INFUSION BAG

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/EBM) and the styrene-ethylene/butylene-styrene block copolymer (SEBS) of the outer layer has a styrene-ethylene/butylene ratio (S/EBA), in which S/EBA>S/EBM. 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.