| 摘要 |
<p>The machine has a rotary drum (29) with its inside linked to a vacuum source, made with surface slits and covered by a permeable sleeve (30) made from a woven bronze, brass or copper fabric with a series of embossed motifs in high and low relief. - The sleeve, which has an aperture ratio of 5 - 50 per cent, is coated with a layer of copper or nickel between 50 and 500 microns thick, applied by electro- deposition. The sleeve can be fitted over a perforated covering on the drum which has perforations of 1 - 5 mm diameter spaced with 2 - 6 mm between centers.</p> |
