Packaging material and item of packaging

Abstract

Packaging material for producing deep-drawn plastics material packagings, particularly of multipack packagings, wherein the material is constructed to be breakable, and packaging produced therefrom.

Claims

1. A packaging material for producing deep-drawn plastics material packagings, characterised in that: the packaging material is based on polypropylene, bio-polypropylene or plastics materials containing polypropylene or bio-polypropylene; the packaging material is of multi-layered construction; fillers are added to at least one material layer of the packaging material; at least one material layer of the packaging material is of foamed construction; and the packaging material is constructed to be breakable due to the interaction of the fillers in the at least one material layer and the at least one material layer of foamed construction.

2. The packaging material according to claim 1, characterised in that the packaging material is of at least triple-layered construction.

3. The packaging material according to claim 1, characterised in that the foamed material layer was physically foamed by nitrogen, carbon dioxide, water steam or other standard gases.

4. The packaging material according to claim 1, characterised in that the foamed material layer was chemically foamed.

5. The packaging material according to claim 1, characterised in that the density of the foamed material is between 0.50 and 0.90 g/cm.sup.3.

6. The packaging material according to claim 1, characterised in that the foamed layer is provided as an inner layer of the packaging material.

7. The packaging material according to claim 1, characterised in that at least one layer on either side of the middle layer is provided with fillers.

8. The packaging material according to claim 1, characterised in that at least one material layer contains a component of a regrind of the packaging material, wherein this is provided in the filled material layer.

9. The packaging material according to claim 1, characterised in that a cover layer is provided as a skin layer on at least one filled layer, wherein each skin layer can have a thickness of 2 to 10% of the thickness of the overall material.

10. The packaging material according to claim 1, characterised in that the material is provided for breaking by hand at room temperature and thereunder, wherein the breakability is defined by the ratio of fillers to the foaming or degree of foaming.

11. The packaging material according to claim 1, characterised in that at least one outer layer is punched or scored, wherein the punching or scoring has a depth of 0.03 to 0.1 millimeters.

12. The packaging material according to claim 1, characterised in that at least one barrier layer is provided.

13. The packaging material according to claim 1, characterised in that the material is constructed as a film web for a section.

14. The packaging material according to claim 1, characterised in that the material has a thickness of between 0.6 and 1.5 millimeters and/or the density of the material is between 0.6 and 1.2 g/cm.sup.3, principally between 0.95 and 1.05 g/cm.sup.3.

15. A packaging material for producing deep-drawn plastics material packagings, characterised in that: the packaging material is based on polypropylene, bio-polypropylene or plastics materials containing polypropylene or bio-polypropylene; the packaging material is of multi-layered construction; fillers are added to at least one material layer of the packaging material; at least one material layer of the packaging material is a foamed material layer of a foamed construction having a density between 0.50 and 0.90 g/cm.sup.3; and the packaging material is constructed to be breakable due to an interaction of the at least one material layer in which the fillers are added and the foamed material layer of foamed construction.

16. The packaging material according to claim 15, characterised in that the foamed material layer was physically foamed by nitrogen, carbon dioxide, water steam or other standard gases.

17. The packaging material according to claim 15, characterised in that the foamed material layer was chemically foamed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail in the following by way of a number of embodiments, wherein:

(2) FIG. 1 shows a schematic layer construction of a triple-layered material,

(3) FIG. 2 shows a schematic layer construction of a five-layered material and

(4) FIG. 3 shows a schematic layer construction of a seven-layered material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) A multi-layered material construction with an inner material layer 2 and two outer layers 3 and 4 each arranged on a respective side of the inner material layer 2 is denoted by 1 in FIG. 1.

(6) The inner material layer 2 is made of a foamed polypropylene. It is in that case conceivable to use bio-polypropylene and also blends, copolymers or the like, which, however, usually contain polypropylene or bio-polypropylene at least to a major extent. Also conceivable is the use of other foamable plastics materials.

