Infusion bag

Abstract

The invention relates to a medical package designed as an infusion bag, which medical package is made from multi-layer films that are welded to one another and is filled with a medical liquid for infusion and/or for parenteral nutrition. The invention is described by a medical package designed as an infusion bag, which is made up of a film comprising multiple layers welded to one another and has at least one weld seam, preferably longitudinal and transverse weld seams, and is filled with a medical liquid. The multi-layer film has at least one inner layer of a matrix-phase polymer system, an intermediate layer of a matrix-phase polymer system, and an outer layer of a matrix-phase polymer system. The matrix polymer of the matrix-phase polymer system of the inner layer, the intermediate layer and the outer layer in each case comprises a polypropylene polymer (PP) having defined parts by weight in the individual layers, and the phase polymer of the matrix-phase polymer system of the inner layer, the intermediate layer and the outer layer in each case comprises a styrene-ethylene/butyl-styrene block copolymer (SEBS) having defined parts by weight in the individual layers. The film is characterised in that the styrene-ethylene/butyl-styrene block copolymer (SEBS) of the intermediate layer has a styrene-ethylene/butylene ratio (S/EB.sub.M) and the styrene-ethylene/butylene-styrene block copolymer (SEBS) of the outer layer has a styrene-ethylene/butylene ratio (S/EB.sub.A), in which S/EB.sub.A>S/EB.sub.M. It has been shown that in this way the mechanical properties of the multi-layer film can be improved, in particular in the event of expansion of the multi-layer film in the region of the weld seams. The improved mechanical properties appear both at room temperature and also at lower temperatures of down to 4? C.

Claims

1. A film comprising: an inner layer; an outer layer comprising a styrene-ethylene/butylene-styrene block copolymer in a matrix of a polymer; and an intermediate layer disposed between the inner layer and the outer layer, the intermediate layer comprising a styrene-ethylene/butylene-styrene block copolymer in a matrix of a polymer, wherein a ratio, by weight, of styrene to ethylene and butylene of the outer layer is between 0.18 and 0.28, and wherein a ratio, by weight, of styrene to ethylene and butylene of the intermediate layer is between 0.10 and 0.16.

2. The film of claim 1, wherein the ratio, by weight, of styrene to ethylene and butylene of the outer layer is greater than 1.2 times the ratio, by weight, of styrene to ethylene and butylene of the intermediate layer.

3. The film of claim 2, wherein the ratio, by weight, of styrene to ethylene and butylene of the outer layer is greater than 1.5 times the ratio, by weight, of styrene to ethylene and butylene of the intermediate layer.

4. The film of claim 1, wherein the polymer of the outer layer is polypropylene, and wherein the polymer of the intermediate layer is polypropylene.

5. The film of claim 4, wherein the inner layer comprises a styrene-ethylene/butylene-styrene block copolymer in a matrix of polypropylene.

6. The film of claim 5, wherein a ratio, by weight, of styrene to ethylene and butylene of the inner layer is greater than the ratio, by weight, of styrene to ethylene and butylene of the intermediate layer.

7. The film of claim 6, wherein the ratio, by weight, of styrene to ethylene and butylene of the inner layer is greater than 1.2 times the ratio, by weight, of styrene to ethylene and butylene of the intermediate layer.

8. The film of claim 7, wherein the ratio, by weight, of styrene to ethylene and butylene of the inner layer is greater than 1.5 times the ratio, by weight, of styrene to ethylene and butylene of the intermediate layer.

9. The film of claim 5, wherein a ratio, by weight, of styrene to ethylene and butylene of the inner layer is equal to the ratio, by weight, of styrene to ethylene and butylene of the outer layer.

10. The film of claim 1, wherein the intermediate layer further comprises a styrene-isoprene-styrene block copolymer in the matrix of the polymer.

11. The film of claim 1, wherein the ratio, by weight, of styrene to ethylene and butylene of the outer layer is between 0.20 and 0.24, and wherein the ratio, by weight, of styrene to ethylene and butylene of the intermediate layer is between 0.13 and 0.14.

