摘要 |
A tube of microporous thermal insulation material is manufactured by compacting the microporous material to a slab 1 having a density of about 150 - 400 Kg/m and a thickness of about 1 to 5 mm, applying to one surface of the slab a membrane 3, for example of self-adhesive aluminium foil, wrapping the slab around a mandrel so that the ends of the slab abut substantially against each other and securing the ends of the slab relative to each other, for example by means of a protruding flap of the aluminium foil. |