| 摘要 |
The present invention relates to a cylindrical shuttering which, while being of the type made from several strips of cardboard wound up helically, is characterised essentially in that these strips are connected together by means of the interposition of aluminium strips of reduced thickness, also wound up helically, these aluminium strips having been provided in order, also, to act as sealing means for the shuttering overall and to serve as links for the coils of cardboard fastened to the latter by heat-sealing (-welding), this being so that the tubular cardboard body is resistant to damp (humidity) both in order to constitute a barrier in the shuttering itself and in order to hold the fastening between the layers. <IMAGE>
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