| 摘要 |
<p>A procedure for making a tube (1) of a porous material consists of winding a strip (2) of the material in a spiral with overlapping edges. The wound spirals are stuck together by a layer of adhesive applied in a predetermined quantity to a portion (2b) of the strip. The amount of adhesive applied is determined by the nature of the porous material and the characteristics of the adhesive. The adhesive layer can be applied by moistening or by hot-melt application, while the sound strip is of a fibrous material, especially polyester. The tube can be reinforced during winding by a filament (3) applied between the overlapping surface. The filament can be of a synthetic material, especially polyester, or a metal, especially spring steel, and a clear space 1 - 4 mm wide with no adhesive is left on each side of it.</p> |