(7) The density of the foamed material is in that case between 0.50 and 0.90, particularly between 0.65 and 0.90, g/cm.sup.3. The foaming can be carried out in a physical or chemical way. In the case of physical foaming, use of nitrogen, carbon dioxide, water steam or other standard gases is possible. Very satisfactory foaming is achieved in environmentally friendly manner by this. The addition of fillers, particularly for improving foaming, is conceivable.

(8) At least one of the two outer layers 3 and 4 is provided with a filler. This filler can contain mineral fillers and also regrinds or the like. Conceivable as mineral fillers are CaCO.sub.3, talcum or the like. The density of the filled layers 3 and 4 can in that case be up to 1.35 g/cm.sup.3.

(9) In this connection it is conceivable for each of the two outer layers 3 and 4 to be provided with filler.

(10) The foamed layer 2 and the two outer layers 3 and 4 so co-operate that a material breakable at room temperature results, as is known from, for example, multipack packagings of polystyrol, in which individual packagings can be separated by breaking away. The breakability is defined by the interaction of the filled layers 3 and 4 and the foamed layer 2.

(11) According to a further embodiment of the invention it is also conceivable to provide a respective skin layer 5 and 6 on the outer side of the outer layers 3 and 4.

(12) This can be useful particularly on the inner side of the finished packaging so as to prevent undesired effects of the filled layer on the content. It is also conceivable that, by virtue of this skin layer, barrier properties are also added or smooth surfaces produced. The thickness of a skin layer 5 or 6 is usually two to ten percent, preferably two to five percent of the total thickness of the material.

(13) Surfaces which are especially smooth can be very satisfactorily printed, so that a uniform and high-quality printed image can be applied.

(14) In order to facilitate breaking and/or control the fracture the surface of the material 1 can be lightly punched or scored.

(15) In that case, the punching or scoring can have a maximum depth of between 0.03 and 0.1 millimeters.

(16) Forming of such small punching or scoring depths has proved sufficient. The fracture is nevertheless significantly facilitated and reliably controlled.

(17) According to a further embodiment of the invention, which is illustrated in FIG. 3, it is possible to provide, for example between the inner layer 2 and the two outer layers 3 and 4, tie, barrier or other functional layers, here denoted by the numerals 7 and 8.

(18) The entire material usually has a thickness of between 0.6 and 1.5 millimeters.

(19) The density is between 0.6 and 1.2 g/cm.sup.3, preferably between 0.95 and 1.05 g/cm.sup.3.

(20) The material can, for further processing, be provided as a film web or as a web section, i.e. as a sheet.

(21) In order to form an item of packaging from the material, the material is deep-drawn.

(22) In that case, the deep-drawing parameters have to controlled and maintained within usual limits.

(23) The use of a deep-drawing device with a matched profile with undercuts of the deep-drawing punch, this also being known by the catchword Innoform, is particularly advantageous, since the material thickness in the deep-drawing packaging is thereby kept substantially constant.

(24) The thus-produced packagings, particularly multipack packagings, can be provided on the outer side with printings, labels and also sleeves.

(25) The individual packagings of the multipack can be separated as required by simple breaking off from the multipack.

(26) The packaging material according to the invention is particularly suitable in all its variants for the form-fill-seal process.

(27) Due to low storage cost and only small problems with hygiene this process is often used for foodstuff products, particularly yoghurt and the like.

(28) Multipacks are also common there, these then being separated by the end user as required.

(29) Other possibilities of use are conceivable.

(30) It is additionally conceivable that the packaging material according to the invention can also be varied. Further additional layers are conceivable. Equally, it is conceivable that only one tie layer or intermediate layer 7 and 8 is provided. Equally, it is conceivable that only one skin layer 5 and 6 is provided.

(31) The foamed layer 2 and a layer 3 or 4 provided with fillers can be regarded as a minimum requirement of the packaging material according to the invention.