| 摘要 |
A seal (4) between a first and second polymeric sheet material (5, 3) is described, the first sheet material (5) being sufficiently porous to permit gas or steam sterilisation but substantially impervious to bacteria, and the second sheet material (3) being substantially gas impervious, and the second sheet material (3) comprising at least an outer heat sealable layer, the seal (4) comprising: a first thermal surface weld (15) between the heat sealable layer of the second sheet material (3) and the first sheet material (5); and a second thermal melt weld (12) between at least the heat sealable layer of the second sheet material (3) and the first sheet material (5), the thermal melt weld (12) being narrower than the first weld (11) and lying within the boundaries of the first weld (11). The seal 4 is sufficiently flat to allow a cross-heat seal using conventional equipment. <IMAGE> <IMAGE> |