12. The film of claim 1, wherein the inner layer comprises styrene-ethylene/butylene-styrene block copolymer in a matrix of a polymer, wherein a ratio, by weight, of styrene to ethylene and butylene of the inner layer is between 0.18 and 0.28.

13. The film of claim 12, wherein the ratio, by weight, of styrene to ethylene and butylene of the inner layer is between 0.20 and 0.24, and wherein the ratio, by weight, of styrene to ethylene and butylene of the intermediate layer is between 0.13 and 0.14.

14. A medical package comprising a film, the medical package having at least one seam, and the medical package configured to be filled with a liquid, wherein the film comprises: an inner layer; an outer layer comprising a styrene-ethylene/butylene-styrene block copolymer in a matrix of a polymer; and an intermediate layer disposed between the inner layer and the outer layer, the intermediate layer comprising a styrene-ethylene/butylene-styrene block copolymer in a matrix of a polymer, wherein a ratio, by weight, of styrene to ethylene and butylene of the outer layer is between 0.18 and 0.28, and wherein a ratio, by weight, of styrene to ethylene and butylene of the intermediate layer is between 0.10 and 0.16.

15. The medical package of claim 14, wherein the ratio, by weight, of styrene to ethylene and butylene of the outer layer is greater than 1.2 times the ratio, by weight, of styrene to ethylene and butylene of the intermediate layer.

16. The medical package of claim 14, wherein the polymer of the outer layer is polypropylene, wherein the polymer of the matrix of the intermediate layer is polypropylene, and wherein the inner layer comprises a styrene-ethylene/butylene-styrene block copolymer in a matrix of polypropylene.

17. The medical package of claim 14, wherein the intermediate layer further comprises a styrene-isoprene-styrene block copolymer in the matrix of the polymer.

18. The medical package of claim 14, wherein the inner layer comprises a styrene-ethylene/butylene-styrene block copolymer in a matrix of a polymer, and wherein a ratio, by weight, of styrene to ethylene and butylene of the inner layer is between 0.18 and 0.28.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject matter of the invention will be explained in more detail below with reference to a schematically represented exemplary embodiment on the basis of the drawings FIG. 1 to FIG. 4.

(2) FIG. 1 shows a medical package designed as an infusion bag.

(3) FIG. 2 is a schematic sectional view of the multi-layer PP film used for the infusion bag.

DETAILED DESCRIPTION OF THE DRAWINGS

(4) FIG. 1 shows a medical package designed as an infusion bag 1.

(5) The infusion bag 1 consists of two multi-layer films 8 welded to one another. The multi-layer films 8 are connected to one another via the longitudinal weld seams 7 and the transverse weld seams 6, such that a bag is formed, which is filled with a medical liquid. The bag 1 is here a single-chamber bag.

(6) The multi-layer films 8 are for example connected to one another by means of an impulse welding method. In this case, the films 8 are welded by means of a welding tool with heatable sealing strips, which come into contact with the film, by the sealing strips being temporarily heated, such that the films clamped between the sealing strips are molten at least in sections and are thus welded. An impulse welding method is for example illustrated in the published patent application EP 0 911 141 A2 (Fresenius Medical Care Deutschland GmbH).

(7) The infusion bag 1 comprises at least one port, in this exemplary embodiment two ports 2a, 3a, of which one port 2a serves to fill liquid, for example to dose a medicine, and another port 3a to withdraw the medical liquid.

(8) The ports 2a, 3a comprise in this exemplary embodiment a weld-in shuttle, by means of which they are welded in a region 5 of a transverse weld seam 6.

