| 摘要 |
<p>1,273,159. Powdered webs. HEAD WRIGHTSON & CO. Ltd. 15 Sept., 1969 [19 Sept., 1968], No. 44607/68. Heading D1L. [Also in Division C7] Continuously moving web or strip of e.g. metal, plastics, paper or textiles is coated with a powder e.g. Al, Cr, Ni, Cu, Pb on plastics by directing a jet or jets of gas transversely to a thin continuous curtain of powder to blow the powder into one or both surfaces of the web or strip and an electrostatic field is applied to the strip. The gas may be air or N 2 enriched air. Flared nozzles 6, 6a direct gas jets of minimum width equal to strip width transversely of powder curtain formed by vibratory feeder tables 3, 3a. Powder flows along tables via weirs and a curtain less than the width of the strip falls over edge 4 and is projected towards the strip S moving through reposition zones 8 which are suspended in housing 9 and earthed by insulators 11. Wires 10, 0.008" dia. alone and below the strip are negatively enlarged to 30,000 V. Gas may be recirculated through a cyclone and/or filter and mixed with fresh gas.</p> |
