastic film, wherein the plastic is a mixture of such plastics that forms at least two or more phases in the melt and then in the film formed therefrom. This corresponding material differences arise in the press-through foil 2, favoring the breaking and tearing. By using at least two different types of thermoplastics that are actually incompatible with each other, formed as it were from the outset intended breaking or predetermined tearing points, although not everybody be prefabricated as such in the form of weakening of the foil sheet. 2 In this way the packages allow 1 after removal of the packaged goods both stoffliches and thermal recycling without a complicated separation of different materials must be carried out and less energy is required than is the case for example with plastic packaging whose rupture foil is made of aluminum ,

The press-through foil 2 is welded to the blister 3 or the like adhesion promoter-free, since the plastic mixtures facilitate adequate weldability or sealability with the plastic blister. Depending on the choice of the composition of the plastic mixture for the push-through film, and also the choice of the thickness of this foil sheet 2, the Durchdrückbarkeit or the tightness of the packing as well as the weldability can be influenced and adapted to respective requirements.

The push-through film 2 for press-through pack 1 consists of a plastic mixture of plastics which forms in the melt and the film formed therefrom at least two phases, ie inhomogeneities, so that the tear and Schlagzugfestigkeit is reduced. According effectively it can be a packaged good by pushing through this film, complete a full course but before.