(9) The two ports 2a and 3a here each provide the lower part of a connector 2 and 3. The two connectors 2 and 3 are each formed by the two mentioned lower parts 2a and 3a and by the upper parts 2b and 3b. The upper part 2b, 3b, is preferably placed on the lower part 2a, 3a, in particular snapped-on. A sealing element (not represented here in the figures), which welds the passage in the port 2a, 3a or in the connector 2, 3 to the bag volume, is preferably enclosed in a positive-locking manner, between the respective lower part 2a, 3a and the upper part 2b, 3b. The mentioned sealing element is a self-closing, resealable elastomer element, which can be penetrated with a spike and/or even with a needle, in order to withdraw or supply liquid. After removing the spike and/or the needle, the sealing element closes automatically. Polyisoprene can e.g. be used as the elastomer material. The upper part 2b, 3b of the connector 2, 3 also in each case comprises a covering, preferably a breakable cap 2c, 3c which covers the sealing element. The respective sealing element is therefore accessible only after removing or breaking off the cap 2c, 3c.

(10) The infusion bag 1 also comprises, on the side opposite at least one port 2a, 3a, a hanger 4 for attaching the infusion bag to an infusion stand or a rack. The hanger 4 can be designed as a indent or stamped-out slot in the transverse weld seam 6.

(11) FIG. 2 is a schematic view of the multi-layer film 8 used for the infusion bag 1.

(12) The film 8 consists of an inner layer 9c in contact with the medical liquid, an intermediate layer 9b and an outer layer 9a. When the films 8 are welded, the layers 9a, 9b, 9c become molten. In this case, all the material in the region of the weld seam passes to a molten state during the impulse welding.

(13) The inner and the outer layer 9c, 9a are each 25-45 ?m thick. The intermediate layer 9b has a thickness of 125-145 ?m.

(14) The outer layer 9a consists of a PP homopolymer, to which is added SEBS to improve the mechanical properties. The proportion by weight G.sub.AM of the PP homopolymer is in a range of 82-88% by weight. The proportion by weight G.sub.AP of the SEBS is in a range of 12-18% by weight.

(15) The inner layer 9c consists of a PP random copolymer, to which is added SEBS to improve the mechanical properties. The proportion by weight G.sub.IM of the PP random copolymer is in a range of 77-83% by weight. The proportion by weight G.sub.IP of the SEBS is in a range of 17-23% by weight.

(16) The intermediate layer 9b is softer than at least the outer layer 9a. It is also preferably softer than the inner layer 9c. The intermediate layer 9b consists of a PP random copolymer which is softer compared to the PP of the outer layer 9a, to which SEBS and optionally SIS is added. The proportion by weight G.sub.MM of the PP random copolymer is in a range of 47-53% by weight. The proportion by weight G.sub.MP1 of the SEBS is in the range of 37-43% by weight. The proportion by weight G.sub.MP2 of the second thermoplastic elastomer SIS is in the range of 7-13% by weight. The proportion by weight of thermoplastic elastomers (i.e. SEBS and optionally SIS) is in the intermediate layer 9b higher than in the inner and outer layer 9a, 9c.

(17) The SEBS of the intermediate layer 9b also has a higher proportion by weight of ethylene/butylene than the SEBS in the inner and outer layer 9a, 9c. The S/EB.sub.M ratio in the intermediate layer 9b is 12/88. The S/EB.sub.A ratio in the outer layer 9a and/or in the inner layer 9c is, in contrast, 18/82.

(18) In this way, a soft intermediate later 9b is provided with SEBS more finely distributed compared to the inner and outer layer 9c, 9a which improves to a great extent the mechanical properties of the infusion bag, in particular in the case of fall tests. These improved mechanical properties appear both at room temperature and also at lower temperatures of down to 4? C.

(19) The film 8 is produced by co-extrusion of the individual layers 9a-9c.

(20) The mechanical properties of an infusion bag 1 can be easily improved by the invention in particular in the region of the weld seams 6, 7 and over a wide temperature range.

LIST OF REFERENCE NUMERALS

(21) 1 Infusion bag 2 Connector for supplying an additive or medicine 2a Lower part or port of the connector 2b Upper part of the connector 2c Break-off part of the upper part 3 Connector for withdrawing a medical liquid 3a Lower part or port of the connector 3b Upper part of the connector 3c Break-off part of the upper part 4 Hanger 5 Region weld-in shuttle 6 Transverse weld seam 7 Longitudinal weld seam 8 Film 9a Outer layer 9b Intermediate layer 9c Inner layer